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ruby--ruby/cont.c
normal 74fdf5232d cont.c: cleanup needless cast 
It seems like leftover development step from r59557
("refactoring Fiber status").

I will make fiber_status use BITFIELD macro in a future
commit.

* cont.c (struct rb_fiber_struct): drop const from fiber_status
  (fiber_status_set): remove cast
  [ruby-core:86788] [Misc #14720]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63315 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2018-05-01 20:55:39 +00:00

2002 lines
52 KiB
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/**********************************************************************
cont.c -
$Author$
created at: Thu May 23 09:03:43 2007
Copyright (C) 2007 Koichi Sasada
**********************************************************************/
#include "internal.h"
#include "vm_core.h"
#include "gc.h"
#include "eval_intern.h"
#include "mjit.h"
/* FIBER_USE_NATIVE enables Fiber performance improvement using system
* dependent method such as make/setcontext on POSIX system or
* CreateFiber() API on Windows.
* This hack make Fiber context switch faster (x2 or more).
* However, it decrease maximum number of Fiber. For example, on the
* 32bit POSIX OS, ten or twenty thousands Fiber can be created.
*
* Details is reported in the paper "A Fast Fiber Implementation for Ruby 1.9"
* in Proc. of 51th Programming Symposium, pp.21--28 (2010) (in Japanese).
*/
#if !defined(FIBER_USE_NATIVE)
# if defined(HAVE_GETCONTEXT) && defined(HAVE_SETCONTEXT)
# if 0
# elif defined(__NetBSD__)
/* On our experience, NetBSD doesn't support using setcontext() and pthread
* simultaneously. This is because pthread_self(), TLS and other information
* are represented by stack pointer (higher bits of stack pointer).
* TODO: check such constraint on configure.
*/
# define FIBER_USE_NATIVE 0
# elif defined(__sun)
/* On Solaris because resuming any Fiber caused SEGV, for some reason.
*/
# define FIBER_USE_NATIVE 0
# elif defined(__ia64)
/* At least, Linux/ia64's getcontext(3) doesn't save register window.
*/
# define FIBER_USE_NATIVE 0
# elif defined(__GNU__)
/* GNU/Hurd doesn't fully support getcontext, setcontext, makecontext
* and swapcontext functions. Disabling their usage till support is
* implemented. More info at
* http://darnassus.sceen.net/~hurd-web/open_issues/glibc/#getcontext
*/
# define FIBER_USE_NATIVE 0
# else
# define FIBER_USE_NATIVE 1
# endif
# elif defined(_WIN32)
# define FIBER_USE_NATIVE 1
# endif
#endif
#if !defined(FIBER_USE_NATIVE)
#define FIBER_USE_NATIVE 0
#endif
#if FIBER_USE_NATIVE
#ifndef _WIN32
#include <unistd.h>
#include <sys/mman.h>
#include <ucontext.h>
#endif
#define RB_PAGE_SIZE (pagesize)
#define RB_PAGE_MASK (~(RB_PAGE_SIZE - 1))
static long pagesize;
#endif /*FIBER_USE_NATIVE*/
#define CAPTURE_JUST_VALID_VM_STACK 1
enum context_type {
CONTINUATION_CONTEXT = 0,
FIBER_CONTEXT = 1,
ROOT_FIBER_CONTEXT = 2
};
struct cont_saved_vm_stack {
VALUE *ptr;
#ifdef CAPTURE_JUST_VALID_VM_STACK
size_t slen; /* length of stack (head of ec->vm_stack) */
size_t clen; /* length of control frames (tail of ec->vm_stack) */
#endif
};
typedef struct rb_context_struct {
enum context_type type;
int argc;
VALUE self;
VALUE value;
struct cont_saved_vm_stack saved_vm_stack;
struct {
VALUE *stack;
VALUE *stack_src;
size_t stack_size;
#ifdef __ia64
VALUE *register_stack;
VALUE *register_stack_src;
int register_stack_size;
#endif
} machine;
rb_execution_context_t saved_ec;
rb_jmpbuf_t jmpbuf;
rb_ensure_entry_t *ensure_array;
rb_ensure_list_t *ensure_list;
/* Pointer to MJIT info about the continuation. */
struct mjit_cont *mjit_cont;
} rb_context_t;
/*
* Fiber status:
* [Fiber.new] ------> FIBER_CREATED
* | [Fiber#resume]
* v
* +--> FIBER_RESUMED ----+
* [Fiber#resume] | | [Fiber.yield] |
* | v |
* +-- FIBER_SUSPENDED | [Terminate]
* |
* FIBER_TERMINATED <-+
*/
enum fiber_status {
FIBER_CREATED,
FIBER_RESUMED,
FIBER_SUSPENDED,
FIBER_TERMINATED
};
#define FIBER_CREATED_P(fib) ((fib)->status == FIBER_CREATED)
#define FIBER_RESUMED_P(fib) ((fib)->status == FIBER_RESUMED)
#define FIBER_SUSPENDED_P(fib) ((fib)->status == FIBER_SUSPENDED)
#define FIBER_TERMINATED_P(fib) ((fib)->status == FIBER_TERMINATED)
#define FIBER_RUNNABLE_P(fib) (FIBER_CREATED_P(fib) || FIBER_SUSPENDED_P(fib))
#if FIBER_USE_NATIVE && !defined(_WIN32)
#define MAX_MACHINE_STACK_CACHE 10
static int machine_stack_cache_index = 0;
typedef struct machine_stack_cache_struct {
void *ptr;
size_t size;
} machine_stack_cache_t;
static machine_stack_cache_t machine_stack_cache[MAX_MACHINE_STACK_CACHE];
static machine_stack_cache_t terminated_machine_stack;
#endif
struct rb_fiber_struct {
rb_context_t cont;
VALUE first_proc;
struct rb_fiber_struct *prev;
enum fiber_status status;
/* If a fiber invokes "transfer",
* then this fiber can't "resume" any more after that.
* You shouldn't mix "transfer" and "resume".
