ruby--ruby/ext/tcltklib/tcltklib.c

/*
 *	tcltklib.c
 *		Aug. 27, 1997	Y. Shigehiro
 *		Oct. 24, 1997	Y. Matsumoto
 */

#include "ruby.h"
#include "rubysig.h"
#undef EXTERN	/* avoid conflict with tcl.h of tcl8.2 or before */
#include <stdio.h>
#ifdef HAVE_STDARG_PROTOTYPES
#include <stdarg.h>
#define va_init_list(a,b) va_start(a,b)
#else
#include <varargs.h>
#define va_init_list(a,b) va_start(a)
#endif
#include <string.h>
#include <tcl.h>
#include <tk.h>

#ifdef __MACOS__
# include <tkMac.h>
# include <Quickdraw.h>
#endif

#if TCL_MAJOR_VERSION >= 8
# ifndef CONST84
#  if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION <= 4 /* Tcl8.0.x -- 8.4b1 */
#   define CONST84
#  else /* unknown (maybe TCL_VERSION >= 8.5) */
#   ifdef CONST
#    define CONST84 CONST
#   else
#    define CONST84
#   endif
#  endif
# endif
#else  /* TCL_MAJOR_VERSION < 8 */
# ifdef CONST
#  define CONST84 CONST
# else
#  define CONST
#  define CONST84
# endif
#endif

/* copied from eval.c */
#define TAG_RETURN      0x1
#define TAG_BREAK       0x2
#define TAG_NEXT        0x3
#define TAG_RETRY       0x4
#define TAG_REDO        0x5
#define TAG_RAISE       0x6
#define TAG_FATAL       0x8

/* for ruby_debug */
#define DUMP1(ARG1) if (ruby_debug) { fprintf(stderr, "tcltklib: %s\n", ARG1); fflush(stderr); }
#define DUMP2(ARG1, ARG2) if (ruby_debug) { fprintf(stderr, "tcltklib: ");\
fprintf(stderr, ARG1, ARG2); fprintf(stderr, "\n"); fflush(stderr); }
/*
#define DUMP1(ARG1)
#define DUMP2(ARG1, ARG2)
*/

/* finalize_proc_name */
static char *finalize_hook_name = "INTERP_FINALIZE_HOOK";

/* for callback break & continue */
static VALUE eTkCallbackReturn;
static VALUE eTkCallbackBreak;
static VALUE eTkCallbackContinue;

static VALUE eLocalJumpError;

static ID ID_at_enc;
static ID ID_at_interp;

static ID ID_stop_p;
static ID ID_kill;
static ID ID_join;

static ID ID_call;
static ID ID_backtrace;
static ID ID_message;

static ID ID_at_reason;
static ID ID_return;
static ID ID_break;
static ID ID_next;

static ID ID_to_s;
static ID ID_inspect;

static VALUE ip_invoke_real _((int, VALUE*, VALUE));
static VALUE ip_invoke _((int, VALUE*, VALUE));

/* from tkAppInit.c */

#if !defined __MINGW32__
/*
 * The following variable is a special hack that is needed in order for
 * Sun shared libraries to be used for Tcl.
 */

extern int matherr();
int *tclDummyMathPtr = (int *) matherr;
#endif

/*---- module TclTkLib ----*/

struct invoke_queue {
    Tcl_Event ev;
    int argc;
#if TCL_MAJOR_VERSION >= 8
    Tcl_Obj **argv;
#else /* TCL_MAJOR_VERSION < 8 */
    char **argv;
#endif
    VALUE interp;
    int *done;
    int safe_level;
    VALUE result;
    VALUE thread;
};

struct eval_queue {
    Tcl_Event ev;
    char *str;
    int len;
    VALUE interp;
    int *done;
    int safe_level;
    VALUE result;
    VALUE thread;
};

void 
invoke_queue_mark(struct invoke_queue *q)
{
    rb_gc_mark(q->interp);
    rb_gc_mark(q->result);
    rb_gc_mark(q->thread);
}

void 
eval_queue_mark(struct eval_queue *q)
{
    rb_gc_mark(q->interp);
    rb_gc_mark(q->result);
    rb_gc_mark(q->thread);
}

 
static VALUE eventloop_thread;
static VALUE watchdog_thread;
Tcl_Interp  *current_interp;

/* 
 *  'event_loop_max' is a maximum events which the eventloop processes in one 
 *  term of thread scheduling. 'no_event_tick' is the count-up value when 
 *  there are no event for processing. 
 *  'timer_tick' is a limit of one term of thread scheduling. 
 *  If 'timer_tick' == 0, then not use the timer for thread scheduling.
 */
#define DEFAULT_EVENT_LOOP_MAX    800/*counts*/
#define DEFAULT_NO_EVENT_TICK      10/*counts*/
#define DEFAULT_NO_EVENT_WAIT      20/*milliseconds ( 1 -- 999 ) */
#define WATCHDOG_INTERVAL          10/*milliseconds ( 1 -- 999 ) */
#define DEFAULT_TIMER_TICK          0/*milliseconds ( 0 -- 999 ) */
#define NO_THREAD_INTERRUPT_TIME  100/*milliseconds ( 1 -- 999 ) */

static int event_loop_max = DEFAULT_EVENT_LOOP_MAX;
static int no_event_tick  = DEFAULT_NO_EVENT_TICK;
static int no_event_wait  = DEFAULT_NO_EVENT_WAIT;
static int timer_tick     = DEFAULT_TIMER_TICK;
static int req_timer_tick = DEFAULT_TIMER_TICK;
static int run_timer_flag = 0;

static int event_loop_wait_event   = 0;
static int event_loop_abort_on_exc = 1;
static int loop_counter = 0;

static int check_rootwidget_flag = 0;

#if TCL_MAJOR_VERSION >= 8
static int ip_ruby_eval _((ClientData, Tcl_Interp *, int, Tcl_Obj *CONST*));
static int ip_ruby_cmd _((ClientData, Tcl_Interp *, int, Tcl_Obj *CONST*));
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_ruby_eval _((ClientData, Tcl_Interp *, int, char **));
static int ip_ruby_cmd _((ClientData, Tcl_Interp *, int, char **));
#endif

/*---- class TclTkIp ----*/
struct tcltkip {
    Tcl_Interp *ip;		/* the interpreter */
    int return_value;		/* return value */
};

static struct tcltkip *
get_ip(self)
    VALUE self;
{
    struct tcltkip *ptr;

    Data_Get_Struct(self, struct tcltkip, ptr);
    if (ptr == 0) {
	rb_raise(rb_eTypeError, "uninitialized TclTkIp");
    }
    return ptr;
}

/* Tk_ThreadTimer */
static Tcl_TimerToken timer_token = (Tcl_TimerToken)NULL;

/* timer callback */
static void _timer_for_tcl _((ClientData));
static void
_timer_for_tcl(clientData)
    ClientData clientData;
{
    int thr_crit_bup;

    /* struct invoke_queue *q, *tmp; */
    /* VALUE thread; */

    DUMP1("called timer_for_tcl");

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    Tk_DeleteTimerHandler(timer_token);

    run_timer_flag = 1;

    if (timer_tick > 0) {
	timer_token = Tk_CreateTimerHandler(timer_tick, _timer_for_tcl, 
					    (ClientData)0);
    } else {
	timer_token = (Tcl_TimerToken)NULL;
    }

    rb_thread_critical = thr_crit_bup;

    /* rb_thread_schedule(); */
    /* tick_counter += event_loop_max; */
}

static VALUE
set_eventloop_tick(self, tick)
    VALUE self;
    VALUE tick;
{
    int ttick = NUM2INT(tick);
    int thr_crit_bup;

    rb_secure(4);

    if (ttick < 0) {
	rb_raise(rb_eArgError, 
		 "timer-tick parameter must be 0 or positive number");
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* delete old timer callback */
    Tk_DeleteTimerHandler(timer_token);

    timer_tick = req_timer_tick = ttick;
    if (timer_tick > 0) {
	/* start timer callback */
	timer_token = Tk_CreateTimerHandler(timer_tick, _timer_for_tcl, 
					    (ClientData)0);
    } else {
	timer_token = (Tcl_TimerToken)NULL;
    }

    rb_thread_critical = thr_crit_bup;

    return tick;
}

static VALUE
get_eventloop_tick(self)
    VALUE self;
{
    return INT2NUM(timer_tick);
}

static VALUE
ip_set_eventloop_tick(self, tick)
    VALUE self;
    VALUE tick;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return get_eventloop_tick(self);
    }
    return set_eventloop_tick(self, tick);
}

static VALUE
ip_get_eventloop_tick(self)
    VALUE self;
{
    return get_eventloop_tick(self);
}

static VALUE
set_no_event_wait(self, wait)
    VALUE self;
    VALUE wait;
{
    int t_wait = NUM2INT(wait);

    rb_secure(4);

    if (t_wait <= 0) {
	rb_raise(rb_eArgError, 
		 "no_event_wait parameter must be positive number");
    }

    no_event_wait = t_wait;

    return wait;
}

static VALUE
get_no_event_wait(self)
    VALUE self;
{
    return INT2NUM(no_event_wait);
}

static VALUE
ip_set_no_event_wait(self, wait)
    VALUE self;
    VALUE wait;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return get_no_event_wait(self);
    }
    return set_no_event_wait(self, wait);
}

static VALUE
ip_get_no_event_wait(self)
    VALUE self;
{
    return get_no_event_wait(self);
}

static VALUE
set_eventloop_weight(self, loop_max, no_event)
    VALUE self;
    VALUE loop_max;
    VALUE no_event;
{
    int lpmax = NUM2INT(loop_max);
    int no_ev = NUM2INT(no_event);

    rb_secure(4);

    if (lpmax <= 0 || no_ev <= 0) {
	rb_raise(rb_eArgError, "weight parameters must be positive numbers");
    }

    event_loop_max = lpmax;
    no_event_tick  = no_ev;

    return rb_ary_new3(2, loop_max, no_event);
}

static VALUE
get_eventloop_weight(self)
    VALUE self;
{
    return rb_ary_new3(2, INT2NUM(event_loop_max), INT2NUM(no_event_tick));
}

static VALUE
ip_set_eventloop_weight(self, loop_max, no_event)
    VALUE self;
    VALUE loop_max;
    VALUE no_event;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return get_eventloop_weight(self);
    }
    return set_eventloop_weight(self, loop_max, no_event);
}

static VALUE
ip_get_eventloop_weight(self)
    VALUE self;
{
    return get_eventloop_weight(self);
}

static VALUE
set_max_block_time(self, time)
    VALUE self;
    VALUE time;
{
    struct Tcl_Time tcl_time;
    VALUE divmod;

    switch(TYPE(time)) {
    case T_FIXNUM:
    case T_BIGNUM:
	/* time is micro-second value */
	divmod = rb_funcall(time, rb_intern("divmod"), 1, LONG2NUM(1000000));
	tcl_time.sec  = NUM2LONG(RARRAY(divmod)->ptr[0]);
	tcl_time.usec = NUM2LONG(RARRAY(divmod)->ptr[1]);
	break;

    case T_FLOAT:
	/* time is second value */
	divmod = rb_funcall(time, rb_intern("divmod"), 1, INT2FIX(1));
	tcl_time.sec  = NUM2LONG(RARRAY(divmod)->ptr[0]);
	tcl_time.usec = (long)(NUM2DBL(RARRAY(divmod)->ptr[1]) * 1000000);

    default:
	rb_raise(rb_eArgError, "invalid value for time: '%s'", 
		 RSTRING(rb_funcall(time, ID_inspect, 0, 0))->ptr);
    }

    Tcl_SetMaxBlockTime(&tcl_time);

    return Qnil;
}

static VALUE
lib_evloop_abort_on_exc(self)
    VALUE self;
{
    if (event_loop_abort_on_exc > 0) {
	return Qtrue;
    } else if (event_loop_abort_on_exc == 0) {
	return Qfalse;
    } else {
	return Qnil;
    }
}

static VALUE
ip_evloop_abort_on_exc(self)
    VALUE self;
{
    return lib_evloop_abort_on_exc(self);
}

static VALUE
lib_evloop_abort_on_exc_set(self, val)
    VALUE self, val;
{
    rb_secure(4);
    if (RTEST(val)) {
	event_loop_abort_on_exc =  1;
    } else if (NIL_P(val)) {
	event_loop_abort_on_exc = -1;
    } else {
	event_loop_abort_on_exc =  0;
    }
    return lib_evloop_abort_on_exc(self);
}

static VALUE
ip_evloop_abort_on_exc_set(self, val)
    VALUE self, val;
{
    struct tcltkip *ptr = get_ip(self);

    rb_secure(4);
    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return lib_evloop_abort_on_exc(self);
    }
    return lib_evloop_abort_on_exc_set(self, val);
}

static VALUE
lib_num_of_mainwindows(self)
    VALUE self;
{
    return INT2FIX(Tk_GetNumMainWindows());
}

static int
lib_eventloop_core(check_root, update_flag, check_var)
    int check_root;
    int update_flag;
    int *check_var;
{
    VALUE current = eventloop_thread;
    int found_event = 1;
    int event_flag;
    struct timeval t;
    int thr_crit_bup;


    if (update_flag) DUMP1("update loop start!!");

    t.tv_sec = (time_t)0;
    t.tv_usec = (time_t)(no_event_wait*1000.0);

    Tk_DeleteTimerHandler(timer_token);
    run_timer_flag = 0;
    if (timer_tick > 0) {
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;
	timer_token = Tk_CreateTimerHandler(timer_tick, _timer_for_tcl, 
					    (ClientData)0);
	rb_thread_critical = thr_crit_bup;
    } else {
	timer_token = (Tcl_TimerToken)NULL;
    }

    for(;;) {
	if (rb_thread_alone()) {
	    DUMP1("no other thread");
	    event_loop_wait_event = 0;

	    if (update_flag) {
		event_flag = update_flag | TCL_DONT_WAIT; /* for safety */
	    } else {
		event_flag = TCL_ALL_EVENTS;
	    }

	    if (timer_tick == 0 && update_flag == 0) {
		timer_tick = NO_THREAD_INTERRUPT_TIME;
		timer_token = Tk_CreateTimerHandler(timer_tick, 
						    _timer_for_tcl, 
						    (ClientData)0);
	    }

	    if (check_var != (int *)NULL) {
		if (*check_var || !found_event) {
		    return found_event;
		}
	    }

	    found_event = Tcl_DoOneEvent(event_flag);

	    if (update_flag != 0) {
	      if (found_event) {
		DUMP1("next update loop");
		continue;
	      } else {
		DUMP1("update complete");
		return 0;
	      }
	    }

	    DUMP1("check Root Widget");
	    if (check_root && Tk_GetNumMainWindows() == 0) {
		run_timer_flag = 0;
		if (!rb_prohibit_interrupt) {
		  if (rb_trap_pending) rb_trap_exec();
		}
		return 1;
	    }

	    if (loop_counter++ > 30000) {
		/* fprintf(stderr, "loop_counter > 30000\n"); */
		loop_counter = 0;
	    }

	} else {
	    int tick_counter;

	    DUMP1("there are other threads");
	    event_loop_wait_event = 1;

	    found_event = 1;

	    if (update_flag) {
		event_flag = update_flag | TCL_DONT_WAIT; /* for safety */
	    } else {
		event_flag = TCL_ALL_EVENTS | TCL_DONT_WAIT;
	    }

	    timer_tick = req_timer_tick;
	    tick_counter = 0;
	    while(tick_counter < event_loop_max) {
		if (check_var != (int *)NULL) {
		    if (*check_var || !found_event) {
			return found_event;
		    }
		}

		if (Tcl_DoOneEvent(event_flag)) {
		    tick_counter++;
		} else {
		    if (update_flag != 0) {
			DUMP1("update complete");
			return 0;
		    }
		    tick_counter += no_event_tick;
		    rb_thread_wait_for(t);
		}

		if (watchdog_thread != 0 && eventloop_thread != current) {
		    return 1;
		}

		DUMP1("check Root Widget");
		if (check_root && Tk_GetNumMainWindows() == 0) {
		    run_timer_flag = 0;
		    if (!rb_prohibit_interrupt) {
		      if (rb_trap_pending) rb_trap_exec();
		    }
		    return 1;
		}

		DUMP1("trap check");
		if (!rb_prohibit_interrupt) {
		  if (rb_trap_pending) rb_trap_exec();
		}

		if (loop_counter++ > 30000) {
		    /* fprintf(stderr, "loop_counter > 30000\n"); */
		    loop_counter = 0;
		}

		if (run_timer_flag) {
		    /*
		    DUMP1("timer interrupt");
		    run_timer_flag = 0;
		    */
		    break; /* switch to other thread */
		}
	    }
	}

	DUMP1("trap check & thread scheduling");
	if (update_flag == 0) CHECK_INTS;

    }
    return 1;
}

VALUE
lib_eventloop_main(check_rootwidget)
    VALUE check_rootwidget;
{
    check_rootwidget_flag = RTEST(check_rootwidget);

    if (lib_eventloop_core(check_rootwidget_flag, 0, (int *)NULL)) {
	return Qtrue;
    } else {
	return Qfalse;
    }
}

VALUE
lib_eventloop_ensure(parent_evloop)
    VALUE parent_evloop;
{
    Tk_DeleteTimerHandler(timer_token);
    timer_token = (Tcl_TimerToken)NULL;
    DUMP2("eventloop-ensure: current-thread : %lx\n", rb_thread_current());
    DUMP2("eventloop-ensure: eventloop-thread : %lx\n", eventloop_thread);
    if (eventloop_thread == rb_thread_current()) {
	DUMP2("eventloop-thread -> %lx\n", parent_evloop);
	eventloop_thread = parent_evloop;
    }
    return Qnil;
}

static VALUE
lib_eventloop_launcher(check_rootwidget)
    VALUE check_rootwidget;
{
    VALUE parent_evloop = eventloop_thread;

    eventloop_thread = rb_thread_current();

    if (ruby_debug) { 
	fprintf(stderr, "tcltklib: eventloop-thread : %lx -> %lx\n", 
		parent_evloop, eventloop_thread);
    }

    return rb_ensure(lib_eventloop_main, check_rootwidget, 
		     lib_eventloop_ensure, parent_evloop);
}

/* execute Tk_MainLoop */
static VALUE
lib_mainloop(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE check_rootwidget;

    if (rb_scan_args(argc, argv, "01", &check_rootwidget) == 0) {
	check_rootwidget = Qtrue;
    } else if (RTEST(check_rootwidget)) {
	check_rootwidget = Qtrue;
    } else {
	check_rootwidget = Qfalse;
    }

    return lib_eventloop_launcher(check_rootwidget);
}

static VALUE
ip_mainloop(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return Qnil;
    }
    return lib_mainloop(argc, argv, self);
}