*/
int transferred;
#if FIBER_USE_NATIVE
#ifdef _WIN32
void *fib_handle;
#else
ucontext_t context;
/* Because context.uc_stack.ss_sp and context.uc_stack.ss_size
* are not necessarily valid after makecontext() or swapcontext(),
* they are saved in these variables for later use.
*/
void *ss_sp;
size_t ss_size;
#endif
#endif
};
static const char *
fiber_status_name(enum fiber_status s)
{
switch (s) {
case FIBER_CREATED: return "created";
case FIBER_RESUMED: return "resumed";
case FIBER_SUSPENDED: return "suspended";
case FIBER_TERMINATED: return "terminated";
}
VM_UNREACHABLE(fiber_status_name);
return NULL;
}
static void
fiber_verify(const rb_fiber_t *fib)
{
#if VM_CHECK_MODE > 0
VM_ASSERT(fib->cont.saved_ec.fiber_ptr == fib);
switch (fib->status) {
case FIBER_RESUMED:
VM_ASSERT(fib->cont.saved_ec.vm_stack != NULL);
break;
case FIBER_SUSPENDED:
VM_ASSERT(fib->cont.saved_ec.vm_stack != NULL);
break;
case FIBER_CREATED:
case FIBER_TERMINATED:
/* TODO */
break;
default:
VM_UNREACHABLE(fiber_verify);
}
#endif
}
#if VM_CHECK_MODE > 0
void
rb_ec_verify(const rb_execution_context_t *ec)
{
/* TODO */
}
#endif
static void
fiber_status_set(rb_fiber_t *fib, enum fiber_status s)
{
if (0) fprintf(stderr, "fib: %p, status: %s -> %s\n", (void *)fib, fiber_status_name(fib->status), fiber_status_name(s));
VM_ASSERT(!FIBER_TERMINATED_P(fib));
VM_ASSERT(fib->status != s);
fiber_verify(fib);
fib->status = s;
}
void
ec_set_vm_stack(rb_execution_context_t *ec, VALUE *stack, size_t size)
{
*(VALUE **)(&ec->vm_stack) = stack;
*(size_t *)(&ec->vm_stack_size) = size;
}
static inline void
ec_switch(rb_thread_t *th, rb_fiber_t *fib)
{
rb_execution_context_t *ec = &fib->cont.saved_ec;
ruby_current_execution_context_ptr = th->ec = ec;
VM_ASSERT(ec->fiber_ptr->cont.self == 0 || ec->vm_stack != NULL);
}
static const rb_data_type_t cont_data_type, fiber_data_type;
static VALUE rb_cContinuation;
static VALUE rb_cFiber;
static VALUE rb_eFiberError;
#define GetContPtr(obj, ptr) \
TypedData_Get_Struct((obj), rb_context_t, &cont_data_type, (ptr))
#define GetFiberPtr(obj, ptr) do {\
TypedData_Get_Struct((obj), rb_fiber_t, &fiber_data_type, (ptr)); \
if (!(ptr)) rb_raise(rb_eFiberError, "uninitialized fiber"); \
} while (0)
NOINLINE(static VALUE cont_capture(volatile int *volatile stat));
#define THREAD_MUST_BE_RUNNING(th) do { \
if (!(th)->ec->tag) rb_raise(rb_eThreadError, "not running thread"); \
} while (0)
static VALUE
cont_thread_value(const rb_context_t *cont)
{
return cont->saved_ec.thread_ptr->self;
}
static void
cont_mark(void *ptr)
{
rb_context_t *cont = ptr;
RUBY_MARK_ENTER("cont");
rb_gc_mark(cont->value);
rb_execution_context_mark(&cont->saved_ec);
rb_gc_mark(cont_thread_value(cont));
if (cont->saved_vm_stack.ptr) {
#ifdef CAPTURE_JUST_VALID_VM_STACK
rb_gc_mark_locations(cont->saved_vm_stack.ptr,
cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen + cont->saved_vm_stack.clen);
#else
rb_gc_mark_locations(cont->saved_vm_stack.ptr,
cont->saved_vm_stack.ptr, cont->saved_ec.stack_size);
#endif
}
if (cont->machine.stack) {
if (cont->type == CONTINUATION_CONTEXT) {
/* cont */
rb_gc_mark_locations(cont->machine.stack,
cont->machine.stack + cont->machine.stack_size);
}
else {
/* fiber */
const rb_fiber_t *fib = (rb_fiber_t*)cont;
if (!FIBER_TERMINATED_P(fib)) {
rb_gc_mark_locations(cont->machine.stack,
cont->machine.stack + cont->machine.stack_size);
}
}
}
#ifdef __ia64
if (cont->machine.register_stack) {
rb_gc_mark_locations(cont->machine.register_stack,
cont->machine.register_stack + cont->machine.register_stack_size);
}
#endif
RUBY_MARK_LEAVE("cont");
}
static void
cont_free(void *ptr)
{
rb_context_t *cont = ptr;
RUBY_FREE_ENTER("cont");
ruby_xfree(cont->saved_ec.vm_stack);
#if FIBER_USE_NATIVE
if (cont->type == CONTINUATION_CONTEXT) {
/* cont */
ruby_xfree(cont->ensure_array);
RUBY_FREE_UNLESS_NULL(cont->machine.stack);
}
else {
/* fiber */
const rb_fiber_t *fib = (rb_fiber_t*)cont;
#ifdef _WIN32
if (cont->type != ROOT_FIBER_CONTEXT) {
/* don't delete root fiber handle */
if (fib->fib_handle) {
DeleteFiber(fib->fib_handle);
}
}
#else /* not WIN32 */
if (fib->ss_sp != NULL) {
if (cont->type == ROOT_FIBER_CONTEXT) {
rb_bug("Illegal root fiber parameter");
}
munmap((void*)fib->ss_sp, fib->ss_size);
}
else {
/* It may reached here when finalize */
/* TODO examine whether it is a bug */
/* rb_bug("cont_free: release self"); */
}
#endif
}
#else /* not FIBER_USE_NATIVE */
ruby_xfree(cont->ensure_array);
RUBY_FREE_UNLESS_NULL(cont->machine.stack);
#endif