VALUE
lib_watchdog_core(check_rootwidget)
    VALUE check_rootwidget;
{
    VALUE evloop;
    int   prev_val = -1;
    int   chance = 0;
    int   check = RTEST(check_rootwidget);
    struct timeval t0, t1;

    t0.tv_sec  = (time_t)0;
    t0.tv_usec = (time_t)((NO_THREAD_INTERRUPT_TIME)*1000.0);
    t1.tv_sec  = (time_t)0;
    t1.tv_usec = (time_t)((WATCHDOG_INTERVAL)*1000.0);

    /* check other watchdog thread */
    if (watchdog_thread != 0) {
	if (RTEST(rb_funcall(watchdog_thread, ID_stop_p, 0))) {
	    rb_funcall(watchdog_thread, ID_kill, 0);
	} else {
	    return Qnil;
	}
    }
    watchdog_thread = rb_thread_current();

    /* watchdog start */
    do {
	if (eventloop_thread == 0 
	    || (loop_counter == prev_val
		&& RTEST(rb_funcall(eventloop_thread, ID_stop_p, 0))
		&& ++chance >= 3 )
	    ) {
	    /* start new eventloop thread */
	    DUMP2("eventloop thread %lx is sleeping or dead", 
		  eventloop_thread);
	    evloop = rb_thread_create(lib_eventloop_launcher, 
				      (void*)&check_rootwidget);
	    DUMP2("create new eventloop thread %lx", evloop);
	    loop_counter = -1;
	    chance = 0;
	    rb_thread_run(evloop);
	} else {
	    loop_counter = prev_val;
	    chance = 0;
	    if (event_loop_wait_event) {
		rb_thread_wait_for(t0);
	    } else {
		rb_thread_wait_for(t1);
	    }
	    /* rb_thread_schedule(); */
	}
    } while(!check || Tk_GetNumMainWindows() != 0);

    return Qnil;
}

VALUE
lib_watchdog_ensure(arg)
    VALUE arg;
{
    eventloop_thread = 0; /* stop eventloops */
    return Qnil;
}

static VALUE
lib_mainloop_watchdog(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE check_rootwidget;

    if (rb_scan_args(argc, argv, "01", &check_rootwidget) == 0) {
	check_rootwidget = Qtrue;
    } else if (RTEST(check_rootwidget)) {
	check_rootwidget = Qtrue;
    } else {
	check_rootwidget = Qfalse;
    }

    return rb_ensure(lib_watchdog_core, check_rootwidget, 
		     lib_watchdog_ensure, Qnil);
}

static VALUE
ip_mainloop_watchdog(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return Qnil;
    }
    return lib_mainloop_watchdog(argc, argv, self);
}

static VALUE
lib_do_one_event_core(argc, argv, self, is_ip)
    int   argc;
    VALUE *argv;
    VALUE self;
    int   is_ip;
{
    volatile VALUE vflags;
    int flags;
    int found_event;

    if (rb_scan_args(argc, argv, "01", &vflags) == 0) {
	flags = TCL_ALL_EVENTS | TCL_DONT_WAIT;
    } else {
	Check_Type(vflags, T_FIXNUM);
	flags = FIX2INT(vflags);
    }

    if (rb_safe_level() >= 4 || (rb_safe_level() >=1 && OBJ_TAINTED(vflags))) {
      flags |= TCL_DONT_WAIT;
    }

    if (is_ip) {
	/* check IP */
	struct tcltkip *ptr = get_ip(self);
	if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	    /* slave IP */
	    flags |= TCL_DONT_WAIT;
	}
    }

    /* found_event = Tcl_DoOneEvent(TCL_ALL_EVENTS | TCL_DONT_WAIT); */
    found_event = Tcl_DoOneEvent(flags);

    if (found_event) {
	return Qtrue;
    } else {
	return Qfalse;
    }
}

static VALUE
lib_do_one_event(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    return lib_do_one_event_core(argc, argv, self, 0);
}

static VALUE
ip_do_one_event(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    return lib_do_one_event_core(argc, argv, self, 0);
}


static void
ip_set_exc_message(interp, exc)
    Tcl_Interp *interp;
    VALUE exc;
{
    char *buf;
    Tcl_DString dstr;
    volatile VALUE msg;
    int thr_crit_bup;

#if TCL_MAJOR_VERSION > 8 || (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION > 0)
    volatile VALUE enc;
    Tcl_Encoding encoding;
#endif

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    msg = rb_funcall(exc, ID_message, 0, 0);

#if TCL_MAJOR_VERSION > 8 || (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION > 0)
    enc = rb_ivar_get(exc, ID_at_enc);
    if (NIL_P(enc)) {
      enc = rb_ivar_get(msg, ID_at_enc);
    }
    if (NIL_P(enc)) {
      encoding = (Tcl_Encoding)NULL;
    } else if (TYPE(enc) == T_STRING) {
      encoding = Tcl_GetEncoding(interp, RSTRING(enc)->ptr);
    } else {
      enc = rb_funcall(enc, ID_to_s, 0, 0);
      encoding = Tcl_GetEncoding(interp, RSTRING(enc)->ptr);
    }

    /* to avoid a garbled error message dialog */
    buf = ALLOC_N(char, (RSTRING(msg)->len)+1);
    strncpy(buf, RSTRING(msg)->ptr, RSTRING(msg)->len);
    buf[RSTRING(msg)->len] = 0;

    Tcl_DStringInit(&dstr);
    Tcl_DStringFree(&dstr);
    Tcl_ExternalToUtfDString(encoding, buf, RSTRING(msg)->len, &dstr);

    Tcl_AppendResult(interp, Tcl_DStringValue(&dstr), (char*)NULL);
    DUMP2("error message:%s", Tcl_DStringValue(&dstr));
    free(buf);

#else /* TCL_VERSION <= 8.0 */
    Tcl_AppendResult(interp, RSTRING(msg)->ptr, (char*)NULL);
#endif

    rb_thread_critical = thr_crit_bup;
}

static VALUE
TkStringValue(obj)
    VALUE obj;
{
    switch(TYPE(obj)) {
    case T_STRING:
	return obj;

    case T_NIL:
	return rb_str_new2("");

    case T_TRUE:
	return rb_str_new2("1");

    case T_FALSE:
	return rb_str_new2("0");

    case T_ARRAY:
	return rb_funcall(obj, ID_join, 1, rb_str_new2(" "));

    default:
	if (rb_respond_to(obj, ID_to_s)) {
	    return rb_funcall(obj, ID_to_s, 0, 0);
	}
    }

    return rb_funcall(obj, ID_inspect, 0, 0);
}

/* Tcl command `ruby'|`ruby_eval' */
static VALUE
ip_ruby_eval_rescue(failed, einfo)
    VALUE failed;
    VALUE einfo;
{
    DUMP1("call ip_ruby_eval_rescue");
    RARRAY(failed)->ptr[0] = einfo;
    return Qnil;
}

struct eval_body_arg {
    char  *string;
    VALUE failed;
};

static VALUE
ip_ruby_eval_body(arg)
    struct eval_body_arg *arg;
{
    VALUE ret;
    int status = 0;
    int thr_crit_bup;

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    DUMP1("call ip_ruby_eval_body");
    rb_trap_immediate = 0;

#if 0
    ret = rb_rescue2(rb_eval_string, (VALUE)arg->string, 
		      ip_ruby_eval_rescue, arg->failed,
		      rb_eStandardError, rb_eScriptError, rb_eSystemExit, 
		      (VALUE)0);
#else

    ret = rb_eval_string_protect(arg->string, &status);
    if (status) {
	char *errtype, *buf;
	int  errtype_len, len;
	VALUE old_gc;

	old_gc = rb_gc_disable();

	switch(status) {
	case TAG_RETURN:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackReturn, buf);
	    free(buf);
	    break;

	case TAG_BREAK:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackBreak, buf);
	    free(buf);
	    break;

	case TAG_NEXT:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackContinue,buf);
	    free(buf);
	    break;

	case TAG_RETRY:
	case TAG_REDO:
	    RARRAY(arg->failed)->ptr[0] = ruby_errinfo;
	    break;

	case TAG_RAISE:
	case TAG_FATAL:
	    RARRAY(arg->failed)->ptr[0] = ruby_errinfo;
	    break;

	default:
	    buf = ALLOC_N(char, 256);
	    sprintf(buf, "unknown loncaljmp status %d", status);
	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(rb_eException, buf);
	    free(buf);
	    break;
	}

	if (old_gc == Qfalse) rb_gc_enable();

	ret = Qnil;
    }
#endif

    rb_thread_critical = thr_crit_bup;

    return ret;
}

static VALUE
ip_ruby_eval_ensure(trapflag)
    VALUE trapflag;
{
    rb_trap_immediate = NUM2INT(trapflag);
    return Qnil;
}


static int
#if TCL_MAJOR_VERSION >= 8
ip_ruby_eval(clientData, interp, argc, argv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int argc;
    Tcl_Obj *CONST argv[];
#else /* TCL_MAJOR_VERSION < 8 */
ip_ruby_eval(clientData, interp, argc, argv)
    ClientData clientData;
    Tcl_Interp *interp;
    int argc;
    char *argv[];
#endif
{
    volatile VALUE res;
    volatile VALUE exception = rb_ary_new2(1);
    int old_trapflag;
    struct eval_body_arg *arg;
    int thr_crit_bup;

    /* ruby command has 1 arg. */
    if (argc != 2) {
	rb_raise(rb_eArgError, "wrong number of arguments (%d for 1)", 
		 argc - 1);
    }

    /* allocate */
    arg = ALLOC(struct eval_body_arg);

    /* get C string from Tcl object */
#if TCL_MAJOR_VERSION >= 8
    {
      char *str;
      int  len;

      thr_crit_bup = rb_thread_critical;
      rb_thread_critical = Qtrue;

      str = Tcl_GetStringFromObj(argv[1], &len);
      arg->string = ALLOC_N(char, len + 1);
      strncpy(arg->string, str, len);
      arg->string[len] = 0;

      rb_thread_critical = thr_crit_bup;

    }
#else /* TCL_MAJOR_VERSION < 8 */
    arg->string = argv[1];
#endif
    /* arg.failed = 0; */
    RARRAY(exception)->ptr[0] = Qnil;
    arg->failed = exception;

    /* evaluate the argument string by ruby */
    DUMP2("rb_eval_string(%s)", arg->string);
    old_trapflag = rb_trap_immediate;
#ifdef HAVE_NATIVETHREAD
    if (!is_ruby_native_thread()) {
	rb_bug("cross-thread violation on ip_ruby_eval()");
    }
#endif
    res = rb_ensure(ip_ruby_eval_body, (VALUE)arg, 
		    ip_ruby_eval_ensure, INT2FIX(old_trapflag));

#if TCL_MAJOR_VERSION >= 8
    free(arg->string);
#endif

    free(arg);

    /* status check */
    /* if (arg.failed) { */
    if (!NIL_P(RARRAY(exception)->ptr[0])) {
        VALUE eclass;
        volatile VALUE backtrace;

	DUMP1("(rb_eval_string result) failed");

	Tcl_ResetResult(interp);

	res = RARRAY(exception)->ptr[0];
	eclass = rb_obj_class(res);

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	DUMP1("set backtrace");
	backtrace = rb_ary_join(rb_funcall(res, ID_backtrace, 0, 0), 
				rb_str_new2("\n"));
	StringValue(backtrace);
	Tcl_AddErrorInfo(interp, RSTRING(backtrace)->ptr);

	rb_thread_critical = thr_crit_bup;

	if (eclass == eTkCallbackReturn) {
	    return TCL_RETURN;

	} else if (eclass == eTkCallbackBreak) {
	    return TCL_BREAK;

	} else if (eclass == eTkCallbackContinue) {
	    return TCL_CONTINUE;

	} else if (eclass == rb_eSystemExit) {
	    thr_crit_bup = rb_thread_critical;
	    rb_thread_critical = Qtrue;

	    /* Tcl_Eval(interp, "destroy ."); */
	    if (Tk_GetNumMainWindows() > 0) {
		Tk_Window main_win = Tk_MainWindow(interp);
		if (main_win != (Tk_Window)NULL) {
		    Tk_DestroyWindow(main_win);
		}
	    }

	    /* StringValue(res); */
	    res = rb_funcall(res, ID_message, 0, 0);

	    Tcl_AppendResult(interp, RSTRING(res)->ptr, (char*)NULL);

	    rb_thread_critical = thr_crit_bup;

	    rb_raise(rb_eSystemExit, RSTRING(res)->ptr);

	} else if (rb_obj_is_kind_of(res, eLocalJumpError)) {
	    VALUE reason = rb_ivar_get(res, ID_at_reason);

	    if (TYPE(reason) != T_SYMBOL) {
		ip_set_exc_message(interp, res);
		return TCL_ERROR;
	    }

	    if (SYM2ID(reason) == ID_return) {
		return TCL_RETURN;

	    } else if (SYM2ID(reason) == ID_break) {
		return TCL_BREAK;

	    } else if (SYM2ID(reason) == ID_next) {
		return TCL_CONTINUE;

	    } else {
		ip_set_exc_message(interp, res);
		return TCL_ERROR;
	    }
	} else {
	    ip_set_exc_message(interp, res);
	    return TCL_ERROR;
	}
    }

    /* result must be string or nil */
    if (NIL_P(res)) {
	DUMP1("(rb_eval_string result) nil");
	Tcl_ResetResult(interp);
	return TCL_OK;
    }

    /* copy result to the tcl interpreter */
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    res = TkStringValue(res);
    DUMP2("(rb_eval_string result) %s", RSTRING(res)->ptr);
    DUMP1("Tcl_AppendResult");
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, RSTRING(res)->ptr, (char *)NULL);

    rb_thread_critical = thr_crit_bup;

    return TCL_OK;
}


/* Tcl command `ruby_cmd' */
struct cmd_body_arg {
    VALUE receiver;
    ID    method;
    VALUE args;
    VALUE failed;
};

static VALUE
ip_ruby_cmd_core(arg)
    struct cmd_body_arg *arg;
{
    VALUE ret;

    DUMP1("call ip_ruby_cmd_core");
    ret = rb_apply(arg->receiver, arg->method, arg->args);
    DUMP1("finish ip_ruby_cmd_core");

    return ret;
}

static VALUE
ip_ruby_cmd_rescue(failed, einfo)
    VALUE failed;
    VALUE einfo;
{
    DUMP1("call ip_ruby_cmd_rescue");
    RARRAY(failed)->ptr[0] = einfo;
    return Qnil;
}

static VALUE
ip_ruby_cmd_body(arg)
    struct cmd_body_arg *arg;
{
    VALUE ret;
    int status = 0;
    int thr_crit_bup;
    VALUE old_gc;

    volatile VALUE receiver = arg->receiver;
    volatile VALUE args     = arg->args;
    volatile VALUE failed   = arg->failed;

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    DUMP1("call ip_ruby_cmd_body");
    rb_trap_immediate = 0;

#if 0
    ret = rb_rescue2(ip_ruby_cmd_core, (VALUE)arg, 
		     ip_ruby_cmd_rescue, arg->failed,
		     rb_eStandardError, rb_eScriptError, rb_eSystemExit, 
		     (VALUE)0);
#else
    ret = rb_protect(ip_ruby_cmd_core, (VALUE)arg, &status);

    if (status) {
	char *errtype, *buf;
	int  errtype_len, len;

	old_gc = rb_gc_disable();

	switch(status) {
	case TAG_RETURN:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackReturn, buf);
	    free(buf);
	    break;

	case TAG_BREAK:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackBreak, buf);
	    free(buf);
	    break;

	case TAG_NEXT:
	    errtype = "LocalJumpError: ";
	    errtype_len = strlen(errtype);
	    len = errtype_len + RSTRING(rb_obj_as_string(ruby_errinfo))->len;
	    buf = ALLOC_N(char, len + 1);
	    strncpy(buf, errtype, errtype_len);
	    strncpy(buf + errtype_len, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->ptr, 
		    RSTRING(rb_obj_as_string(ruby_errinfo))->len);
	    *(buf + len) = 0;

	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(eTkCallbackContinue,buf);
	    free(buf);
	    break;

	case TAG_RETRY:
	case TAG_REDO:
	    RARRAY(arg->failed)->ptr[0] = ruby_errinfo;
	    break;

	case TAG_RAISE:
	case TAG_FATAL:
	    RARRAY(arg->failed)->ptr[0] = ruby_errinfo;
	    break;

	default:
	    buf = ALLOC_N(char, 256);
	    rb_warn(buf, "unknown loncaljmp status %d", status);
	    RARRAY(arg->failed)->ptr[0] = rb_exc_new2(rb_eException, buf);
	    free(buf);
	    break;
	}

	if (old_gc == Qfalse) rb_gc_enable();

	ret = Qnil;
    }
#endif

    rb_thread_critical = thr_crit_bup;
    DUMP1("finish ip_ruby_cmd_body");

    return ret;
}

static VALUE
ip_ruby_cmd_ensure(trapflag)
    VALUE trapflag;
{
    rb_trap_immediate = NUM2INT(trapflag);
    return Qnil;
}

/* ruby_cmd receiver method arg ... */
static int
#if TCL_MAJOR_VERSION >= 8
ip_ruby_cmd(clientData, interp, argc, argv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int argc;
    Tcl_Obj *CONST argv[];
#else /* TCL_MAJOR_VERSION < 8 */
ip_ruby_cmd(clientData, interp, argc, argv)
    ClientData clientData;
    Tcl_Interp *interp;
    int argc;
    char *argv[];
#endif
{
    volatile VALUE res;
    volatile VALUE receiver;
    volatile ID method;
    volatile VALUE args = rb_ary_new2(argc - 2);
    volatile VALUE exception = rb_ary_new2(1);
    char *str;
    int i;
    int  len;
    int old_trapflag;
    struct cmd_body_arg *arg;
    int thr_crit_bup;
    VALUE old_gc;

    if (argc < 3) {
	rb_raise(rb_eArgError, "too few arguments");
    }

    /* allocate */
    arg = ALLOC(struct cmd_body_arg);

    /* get arguments from Tcl objects */
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;
    old_gc = rb_gc_disable();