#ifdef __ia64
RUBY_FREE_UNLESS_NULL(cont->machine.register_stack);
#endif
RUBY_FREE_UNLESS_NULL(cont->saved_vm_stack.ptr);
if (mjit_init_p && cont->mjit_cont != NULL) {
mjit_cont_free(cont->mjit_cont);
}
/* free rb_cont_t or rb_fiber_t */
ruby_xfree(ptr);
RUBY_FREE_LEAVE("cont");
}
static size_t
cont_memsize(const void *ptr)
{
const rb_context_t *cont = ptr;
size_t size = 0;
size = sizeof(*cont);
if (cont->saved_vm_stack.ptr) {
#ifdef CAPTURE_JUST_VALID_VM_STACK
size_t n = (cont->saved_vm_stack.slen + cont->saved_vm_stack.clen);
#else
size_t n = cont->saved_ec.vm_stack_size;
#endif
size += n * sizeof(*cont->saved_vm_stack.ptr);
}
if (cont->machine.stack) {
size += cont->machine.stack_size * sizeof(*cont->machine.stack);
}
#ifdef __ia64
if (cont->machine.register_stack) {
size += cont->machine.register_stack_size * sizeof(*cont->machine.register_stack);
}
#endif
return size;
}
void
rb_fiber_mark_self(const rb_fiber_t *fib)
{
if (fib->cont.self) {
rb_gc_mark(fib->cont.self);
}
else {
rb_execution_context_mark(&fib->cont.saved_ec);
}
}
static void
fiber_mark(void *ptr)
{
rb_fiber_t *fib = ptr;
RUBY_MARK_ENTER("cont");
fiber_verify(fib);
rb_gc_mark(fib->first_proc);
if (fib->prev) rb_fiber_mark_self(fib->prev);
#if !FIBER_USE_NATIVE
if (fib->status == FIBER_TERMINATED) {
/* FIBER_TERMINATED fiber should not mark machine stack */
if (fib->cont.saved_ec.machine.stack_end != NULL) {
fib->cont.saved_ec.machine.stack_end = NULL;
}
}
#endif
cont_mark(&fib->cont);
RUBY_MARK_LEAVE("cont");
}
static void
fiber_free(void *ptr)
{
rb_fiber_t *fib = ptr;
RUBY_FREE_ENTER("fiber");
if (fib->cont.saved_ec.local_storage) {
st_free_table(fib->cont.saved_ec.local_storage);
}
cont_free(&fib->cont);
RUBY_FREE_LEAVE("fiber");
}
static size_t
fiber_memsize(const void *ptr)
{
const rb_fiber_t *fib = ptr;
size_t size = 0;
size = sizeof(*fib);
if (fib->cont.type != ROOT_FIBER_CONTEXT &&
fib->cont.saved_ec.local_storage != NULL) {
size += st_memsize(fib->cont.saved_ec.local_storage);
}
size += cont_memsize(&fib->cont);
return size;
}
VALUE
rb_obj_is_fiber(VALUE obj)
{
if (rb_typeddata_is_kind_of(obj, &fiber_data_type)) {
return Qtrue;
}
else {
return Qfalse;
}
}
static void
cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont)
{
size_t size;
SET_MACHINE_STACK_END(&th->ec->machine.stack_end);
#ifdef __ia64
th->ec->machine.register_stack_end = rb_ia64_bsp();
#endif
if (th->ec->machine.stack_start > th->ec->machine.stack_end) {
size = cont->machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end;
cont->machine.stack_src = th->ec->machine.stack_end;
}
else {
size = cont->machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start;
cont->machine.stack_src = th->ec->machine.stack_start;
}
if (cont->machine.stack) {
REALLOC_N(cont->machine.stack, VALUE, size);
}
else {
cont->machine.stack = ALLOC_N(VALUE, size);
}
FLUSH_REGISTER_WINDOWS;
MEMCPY(cont->machine.stack, cont->machine.stack_src, VALUE, size);
#ifdef __ia64
rb_ia64_flushrs();
size = cont->machine.register_stack_size = th->ec->machine.register_stack_end - th->ec->machine.register_stack_start;
cont->machine.register_stack_src = th->ec->machine.register_stack_start;
if (cont->machine.register_stack) {
REALLOC_N(cont->machine.register_stack, VALUE, size);
}
else {
cont->machine.register_stack = ALLOC_N(VALUE, size);
}
MEMCPY(cont->machine.register_stack, cont->machine.register_stack_src, VALUE, size);
#endif
}
static const rb_data_type_t cont_data_type = {
"continuation",
{cont_mark, cont_free, cont_memsize,},
0, 0, RUBY_TYPED_FREE_IMMEDIATELY
};
static inline void
cont_save_thread(rb_context_t *cont, rb_thread_t *th)
{
rb_execution_context_t *sec = &cont->saved_ec;
VM_ASSERT(th->status == THREAD_RUNNABLE);
/* save thread context */
*sec = *th->ec;
/* saved_ec->machine.stack_end should be NULL */
/* because it may happen GC afterward */
sec->machine.stack_end = NULL;
#ifdef __ia64
sec->machine.register_stack_start = NULL;
sec->machine.register_stack_end = NULL;
#endif
}
static void
cont_init(rb_context_t *cont, rb_thread_t *th)
{
/* save thread context */
cont_save_thread(cont, th);
cont->saved_ec.thread_ptr = th;
cont->saved_ec.local_storage = NULL;
cont->saved_ec.local_storage_recursive_hash = Qnil;
cont->saved_ec.local_storage_recursive_hash_for_trace = Qnil;
if (mjit_init_p) {
cont->mjit_cont = mjit_cont_new(&cont->saved_ec);
}
}
static rb_context_t *
cont_new(VALUE klass)
{
rb_context_t *cont;
volatile VALUE contval;
rb_thread_t *th = GET_THREAD();
THREAD_MUST_BE_RUNNING(th);
contval = TypedData_Make_Struct(klass, rb_context_t, &cont_data_type, cont);
cont->self = contval;
cont_init(cont, th);
return cont;
}
#if 0
void
show_vm_stack(const rb_execution_context_t *ec)
{
VALUE *p = ec->vm_stack;
while (p < ec->cfp->sp) {
fprintf(stderr, "%3d ", (int)(p - ec->vm_stack));
rb_obj_info_dump(*p);
p++;
}
}
void
show_vm_pcs(const rb_control_frame_t *cfp,
const rb_control_frame_t *end_of_cfp)
{
int i=0;
while (cfp != end_of_cfp) {
int pc = 0;
if (cfp->iseq) {
pc = cfp->pc - cfp->iseq->body->iseq_encoded;
}
fprintf(stderr, "%2d pc: %d\n", i++, pc);
cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
}
}
#endif
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wduplicate-decl-specifier"
#endif
static VALUE
cont_capture(volatile int *volatile stat)
{
rb_context_t *volatile cont;
rb_thread_t *th = GET_THREAD();
volatile VALUE contval;
const rb_execution_context_t *ec = th->ec;
THREAD_MUST_BE_RUNNING(th);
rb_vm_stack_to_heap(th->ec);
cont = cont_new(rb_cContinuation);
contval = cont->self;
#ifdef CAPTURE_JUST_VALID_VM_STACK
cont->saved_vm_stack.slen = ec->cfp->sp - ec->vm_stack;
cont->saved_vm_stack.clen = ec->vm_stack + ec->vm_stack_size - (VALUE*)ec->cfp;
cont->saved_vm_stack.ptr = ALLOC_N(VALUE, cont->saved_vm_stack.slen + cont->saved_vm_stack.clen);
MEMCPY(cont->saved_vm_stack.ptr,
ec->vm_stack,
VALUE, cont->saved_vm_stack.slen);
MEMCPY(cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen,
(VALUE*)ec->cfp,
VALUE,
cont->saved_vm_stack.clen);
#else
cont->saved_vm_stack.ptr = ALLOC_N(VALUE, ec->vm_stack_size);
MEMCPY(cont->saved_vm_stack.ptr, ec->vm_stack, VALUE, ec->vm_stack_size);
#endif
ec_set_vm_stack(&cont->saved_ec, NULL, 0);
cont_save_machine_stack(th, cont);
/* backup ensure_list to array for search in another context */
{
rb_ensure_list_t *p;
int size = 0;
rb_ensure_entry_t *entry;
for (p=th->ec->ensure_list; p; p=p->next)
size++;
entry = cont->ensure_array = ALLOC_N(rb_ensure_entry_t,size+1);
for (p=th->ec->ensure_list; p; p=p->next) {
if (!p->entry.marker)
p->entry.marker = rb_ary_tmp_new(0); /* dummy object */
*entry++ = p->entry;
}
entry->marker = 0;
}
if (ruby_setjmp(cont->jmpbuf)) {
VALUE value;
VAR_INITIALIZED(cont);
value = cont->value;
if (cont->argc == -1) rb_exc_raise(value);
cont->value = Qnil;
*stat = 1;
return value;
}
else {
*stat = 0;
return contval;
}
}
#ifdef __clang__
#pragma clang diagnostic pop
#endif
static inline void
fiber_restore_thread(rb_thread_t *th, rb_fiber_t *fib)
{
ec_switch(th, fib);
VM_ASSERT(th->ec->fiber_ptr == fib);
}
static inline void
cont_restore_thread(rb_context_t *cont)
{
rb_thread_t *th = GET_THREAD();
/* restore thread context */
if (cont->type == CONTINUATION_CONTEXT) {
/* continuation */
rb_execution_context_t *sec = &cont->saved_ec;
rb_fiber_t *fib = NULL;
if (sec->fiber_ptr != NULL) {
fib = sec->fiber_ptr;
}
else if (th->root_fiber) {
fib = th->root_fiber;
}
if (fib && th->ec != &fib->cont.saved_ec) {
ec_switch(th, fib);
}
/* copy vm stack */
#ifdef CAPTURE_JUST_VALID_VM_STACK
MEMCPY(th->ec->vm_stack,
cont->saved_vm_stack.ptr,
VALUE, cont->saved_vm_stack.slen);
MEMCPY(th->ec->vm_stack + th->ec->vm_stack_size - cont->saved_vm_stack.clen,
cont->saved_vm_stack.ptr + cont->saved_vm_stack.slen,
VALUE, cont->saved_vm_stack.clen);
#else
MEMCPY(th->ec->vm_stack, cont->saved_vm_stack.ptr, VALUE, sec->vm_stack_size);
#endif
/* other members of ec */
th->ec->cfp = sec->cfp;
th->ec->raised_flag = sec->raised_flag;
th->ec->tag = sec->tag;
th->ec->protect_tag = sec->protect_tag;
th->ec->root_lep = sec->root_lep;
th->ec->root_svar = sec->root_svar;
th->ec->ensure_list = sec->ensure_list;
th->ec->errinfo = sec->errinfo;
/* trace on -> trace off */
if (th->ec->trace_arg != NULL && sec->trace_arg == NULL) {
GET_VM()->trace_running--;
}
/* trace off -> trace on */
else if (th->ec->trace_arg == NULL && sec->trace_arg != NULL) {
GET_VM()->trace_running++;
}
th->ec->trace_arg = sec->trace_arg;
VM_ASSERT(th->ec->vm_stack != NULL);
}
else {
/* fiber */
fiber_restore_thread(th, (rb_fiber_t*)cont);
}
}
#if FIBER_USE_NATIVE
#ifdef _WIN32
static void
fiber_set_stack_location(void)
{
rb_thread_t *th = GET_THREAD();
VALUE *ptr;
SET_MACHINE_STACK_END(&ptr);
th->ec->machine.stack_start = (void*)(((VALUE)ptr & RB_PAGE_MASK) + STACK_UPPER((void *)&ptr, 0, RB_PAGE_SIZE));
}
static VOID CALLBACK
fiber_entry(void *arg)
{
fiber_set_stack_location();
rb_fiber_start();
}
#else /* _WIN32 */
/*
* FreeBSD require a first (i.e. addr) argument of mmap(2) is not NULL
* if MAP_STACK is passed.