    /* get receiver */
#if TCL_MAJOR_VERSION >= 8
    str = Tcl_GetStringFromObj(argv[1], &len);
#else /* TCL_MAJOR_VERSION < 8 */
    str = argv[1];
#endif
    DUMP2("receiver:%s",str);
    if (str[0] == ':' || ('A' <= str[0] && str[0] <= 'Z')) {
	/* class | module | constant */
	receiver = rb_const_get(rb_cObject, rb_intern(str));
    } else if (str[0] == '$') {
	/* global variable */
	receiver = rb_gv_get(str);
    } else {
	/* global variable omitted '$' */
	char *buf;

	len = strlen(str);
	buf = ALLOC_N(char, len + 2);
	buf[0] = '$';
	strncpy(buf + 1, str, len);
	buf[len + 1] = 0;
	receiver = rb_gv_get(buf);
	free(buf);
    }
    if (NIL_P(receiver)) {
	rb_raise(rb_eArgError, "unknown class/module/global-variable '%s'", 
		 str);
    }

    /* get metrhod */
#if TCL_MAJOR_VERSION >= 8
    str = Tcl_GetStringFromObj(argv[2], &len);
#else /* TCL_MAJOR_VERSION < 8 */
    str = argv[2];
#endif
    method = rb_intern(str);

    /* get args */
    RARRAY(args)->len = 0;
    for(i = 3; i < argc; i++) {
#if TCL_MAJOR_VERSION >= 8
	str = Tcl_GetStringFromObj(argv[i], &len);
	DUMP2("arg:%s",str);
	RARRAY(args)->ptr[RARRAY(args)->len++] = rb_tainted_str_new(str, len);
#else /* TCL_MAJOR_VERSION < 8 */
	DUMP2("arg:%s",argv[i]);
	RARRAY(args)->ptr[RARRAY(args)->len++] = rb_tainted_str_new2(argv[i]);
#endif
    }

    if (old_gc == Qfalse) rb_gc_enable();
    rb_thread_critical = thr_crit_bup;

    RARRAY(exception)->ptr[0] = Qnil;

    arg->receiver = receiver;
    arg->method = method;
    arg->args = args;
    arg->failed = exception;

    /* evaluate the argument string by ruby */
    old_trapflag = rb_trap_immediate;
#ifdef HAVE_NATIVETHREAD
    if (!is_ruby_native_thread()) {
	rb_bug("cross-thread violation on ip_ruby_cmd()");
    }
#endif

    res = rb_ensure(ip_ruby_cmd_body, (VALUE)arg, 
		    ip_ruby_cmd_ensure, INT2FIX(old_trapflag));

    free(arg);

    /* status check */
    /* if (arg.failed) { */
    if (!NIL_P(RARRAY(exception)->ptr[0])) {
        VALUE eclass;
        volatile VALUE backtrace;

	DUMP1("(rb_eval_cmd result) failed");

	Tcl_ResetResult(interp);

	res = RARRAY(exception)->ptr[0];
	eclass = rb_obj_class(res);

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	DUMP1("set backtrace");
	backtrace = rb_ary_join(rb_funcall(res, ID_backtrace, 0, 0), 
				rb_str_new2("\n"));
	StringValue(backtrace);
	Tcl_AddErrorInfo(interp, RSTRING(backtrace)->ptr);

	rb_thread_critical = thr_crit_bup;

	if (eclass == eTkCallbackReturn) {
	    return TCL_RETURN;

	} else if (eclass == eTkCallbackBreak) {
	    return TCL_BREAK;

	} else if (eclass == eTkCallbackContinue) {
	    return TCL_CONTINUE;

	} else if (eclass == rb_eSystemExit) {
	    thr_crit_bup = rb_thread_critical;
	    rb_thread_critical = Qtrue;

	    /* Tcl_Eval(interp, "destroy ."); */
	    if (Tk_GetNumMainWindows() > 0) {
		Tk_Window main_win = Tk_MainWindow(interp);
		if (main_win != (Tk_Window)NULL) {
		    Tk_DestroyWindow(main_win);
		}
	    }

	    /* StringValue(res); */
	    res = rb_funcall(res, ID_message, 0, 0);

	    Tcl_AppendResult(interp, RSTRING(res)->ptr, (char*)NULL);

	    rb_thread_critical = thr_crit_bup;

	    rb_raise(rb_eSystemExit, RSTRING(res)->ptr);
	} else if (rb_obj_is_kind_of(res, eLocalJumpError)) {
	    VALUE reason = rb_ivar_get(res, ID_at_reason);

	    if (TYPE(reason) != T_SYMBOL) {
		ip_set_exc_message(interp, res);
		return TCL_ERROR;
	    }

	    if (SYM2ID(reason) == ID_return) {
		return TCL_RETURN;

	    } else if (SYM2ID(reason) == ID_break) {
		return TCL_BREAK;

	    } else if (SYM2ID(reason) == ID_next) {
		return TCL_CONTINUE;

	    } else {
		ip_set_exc_message(interp, res);
		return TCL_ERROR;
	    }
	} else {
	    ip_set_exc_message(interp, res);
	    return TCL_ERROR;
	}
    }

    /* result must be string or nil */
    if (NIL_P(res)) {
	DUMP1("(rb_eval_cmd result) nil");
	Tcl_ResetResult(interp);
	return TCL_OK;
    }


    /* copy result to the tcl interpreter */
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

   
    old_gc = rb_gc_disable();

    res = TkStringValue(res);

    if (old_gc == Qfalse) rb_gc_enable();
    DUMP2("(rb_eval_cmd result) '%s'", RSTRING(res)->ptr);
    DUMP1("Tcl_AppendResult");
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, RSTRING(res)->ptr, (char *)NULL);

    rb_thread_critical = thr_crit_bup;

    DUMP1("end of ip_ruby_cmd");
    return TCL_OK;
}


/**************************/
/*  based on tclEvent.c   */
/**************************/

#if 0  /* 
	  Disable the following "update" and "thread_update". Bcause, 
	  they don't work in a callback-proc. After calling update in 
	  a callback-proc, the callback proc never be worked. 
	  If the problem will be fixed in the future, may enable the 
          functions. 
       */
/*********************/
/* replace of update */
/*********************/
#if TCL_MAJOR_VERSION >= 8
static int ip_rbUpdateObjCmd _((ClientData, Tcl_Interp *, int,
			       Tcl_Obj *CONST []));
static int
ip_rbUpdateObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rbUpdateCommand _((ClientData, Tcl_Interp *, int, char *[]));
static int
ip_rbUpdateCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    int  optionIndex;
    int  ret, done;
    int  flags = 0;
    static CONST char *updateOptions[] = {"idletasks", (char *) NULL};
    enum updateOptions {REGEXP_IDLETASKS};
    char *nameString;
    int  dummy;

    DUMP1("Ruby's 'update' is called");
    if (objc == 1) {
	flags = TCL_ALL_EVENTS|TCL_DONT_WAIT;

    } else if (objc == 2) {
	if (Tcl_GetIndexFromObj(interp, objv[1], updateOptions,
		"option", 0, &optionIndex) != TCL_OK) {
	    return TCL_ERROR;
	}
	switch ((enum updateOptions) optionIndex) {
	    case REGEXP_IDLETASKS: {
		flags = TCL_WINDOW_EVENTS|TCL_IDLE_EVENTS|TCL_DONT_WAIT;
		break;
	    }
	    default: {
                Tcl_Panic("ip_rbUpdateObjCmd: bad option index to UpdateOptions");
	    }
	}
    } else {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "[ idletasks ]");
#else
# if TCL_MAJOR_VERSION >= 8
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 Tcl_GetStringFromObj(objv[0], &dummy), 
			 " [ idletasks ]\"", 
			 (char *) NULL);
# else /* TCL_MAJOR_VERSION < 8 */
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 objv[0], " [ idletasks ]\"", (char *) NULL);
# endif
#endif
	return TCL_ERROR;
    }

    /* call eventloop */
#if 1
    ret = lib_eventloop_core(0, flags, (int *)NULL); /* ignore result */
#else
    Tcl_UpdateObjCmd(clientData, interp, objc, objv);
#endif

    /*
     * Must clear the interpreter's result because event handlers could
     * have executed commands.
     */

    DUMP2("last result '%s'", Tcl_GetStringResult(interp));
    Tcl_ResetResult(interp);
    DUMP1("finish Ruby's 'update'");
    return TCL_OK;
}


/**********************/
/* update with thread */
/**********************/
struct th_update_param {
    VALUE thread;
    int   done;
};

static void rb_threadUpdateProc _((ClientData));
static void 
rb_threadUpdateProc(clientData)
    ClientData clientData;      /* Pointer to integer to set to 1. */
{
    struct th_update_param *param = (struct th_update_param *) clientData;

    DUMP1("threadUpdateProc is called");
    param->done = 1;
    rb_thread_run(param->thread);

    return;
}

#if TCL_MAJOR_VERSION >= 8
static int ip_rb_threadUpdateObjCmd _((ClientData, Tcl_Interp *, int,
				       Tcl_Obj *CONST []));
static int
ip_rb_threadUpdateObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rb_threadUpdateCommand _((ClientData, Tcl_Interp *, int,
				       char *[]));
static int
ip_rb_threadUpdateCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    int  optionIndex;
    int  ret, done;
    int  flags = 0;
    int  dummy;
    struct th_update_param *param;
    static CONST char *updateOptions[] = {"idletasks", (char *) NULL};
    enum updateOptions {REGEXP_IDLETASKS};
    volatile VALUE current_thread = rb_thread_current();

    DUMP1("Ruby's 'thread_update' is called");

    if (rb_thread_alone() || eventloop_thread == current_thread) {
#define USE_TCL_UPDATE 0
#if TCL_MAJOR_VERSION >= 8
# if USE_TCL_UPDATE
	DUMP1("call Tcl_UpdateObjCmd");
	return Tcl_UpdateObjCmd(clientData, interp, objc, objv);
# else
	DUMP1("call ip_rbUpdateObjCmd");
	return ip_rbUpdateObjCmd(clientData, interp, objc, objv);
# endif
#else /* TCL_MAJOR_VERSION < 8 */
# if USE_TCL_UPDATE
	DUMP1("call ip_rbUpdateCommand");
	return Tcl_UpdateCommand(clientData, interp, objc, objv);
# else
	DUMP1("call ip_rbUpdateCommand");
	return ip_rbUpdateCommand(clientData, interp, objc, objv);
# endif 
#endif
    }

    DUMP1("start Ruby's 'thread_update' body");

    if (objc == 1) {
	flags = TCL_ALL_EVENTS|TCL_DONT_WAIT;

    } else if (objc == 2) {
	if (Tcl_GetIndexFromObj(interp, objv[1], updateOptions,
		"option", 0, &optionIndex) != TCL_OK) {
	    return TCL_ERROR;
	}
	switch ((enum updateOptions) optionIndex) {
	    case REGEXP_IDLETASKS: {
		flags = TCL_WINDOW_EVENTS|TCL_IDLE_EVENTS|TCL_DONT_WAIT;
		break;
	    }
	    default: {
                Tcl_Panic("ip_rb_threadUpdateObjCmd: bad option index to UpdateOptions");
	    }
	}
    } else {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "[ idletasks ]");
#else
# if TCL_MAJOR_VERSION >= 8
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 Tcl_GetStringFromObj(objv[0], &dummy), 
			 " [ idletasks ]\"", 
			 (char *) NULL);
# else /* TCL_MAJOR_VERSION < 8 */
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 objv[0], " [ idletasks ]\"", (char *) NULL);
# endif
#endif
	return TCL_ERROR;
    }

    DUMP1("pass argument check");

    param = (struct th_update_param *)Tcl_Alloc(sizeof(struct th_update_param));
    param->thread = current_thread;
    param->done = 0;

    DUMP1("set idle proc");
    Tcl_DoWhenIdle(rb_threadUpdateProc, (ClientData) param);

    while(!param->done) {
	DUMP1("wait for complete idle proc");
	rb_thread_stop();
    }

    Tcl_Free((char *)param);

    DUMP1("finish Ruby's 'thread_update'");
    return TCL_OK;
}
#endif  /* update and thread_update don't work internal callback proc */


/***************************/
/* replace of vwait/tkwait */
/***************************/
#if TCL_MAJOR_VERSION >= 8
static char *VwaitVarProc _((ClientData, Tcl_Interp *, 
			     CONST84 char *,CONST84 char *, int));
static char *
VwaitVarProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    CONST84 char *name1;        /* Name of variable. */
    CONST84 char *name2;        /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#else /* TCL_MAJOR_VERSION < 8 */
static char *VwaitVarProc _((ClientData, Tcl_Interp *, char *, char *, int));
static char *
VwaitVarProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    char *name1;                /* Name of variable. */
    char *name2;                /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#endif
{
    int *donePtr = (int *) clientData;

    *donePtr = 1;
    return (char *) NULL;
}

#if TCL_MAJOR_VERSION >= 8
static int ip_rbVwaitObjCmd _((ClientData, Tcl_Interp *, int,
			       Tcl_Obj *CONST []));
static int
ip_rbVwaitObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rbVwaitCommand _((ClientData, Tcl_Interp *, int, char *[]));
static int
ip_rbVwaitCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    int  ret, done, foundEvent;
    char *nameString;
    int  dummy;
    int thr_crit_bup;

    DUMP1("Ruby's 'vwait' is called");
    if (objc != 2) {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "name");
#else
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
	/* nameString = Tcl_GetString(objv[0]); */
	nameString = Tcl_GetStringFromObj(objv[0], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
	nameString = objv[0];
#endif
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 nameString, " name\"", (char *) NULL);

	rb_thread_critical = thr_crit_bup;
#endif
        return TCL_ERROR;
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
    /* nameString = Tcl_GetString(objv[1]); */
    nameString = Tcl_GetStringFromObj(objv[1], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
    nameString = objv[1];
#endif

    /* 
    if (Tcl_TraceVar(interp, nameString,
		     TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		     VwaitVarProc, (ClientData) &done) != TCL_OK) {
        return TCL_ERROR;
    }
    */
    ret = Tcl_TraceVar(interp, nameString,
		       TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		       VwaitVarProc, (ClientData) &done);

    rb_thread_critical = thr_crit_bup;

    if (ret != TCL_OK) {
        return TCL_ERROR;
    }
    done = 0;
    foundEvent = lib_eventloop_core(/* not check root-widget */0, 0, &done);

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    Tcl_UntraceVar(interp, nameString,
		   TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		   VwaitVarProc, (ClientData) &done);

    rb_thread_critical = thr_crit_bup;

    /*
     * Clear out the interpreter's result, since it may have been set
     * by event handlers.
     */

    Tcl_ResetResult(interp);
    if (!foundEvent) {
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

        Tcl_AppendResult(interp, "can't wait for variable \"", nameString,
			 "\":  would wait forever", (char *) NULL);

	rb_thread_critical = thr_crit_bup;

        return TCL_ERROR;
    }
    return TCL_OK;
}


/**************************/
/*  based on tkCmd.c      */
/**************************/
#if TCL_MAJOR_VERSION >= 8
static char *WaitVariableProc _((ClientData, Tcl_Interp *, 
				 CONST84 char *,CONST84 char *, int));
static char *
WaitVariableProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    CONST84 char *name1;        /* Name of variable. */
    CONST84 char *name2;        /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#else /* TCL_MAJOR_VERSION < 8 */
static char *WaitVariableProc _((ClientData, Tcl_Interp *, 
				 char *, char *, int));
static char *
WaitVariableProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    char *name1;                /* Name of variable. */
    char *name2;                /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#endif
{
    int *donePtr = (int *) clientData;

    *donePtr = 1;
    return (char *) NULL;
}

static void WaitVisibilityProc _((ClientData, XEvent *));
static void
WaitVisibilityProc(clientData, eventPtr)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    XEvent *eventPtr;           /* Information about event (not used). */
{
    int *donePtr = (int *) clientData;

    if (eventPtr->type == VisibilityNotify) {
        *donePtr = 1;
    }
    if (eventPtr->type == DestroyNotify) {
        *donePtr = 2;
    }
}

static void WaitWindowProc _((ClientData, XEvent *));
static void
WaitWindowProc(clientData, eventPtr)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    XEvent *eventPtr;           /* Information about event. */
{
    int *donePtr = (int *) clientData;

    if (eventPtr->type == DestroyNotify) {
        *donePtr = 1;
    }
}

#if TCL_MAJOR_VERSION >= 8
static int ip_rbTkWaitObjCmd _((ClientData, Tcl_Interp *, int,
				Tcl_Obj *CONST []));
static int
ip_rbTkWaitObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rbTkWaitCommand _((ClientData, Tcl_Interp *, int, char *[]));
static int
ip_rbTkWaitCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    Tk_Window tkwin = (Tk_Window) clientData;
    int done, index;
    static CONST char *optionStrings[] = { "variable", "visibility", "window",
					   (char *) NULL };
    enum options { TKWAIT_VARIABLE, TKWAIT_VISIBILITY, TKWAIT_WINDOW };
    char *nameString;
    int ret, dummy;
    int thr_crit_bup;

    DUMP1("Ruby's 'tkwait' is called");

    if (objc != 3) {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "variable|visibility|window name");
#else
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 Tcl_GetStringFromObj(objv[0], &dummy), 
			 " variable|visibility|window name\"", 
			 (char *) NULL);
#else /* TCL_MAJOR_VERSION < 8 */
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 objv[0], " variable|visibility|window name\"", 
			 (char *) NULL);
#endif

	rb_thread_critical = thr_crit_bup;
#endif
        return TCL_ERROR;
    }

#if TCL_MAJOR_VERSION >= 8
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /*
    if (Tcl_GetIndexFromObj(interp, objv[1], 
                            (CONST84 char **)optionStrings, 
			    "option", 0, &index) != TCL_OK) {
        return TCL_ERROR;
    }
    */
    ret = Tcl_GetIndexFromObj(interp, objv[1], 
			      (CONST84 char **)optionStrings, 
			      "option", 0, &index);

    rb_thread_critical = thr_crit_bup;

    if (ret != TCL_OK) {
        return TCL_ERROR;
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	int c = objv[1][0];
	size_t length = strlen(objv[1]);

	if ((c == 'v') && (strncmp(objv[1], "variable", length) == 0)
	    && (length >= 2)) {
	    index = TKWAIT_VARIABLE;
	} else if ((c == 'v') && (strncmp(objv[1], "visibility", length) == 0)
		   && (length >= 2)) {
	    index = TKWAIT_VISIBILITY;
	} else if ((c == 'w') && (strncmp(objv[1], "window", length) == 0)) {
	    index = TKWAIT_WINDOW;
	} else {
	    Tcl_AppendResult(interp, "bad option \"", objv[1],
			     "\": must be variable, visibility, or window", 
			     (char *) NULL);
	    return TCL_ERROR;
	}
    }
#endif

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
    /* nameString = Tcl_GetString(objv[2]); */
    nameString = Tcl_GetStringFromObj(objv[2], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
    nameString = objv[2];
#endif

    rb_thread_critical = thr_crit_bup;

    switch ((enum options) index) {
    case TKWAIT_VARIABLE: {
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;
	/*
	if (Tcl_TraceVar(interp, nameString,
			 TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
			 WaitVariableProc, (ClientData) &done) != TCL_OK) {
	    return TCL_ERROR;
	}
	*/
	ret = Tcl_TraceVar(interp, nameString,
			   TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
			   WaitVariableProc, (ClientData) &done);

	rb_thread_critical = thr_crit_bup;

	if (ret != TCL_OK) {
	    return TCL_ERROR;
	}
	done = 0;
	lib_eventloop_core(check_rootwidget_flag, 0, &done);

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	Tcl_UntraceVar(interp, nameString,
		       TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		       WaitVariableProc, (ClientData) &done);

	rb_thread_critical = thr_crit_bup;

	break;
    }

    case TKWAIT_VISIBILITY: {
	Tk_Window window;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	window = Tk_NameToWindow(interp, nameString, tkwin);
	if (window == NULL) {
	    rb_thread_critical = thr_crit_bup;
	    return TCL_ERROR;
	}

	Tk_CreateEventHandler(window,
			      VisibilityChangeMask|StructureNotifyMask,
			      WaitVisibilityProc, (ClientData) &done);

	rb_thread_critical = thr_crit_bup;

	done = 0;
	lib_eventloop_core(check_rootwidget_flag, 0, &done);
	if (done != 1) {
	    /*
	     * Note that we do not delete the event handler because it
	     * was deleted automatically when the window was destroyed.
	     */
	    thr_crit_bup = rb_thread_critical;
	    rb_thread_critical = Qtrue;

	    Tcl_ResetResult(interp);
	    Tcl_AppendResult(interp, "window \"", nameString,
			     "\" was deleted before its visibility changed",
			     (char *) NULL);

	    rb_thread_critical = thr_crit_bup;

	    return TCL_ERROR;
	}

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	Tk_DeleteEventHandler(window,
			      VisibilityChangeMask|StructureNotifyMask,
			      WaitVisibilityProc, (ClientData) &done);

	rb_thread_critical = thr_crit_bup;

	break;
    }

    case TKWAIT_WINDOW: {
	Tk_Window window;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;
            
	window = Tk_NameToWindow(interp, nameString, tkwin);
	if (window == NULL) {
	    rb_thread_critical = thr_crit_bup;
	    return TCL_ERROR;
	}

	Tk_CreateEventHandler(window, StructureNotifyMask,
			      WaitWindowProc, (ClientData) &done);

	rb_thread_critical = thr_crit_bup;

	done = 0;
	lib_eventloop_core(check_rootwidget_flag, 0, &done);
	/*
	 * Note:  there's no need to delete the event handler.  It was
	 * deleted automatically when the window was destroyed.
	 */
	break;
    }
    }

    /*
     * Clear out the interpreter's result, since it may have been set
     * by event handlers.
     */

    Tcl_ResetResult(interp);
    return TCL_OK;
}

/****************************/
/* vwait/tkwait with thread */
/****************************/
struct th_vwait_param {
    VALUE thread;
    int   done;
};

#if TCL_MAJOR_VERSION >= 8
static char *rb_threadVwaitProc _((ClientData, Tcl_Interp *, 
				   CONST84 char *,CONST84 char *, int));
static char *
rb_threadVwaitProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    CONST84 char *name1;        /* Name of variable. */
    CONST84 char *name2;        /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#else /* TCL_MAJOR_VERSION < 8 */
static char *rb_threadVwaitProc _((ClientData, Tcl_Interp *, 
				   char *, char *, int));
static char *
rb_threadVwaitProc(clientData, interp, name1, name2, flags)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    Tcl_Interp *interp;         /* Interpreter containing variable. */
    char *name1;                /* Name of variable. */
    char *name2;                /* Second part of variable name. */
    int flags;                  /* Information about what happened. */
#endif
{
    struct th_vwait_param *param = (struct th_vwait_param *) clientData;

    param->done = 1;
    rb_thread_run(param->thread);

    return (char *)NULL;
}

static void rb_threadWaitVisibilityProc _((ClientData, XEvent *));
static void
rb_threadWaitVisibilityProc(clientData, eventPtr)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    XEvent *eventPtr;           /* Information about event (not used). */
{
    struct th_vwait_param *param = (struct th_vwait_param *) clientData;

    if (eventPtr->type == VisibilityNotify) {
        param->done = 1;
    }
    if (eventPtr->type == DestroyNotify) {
        param->done = 2;
    }
    rb_thread_run(param->thread);
}

static void rb_threadWaitWindowProc _((ClientData, XEvent *));
static void
rb_threadWaitWindowProc(clientData, eventPtr)
    ClientData clientData;      /* Pointer to integer to set to 1. */
    XEvent *eventPtr;           /* Information about event. */
{
    struct th_vwait_param *param = (struct th_vwait_param *) clientData;

    if (eventPtr->type == DestroyNotify) {
        param->done = 1;
    }
    rb_thread_run(param->thread);
}

#if TCL_MAJOR_VERSION >= 8
static int ip_rb_threadVwaitObjCmd _((ClientData, Tcl_Interp *, int,
				      Tcl_Obj *CONST []));
static int
ip_rb_threadVwaitObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rb_threadVwaitCommand _((ClientData, Tcl_Interp *, int,
				       char *[]));
static int
ip_rb_threadVwaitCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    struct th_vwait_param *param;
    char *nameString;
    int ret, dummy;
    int thr_crit_bup;
    volatile VALUE current_thread = rb_thread_current();

    DUMP1("Ruby's 'thread_vwait' is called");

    if (rb_thread_alone() || eventloop_thread == current_thread) {
#if TCL_MAJOR_VERSION >= 8
	DUMP1("call ip_rbVwaitObjCmd");
	return ip_rbVwaitObjCmd(clientData, interp, objc, objv);
#else /* TCL_MAJOR_VERSION < 8 */
	DUMP1("call ip_rbVwaitCommand");
	return ip_rbVwaitCommand(clientData, interp, objc, objv);
#endif
    }

    if (objc != 2) {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "name");
#else
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
	/* nameString = Tcl_GetString(objv[0]); */
	nameString = Tcl_GetStringFromObj(objv[0], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
	nameString = objv[0];
#endif
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 nameString, " name\"", (char *) NULL);

	rb_thread_critical = thr_crit_bup;
#endif
        return TCL_ERROR;
    }
#if TCL_MAJOR_VERSION >= 8
    /* nameString = Tcl_GetString(objv[1]); */
    nameString = Tcl_GetStringFromObj(objv[1], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
    nameString = objv[1];
#endif
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    param = (struct th_vwait_param *)Tcl_Alloc(sizeof(struct th_vwait_param));
    param->thread = current_thread;
    param->done = 0;

    /*
    if (Tcl_TraceVar(interp, nameString,
		     TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		     rb_threadVwaitProc, (ClientData) param) != TCL_OK) {
        return TCL_ERROR;
    }
    */
    ret = Tcl_TraceVar(interp, nameString,
		       TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		       rb_threadVwaitProc, (ClientData) param);

    rb_thread_critical = thr_crit_bup;

    if (ret != TCL_OK) {
        return TCL_ERROR;
    }

    /* if (!param->done) { */
    while(!param->done) {
	rb_thread_stop();
    }


    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    Tcl_UntraceVar(interp, nameString,
		   TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		   rb_threadVwaitProc, (ClientData) param);

    Tcl_Free((char *)param);

    rb_thread_critical = thr_crit_bup;

    return TCL_OK;
}

#if TCL_MAJOR_VERSION >= 8
static int ip_rb_threadTkWaitObjCmd _((ClientData, Tcl_Interp *, int,
				       Tcl_Obj *CONST []));
static int
ip_rb_threadTkWaitObjCmd(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp; 
    int objc;
    Tcl_Obj *CONST objv[];
#else /* TCL_MAJOR_VERSION < 8 */
static int ip_rb_threadTkWaitCommand _((ClientData, Tcl_Interp *, int,
					char *[]));
static int
ip_rb_threadTkWaitCommand(clientData, interp, objc, objv)
    ClientData clientData;
    Tcl_Interp *interp;
    int objc;
    char *objv[];
#endif
{
    struct th_vwait_param *param;
    Tk_Window tkwin = (Tk_Window) clientData;
    int index;
    static CONST char *optionStrings[] = { "variable", "visibility", "window",
					   (char *) NULL };
    enum options { TKWAIT_VARIABLE, TKWAIT_VISIBILITY, TKWAIT_WINDOW };
    char *nameString;
    int ret, dummy;
    int thr_crit_bup;
    volatile VALUE current_thread = rb_thread_current();

    DUMP1("Ruby's 'thread_tkwait' is called");

    if (rb_thread_alone() || eventloop_thread == current_thread) {
#if TCL_MAJOR_VERSION >= 8
	DUMP1("call ip_rbTkWaitObjCmd");
	return ip_rbTkWaitObjCmd(clientData, interp, objc, objv);
#else /* TCL_MAJOR_VERSION < 8 */
	DUMP1("call rb_VwaitCommand");
	return ip_rbTkWaitCommand(clientData, interp, objc, objv);
#endif
    }

    if (objc != 3) {
#ifdef Tcl_WrongNumArgs
        Tcl_WrongNumArgs(interp, 1, objv, "variable|visibility|window name");
#else
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 Tcl_GetStringFromObj(objv[0], &dummy), 
			 " variable|visibility|window name\"", 
			 (char *) NULL);
#else /* TCL_MAJOR_VERSION < 8 */
        Tcl_AppendResult(interp, "wrong number of arguments: should be \"",
			 objv[0], " variable|visibility|window name\"", 
			 (char *) NULL);
#endif

	rb_thread_critical = thr_crit_bup;
#endif
        return TCL_ERROR;
    }

#if TCL_MAJOR_VERSION >= 8
    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;
    /*
    if (Tcl_GetIndexFromObj(interp, objv[1], 
                            (CONST84 char **)optionStrings, 
			    "option", 0, &index) != TCL_OK) {
        return TCL_ERROR;
    }
    */
    ret = Tcl_GetIndexFromObj(interp, objv[1], 
			      (CONST84 char **)optionStrings, 
			      "option", 0, &index);

    rb_thread_critical = thr_crit_bup;

    if (ret != TCL_OK) {
        return TCL_ERROR;
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	int c = objv[1][0];
	size_t length = strlen(objv[1]);

	if ((c == 'v') && (strncmp(objv[1], "variable", length) == 0)
	    && (length >= 2)) {
	    index = TKWAIT_VARIABLE;
	} else if ((c == 'v') && (strncmp(objv[1], "visibility", length) == 0)
		   && (length >= 2)) {
	    index = TKWAIT_VISIBILITY;
	} else if ((c == 'w') && (strncmp(objv[1], "window", length) == 0)) {
	    index = TKWAIT_WINDOW;
	} else {
	    Tcl_AppendResult(interp, "bad option \"", objv[1],
			     "\": must be variable, visibility, or window", 
			     (char *) NULL);
	    return TCL_ERROR;
	}
    }
#endif

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

#if TCL_MAJOR_VERSION >= 8
    /* nameString = Tcl_GetString(objv[2]); */
    nameString = Tcl_GetStringFromObj(objv[2], &dummy);
#else /* TCL_MAJOR_VERSION < 8 */
    nameString = objv[2];
#endif

    param = (struct th_vwait_param *)Tcl_Alloc(sizeof(struct th_vwait_param));
    param->thread = current_thread;
    param->done = 0;

    rb_thread_critical = thr_crit_bup;

    switch ((enum options) index) {
    case TKWAIT_VARIABLE: {
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;
	/* 
	if (Tcl_TraceVar(interp, nameString,
			 TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
			 rb_threadVwaitProc, (ClientData) param) != TCL_OK) {
	    return TCL_ERROR;
	}
	*/
	ret = Tcl_TraceVar(interp, nameString,
			 TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
			 rb_threadVwaitProc, (ClientData) param);

	rb_thread_critical = thr_crit_bup;

	if (ret != TCL_OK) {
	    return TCL_ERROR;
	}

	/* if (!param->done) { */
	while(!param->done) {
	    rb_thread_stop();
	}

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	Tcl_UntraceVar(interp, nameString,
		       TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		       rb_threadVwaitProc, (ClientData) param);

	rb_thread_critical = thr_crit_bup;

	break;
    }

    case TKWAIT_VISIBILITY: {
	Tk_Window window;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	window = Tk_NameToWindow(interp, nameString, tkwin);
	if (window == NULL) {
	    rb_thread_critical = thr_crit_bup;
	    return TCL_ERROR;
	}

	Tk_CreateEventHandler(window,
			      VisibilityChangeMask|StructureNotifyMask,
			      rb_threadWaitVisibilityProc, (ClientData) param);

	rb_thread_critical = thr_crit_bup;

	/* if (!param->done) { */
	while(!param->done) {
	    rb_thread_stop();
	}

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	Tk_DeleteEventHandler(window,
			      VisibilityChangeMask|StructureNotifyMask,
			      rb_threadWaitVisibilityProc, (ClientData) param);

	if (param->done != 1) {
	    Tcl_ResetResult(interp);
	    Tcl_AppendResult(interp, "window \"", nameString,
			     "\" was deleted before its visibility changed",
			     (char *) NULL);

	    rb_thread_critical = thr_crit_bup;

	    return TCL_ERROR;
	}

	rb_thread_critical = thr_crit_bup;

	break;
    }

    case TKWAIT_WINDOW: {
	Tk_Window window;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;
            
	window = Tk_NameToWindow(interp, nameString, tkwin);
	if (window == NULL) {
	    rb_thread_critical = thr_crit_bup;
	    return TCL_ERROR;
	}

	Tk_CreateEventHandler(window, StructureNotifyMask,
			      rb_threadWaitWindowProc, (ClientData) param);

	rb_thread_critical = thr_crit_bup;

	/* if (!param->done) { */
	while(!param->done) {
	    rb_thread_stop();
	}

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	Tk_DeleteEventHandler(window, StructureNotifyMask,
			      rb_threadWaitWindowProc, (ClientData) param);

	rb_thread_critical = thr_crit_bup;

	break;
    }
    } /* end of 'switch' statement */

    Tcl_Free((char *)param);

    /*
     * Clear out the interpreter's result, since it may have been set
     * by event handlers.
     */

    Tcl_ResetResult(interp);
    return TCL_OK;
}

static VALUE
ip_thread_vwait(self, var)
    VALUE self;
    VALUE var;
{
    VALUE argv[2];

    argv[0] = rb_str_new2("thread_vwait");
    argv[1] = var;
    return ip_invoke_real(2, argv, self);
}

static VALUE
ip_thread_tkwait(self, mode, target)
    VALUE self;
    VALUE mode;
    VALUE target;
{
    VALUE argv[3];

    argv[0] = rb_str_new2("thread_tkwait");
    argv[1] = mode;
    argv[2] = target;
    return ip_invoke_real(3, argv, self);
}


/* destroy interpreter */
VALUE del_root(ip)
    Tcl_Interp *ip;
{
    Tcl_Preserve(ip);
    Tk_DestroyWindow(Tk_MainWindow(ip));
    Tcl_Release(ip);
    return Qnil;
}

static void
ip_free(ptr)
    struct tcltkip *ptr;
{
    int try = 3;
    Tcl_CmdInfo info;
    int thr_crit_bup;

    DUMP1("free Tcl Interp");
    if (ptr) {
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	if (!Tcl_InterpDeleted(ptr->ip)) {
	    Tcl_ResetResult(ptr->ip);
	    Tcl_Preserve(ptr->ip);
	    if (Tcl_GetCommandInfo(ptr->ip, finalize_hook_name, &info)) {
		DUMP2("call finalize hook proc '%s'", finalize_hook_name);
		Tcl_Eval(ptr->ip, finalize_hook_name);
	    }
	    for(; try > 0; try--) {
		if (!Tk_GetNumMainWindows()) break;
		rb_protect(del_root, (VALUE)(ptr->ip), 0);
	    }
	    Tcl_Release(ptr->ip);
	    Tcl_DeleteInterp(ptr->ip);
	}
	Tcl_Release((ClientData)ptr->ip);
	free(ptr);

	rb_thread_critical = thr_crit_bup;
    }
    DUMP1("complete freeing Tcl Interp");
}

/* create and initialize interpreter */
static VALUE ip_alloc _((VALUE));
static VALUE
ip_alloc(self)
    VALUE self;
{
    return Data_Wrap_Struct(self, 0, ip_free, 0);
}

static VALUE
ip_init(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    struct tcltkip *ptr;	/* tcltkip data struct */
    VALUE argv0, opts;
    int cnt;
    int with_tk = 1;
    Tk_Window mainWin;

    /* create object */
    Data_Get_Struct(self, struct tcltkip, ptr);
    ptr = ALLOC(struct tcltkip);
    DATA_PTR(self) = ptr;
    ptr->return_value = 0;

    /* from Tk_Main() */
    DUMP1("Tcl_CreateInterp");
    ptr->ip = Tcl_CreateInterp();
    Tcl_Preserve((ClientData)ptr->ip);
    current_interp = ptr->ip;

    /* from Tcl_AppInit() */
    DUMP1("Tcl_Init");
    if (Tcl_Init(ptr->ip) == TCL_ERROR) {
#if TCL_MAJOR_VERSION >= 8
	rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
    }

    /* set variables */
    cnt = rb_scan_args(argc, argv, "02", &argv0, &opts);
    switch(cnt) {
    case 2:
	/* options */
	if (NIL_P(opts) || opts == Qfalse) {
	    /* without Tk */
	    with_tk = 0;
	} else {
	    Tcl_SetVar(ptr->ip, "argv", StringValuePtr(opts), 0);
	}
    case 1:
	/* argv0 */
	if (!NIL_P(argv0)) {
	    Tcl_SetVar(ptr->ip, "argv0", StringValuePtr(argv0), 0);
	}
    case 0:
	/* no args */
	;
    }