* http://www.FreeBSD.org/cgi/query-pr.cgi?pr=158755
*/
#if defined(MAP_STACK) && !defined(__FreeBSD__) && !defined(__FreeBSD_kernel__)
#define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON | MAP_STACK)
#else
#define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON)
#endif
static char*
fiber_machine_stack_alloc(size_t size)
{
char *ptr;
if (machine_stack_cache_index > 0) {
if (machine_stack_cache[machine_stack_cache_index - 1].size == (size / sizeof(VALUE))) {
ptr = machine_stack_cache[machine_stack_cache_index - 1].ptr;
machine_stack_cache_index--;
machine_stack_cache[machine_stack_cache_index].ptr = NULL;
machine_stack_cache[machine_stack_cache_index].size = 0;
}
else{
/* TODO handle multiple machine stack size */
rb_bug("machine_stack_cache size is not canonicalized");
}
}
else {
void *page;
STACK_GROW_DIR_DETECTION;
errno = 0;
ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, FIBER_STACK_FLAGS, -1, 0);
if (ptr == MAP_FAILED) {
rb_raise(rb_eFiberError, "can't alloc machine stack to fiber: %s", strerror(errno));
}
/* guard page setup */
page = ptr + STACK_DIR_UPPER(size - RB_PAGE_SIZE, 0);
if (mprotect(page, RB_PAGE_SIZE, PROT_NONE) < 0) {
rb_raise(rb_eFiberError, "mprotect failed");
}
}
return ptr;
}
#endif
static void
fiber_initialize_machine_stack_context(rb_fiber_t *fib, size_t size)
{
rb_execution_context_t *sec = &fib->cont.saved_ec;
#ifdef _WIN32
# if defined(_MSC_VER) && _MSC_VER <= 1200
# define CreateFiberEx(cs, stacksize, flags, entry, param) \
CreateFiber((stacksize), (entry), (param))
# endif
fib->fib_handle = CreateFiberEx(size - 1, size, 0, fiber_entry, NULL);
if (!fib->fib_handle) {
/* try to release unnecessary fibers & retry to create */
rb_gc();
fib->fib_handle = CreateFiberEx(size - 1, size, 0, fiber_entry, NULL);
if (!fib->fib_handle) {
rb_raise(rb_eFiberError, "can't create fiber");
}
}
sec->machine.stack_maxsize = size;
#else /* not WIN32 */
ucontext_t *context = &fib->context;
char *ptr;
STACK_GROW_DIR_DETECTION;
getcontext(context);
ptr = fiber_machine_stack_alloc(size);
context->uc_link = NULL;
context->uc_stack.ss_sp = ptr;
context->uc_stack.ss_size = size;
fib->ss_sp = ptr;
fib->ss_size = size;
makecontext(context, rb_fiber_start, 0);
sec->machine.stack_start = (VALUE*)(ptr + STACK_DIR_UPPER(0, size));
sec->machine.stack_maxsize = size - RB_PAGE_SIZE;
#endif
#ifdef __ia64
sth->machine.register_stack_maxsize = sth->machine.stack_maxsize;
#endif
}
NOINLINE(static void fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib));
static void
fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib)
{
rb_thread_t *th = GET_THREAD();
/* save oldfib's machine stack / TODO: is it needed? */
if (!FIBER_TERMINATED_P(oldfib)) {
STACK_GROW_DIR_DETECTION;
SET_MACHINE_STACK_END(&th->ec->machine.stack_end);
if (STACK_DIR_UPPER(0, 1)) {
oldfib->cont.machine.stack_size = th->ec->machine.stack_start - th->ec->machine.stack_end;
oldfib->cont.machine.stack = th->ec->machine.stack_end;
}
else {
oldfib->cont.machine.stack_size = th->ec->machine.stack_end - th->ec->machine.stack_start;
oldfib->cont.machine.stack = th->ec->machine.stack_start;
}
}
/* exchange machine_stack_start between oldfib and newfib */
oldfib->cont.saved_ec.machine.stack_start = th->ec->machine.stack_start;
/* oldfib->machine.stack_end should be NULL */
oldfib->cont.saved_ec.machine.stack_end = NULL;
/* restore thread context */
fiber_restore_thread(th, newfib);
#ifndef _WIN32
if (!newfib->context.uc_stack.ss_sp && th->root_fiber != newfib) {
rb_bug("non_root_fiber->context.uc_stac.ss_sp should not be NULL");
}
#endif
/* swap machine context */
#ifdef _WIN32
SwitchToFiber(newfib->fib_handle);
#else
swapcontext(&oldfib->context, &newfib->context);
#endif
}
#endif
NOINLINE(NORETURN(static void cont_restore_1(rb_context_t *)));
static void
cont_restore_1(rb_context_t *cont)
{
cont_restore_thread(cont);
/* restore machine stack */
#ifdef _M_AMD64
{
/* workaround for x64 SEH */
jmp_buf buf;
setjmp(buf);
((_JUMP_BUFFER*)(&cont->jmpbuf))->Frame =
((_JUMP_BUFFER*)(&buf))->Frame;
}
#endif
if (cont->machine.stack_src) {
FLUSH_REGISTER_WINDOWS;
MEMCPY(cont->machine.stack_src, cont->machine.stack,
VALUE, cont->machine.stack_size);
}
#ifdef __ia64
if (cont->machine.register_stack_src) {
MEMCPY(cont->machine.register_stack_src, cont->machine.register_stack,
VALUE, cont->machine.register_stack_size);
}
#endif
ruby_longjmp(cont->jmpbuf, 1);
}
NORETURN(NOINLINE(static void cont_restore_0(rb_context_t *, VALUE *)));
#ifdef __ia64
#define C(a) rse_##a##0, rse_##a##1, rse_##a##2, rse_##a##3, rse_##a##4
#define E(a) rse_##a##0= rse_##a##1= rse_##a##2= rse_##a##3= rse_##a##4
static volatile int C(a), C(b), C(c), C(d), C(e);
static volatile int C(f), C(g), C(h), C(i), C(j);
static volatile int C(k), C(l), C(m), C(n), C(o);
static volatile int C(p), C(q), C(r), C(s), C(t);
#if 0
{/* the above lines make cc-mode.el confused so much */}
#endif
int rb_dummy_false = 0;
NORETURN(NOINLINE(static void register_stack_extend(rb_context_t *, VALUE *, VALUE *)));
static void
register_stack_extend(rb_context_t *cont, VALUE *vp, VALUE *curr_bsp)
{
if (rb_dummy_false) {
/* use registers as much as possible */
E(a) = E(b) = E(c) = E(d) = E(e) =
E(f) = E(g) = E(h) = E(i) = E(j) =
E(k) = E(l) = E(m) = E(n) = E(o) =
E(p) = E(q) = E(r) = E(s) = E(t) = 0;
E(a) = E(b) = E(c) = E(d) = E(e) =
E(f) = E(g) = E(h) = E(i) = E(j) =
E(k) = E(l) = E(m) = E(n) = E(o) =
E(p) = E(q) = E(r) = E(s) = E(t) = 0;
}
if (curr_bsp < cont->machine.register_stack_src+cont->machine.register_stack_size) {
register_stack_extend(cont, vp, (VALUE*)rb_ia64_bsp());
}
cont_restore_0(cont, vp);
}
#undef C
#undef E
#endif
static void
cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame)
{
if (cont->machine.stack_src) {
#ifdef HAVE_ALLOCA
#define STACK_PAD_SIZE 1
#else
#define STACK_PAD_SIZE 1024
#endif
VALUE space[STACK_PAD_SIZE];
#if !STACK_GROW_DIRECTION
if (addr_in_prev_frame > &space[0]) {
/* Stack grows downward */
#endif
#if STACK_GROW_DIRECTION <= 0
volatile VALUE *const end = cont->machine.stack_src;
if (&space[0] > end) {
# ifdef HAVE_ALLOCA
volatile VALUE *sp = ALLOCA_N(VALUE, &space[0] - end);
space[0] = *sp;
# else
cont_restore_0(cont, &space[0]);
# endif
}
#endif
#if !STACK_GROW_DIRECTION
}
else {
/* Stack grows upward */
#endif
#if STACK_GROW_DIRECTION >= 0
volatile VALUE *const end = cont->machine.stack_src + cont->machine.stack_size;
if (&space[STACK_PAD_SIZE] < end) {
# ifdef HAVE_ALLOCA
volatile VALUE *sp = ALLOCA_N(VALUE, end - &space[STACK_PAD_SIZE]);
space[0] = *sp;
# else
cont_restore_0(cont, &space[STACK_PAD_SIZE-1]);
# endif
}
#endif
#if !STACK_GROW_DIRECTION
}
#endif
}
cont_restore_1(cont);
}
#ifdef __ia64
#define cont_restore_0(cont, vp) register_stack_extend((cont), (vp), (VALUE*)rb_ia64_bsp())
#endif
/*
* Document-class: Continuation
*
* Continuation objects are generated by Kernel#callcc,
* after having +require+d <i>continuation</i>. They hold
* a return address and execution context, allowing a nonlocal return
* to the end of the <code>callcc</code> block from anywhere within a
* program. Continuations are somewhat analogous to a structured
* version of C's <code>setjmp/longjmp</code> (although they contain
* more state, so you might consider them closer to threads).
*
* For instance:
*
* require "continuation"
* arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ]
* callcc{|cc| $cc = cc}
* puts(message = arr.shift)
* $cc.call unless message =~ /Max/
*
* <em>produces:</em>
*
* Freddie
* Herbie
* Ron
* Max
*
* Also you can call callcc in other methods:
*
* require "continuation"
*
* def g
* arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ]
* cc = callcc { |cc| cc }
* puts arr.shift
* return cc, arr.size
* end
*
* def f
* c, size = g
* c.call(c) if size > 1
* end
*
* f
*
* This (somewhat contrived) example allows the inner loop to abandon
* processing early:
*
* require "continuation"
* callcc {|cont|
* for i in 0..4
* print "\n#{i}: "
* for j in i*5...(i+1)*5
* cont.call() if j == 17
* printf "%3d", j
* end
* end
* }
* puts
*
* <em>produces:</em>
*
* 0: 0 1 2 3 4
* 1: 5 6 7 8 9
* 2: 10 11 12 13 14
* 3: 15 16
*/
/*
* call-seq:
* callcc {|cont| block } -> obj
*
* Generates a Continuation object, which it passes to
* the associated block. You need to <code>require
* 'continuation'</code> before using this method. Performing a
* <em>cont</em><code>.call</code> will cause the #callcc
* to return (as will falling through the end of the block). The
* value returned by the #callcc is the value of the
* block, or the value passed to <em>cont</em><code>.call</code>. See
* class Continuation for more details. Also see
* Kernel#throw for an alternative mechanism for
* unwinding a call stack.