    /* from Tcl_AppInit() */
    if (with_tk) {
	DUMP1("Tk_Init");
	if (Tk_Init(ptr->ip) == TCL_ERROR) {
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}
	DUMP1("Tcl_StaticPackage(\"Tk\")");
#if TCL_MAJOR_VERSION >= 8
	Tcl_StaticPackage(ptr->ip, "Tk", Tk_Init, Tk_SafeInit);
#else /* TCL_MAJOR_VERSION < 8 */
	Tcl_StaticPackage(ptr->ip, "Tk", Tk_Init,
			  (Tcl_PackageInitProc *) NULL);
#endif
    }

    /* get main window */
    mainWin = Tk_MainWindow(ptr->ip);

    /* add ruby command to the interpreter */
#if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"ruby\")");
    Tcl_CreateObjCommand(ptr->ip, "ruby", ip_ruby_eval, (ClientData)NULL,
			 (Tcl_CmdDeleteProc *)NULL);
    DUMP1("Tcl_CreateObjCommand(\"ruby_eval\")");
    Tcl_CreateObjCommand(ptr->ip, "ruby_eval", ip_ruby_eval, (ClientData)NULL,
			 (Tcl_CmdDeleteProc *)NULL);
    DUMP1("Tcl_CreateObjCommand(\"ruby_cmd\")");
    Tcl_CreateObjCommand(ptr->ip, "ruby_cmd", ip_ruby_cmd, (ClientData)NULL,
			 (Tcl_CmdDeleteProc *)NULL);
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"ruby\")");
    Tcl_CreateCommand(ptr->ip, "ruby", ip_ruby_eval, (ClientData)NULL,
		      (Tcl_CmdDeleteProc *)NULL);
    DUMP1("Tcl_CreateCommand(\"ruby_eval\")");
    Tcl_CreateCommand(ptr->ip, "ruby_eval", ip_ruby_eval, (ClientData)NULL,
		      (Tcl_CmdDeleteProc *)NULL);
    DUMP1("Tcl_CreateCommand(\"ruby_cmd\")");
    Tcl_CreateCommand(ptr->ip, "ruby_cmd", ip_ruby_cmd, (ClientData)NULL,
		      (Tcl_CmdDeleteProc *)NULL);
#endif

#if 0  /* 
	  Disable the following "update" and "thread_update". Bcause, 
	  they don't work in a callback-proc. After calling update in 
	  a callback-proc, the callback proc never be worked. 
	  If the problem will be fixed in the future, may enable the 
          functions. 
       */
    /* replace 'update' command */
# if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"update\")");
    Tcl_CreateObjCommand(ptr->ip, "update", ip_rbUpdateObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
# else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"update\")");
    Tcl_CreateCommand(ptr->ip, "update", ip_rbUpdateCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
# endif

    /* add 'thread_update' command */
# if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"thread_update\")");
    Tcl_CreateObjCommand(ptr->ip, "thread_update", ip_rb_threadUpdateObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
# else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"thread_update\")");
    Tcl_CreateCommand(ptr->ip, "thread_update", ip_rb_threadUpdateCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
# endif
#endif

    /* replace 'vwait' command */
#if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"vwait\")");
    Tcl_CreateObjCommand(ptr->ip, "vwait", ip_rbVwaitObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"vwait\")");
    Tcl_CreateCommand(ptr->ip, "vwait", ip_rbVwaitCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#endif

    /* replace 'tkwait' command */
#if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"tkwait\")");
    Tcl_CreateObjCommand(ptr->ip, "tkwait", ip_rbTkWaitObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"tkwait\")");
    Tcl_CreateCommand(ptr->ip, "tkwait", ip_rbTkWaitCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#endif

    /* add 'thread_vwait' command */
#if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"thread_vwait\")");
    Tcl_CreateObjCommand(ptr->ip, "thread_vwait", ip_rb_threadVwaitObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"thread_vwait\")");
    Tcl_CreateCommand(ptr->ip, "thread_vwait", ip_rb_threadVwaitCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#endif

    /* add 'thread_tkwait' command */
#if TCL_MAJOR_VERSION >= 8
    DUMP1("Tcl_CreateObjCommand(\"thread_tkwait\")");
    Tcl_CreateObjCommand(ptr->ip, "thread_tkwait", ip_rb_threadTkWaitObjCmd, 
			 (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tcl_CreateCommand(\"thread_tkwait\")");
    Tcl_CreateCommand(ptr->ip, "thread_tkwait", ip_rb_threadTkWaitCommand, 
		      (ClientData)mainWin, (Tcl_CmdDeleteProc *)NULL);
#endif

    return self;
}

static VALUE
ip_create_slave(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    struct tcltkip *master = get_ip(self);
    struct tcltkip *slave = ALLOC(struct tcltkip);
    VALUE safemode;
    VALUE name;
    int safe;
    int thr_crit_bup;

    /* safe-mode check */
    if (rb_scan_args(argc, argv, "11", &name, &safemode) == 1) {
	safemode = Qfalse;
    }
    if (Tcl_IsSafe(master->ip) == 1) {
	safe = 1;
    } else if (safemode == Qfalse || NIL_P(safemode)) {
	safe = 0;
	rb_secure(4);
    } else {
	safe = 1;
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* create slave-ip */
    slave->ip = Tcl_CreateSlave(master->ip, StringValuePtr(name), safe);
    if (slave->ip == NULL) {
	rb_raise(rb_eRuntimeError, "fail to create the new slave interpreter");
    }
    Tcl_Preserve((ClientData)slave->ip);
    slave->return_value = 0;

    rb_thread_critical = thr_crit_bup;

    return Data_Wrap_Struct(CLASS_OF(self), 0, ip_free, slave);
}

/* make ip "safe" */
static VALUE
ip_make_safe(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);
    
    if (Tcl_MakeSafe(ptr->ip) == TCL_ERROR) {
#if TCL_MAJOR_VERSION >= 8
	rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
    }

    return self;
}

/* is safe? */
static VALUE
ip_is_safe_p(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);
    
    if (Tcl_IsSafe(ptr->ip)) {
	return Qtrue;
    } else {
	return Qfalse;
    }
}

/* delete interpreter */
static VALUE
ip_delete(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);

    Tcl_DeleteInterp(ptr->ip);

    return Qnil;
}

/* is deleted? */
static VALUE
ip_is_deleted_p(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);

    if (Tcl_InterpDeleted(ptr->ip)) {
	return Qtrue;
    } else {
	return Qfalse;
    }
}


static VALUE
#ifdef HAVE_STDARG_PROTOTYPES
create_ip_exc(VALUE interp, VALUE exc, const char *fmt, ...)
#else
create_ip_exc(interp, exc, fmt, va_alist)
    VALUE interp:
    VALUE exc;
    const char *fmt;
    va_dcl
#endif
{
    va_list args;
    char buf[BUFSIZ];
    VALUE einfo;

    va_init_list(args,fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    buf[BUFSIZ - 1] = '\0';
    va_end(args);
    einfo = rb_exc_new2(exc, buf);
    rb_ivar_set(einfo, ID_at_interp, interp);
    Tcl_ResetResult(get_ip(interp)->ip);

    return einfo;
}

static VALUE
ip_get_result_string_obj(interp)
    Tcl_Interp *interp;
{
#if TCL_MAJOR_VERSION >= 8
    int len;
    char *s;

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
    s = Tcl_GetStringFromObj(Tcl_GetObjResult(interp), &len);
    return(rb_tainted_str_new(s, len));

# else /* TCL_VERSION >= 8.1 */
    volatile VALUE strval;
    Tcl_Obj *retobj = Tcl_GetObjResult(interp);
    int thr_crit_bup;

    Tcl_IncrRefCount(retobj);

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    if (Tcl_GetCharLength(retobj) != Tcl_UniCharLen(Tcl_GetUnicode(retobj))) {
	/* possibly binary string */
	s = Tcl_GetByteArrayFromObj(retobj, &len);
	strval = rb_tainted_str_new(s, len);
	rb_ivar_set(strval, ID_at_enc, rb_str_new2("binary"));
    } else {
	/* possibly text string */
	s = Tcl_GetStringFromObj(retobj, &len);
	strval = rb_tainted_str_new(s, len);
    }

    rb_thread_critical = thr_crit_bup;

    Tcl_DecrRefCount(retobj);

    return(strval);

# endif
#else /* TCL_MAJOR_VERSION < 8 */
    return(rb_tainted_str_new2(interp->result));
#endif
}

/* eval string in tcl by Tcl_Eval() */
static VALUE
ip_eval_real(self, cmd_str, cmd_len)
    VALUE self;
    char *cmd_str;
    int  cmd_len;
{
    char *s;
    int  len;
    struct tcltkip *ptr = get_ip(self);
    int thr_crit_bup;

#if TCL_MAJOR_VERSION >= 8
    /* call Tcl_EvalObj() */
    {
      Tcl_Obj *cmd;

      thr_crit_bup = rb_thread_critical;
      rb_thread_critical = Qtrue;

      cmd = Tcl_NewStringObj(cmd_str, cmd_len);
      Tcl_IncrRefCount(cmd);
      ptr->return_value = Tcl_EvalObj(ptr->ip, cmd);
      /* ptr->return_value = Tcl_GlobalEvalObj(ptr->ip, cmd); */
      Tcl_DecrRefCount(cmd);

      rb_thread_critical = thr_crit_bup;
    }
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP2("Tcl_Eval(%s)", cmd_str);
    ptr->return_value = Tcl_Eval(ptr->ip, cmd_str);
    /* ptr->return_value = Tcl_GlobalEval(ptr->ip, cmd_str); */
#endif

    if (ptr->return_value == TCL_ERROR) {
#if TCL_MAJOR_VERSION >= 8
	return create_ip_exc(self, rb_eRuntimeError, 
			     "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	return create_ip_exc(self, rb_eRuntimeError, 
			     "%s", ptr->ip->result);
#endif
    }
    DUMP2("(TCL_Eval result) %d", ptr->return_value);

    /* pass back the result (as string) */
    return ip_get_result_string_obj(ptr->ip);
}

static VALUE
evq_safelevel_handler(arg, evq)
    VALUE arg;
    VALUE evq;
{
    struct eval_queue *q;

    Data_Get_Struct(evq, struct eval_queue, q);
    DUMP2("(safe-level handler) $SAFE = %d", q->safe_level);
    rb_set_safe_level(q->safe_level);
    return ip_eval_real(q->interp, q->str, q->len);
}

int eval_queue_handler _((Tcl_Event *, int));
int
eval_queue_handler(evPtr, flags)
    Tcl_Event *evPtr;
    int flags;
{
    struct eval_queue *q = (struct eval_queue *)evPtr;
    volatile VALUE ret;

    DUMP2("do_eval_queue_handler : evPtr = %p", evPtr);
    DUMP2("eval queue_thread : %lx", rb_thread_current());
    DUMP2("added by thread : %lx", q->thread);

    if (*(q->done)) {
	DUMP1("processed by another event-loop");
	return 0;
    } else {
	DUMP1("process it on current event-loop");
    }

    /* process it */
    *(q->done) = 1;

    /* check safe-level */
    if (rb_safe_level() != q->safe_level) {
	volatile VALUE q_dat;
#ifdef HAVE_NATIVETHREAD
	if (!is_ruby_native_thread()) {
	    rb_bug("cross-thread violation on eval_queue_handler()");
	}
#endif
	q_dat = Data_Wrap_Struct(rb_cData,eval_queue_mark,0,q);
	ret = rb_funcall(rb_proc_new(evq_safelevel_handler, q_dat), 
			 ID_call, 0);
    } else {
	DUMP2("call eval_real (for caller thread:%lx)", q->thread);
	DUMP2("call eval_real (current thread:%lx)", rb_thread_current());
	ret = ip_eval_real(q->interp, q->str, q->len);
    }

    /* set result */
    RARRAY(q->result)->ptr[0] = ret;

    /* complete */
    *(q->done) = -1;

    /* back to caller */
    DUMP2("back to caller (caller thread:%lx)", q->thread);
    DUMP2("               (current thread:%lx)", rb_thread_current());
    rb_thread_run(q->thread);
    DUMP1("finish back to caller");

    /* end of handler : remove it */
    return 1;
}

static VALUE
ip_eval(self, str)
    VALUE self;
    VALUE str;
{
    struct eval_queue *evq;
    char *eval_str;
    int  *alloc_done;
    int  thr_crit_bup;
    VALUE current = rb_thread_current();
    volatile VALUE result = rb_ary_new2(1);
    volatile VALUE ret;
    Tcl_QueuePosition position;

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;
    StringValue(str);
    rb_thread_critical = thr_crit_bup;

    if (eventloop_thread == 0 || current == eventloop_thread) {
	if (eventloop_thread) {
	    DUMP2("eval from current eventloop %lx", current);
	} else {
	    DUMP2("eval from thread:%lx but no eventloop", current);
	}
	result = ip_eval_real(self, RSTRING(str)->ptr, RSTRING(str)->len);
	if (rb_obj_is_kind_of(result, rb_eException)) {
	    rb_exc_raise(result);
	}
	return result;
    }

    DUMP2("eval from thread %lx (NOT current eventloop)", current);

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* allocate memory (protected from Tcl_ServiceEvent) */
    alloc_done = (int*)ALLOC(int);
    *alloc_done = 0;

    eval_str = ALLOC_N(char, RSTRING(str)->len + 1);
    strncpy(eval_str, RSTRING(str)->ptr, RSTRING(str)->len);
    eval_str[RSTRING(str)->len] = 0;

    /* allocate memory (freed by Tcl_ServiceEvent) */
    evq = (struct eval_queue *)Tcl_Alloc(sizeof(struct eval_queue));

    /* construct event data */
    evq->done = alloc_done;
    evq->str = eval_str;
    evq->len = RSTRING(str)->len;
    evq->interp = self;
    evq->result = result;
    evq->thread = current;
    evq->safe_level = rb_safe_level();
    evq->ev.proc = eval_queue_handler;
    position = TCL_QUEUE_TAIL;

    /* add the handler to Tcl event queue */
    DUMP1("add handler");
    Tcl_QueueEvent(&(evq->ev), position);

    rb_thread_critical = thr_crit_bup;

    /* wait for the handler to be processed */
    DUMP2("wait for handler (current thread:%lx)", current);
    while(*alloc_done >= 0) {
	rb_thread_stop();
    }
    DUMP2("back from handler (current thread:%lx)", current);

    /* get result & free allocated memory */
    ret = RARRAY(result)->ptr[0];
    free(alloc_done);
    free(eval_str);
    if (rb_obj_is_kind_of(ret, rb_eException)) {
	rb_exc_raise(ret);
    }

    return ret;
}


/* restart Tk */
static VALUE
lib_restart(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);
    int  thr_crit_bup;

    rb_secure(4);

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* destroy the root wdiget */
    ptr->return_value = Tcl_Eval(ptr->ip, "destroy .");
    /* ignore ERROR */
    DUMP2("(TCL_Eval result) %d", ptr->return_value);
    Tcl_ResetResult(ptr->ip);

    /* delete namespace ( tested on tk8.4.5 ) */
    ptr->return_value = Tcl_Eval(ptr->ip, "namespace delete ::tk::msgcat");
    /* ignore ERROR */
    DUMP2("(TCL_Eval result) %d", ptr->return_value);
    Tcl_ResetResult(ptr->ip);

    /* delete trace proc ( tested on tk8.4.5 ) */
    ptr->return_value = Tcl_Eval(ptr->ip, "trace vdelete ::tk_strictMotif w ::tk::EventMotifBindings");
    /* ignore ERROR */
    DUMP2("(TCL_Eval result) %d", ptr->return_value);
    Tcl_ResetResult(ptr->ip);

    /* execute Tk_Init of Tk_SafeInit */
#if TCL_MAJOR_VERSION >= 8
    if (Tcl_IsSafe(ptr->ip)) {
	DUMP1("Tk_SafeInit");
	if (Tk_SafeInit(ptr->ip) == TCL_ERROR) {
	    rb_thread_critical = thr_crit_bup;
	    /* rb_raise(rb_eRuntimeError, "%s", ptr->ip->result); */
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
	}
    } else {
	DUMP1("Tk_Init");
	if (Tk_Init(ptr->ip) == TCL_ERROR) {
	    rb_thread_critical = thr_crit_bup;
	    /* rb_raise(rb_eRuntimeError, "%s", ptr->ip->result); */
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
	}
    }
#else /* TCL_MAJOR_VERSION < 8 */
    DUMP1("Tk_Init");
    if (Tk_Init(ptr->ip) == TCL_ERROR) {
	rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
    }
#endif

    rb_thread_critical = thr_crit_bup;

    return Qnil;
}


static VALUE
ip_restart(self)
    VALUE self;
{
    struct tcltkip *ptr = get_ip(self);

    rb_secure(4);
    if (Tcl_GetMaster(ptr->ip) != (Tcl_Interp*)NULL) {
	/* slave IP */
	return Qnil;
    }
    return lib_restart(self);
}

static VALUE
lib_toUTF8_core(ip_obj, src, encodename)
    VALUE ip_obj;
    VALUE src;
    VALUE encodename;
{
    volatile VALUE str = src;

#ifdef TCL_UTF_MAX
    Tcl_Interp *interp;
    Tcl_Encoding encoding;
    Tcl_DString dstr;
    int taint_flag = OBJ_TAINTED(str);
    struct tcltkip *ptr;
    char *buf;
    int thr_crit_bup;

    if (NIL_P(ip_obj)) {
	interp = (Tcl_Interp *)NULL;
    } else {
	interp = get_ip(ip_obj)->ip;
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    if (NIL_P(encodename)) {
	if (TYPE(str) == T_STRING) {
	    volatile VALUE enc;

	    enc = rb_ivar_get(str, ID_at_enc);
	    if (NIL_P(enc)) {
		if (NIL_P(ip_obj)) {
		    encoding = (Tcl_Encoding)NULL;
		} else {
		    enc = rb_ivar_get(ip_obj, ID_at_enc);
		    if (NIL_P(enc)) {
			encoding = (Tcl_Encoding)NULL;
		    } else {
			StringValue(enc);
			encoding = Tcl_GetEncoding(interp, RSTRING(enc)->ptr);
			if (encoding == (Tcl_Encoding)NULL) {
			    rb_warning("Tk-interp has unknown encoding information (@encoding:'%s')", RSTRING(enc)->ptr);
			}
		    }
		}
	    } else {
		StringValue(enc);
		if (strcmp(RSTRING(enc)->ptr, "binary") == 0) {
		    rb_thread_critical = thr_crit_bup;
		    return str;
		}
		encoding = Tcl_GetEncoding(interp, RSTRING(enc)->ptr);
		if (encoding == (Tcl_Encoding)NULL) {
		    rb_warning("string has unknown encoding information (@encoding:'%s')", RSTRING(enc)->ptr);
		}
	    }
	} else {
	    encoding = (Tcl_Encoding)NULL;
	}
    } else {
	StringValue(encodename);
	encoding = Tcl_GetEncoding(interp, RSTRING(encodename)->ptr);
	if (encoding == (Tcl_Encoding)NULL) {
	    rb_warning("unknown encoding name '%s'", RSTRING(encodename)->ptr);
	}
    }

    StringValue(str);
    if (!RSTRING(str)->len) {
	rb_thread_critical = thr_crit_bup;
	return str;
    }

    buf = ALLOC_N(char,(RSTRING(str)->len)+1);
    strncpy(buf, RSTRING(str)->ptr, RSTRING(str)->len);
    buf[RSTRING(str)->len] = 0;

    Tcl_DStringInit(&dstr);
    Tcl_DStringFree(&dstr);
    /* Tcl_ExternalToUtfDString(encoding,buf,strlen(buf),&dstr); */
    Tcl_ExternalToUtfDString(encoding, buf, RSTRING(str)->len, &dstr);

    /* str = rb_tainted_str_new2(Tcl_DStringValue(&dstr)); */
    str = rb_str_new2(Tcl_DStringValue(&dstr));
    rb_ivar_set(str, ID_at_enc, rb_tainted_str_new2("utf-8"));
    if (taint_flag) OBJ_TAINT(str);

    if (encoding != (Tcl_Encoding)NULL) {
	Tcl_FreeEncoding(encoding);
    }
    Tcl_DStringFree(&dstr);

    free(buf);

    rb_thread_critical = thr_crit_bup;
#endif

    return str;
}

static VALUE
lib_toUTF8(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE str, encodename;

    if (rb_scan_args(argc, argv, "11", &str, &encodename) == 1) {
	encodename = Qnil;
    }
    return lib_toUTF8_core(Qnil, str, encodename);
}

static VALUE
ip_toUTF8(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE str, encodename;

    if (rb_scan_args(argc, argv, "11", &str, &encodename) == 1) {
	encodename = Qnil;
    }
    return lib_toUTF8_core(self, str, encodename);
}

static VALUE
lib_fromUTF8_core(ip_obj, src, encodename)
    VALUE ip_obj;
    VALUE src;
    VALUE encodename;
{
    volatile VALUE str = src;

#ifdef TCL_UTF_MAX
    Tcl_Interp *interp;
    Tcl_Encoding encoding;
    Tcl_DString dstr;
    int taint_flag = OBJ_TAINTED(str);
    char *buf;
    int thr_crit_bup;

    if (NIL_P(ip_obj)) {
	interp = (Tcl_Interp *)NULL;
    } else {
	interp = get_ip(ip_obj)->ip;
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    if (NIL_P(encodename)) {
	volatile VALUE enc;

	if (TYPE(str) == T_STRING) {
	    enc = rb_ivar_get(str, ID_at_enc);
	    if (!NIL_P(enc) && strcmp(StringValuePtr(enc), "binary") == 0) {
		rb_thread_critical = thr_crit_bup;
		return str;
	    }
	}

	if (NIL_P(ip_obj)) {
	    encoding = (Tcl_Encoding)NULL;
	} else {
	    enc = rb_ivar_get(ip_obj, ID_at_enc);
	    if (NIL_P(enc)) {
		encoding = (Tcl_Encoding)NULL;
	    } else {
		StringValue(enc);
		encoding = Tcl_GetEncoding(interp, RSTRING(enc)->ptr);
		if (encoding == (Tcl_Encoding)NULL) {
		    rb_warning("Tk-interp has unknown encoding information (@encoding:'%s')", RSTRING(enc)->ptr);
		} else {
		  encodename = rb_obj_dup(enc);
		}
	    }
	}

    } else {
	StringValue(encodename);

	if (strcmp(RSTRING(encodename)->ptr, "binary") == 0) {
	    char *s;
	    int  len;

	    s = Tcl_GetByteArrayFromObj(Tcl_NewStringObj(RSTRING(str)->ptr, 
							 RSTRING(str)->len), 
					&len);
	    str = rb_tainted_str_new(s, len);
	    rb_ivar_set(str, ID_at_enc, rb_tainted_str_new2("binary"));

	    rb_thread_critical = thr_crit_bup;
	    return str;
	}

	encoding = Tcl_GetEncoding(interp, RSTRING(encodename)->ptr);
	if (encoding == (Tcl_Encoding)NULL) {
	    rb_warning("unknown encoding name '%s'", RSTRING(encodename)->ptr);
	    encodename = Qnil;
	}
    }

    StringValue(str);

    if (RSTRING(str)->len == 0) {
	rb_thread_critical = thr_crit_bup;
	return rb_tainted_str_new2("");
    }

    buf = ALLOC_N(char,strlen(RSTRING(str)->ptr)+1);
    strncpy(buf, RSTRING(str)->ptr, RSTRING(str)->len);
    buf[RSTRING(str)->len] = 0;

    Tcl_DStringInit(&dstr);
    Tcl_DStringFree(&dstr);
    /* Tcl_UtfToExternalDString(encoding,buf,strlen(buf),&dstr); */
    Tcl_UtfToExternalDString(encoding,buf,RSTRING(str)->len,&dstr);

    /* str = rb_tainted_str_new2(Tcl_DStringValue(&dstr)); */
    str = rb_str_new2(Tcl_DStringValue(&dstr));
    rb_ivar_set(str, ID_at_enc, encodename);
    if (taint_flag) OBJ_TAINT(str);

    if (encoding != (Tcl_Encoding)NULL) {
	Tcl_FreeEncoding(encoding);
    }
    Tcl_DStringFree(&dstr);

    free(buf);

    rb_thread_critical = thr_crit_bup;
#endif

    return str;
}

static VALUE
lib_fromUTF8(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE str, encodename;

    if (rb_scan_args(argc, argv, "11", &str, &encodename) == 1) {
	encodename = Qnil;
    }
    return lib_fromUTF8_core(Qnil, str, encodename);
}

static VALUE
ip_fromUTF8(argc, argv, self)
    int   argc;
    VALUE *argv;
    VALUE self;
{
    VALUE str, encodename;

    if (rb_scan_args(argc, argv, "11", &str, &encodename) == 1) {
	encodename = Qnil;
    }
    return lib_fromUTF8_core(self, str, encodename);
}

static VALUE
lib_UTF_backslash_core(self, str, all_bs)
    VALUE self;
    VALUE str;
    int all_bs;
{
#ifdef TCL_UTF_MAX
    char *src_buf, *dst_buf, *ptr;
    int read_len = 0, dst_len = 0;
    int taint_flag = OBJ_TAINTED(str);
    int thr_crit_bup;

    StringValue(str);
    if (!RSTRING(str)->len) {
	return str;
    }

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    src_buf = ALLOC_N(char,(RSTRING(str)->len)+1);
    strncpy(src_buf, RSTRING(str)->ptr, RSTRING(str)->len);
    src_buf[RSTRING(str)->len] = 0;

    dst_buf = ALLOC_N(char,(RSTRING(str)->len)+1);

    ptr = src_buf;
    while(RSTRING(str)->len > ptr - src_buf) {
	if (*ptr == '\\' && (all_bs || *(ptr + 1) == 'u')) {
	    dst_len += Tcl_UtfBackslash(ptr, &read_len, (dst_buf + dst_len));
	    ptr += read_len;
	} else {
	    *(dst_buf + (dst_len++)) = *(ptr++);
	}
    }

    str = rb_str_new(dst_buf, dst_len);
    if (taint_flag) OBJ_TAINT(str);

    free(src_buf);
    free(dst_buf);

    rb_thread_critical = thr_crit_bup;
#endif

    return str;
}

static VALUE
lib_UTF_backslash(self, str)
    VALUE self;
    VALUE str;
{
    return lib_UTF_backslash_core(self, str, 0);
}

static VALUE
lib_Tcl_backslash(self, str)
    VALUE self;
    VALUE str;
{
    return lib_UTF_backslash_core(self, str, 1);
}

#if TCL_MAJOR_VERSION >= 8
static VALUE
ip_invoke_core(interp, objc, objv)
    VALUE interp;
    int objc;
    Tcl_Obj **objv;
#else
static VALUE
ip_invoke_core(interp, argc, argv)
    VALUE interp;
    int argc;
    char **argv;
#endif
{
    struct tcltkip *ptr;
    int i;
    Tcl_CmdInfo info;
    char *cmd;
    char *s;
    int  len;
    int  thr_crit_bup;

#if TCL_MAJOR_VERSION >= 8
    int argc = objc;
    char **argv = (char **)NULL;
    Tcl_Obj *resultPtr;
#endif

    /* get the data struct */
    ptr = get_ip(interp);

    /* ip is deleted? */
    if (Tcl_InterpDeleted(ptr->ip)) {
	DUMP1("ip is deleted");
	return rb_tainted_str_new2("");
    }

    /* get the command name string */
#if TCL_MAJOR_VERSION >= 8
    cmd = Tcl_GetStringFromObj(objv[0], &len);
#else /* TCL_MAJOR_VERSION < 8 */
    cmd = argv[0];
#endif

    /* map from the command name to a C procedure */
    DUMP2("call Tcl_GetCommandInfo, %s", cmd);
    if (!Tcl_GetCommandInfo(ptr->ip, cmd, &info)) {
	DUMP1("error Tcl_GetCommandInfo");
	/* if (event_loop_abort_on_exc || cmd[0] != '.') { */
	if (event_loop_abort_on_exc > 0) {
	    /*rb_ip_raise(obj,rb_eNameError,"invalid command name `%s'",cmd);*/
	    return create_ip_exc(interp, rb_eNameError, 
				 "invalid command name `%s'", cmd);
	} else {
	    if (event_loop_abort_on_exc < 0) {
		rb_warning("invalid command name `%s' (ignore)", cmd);
	    } else {
		rb_warn("invalid command name `%s' (ignore)", cmd);
	    }
	    Tcl_ResetResult(ptr->ip);
	    return rb_tainted_str_new2("");
	}
    }
    DUMP1("end Tcl_GetCommandInfo");

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* memory allocation for arguments of this command */
#if TCL_MAJOR_VERSION >= 8
    if (!info.isNativeObjectProc) {
	/* string interface */
	argv = (char **)ALLOC_N(char *, argc+1);
	for (i = 0; i < argc; ++i) {
	    argv[i] = Tcl_GetStringFromObj(objv[i], &len);
	}
	argv[argc] = (char *)NULL;
    }
#endif

    Tcl_ResetResult(ptr->ip);

    /* Invoke the C procedure */
#if TCL_MAJOR_VERSION >= 8
    if (info.isNativeObjectProc) {
	ptr->return_value = (*info.objProc)(info.objClientData, ptr->ip, 
					    objc, objv);
#if 0
	/* get the string value from the result object */
	resultPtr = Tcl_GetObjResult(ptr->ip);
	Tcl_SetResult(ptr->ip, Tcl_GetStringFromObj(resultPtr, &len),
		      TCL_VOLATILE);
#endif
    }
    else
#endif
    {
#if TCL_MAJOR_VERSION >= 8
	ptr->return_value = (*info.proc)(info.clientData, ptr->ip, 
					 argc, (CONST84 char **)argv);

	free(argv);

#else /* TCL_MAJOR_VERSION < 8 */
	ptr->return_value = (*info.proc)(info.clientData, ptr->ip, 
					 argc, argv);
#endif
    }

    rb_thread_critical = thr_crit_bup;

    /* exception on mainloop */
    if (ptr->return_value == TCL_ERROR) {
	if (event_loop_abort_on_exc > 0 && !Tcl_InterpDeleted(ptr->ip)) {
#if TCL_MAJOR_VERSION >= 8
	    return create_ip_exc(interp, rb_eRuntimeError, 
				 "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    return create_ip_exc(interp, rb_eRuntimeError, 
				 "%s", ptr->ip->result);
#endif
	} else {
	    if (event_loop_abort_on_exc < 0) {
#if TCL_MAJOR_VERSION >= 8
		rb_warning("%s (ignore)", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
		rb_warning("%s (ignore)", ptr->ip->result);
#endif
	    } else {
#if TCL_MAJOR_VERSION >= 8
		rb_warn("%s (ignore)", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
		rb_warn("%s (ignore)", ptr->ip->result);
#endif
	    }
	    Tcl_ResetResult(ptr->ip);
	    return rb_tainted_str_new2("");
	}
    }

    /* pass back the result (as string) */
    return ip_get_result_string_obj(ptr->ip);
}


#if TCL_MAJOR_VERSION >= 8
static Tcl_Obj **
#else /* TCL_MAJOR_VERSION < 8 */
static char **
#endif
alloc_invoke_arguments(argc, argv)
    int argc;
    VALUE *argv;
{
    int i;
    VALUE v;
    char *s;
    int thr_crit_bup;

#if TCL_MAJOR_VERSION >= 8
    Tcl_Obj **av = (Tcl_Obj **)NULL;
    Tcl_Obj *resultPtr;
#else /* TCL_MAJOR_VERSION < 8 */
    char **av = (char **)NULL;
#endif

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* memory allocation */
#if TCL_MAJOR_VERSION >= 8
    av = (Tcl_Obj **)ALLOC_N(Tcl_Obj *, argc+1);
    for (i = 0; i < argc; ++i) {
	VALUE enc;

	v = argv[i];
	s = StringValuePtr(v);

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	av[i] = Tcl_NewStringObj(s, RSTRING(v)->len);
# else /* TCL_VERSION >= 8.1 */
	enc = rb_ivar_get(v, ID_at_enc);
	if (!NIL_P(enc) && strcmp(StringValuePtr(enc), "binary") == 0) {
	    /* binary string */
	    av[i] = Tcl_NewByteArrayObj(s, RSTRING(v)->len);
	} else if (strlen(s) != RSTRING(v)->len) {
	    /* probably binary string */
	    av[i] = Tcl_NewByteArrayObj(s, RSTRING(v)->len);
	} else {
	    /* probably text string */
	    av[i] = Tcl_NewStringObj(s, RSTRING(v)->len);
	}
# endif
	Tcl_IncrRefCount(av[i]);
    }
    av[argc] = (Tcl_Obj *)NULL;

#else /* TCL_MAJOR_VERSION < 8 */
    /* string interface */
    av = (char **)ALLOC_N(char *, argc+1);
    for (i = 0; i < argc; ++i) {
	v = argv[i];
	s = StringValuePtr(v);
	av[i] = ALLOC_N(char, strlen(s)+1);
	strcpy(av[i], s);
    }
    av[argc] = (char *)NULL;
#endif

    rb_thread_critical = thr_crit_bup;

    return av;
}

static void
free_invoke_arguments(argc, av)
    int argc;
#if TCL_MAJOR_VERSION >= 8
    Tcl_Obj **av;
#else /* TCL_MAJOR_VERSION < 8 */
    char **av;
#endif
{
    int i;

    for (i = 0; i < argc; ++i) {
#if TCL_MAJOR_VERSION >= 8
	Tcl_DecrRefCount(av[i]);
#else /* TCL_MAJOR_VERSION < 8 */
	free(av[i]);
#endif
    }
    free(av);
}

static VALUE
ip_invoke_real(argc, argv, interp)
    int argc;
    VALUE *argv;
    VALUE interp;
{
    VALUE v;
    struct tcltkip *ptr;	/* tcltkip data struct */
    int i;
    Tcl_CmdInfo info;
    char *s;
    int  len;
    int thr_crit_bup;

#if TCL_MAJOR_VERSION >= 8
    Tcl_Obj **av = (Tcl_Obj **)NULL;
    Tcl_Obj *resultPtr;
#else /* TCL_MAJOR_VERSION < 8 */
    char **av = (char **)NULL;
#endif

    DUMP2("invoke_real called by thread:%lx", rb_thread_current());

    /* get the data struct */
    ptr = get_ip(interp);

    /* ip is deleted? */
    if (Tcl_InterpDeleted(ptr->ip)) {
	DUMP1("ip is deleted");
	return rb_tainted_str_new2("");
    }

    /* allocate memory for arguments */
    av = alloc_invoke_arguments(argc, argv);

    /* Invoke the C procedure */
    Tcl_ResetResult(ptr->ip);
    v = ip_invoke_core(interp, argc, av);

    /* free allocated memory */
    free_invoke_arguments(argc, av);

    return v;
}

VALUE
ivq_safelevel_handler(arg, ivq)
    VALUE arg;
    VALUE ivq;
{
    struct invoke_queue *q;

    Data_Get_Struct(ivq, struct invoke_queue, q);
    DUMP2("(safe-level handler) $SAFE = %d", q->safe_level);
    rb_set_safe_level(q->safe_level);
    return ip_invoke_core(q->interp, q->argc, q->argv);
}

int invoke_queue_handler _((Tcl_Event *, int));
int
invoke_queue_handler(evPtr, flags)
    Tcl_Event *evPtr;
    int flags;
{
    struct invoke_queue *q = (struct invoke_queue *)evPtr;
    volatile VALUE ret;

    DUMP2("do_invoke_queue_handler : evPtr = %p", evPtr);
    DUMP2("invoke queue_thread : %lx", rb_thread_current());
    DUMP2("added by thread : %lx", q->thread);

    if (*(q->done)) {
	DUMP1("processed by another event-loop");
	return 0;
    } else {
	DUMP1("process it on current event-loop");
    }

    /* process it */
    *(q->done) = 1;

    /* check safe-level */
    if (rb_safe_level() != q->safe_level) {
	volatile VALUE q_dat;
	q_dat = Data_Wrap_Struct(rb_cData,invoke_queue_mark,0,q);
	ret = rb_funcall(rb_proc_new(evq_safelevel_handler, q_dat), 
			 ID_call, 0);
    } else {
	DUMP2("call invoke_real (for caller thread:%lx)", q->thread);
	DUMP2("call invoke_real (current thread:%lx)", rb_thread_current());
	ret = ip_invoke_core(q->interp, q->argc, q->argv);
    }

    /* set result */
    RARRAY(q->result)->ptr[0] = ret;

    /* complete */
    *(q->done) = -1;

    /* back to caller */
    DUMP2("back to caller (caller thread:%lx)", q->thread);
    DUMP2("               (current thread:%lx)", rb_thread_current());
    rb_thread_run(q->thread);
    DUMP1("finish back to caller");