*/
static VALUE
rb_callcc(VALUE self)
{
volatile int called;
volatile VALUE val = cont_capture(&called);
if (called) {
return val;
}
else {
return rb_yield(val);
}
}
static VALUE
make_passing_arg(int argc, const VALUE *argv)
{
switch (argc) {
case 0:
return Qnil;
case 1:
return argv[0];
default:
return rb_ary_new4(argc, argv);
}
}
/* CAUTION!! : Currently, error in rollback_func is not supported */
/* same as rb_protect if set rollback_func to NULL */
void
ruby_register_rollback_func_for_ensure(VALUE (*ensure_func)(ANYARGS), VALUE (*rollback_func)(ANYARGS))
{
st_table **table_p = &GET_VM()->ensure_rollback_table;
if (UNLIKELY(*table_p == NULL)) {
*table_p = st_init_numtable();
}
st_insert(*table_p, (st_data_t)ensure_func, (st_data_t)rollback_func);
}
static inline VALUE
lookup_rollback_func(VALUE (*ensure_func)(ANYARGS))
{
st_table *table = GET_VM()->ensure_rollback_table;
st_data_t val;
if (table && st_lookup(table, (st_data_t)ensure_func, &val))
return (VALUE) val;
return Qundef;
}
static inline void
rollback_ensure_stack(VALUE self,rb_ensure_list_t *current,rb_ensure_entry_t *target)
{
rb_ensure_list_t *p;
rb_ensure_entry_t *entry;
size_t i;
size_t cur_size;
size_t target_size;
size_t base_point;
VALUE (*func)(ANYARGS);
cur_size = 0;
for (p=current; p; p=p->next)
cur_size++;
target_size = 0;
for (entry=target; entry->marker; entry++)
target_size++;
/* search common stack point */
p = current;
base_point = cur_size;
while (base_point) {
if (target_size >= base_point &&
p->entry.marker == target[target_size - base_point].marker)
break;
base_point --;
p = p->next;
}
/* rollback function check */
for (i=0; i < target_size - base_point; i++) {
if (!lookup_rollback_func(target[i].e_proc)) {
rb_raise(rb_eRuntimeError, "continuation called from out of critical rb_ensure scope");
}
}
/* pop ensure stack */
while (cur_size > base_point) {
/* escape from ensure block */
(*current->entry.e_proc)(current->entry.data2);
current = current->next;
cur_size--;
}
/* push ensure stack */
while (i--) {
func = (VALUE (*)(ANYARGS)) lookup_rollback_func(target[i].e_proc);
if ((VALUE)func != Qundef) {
(*func)(target[i].data2);
}
}
}
/*
* call-seq:
* cont.call(args, ...)
* cont[args, ...]
*
* Invokes the continuation. The program continues from the end of the
* <code>callcc</code> block. If no arguments are given, the original
* <code>callcc</code> returns <code>nil</code>. If one argument is
* given, <code>callcc</code> returns it. Otherwise, an array
* containing <i>args</i> is returned.
*
* callcc {|cont| cont.call } #=> nil
* callcc {|cont| cont.call 1 } #=> 1
* callcc {|cont| cont.call 1, 2, 3 } #=> [1, 2, 3]
*/
static VALUE
rb_cont_call(int argc, VALUE *argv, VALUE contval)
{
rb_context_t *cont;
rb_thread_t *th = GET_THREAD();
GetContPtr(contval, cont);
if (cont_thread_value(cont) != th->self) {
rb_raise(rb_eRuntimeError, "continuation called across threads");
}
if (cont->saved_ec.protect_tag != th->ec->protect_tag) {
rb_raise(rb_eRuntimeError, "continuation called across stack rewinding barrier");
}
if (cont->saved_ec.fiber_ptr) {
if (th->ec->fiber_ptr != cont->saved_ec.fiber_ptr) {
rb_raise(rb_eRuntimeError, "continuation called across fiber");
}
}
rollback_ensure_stack(contval, th->ec->ensure_list, cont->ensure_array);
cont->argc = argc;
cont->value = make_passing_arg(argc, argv);
cont_restore_0(cont, &contval);
return Qnil; /* unreachable */
}
/*********/
/* fiber */
/*********/
/*
* Document-class: Fiber
*
* Fibers are primitives for implementing light weight cooperative
* concurrency in Ruby. Basically they are a means of creating code blocks
* that can be paused and resumed, much like threads. The main difference
* is that they are never preempted and that the scheduling must be done by
* the programmer and not the VM.
*
* As opposed to other stackless light weight concurrency models, each fiber
* comes with a stack. This enables the fiber to be paused from deeply
* nested function calls within the fiber block. See the ruby(1)
* manpage to configure the size of the fiber stack(s).
*
* When a fiber is created it will not run automatically. Rather it must
* be explicitly asked to run using the <code>Fiber#resume</code> method.
* The code running inside the fiber can give up control by calling
* <code>Fiber.yield</code> in which case it yields control back to caller
* (the caller of the <code>Fiber#resume</code>).