    /* end of handler : remove it */
    return 1;
}

static VALUE
ip_invoke_with_position(argc, argv, obj, position)
    int argc;
    VALUE *argv;
    VALUE obj;
    Tcl_QueuePosition position;
{
    struct invoke_queue *ivq;
    char *s;
    int  len;
    int  i;
    int  *alloc_done;
    int  thr_crit_bup;
    VALUE v;
    VALUE current = rb_thread_current();
    volatile VALUE result = rb_ary_new2(1);
    volatile VALUE ret;

#if TCL_MAJOR_VERSION >= 8
    Tcl_Obj **av = (Tcl_Obj **)NULL;
#else /* TCL_MAJOR_VERSION < 8 */
    char **av = (char **)NULL;
#endif

    if (argc < 1) {
	rb_raise(rb_eArgError, "command name missing");
    }
    if (eventloop_thread == 0 || current == eventloop_thread) {
	if (eventloop_thread) {
	    DUMP2("invoke from current eventloop %lx", current);
	} else {
	    DUMP2("invoke from thread:%lx but no eventloop", current);
	}
	result = ip_invoke_real(argc, argv, obj);
	if (rb_obj_is_kind_of(result, rb_eException)) {
	    rb_exc_raise(result);
	}
	return result;
    }

    DUMP2("invoke from thread %lx (NOT current eventloop)", current);

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    /* allocate memory (for arguments) */
    av = alloc_invoke_arguments(argc, argv);

    /* allocate memory (keep result) */
    alloc_done = (int*)ALLOC(int);
    *alloc_done = 0;

    /* allocate memory (freed by Tcl_ServiceEvent) */
    ivq = (struct invoke_queue *)Tcl_Alloc(sizeof(struct invoke_queue));

    /* construct event data */
    ivq->done = alloc_done;
    ivq->argc = argc;
    ivq->argv = av;
    ivq->interp = obj;
    ivq->result = result;
    ivq->thread = current;
    ivq->safe_level = rb_safe_level();
    ivq->ev.proc = invoke_queue_handler;

    /* add the handler to Tcl event queue */
    DUMP1("add handler");
    Tcl_QueueEvent(&(ivq->ev), position);

    rb_thread_critical = thr_crit_bup;

    /* wait for the handler to be processed */
    DUMP2("wait for handler (current thread:%lx)", current);
    while(*alloc_done >= 0) {
	rb_thread_stop();
    }
    DUMP2("back from handler (current thread:%lx)", current);

    /* get result & free allocated memory */
    ret = RARRAY(result)->ptr[0];
    free(alloc_done);

    /* free allocated memory */
    free_invoke_arguments(argc, av);

    /* exception? */
    if (rb_obj_is_kind_of(ret, rb_eException)) {
	DUMP1("raise exception");
	rb_exc_raise(ret);
    }

    DUMP1("exit ip_invoke");
    return ret;
}


/* get return code from Tcl_Eval() */
static VALUE
ip_retval(self)
    VALUE self;
{
    struct tcltkip *ptr;	/* tcltkip data struct */

    /* get the data strcut */
    ptr = get_ip(self);

    return (INT2FIX(ptr->return_value));
}

static VALUE
ip_invoke(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    return ip_invoke_with_position(argc, argv, obj, TCL_QUEUE_TAIL);
}

static VALUE
ip_invoke_immediate(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    return ip_invoke_with_position(argc, argv, obj, TCL_QUEUE_HEAD);
}

/* access Tcl variables */
static VALUE
ip_get_variable(self, varname_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    int thr_crit_bup;
    volatile VALUE varname, flag;

    varname = varname_arg;
    flag    = flag_arg;

    StringValue(varname);

#if TCL_MAJOR_VERSION >= 8
    {
	Tcl_Obj *nameobj, *ret;
	char *s;
	int  len;
	VALUE strval;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	nameobj = Tcl_NewStringObj(RSTRING(varname)->ptr, 
				   RSTRING(varname)->len);
	Tcl_IncrRefCount(nameobj);

	ret = Tcl_ObjGetVar2(ptr->ip, nameobj, (Tcl_Obj*)NULL, FIX2INT(flag));

	Tcl_DecrRefCount(nameobj);

	rb_thread_critical = thr_crit_bup;

	if (ret == (Tcl_Obj*)NULL) {
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}

	Tcl_IncrRefCount(ret);

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	s = Tcl_GetStringFromObj(ret, &len);
	strval = rb_tainted_str_new(s, len);
	Tcl_DecrRefCount(ret);
	return(strval);
# else /* TCL_VERSION >= 8.1 */
	{
	    thr_crit_bup = rb_thread_critical;
	    rb_thread_critical = Qtrue;

	    if (Tcl_GetCharLength(ret) 
		!= Tcl_UniCharLen(Tcl_GetUnicode(ret))) {
		/* possibly binary string */
		s = Tcl_GetByteArrayFromObj(ret, &len);
		strval = rb_tainted_str_new(s, len);
		rb_ivar_set(strval, ID_at_enc, rb_tainted_str_new2("binary"));
	    } else {
		/* possibly text string */
		s = Tcl_GetStringFromObj(ret, &len);
		strval = rb_tainted_str_new(s, len);
	    }

	    rb_thread_critical = thr_crit_bup;
	}

	Tcl_DecrRefCount(ret);
	return(strval);
# endif
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	char *ret;

	ret = Tcl_GetVar2(ptr->ip, RSTRING(varname)->ptr, 
			  (char*)NULL, FIX2INT(flag));
	if (ret == (char*)NULL) {
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
	}
	return(rb_tainted_str_new2(ret));
    }
#endif
}

static VALUE
ip_get_variable2(self, varname_arg, index_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE index_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    int thr_crit_bup;
    volatile VALUE varname, index, flag;

    if (NIL_P(index_arg)) {
      return ip_get_variable(self, varname_arg, flag_arg);
    }

    varname = varname_arg;
    index   = index_arg;
    flag    = flag_arg;

    StringValue(varname);
    StringValue(index);

#if TCL_MAJOR_VERSION >= 8
    {
	Tcl_Obj *nameobj, *idxobj, *ret;
	char *s;
	int  len;
	volatile VALUE strval;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	nameobj = Tcl_NewStringObj(RSTRING(varname)->ptr, 
				   RSTRING(varname)->len);
	Tcl_IncrRefCount(nameobj);
	idxobj  = Tcl_NewStringObj(RSTRING(index)->ptr, RSTRING(index)->len);
	Tcl_IncrRefCount(idxobj);

	ret = Tcl_ObjGetVar2(ptr->ip, nameobj, idxobj, FIX2INT(flag));

	Tcl_IncrRefCount(ret);
	Tcl_DecrRefCount(nameobj);
	Tcl_DecrRefCount(idxobj);

	rb_thread_critical = thr_crit_bup;

	if (ret == (Tcl_Obj*)NULL) {
	    Tcl_DecrRefCount(ret);
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}
# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	s = Tcl_GetStringFromObj(ret, &len);
	strval = rb_tainted_str_new(s, len);
	Tcl_DecrRefCount(ret);
	return(strval);
# else /* TCL_VERSION >= 8.1 */
	{
	    thr_crit_bup = rb_thread_critical;
	    rb_thread_critical = Qtrue;

	    if (Tcl_GetCharLength(ret) 
		!= Tcl_UniCharLen(Tcl_GetUnicode(ret))) {
		/* possibly binary string */
		s = Tcl_GetByteArrayFromObj(ret, &len);
		strval = rb_tainted_str_new(s, len);
		rb_ivar_set(strval, ID_at_enc, rb_tainted_str_new2("binary"));
	    } else {
		/* possibly text string */
		s = Tcl_GetStringFromObj(ret, &len);
		strval = rb_tainted_str_new(s, len);
	    }

	    rb_thread_critical = thr_crit_bup;
	}

	Tcl_DecrRefCount(ret);
	return(strval);
# endif
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	char *ret;

	ret = Tcl_GetVar2(ptr->ip, RSTRING(varname)->ptr, RSTRING(index)->ptr, 
			  FIX2INT(flag));
	if (ret == (char*)NULL) {
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
	}
	return(rb_tainted_str_new2(ret));
    }
#endif
}

static VALUE
ip_set_variable(self, varname_arg, value_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE value_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    int thr_crit_bup;
    volatile VALUE varname, value, flag;

    varname = varname_arg;
    value   = value_arg;
    flag    = flag_arg;
 
    StringValue(varname);
    StringValue(value);

#if TCL_MAJOR_VERSION >= 8
    {
	Tcl_Obj *nameobj, *valobj, *ret;
	char *s;
	int  len;
	volatile VALUE strval;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	nameobj = Tcl_NewStringObj(RSTRING(varname)->ptr, 
				   RSTRING(varname)->len);
	Tcl_IncrRefCount(nameobj);

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	valobj  = Tcl_NewStringObj(RSTRING(value)->ptr, 
				   RSTRING(value)->len); 
	Tcl_IncrRefCount(valobj);
# else /* TCL_VERSION >= 8.1 */
	{
	    VALUE enc = rb_ivar_get(value, ID_at_enc);

	    if (!NIL_P(enc) && strcmp(StringValuePtr(enc), "binary") == 0) {
		/* binary string */
		valobj = Tcl_NewByteArrayObj(RSTRING(value)->ptr, 
					     RSTRING(value)->len);
	    } else if (strlen(RSTRING(value)->ptr) != RSTRING(value)->len) {
		/* probably binary string */
		valobj = Tcl_NewByteArrayObj(RSTRING(value)->ptr, 
					     RSTRING(value)->len);
	    } else {
		/* probably text string */
		valobj = Tcl_NewStringObj(RSTRING(value)->ptr, 
					  RSTRING(value)->len); 
	    }

	    Tcl_IncrRefCount(valobj);
	}
# endif

	ret = Tcl_ObjSetVar2(ptr->ip, nameobj, (Tcl_Obj*)NULL, valobj, 
			     FIX2INT(flag));

	Tcl_DecrRefCount(nameobj);
	Tcl_DecrRefCount(valobj);

	if (ret == (Tcl_Obj*)NULL) {
#if TCL_MAJOR_VERSION >= 8
	  rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	  rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}

	Tcl_IncrRefCount(ret);

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	s = Tcl_GetStringFromObj(ret, &len); 
	strval = rb_tainted_str_new(s, len);
# else /* TCL_VERSION >= 8.1 */
	if (Tcl_GetCharLength(ret) != Tcl_UniCharLen(Tcl_GetUnicode(ret))) {
	    /* possibly binary string */
	    s = Tcl_GetByteArrayFromObj(ret, &len);
	    strval = rb_tainted_str_new(s, len);
	    rb_ivar_set(strval, ID_at_enc, rb_str_new2("binary"));
	} else {
	    /* possibly text string */
	    s = Tcl_GetStringFromObj(ret, &len);
	    strval = rb_tainted_str_new(s, len);
	}
# endif

	rb_thread_critical = thr_crit_bup;

	Tcl_DecrRefCount(ret);

	return(strval);
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	CONST char *ret;

	ret = Tcl_SetVar2(ptr->ip, RSTRING(varname)->ptr, (char*)NULL, 
			  RSTRING(value)->ptr, (int)FIX2INT(flag));
	if (ret == NULL) {
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
	}
	return(rb_tainted_str_new2(ret));
    }
#endif
}

static VALUE
ip_set_variable2(self, varname_arg, index_arg, value_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE index_arg;
    VALUE value_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    int thr_crit_bup;
    volatile VALUE varname, index, value, flag;

    if (NIL_P(index_arg)) {
      return ip_set_variable(self, varname_arg, value_arg, flag_arg);
    }

    varname = varname_arg;
    index   = index_arg;
    value   = value_arg;
    flag    = flag_arg;

    StringValue(varname);
    StringValue(index);
    StringValue(value);

#if TCL_MAJOR_VERSION >= 8
    {
	Tcl_Obj *nameobj, *idxobj, *valobj, *ret;
	char *s;
	int  len;
	volatile VALUE strval;

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	nameobj = Tcl_NewStringObj(RSTRING(varname)->ptr, 
				   RSTRING(varname)->len);
	Tcl_IncrRefCount(nameobj);

	idxobj  = Tcl_NewStringObj(RSTRING(index)->ptr, 
				   RSTRING(index)->len);
	Tcl_IncrRefCount(idxobj);

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	valobj  = Tcl_NewStringObj(RSTRING(value)->ptr, 
				   RSTRING(value)->len); 
# else /* TCL_VERSION >= 8.1 */
	{
	    VALUE enc = rb_ivar_get(value, ID_at_enc);

	    if (!NIL_P(enc) && strcmp(StringValuePtr(enc), "binary") == 0) {
		/* binary string */
		valobj = Tcl_NewByteArrayObj(RSTRING(value)->ptr, 
					     RSTRING(value)->len);
	    } else if (strlen(RSTRING(value)->ptr) != RSTRING(value)->len) {
		/* probably binary string */
		valobj = Tcl_NewByteArrayObj(RSTRING(value)->ptr, 
					     RSTRING(value)->len);
	    } else {
		/* probably text string */
		valobj = Tcl_NewStringObj(RSTRING(value)->ptr, 
					  RSTRING(value)->len); 
	    }
	}

# endif
	Tcl_IncrRefCount(valobj);

	ret = Tcl_ObjSetVar2(ptr->ip, nameobj, idxobj, valobj, FIX2INT(flag));

	Tcl_DecrRefCount(nameobj);
	Tcl_DecrRefCount(idxobj);
	Tcl_DecrRefCount(valobj);

	rb_thread_critical = thr_crit_bup;

	if (ret == (Tcl_Obj*)NULL) {
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}

	Tcl_IncrRefCount(ret);

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

# if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	s = Tcl_GetStringFromObj(ret, &len); 
	strval = rb_tainted_str_new(s, len);
# else /* TCL_VERSION >= 8.1 */
	if (Tcl_GetCharLength(ret) != Tcl_UniCharLen(Tcl_GetUnicode(ret))) {
	    /* possibly binary string */
	    s = Tcl_GetByteArrayFromObj(ret, &len);
	    strval = rb_tainted_str_new(s, len);
	    rb_ivar_set(strval, ID_at_enc, rb_str_new2("binary"));
	} else {
	    /* possibly text string */
	    s = Tcl_GetStringFromObj(ret, &len);
	    strval = rb_tainted_str_new(s, len);
	}
# endif

	rb_thread_critical = thr_crit_bup;

	Tcl_DecrRefCount(ret);

	return(strval);
    }
#else /* TCL_MAJOR_VERSION < 8 */
    {
	CONST char *ret;

	ret = Tcl_SetVar2(ptr->ip, RSTRING(varname)->ptr, RSTRING(index)->ptr, 
			  RSTRING(value)->ptr, FIX2INT(flag));
	if (ret == (char*)NULL) {
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
	}
	return(rb_tainted_str_new2(ret));
    }
#endif
}

static VALUE
ip_unset_variable(self, varname_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    volatile VALUE varname, value, flag;

    varname = varname_arg;
    flag    = flag_arg;

    StringValue(varname);
    ptr->return_value = Tcl_UnsetVar(ptr->ip, RSTRING(varname)->ptr, 
				     FIX2INT(flag));
    if (ptr->return_value == TCL_ERROR) {
	if (FIX2INT(flag) & TCL_LEAVE_ERR_MSG) {
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}
	return Qfalse;
    }
    return Qtrue;
}

static VALUE
ip_unset_variable2(self, varname_arg, index_arg, flag_arg)
    VALUE self;
    VALUE varname_arg;
    VALUE index_arg;
    VALUE flag_arg;
{
    struct tcltkip *ptr = get_ip(self);
    volatile VALUE varname, index, value, flag;

    if (NIL_P(index_arg)) {
      return ip_unset_variable(self, varname_arg, flag_arg);
    }

    varname = varname_arg;
    index   = index_arg;
    flag    = flag_arg;

    StringValue(varname);
    StringValue(index);

    ptr->return_value = Tcl_UnsetVar2(ptr->ip, RSTRING(varname)->ptr, 
				      RSTRING(index)->ptr, FIX2INT(flag));
    if (ptr->return_value == TCL_ERROR) {
	if (FIX2INT(flag) & TCL_LEAVE_ERR_MSG) {
#if TCL_MAJOR_VERSION >= 8
	    rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(ptr->ip));
#else /* TCL_MAJOR_VERSION < 8 */
	    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
#endif
	}
	return Qfalse;
    }
    return Qtrue;
}

static VALUE
ip_get_global_var(self, varname)
    VALUE self;
    VALUE varname;
{
    return ip_get_variable(self, varname, 
			   INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}

static VALUE
ip_get_global_var2(self, varname, index)
    VALUE self;
    VALUE varname;
    VALUE index;
{
    return ip_get_variable2(self, varname, index, 
			    INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}

static VALUE
ip_set_global_var(self, varname, value)
    VALUE self;
    VALUE varname;
    VALUE value;
{
    return ip_set_variable(self, varname, value, 
			   INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}

static VALUE
ip_set_global_var2(self, varname, index, value)
    VALUE self;
    VALUE varname;
    VALUE index;
    VALUE value;
{
    return ip_set_variable2(self, varname, index, value, 
			    INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}

static VALUE
ip_unset_global_var(self, varname)
    VALUE self;
    VALUE varname;
{
    return ip_unset_variable(self, varname, 
			     INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}

static VALUE
ip_unset_global_var2(self, varname, index)
    VALUE self;
    VALUE varname;
    VALUE index;
{
    return ip_unset_variable2(self, varname, index, 
			      INT2FIX(TCL_GLOBAL_ONLY | TCL_LEAVE_ERR_MSG));
}


/* treat Tcl_List */
static VALUE
lib_split_tklist_core(ip_obj, list_str)
    VALUE ip_obj;
    VALUE list_str;
{
    Tcl_Interp *interp;
    volatile VALUE ary, elem;
    int idx;
    int taint_flag = OBJ_TAINTED(list_str);
    int result;
    VALUE old_gc;

    if (NIL_P(ip_obj)) {
	interp = (Tcl_Interp *)NULL;
    } else {
	interp = get_ip(ip_obj)->ip;
    }

    StringValue(list_str);

    {
#if TCL_MAJOR_VERSION >= 8
	/* object style interface */
	Tcl_Obj *listobj;
	int     objc;
	Tcl_Obj **objv;
	int thr_crit_bup;

# if 1
#  if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	listobj = Tcl_NewStringObj(RSTRING(list_str)->ptr, 
				   RSTRING(list_str)->len); 
#  else /* TCL_VERSION >= 8.1 */
	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	{
	    VALUE enc = rb_ivar_get(list_str, ID_at_enc);

	    if (!NIL_P(enc) && strcmp(StringValuePtr(enc), "binary") == 0) {
		/* binary string */
		listobj = Tcl_NewByteArrayObj(RSTRING(list_str)->ptr, 
					      RSTRING(list_str)->len);
	    } else if (strlen(RSTRING(list_str)->ptr)
		                    != RSTRING(list_str)->len) {
		/* probably binary string */
		listobj = Tcl_NewByteArrayObj(RSTRING(list_str)->ptr, 
					      RSTRING(list_str)->len);
	    } else {
		/* probably text string */
		listobj = Tcl_NewStringObj(RSTRING(list_str)->ptr, 
					   RSTRING(list_str)->len); 
	    }
	}

	rb_thread_critical = thr_crit_bup;
#  endif
# else
	listobj = Tcl_NewStringObj(RSTRING(list_str)->ptr, 
				   RSTRING(list_str)->len); 
# endif

	Tcl_IncrRefCount(listobj);

	result = Tcl_ListObjGetElements(interp, listobj, &objc, &objv);

	if (result == TCL_ERROR) {
	    Tcl_DecrRefCount(listobj);
	    if (interp == (Tcl_Interp*)NULL) {
		rb_raise(rb_eRuntimeError, "cannot get elements from list");
	    } else {
#if TCL_MAJOR_VERSION >= 8
		rb_raise(rb_eRuntimeError, "%s", Tcl_GetStringResult(interp));
#else /* TCL_MAJOR_VERSION < 8 */
		rb_raise(rb_eRuntimeError, "%s", interp->result);
#endif
	    }
	}

	for(idx = 0; idx < objc; idx++) {
	    Tcl_IncrRefCount(objv[idx]);
	}

	thr_crit_bup = rb_thread_critical;
	rb_thread_critical = Qtrue;

	ary = rb_ary_new2(objc);
	if (taint_flag) OBJ_TAINT(ary);

	old_gc = rb_gc_disable();

	for(idx = 0; idx < objc; idx++) {
	    char *str;
	    int  len;

# if 1
#  if TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 0
	    str = Tcl_GetStringFromObj(objv[idx], &len);
	    elem = rb_str_new(str, len);
#  else /* TCL_VERSION >= 8.1 */
	    if (Tcl_GetCharLength(objv[idx]) 
		!= Tcl_UniCharLen(Tcl_GetUnicode(objv[idx]))) {
		/* possibly binary string */
		str = Tcl_GetByteArrayFromObj(objv[idx], &len);
		elem = rb_str_new(str, len);
		rb_ivar_set(elem, ID_at_enc, rb_tainted_str_new2("binary"));
	    } else {
		/* possibly text string */
		str = Tcl_GetStringFromObj(objv[idx], &len);
		elem = rb_str_new(str, len);
	    }
#  endif
# else
	    str = Tcl_GetStringFromObj(objv[idx], &len);
	    elem = rb_str_new(str, len);
# endif

	    if (taint_flag) OBJ_TAINT(elem);
	    RARRAY(ary)->ptr[idx] = elem;
	}

	RARRAY(ary)->len = objc;

	if (old_gc == Qfalse) rb_gc_enable();

	rb_thread_critical = thr_crit_bup;

	for(idx = 0; idx < objc; idx++) {
	    Tcl_DecrRefCount(objv[idx]);
	}

	Tcl_DecrRefCount(listobj);

#else /* TCL_MAJOR_VERSION < 8 */
	/* string style interface */
	int  argc;
	char **argv;

	if (Tcl_SplitList(interp, RSTRING(list_str)->ptr, 
			  &argc, &argv) == TCL_ERROR) {
	    if (interp == (Tcl_Interp*)NULL) {
		rb_raise(rb_eRuntimeError, "cannot get elements from list");
	    } else {
		rb_raise(rb_eRuntimeError, "%s", interp->result);
	    }
	}

	ary = rb_ary_new2(argc);
	if (taint_flag) OBJ_TAINT(ary);

	old_gc = rb_gc_disable();

	for(idx = 0; idx < argc; idx++) {
	    if (taint_flag) {
		elem = rb_tainted_str_new2(argv[idx]);
	    } else {
		elem = rb_str_new2(argv[idx]);
	    }
	    /* rb_ivar_set(elem, ID_at_enc, rb_str_new2("binary")); */
	    RARRAY(ary)->ptr[idx] = elem;
	}
	RARRAY(ary)->len = argc;

	if (old_gc == Qfalse) rb_gc_enable();
#endif
    }

    return ary;
}

static VALUE
lib_split_tklist(self, list_str)
    VALUE self;
    VALUE list_str;
{
    return lib_split_tklist_core(Qnil, list_str);
}


static VALUE
ip_split_tklist(self, list_str)
    VALUE self;
    VALUE list_str;
{
    return lib_split_tklist_core(self, list_str);
}

static VALUE
lib_merge_tklist(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    int  num, len;
    int  *flagPtr;
    char *dst, *result;
    volatile VALUE str;
    int taint_flag = 0;
    int thr_crit_bup;
    VALUE old_gc;

    if (argc == 0) return rb_str_new2("");

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;
    old_gc = rb_gc_disable();

    /* based on Tcl/Tk's Tcl_Merge() */
    flagPtr = ALLOC_N(unsigned,  argc);

    /* pass 1 */
    len = 1;
    for(num = 0; num < argc; num++) {
	if (OBJ_TAINTED(argv[num])) taint_flag = 1;
	dst = StringValuePtr(argv[num]);
#if TCL_MAJOR_VERSION >= 8
	len += Tcl_ScanCountedElement(dst, RSTRING(argv[num])->len, 
				      &flagPtr[num]) + 1;
#else /* TCL_MAJOR_VERSION < 8 */
	len += Tcl_ScanElement(dst, &flagPtr[num]) + 1;
#endif
    }

    /* pass 2 */
    result = (char *)Tcl_Alloc(len);
    dst = result;
    for(num = 0; num < argc; num++) {
#if TCL_MAJOR_VERSION >= 8
        len = Tcl_ConvertCountedElement(RSTRING(argv[num])->ptr, 
					RSTRING(argv[num])->len, 
					dst, flagPtr[num]);
#else /* TCL_MAJOR_VERSION < 8 */
        len = Tcl_ConvertElement(RSTRING(argv[num])->ptr, dst, flagPtr[num]);
#endif
        dst += len;
        *dst = ' ';
        dst++;
    }
    if (dst == result) {
        *dst = 0;
    } else {
        dst[-1] = 0;
    }

    free(flagPtr);

    /* create object */
    str = rb_str_new(result, dst - result - 1);
    if (taint_flag) OBJ_TAINT(str);
    Tcl_Free(result);

    if (old_gc == Qfalse) rb_gc_enable();
    rb_thread_critical = thr_crit_bup;

    return str;
}

static VALUE
lib_conv_listelement(self, src)
    VALUE self;
    VALUE src;
{
    int   len, scan_flag;
    volatile VALUE dst;
    int   taint_flag = OBJ_TAINTED(src);
    int thr_crit_bup;

    thr_crit_bup = rb_thread_critical;
    rb_thread_critical = Qtrue;

    StringValue(src);

#if TCL_MAJOR_VERSION >= 8
    len = Tcl_ScanCountedElement(RSTRING(src)->ptr, RSTRING(src)->len, 
				 &scan_flag);
    dst = rb_str_new(0, len + 1);
    len = Tcl_ConvertCountedElement(RSTRING(src)->ptr, RSTRING(src)->len, 
				    RSTRING(dst)->ptr, scan_flag);
#else /* TCL_MAJOR_VERSION < 8 */
    len = Tcl_ScanElement(RSTRING(src)->ptr, &scan_flag);
    dst = rb_str_new(0, len + 1);
    len = Tcl_ConvertElement(RSTRING(src)->ptr, RSTRING(dst)->ptr, scan_flag);
#endif

    RSTRING(dst)->len = len;
    RSTRING(dst)->ptr[len] = '\0';
    if (taint_flag) OBJ_TAINT(dst);

    rb_thread_critical = thr_crit_bup;

    return dst;
}


#ifdef __MACOS__
static void
_macinit()
{
    tcl_macQdPtr = &qd; /* setup QuickDraw globals */
    Tcl_MacSetEventProc(TkMacConvertEvent); /* setup event handler */
}
#endif

/*---- initialization ----*/
void
Init_tcltklib()
{
    int  thr_crit_bup;

    VALUE lib = rb_define_module("TclTkLib");
    VALUE ip = rb_define_class("TclTkIp", rb_cObject);

    VALUE ev_flag = rb_define_module_under(lib, "EventFlag");
    VALUE var_flag = rb_define_module_under(lib, "VarAccessFlag");

    /* --------------------------------------------------------------- */

#if defined USE_TCL_STUBS && defined USE_TK_STUBS
    extern int ruby_tcltk_stubs();
    int ret = ruby_tcltk_stubs();

    if (ret)
	rb_raise(rb_eLoadError, "tcltklib: tcltk_stubs init error(%d)", ret);
#endif

    /* --------------------------------------------------------------- */

    rb_global_variable(&eTkCallbackReturn);
    rb_global_variable(&eTkCallbackBreak);
    rb_global_variable(&eTkCallbackContinue);

    rb_global_variable(&eventloop_thread);
    rb_global_variable(&watchdog_thread);

   /* --------------------------------------------------------------- */

    rb_define_const(lib, "FINALIZE_PROC_NAME", 
		    rb_str_new2(finalize_hook_name));

   /* --------------------------------------------------------------- */

    rb_define_const(ev_flag, "NONE",      INT2FIX(0));
    rb_define_const(ev_flag, "WINDOW",    INT2FIX(TCL_WINDOW_EVENTS));
    rb_define_const(ev_flag, "FILE",      INT2FIX(TCL_FILE_EVENTS));
    rb_define_const(ev_flag, "TIMER",     INT2FIX(TCL_TIMER_EVENTS));
    rb_define_const(ev_flag, "IDLE",      INT2FIX(TCL_IDLE_EVENTS));
    rb_define_const(ev_flag, "ALL",       INT2FIX(TCL_ALL_EVENTS));
    rb_define_const(ev_flag, "DONT_WAIT", INT2FIX(TCL_DONT_WAIT));

    /* --------------------------------------------------------------- */

    rb_define_const(var_flag, "NONE",           INT2FIX(0));
    rb_define_const(var_flag, "GLOBAL_ONLY",    INT2FIX(TCL_GLOBAL_ONLY));
#ifdef TCL_NAMESPACE_ONLY
    rb_define_const(var_flag, "NAMESPACE_ONLY", INT2FIX(TCL_NAMESPACE_ONLY));
#else /* probably Tcl7.6 */
    rb_define_const(var_flag, "NAMESPACE_ONLY", INT2FIX(0));
#endif
    rb_define_const(var_flag, "LEAVE_ERR_MSG",  INT2FIX(TCL_LEAVE_ERR_MSG));
    rb_define_const(var_flag, "APPEND_VALUE",   INT2FIX(TCL_APPEND_VALUE));
    rb_define_const(var_flag, "LIST_ELEMENT",   INT2FIX(TCL_LIST_ELEMENT));
#ifdef TCL_PARSE_PART1
    rb_define_const(var_flag, "PARSE_VARNAME",  INT2FIX(TCL_PARSE_PART1));
#else /* probably Tcl7.6 */
    rb_define_const(var_flag, "PARSE_VARNAME",  INT2FIX(0));
#endif

    /* --------------------------------------------------------------- */

    eTkCallbackBreak = rb_define_class("TkCallbackReturn", rb_eStandardError);
    eTkCallbackBreak = rb_define_class("TkCallbackBreak", rb_eStandardError);
    eTkCallbackContinue = rb_define_class("TkCallbackContinue",
                                          rb_eStandardError);

    /* --------------------------------------------------------------- */

    eLocalJumpError = rb_const_get(rb_cObject, rb_intern("LocalJumpError"));

    ID_at_enc = rb_intern("@encoding");
    ID_at_interp = rb_intern("@interp");

    ID_stop_p = rb_intern("stop?");
    ID_kill = rb_intern("kill");
    ID_join = rb_intern("join");

    ID_call = rb_intern("call");
    ID_backtrace = rb_intern("backtrace");
    ID_message = rb_intern("message");

    ID_at_reason = rb_intern("@reason");
    ID_return = rb_intern("return");
    ID_break = rb_intern("break");
    ID_next = rb_intern("next");

    ID_to_s = rb_intern("to_s");
    ID_inspect = rb_intern("inspect");

    /* --------------------------------------------------------------- */

    rb_define_module_function(lib, "mainloop", lib_mainloop, -1);
    rb_define_module_function(lib, "mainloop_watchdog", 
			      lib_mainloop_watchdog, -1);
    rb_define_module_function(lib, "do_one_event", lib_do_one_event, -1);
    rb_define_module_function(lib, "mainloop_abort_on_exception", 
                             lib_evloop_abort_on_exc, 0);
    rb_define_module_function(lib, "mainloop_abort_on_exception=",  
                             lib_evloop_abort_on_exc_set, 1);
    rb_define_module_function(lib, "set_eventloop_tick",set_eventloop_tick,1);
    rb_define_module_function(lib, "get_eventloop_tick",get_eventloop_tick,0);
    rb_define_module_function(lib, "set_no_event_wait", set_no_event_wait, 1);
    rb_define_module_function(lib, "get_no_event_wait", get_no_event_wait, 0);
    rb_define_module_function(lib, "set_eventloop_weight", 
			      set_eventloop_weight, 2);
    rb_define_module_function(lib, "set_max_block_time", set_max_block_time,1);
    rb_define_module_function(lib, "get_eventloop_weight", 
			      get_eventloop_weight, 0);
    rb_define_module_function(lib, "num_of_mainwindows", 
			      lib_num_of_mainwindows, 0);

    /* --------------------------------------------------------------- */

    rb_define_module_function(lib, "_split_tklist", lib_split_tklist, 1);
    rb_define_module_function(lib, "_merge_tklist", lib_merge_tklist, -1);
    rb_define_module_function(lib, "_conv_listelement", 
			      lib_conv_listelement, 1);
    rb_define_module_function(lib, "_toUTF8", lib_toUTF8, -1);
    rb_define_module_function(lib, "_fromUTF8", lib_fromUTF8, -1);
    rb_define_module_function(lib, "_subst_UTF_backslash", 
			      lib_UTF_backslash, 1);
    rb_define_module_function(lib, "_subst_Tcl_backslash", 
			      lib_Tcl_backslash, 1);

    /* --------------------------------------------------------------- */

    rb_define_alloc_func(ip, ip_alloc);
    rb_define_method(ip, "initialize", ip_init, -1);
    rb_define_method(ip, "create_slave", ip_create_slave, -1);
    rb_define_method(ip, "make_safe", ip_make_safe, 0);
    rb_define_method(ip, "safe?", ip_is_safe_p, 0);
    rb_define_method(ip, "delete", ip_delete, 0);
    rb_define_method(ip, "deleted?", ip_is_deleted_p, 0);
    rb_define_method(ip, "_eval", ip_eval, 1);
    rb_define_method(ip, "_toUTF8", ip_toUTF8, -1);
    rb_define_method(ip, "_fromUTF8", ip_fromUTF8, -1);
    rb_define_method(ip, "_thread_vwait", ip_thread_vwait, 1);
    rb_define_method(ip, "_thread_tkwait", ip_thread_tkwait, 2);
    rb_define_method(ip, "_invoke", ip_invoke, -1);
    rb_define_method(ip, "_return_value", ip_retval, 0);

    /* --------------------------------------------------------------- */

    rb_define_method(ip, "_get_variable", ip_get_variable, 2);
    rb_define_method(ip, "_get_variable2", ip_get_variable2, 3);
    rb_define_method(ip, "_set_variable", ip_set_variable, 3);
    rb_define_method(ip, "_set_variable2", ip_set_variable2, 4);
    rb_define_method(ip, "_unset_variable", ip_unset_variable, 2);
    rb_define_method(ip, "_unset_variable2", ip_unset_variable2, 3);
    rb_define_method(ip, "_get_global_var", ip_get_global_var, 1);
    rb_define_method(ip, "_get_global_var2", ip_get_global_var2, 2);
    rb_define_method(ip, "_set_global_var", ip_set_global_var, 2);
    rb_define_method(ip, "_set_global_var2", ip_set_global_var2, 3);
    rb_define_method(ip, "_unset_global_var", ip_unset_global_var, 1);
    rb_define_method(ip, "_unset_global_var2", ip_unset_global_var2, 2);

    /* --------------------------------------------------------------- */

    rb_define_method(ip, "_split_tklist", ip_split_tklist, 1);
    rb_define_method(ip, "_merge_tklist", lib_merge_tklist, -1);
    rb_define_method(ip, "_conv_listelement", lib_conv_listelement, 1);

    /* --------------------------------------------------------------- */

    rb_define_method(ip, "mainloop", ip_mainloop, -1);
    rb_define_method(ip, "mainloop_watchdog", ip_mainloop_watchdog, -1);
    rb_define_method(ip, "do_one_event", ip_do_one_event, -1);
    rb_define_method(ip, "mainloop_abort_on_exception", 
		    ip_evloop_abort_on_exc, 0);
    rb_define_method(ip, "mainloop_abort_on_exception=", 
		    ip_evloop_abort_on_exc_set, 1);
    rb_define_method(ip, "set_eventloop_tick", ip_set_eventloop_tick, 1);
    rb_define_method(ip, "get_eventloop_tick", ip_get_eventloop_tick, 0);
    rb_define_method(ip, "set_no_event_wait", ip_set_no_event_wait, 1);
    rb_define_method(ip, "get_no_event_wait", ip_get_no_event_wait, 0);
    rb_define_method(ip, "set_eventloop_weight", ip_set_eventloop_weight, 2);
    rb_define_method(ip, "get_eventloop_weight", ip_get_eventloop_weight, 0);
    rb_define_method(ip, "set_max_block_time", set_max_block_time, 1);
    rb_define_method(ip, "restart", ip_restart, 0);

    /* --------------------------------------------------------------- */

    eventloop_thread = 0;
    watchdog_thread  = 0;

    /* --------------------------------------------------------------- */

#ifdef __MACOS__
    _macinit();
#endif

    /* from Tk_Main() */
    DUMP1("Tcl_FindExecutable");
    Tcl_FindExecutable(RSTRING(rb_argv0)->ptr);

    /* --------------------------------------------------------------- */
}

/* eof */