*
* Upon yielding or termination the Fiber returns the value of the last
* executed expression
*
* For instance:
*
* fiber = Fiber.new do
* Fiber.yield 1
* 2
* end
*
* puts fiber.resume
* puts fiber.resume
* puts fiber.resume
*
* <em>produces</em>
*
* 1
* 2
* FiberError: dead fiber called
*
* The <code>Fiber#resume</code> method accepts an arbitrary number of
* parameters, if it is the first call to <code>resume</code> then they
* will be passed as block arguments. Otherwise they will be the return
* value of the call to <code>Fiber.yield</code>
*
* Example:
*
* fiber = Fiber.new do |first|
* second = Fiber.yield first + 2
* end
*
* puts fiber.resume 10
* puts fiber.resume 14
* puts fiber.resume 18
*
* <em>produces</em>
*
* 12
* 14
* FiberError: dead fiber called
*
*/
static const rb_data_type_t fiber_data_type = {
"fiber",
{fiber_mark, fiber_free, fiber_memsize,},
0, 0, RUBY_TYPED_FREE_IMMEDIATELY
};
static VALUE
fiber_alloc(VALUE klass)
{
return TypedData_Wrap_Struct(klass, &fiber_data_type, 0);
}
static rb_fiber_t*
fiber_t_alloc(VALUE fibval)
{
rb_fiber_t *fib;
rb_thread_t *th = GET_THREAD();
if (DATA_PTR(fibval) != 0) {
rb_raise(rb_eRuntimeError, "cannot initialize twice");
}
THREAD_MUST_BE_RUNNING(th);
fib = ZALLOC(rb_fiber_t);
fib->cont.self = fibval;
fib->cont.type = FIBER_CONTEXT;
cont_init(&fib->cont, th);
fib->cont.saved_ec.fiber_ptr = fib;
fib->prev = NULL;
/* fib->status == 0 == CREATED
* So that we don't need to set status: fiber_status_set(fib, FIBER_CREATED); */
VM_ASSERT(FIBER_CREATED_P(fib));
DATA_PTR(fibval) = fib;
return fib;
}
rb_control_frame_t *
rb_vm_push_frame(rb_execution_context_t *sec,
const rb_iseq_t *iseq,
VALUE type,
VALUE self,
VALUE specval,
VALUE cref_or_me,
const VALUE *pc,
VALUE *sp,
int local_size,
int stack_max);
static VALUE
fiber_init(VALUE fibval, VALUE proc)
{
rb_fiber_t *fib = fiber_t_alloc(fibval);
rb_context_t *cont = &fib->cont;
rb_execution_context_t *sec = &cont->saved_ec;
rb_thread_t *cth = GET_THREAD();
size_t fib_stack_size = cth->vm->default_params.fiber_vm_stack_size / sizeof(VALUE);
/* initialize cont */
cont->saved_vm_stack.ptr = NULL;
ec_set_vm_stack(sec, NULL, 0);
ec_set_vm_stack(sec, ALLOC_N(VALUE, fib_stack_size), fib_stack_size);
sec->cfp = (void *)(sec->vm_stack + sec->vm_stack_size);
rb_vm_push_frame(sec,
NULL,
VM_FRAME_MAGIC_DUMMY | VM_ENV_FLAG_LOCAL | VM_FRAME_FLAG_FINISH | VM_FRAME_FLAG_CFRAME,
Qnil, /* self */
VM_BLOCK_HANDLER_NONE,
0, /* specval */
NULL, /* pc */
sec->vm_stack, /* sp */
0, /* local_size */
0);
sec->tag = NULL;
sec->local_storage = NULL;
sec->local_storage_recursive_hash = Qnil;
sec->local_storage_recursive_hash_for_trace = Qnil;
fib->first_proc = proc;
#if !FIBER_USE_NATIVE
MEMCPY(&cont->jmpbuf, &cth->root_jmpbuf, rb_jmpbuf_t, 1);
#endif
return fibval;
}
/* :nodoc: */
static VALUE
rb_fiber_init(VALUE fibval)
{
return fiber_init(fibval, rb_block_proc());
}
VALUE
rb_fiber_new(VALUE (*func)(ANYARGS), VALUE obj)
{
return fiber_init(fiber_alloc(rb_cFiber), rb_proc_new(func, obj));
}
static void rb_fiber_terminate(rb_fiber_t *fib, int need_interrupt);
void
rb_fiber_start(void)
{
rb_thread_t * volatile th = GET_THREAD();
rb_fiber_t *fib = th->ec->fiber_ptr;
rb_proc_t *proc;
enum ruby_tag_type state;
int need_interrupt = TRUE;
VM_ASSERT(th->ec == ruby_current_execution_context_ptr);
VM_ASSERT(FIBER_RESUMED_P(fib));
EC_PUSH_TAG(th->ec);
if ((state = EC_EXEC_TAG()) == TAG_NONE) {
rb_context_t *cont = &VAR_FROM_MEMORY(fib)->cont;
int argc;
const VALUE *argv, args = cont->value;
GetProcPtr(fib->first_proc, proc);
argv = (argc = cont->argc) > 1 ? RARRAY_CONST_PTR(args) : &args;
cont->value = Qnil;
th->ec->errinfo = Qnil;
th->ec->root_lep = rb_vm_proc_local_ep(fib->first_proc);
th->ec->root_svar = Qfalse;
EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
cont->value = rb_vm_invoke_proc(th->ec, proc, argc, argv, VM_BLOCK_HANDLER_NONE);
}
EC_POP_TAG();
if (state) {
VALUE err = th->ec->errinfo;
VM_ASSERT(FIBER_RESUMED_P(fib));
if (state == TAG_RAISE || state == TAG_FATAL) {
rb_threadptr_pending_interrupt_enque(th, err);
}
else {
err = rb_vm_make_jump_tag_but_local_jump(state, err);
if (!NIL_P(err)) {
rb_threadptr_pending_interrupt_enque(th, err);
}
}
need_interrupt = TRUE;
}
rb_fiber_terminate(fib, need_interrupt);
VM_UNREACHABLE(rb_fiber_start);
}
static rb_fiber_t *
root_fiber_alloc(rb_thread_t *th)
{
VALUE fibval = fiber_alloc(rb_cFiber);
rb_fiber_t *fib = th->ec->fiber_ptr;
VM_ASSERT(DATA_PTR(fibval) == NULL);
VM_ASSERT(fib->cont.type == ROOT_FIBER_CONTEXT);
VM_ASSERT(fib->status == FIBER_RESUMED);
th->root_fiber = fib;
DATA_PTR(fibval) = fib;
fib->cont.self = fibval;
#if FIBER_USE_NATIVE
#ifdef _WIN32
/* setup fib_handle for root Fiber */
if (fib->fib_handle == 0) {
if ((fib->fib_handle = ConvertThreadToFiber(0)) == 0) {
rb_bug("root_fiber_alloc: ConvertThreadToFiber() failed - %s\n", rb_w32_strerror(-1));
}
}
else {
rb_bug("root_fiber_alloc: fib_handle is not NULL.");
}
#endif
#endif
return fib;
}
void
rb_threadptr_root_fiber_setup(rb_thread_t *th)
{
rb_fiber_t *fib = ruby_mimmalloc(sizeof(rb_fiber_t));
MEMZERO(fib, rb_fiber_t, 1);
fib->cont.type = ROOT_FIBER_CONTEXT;
fib->cont.saved_ec.fiber_ptr = fib;
fib->cont.saved_ec.thread_ptr = th;
fiber_status_set(fib, FIBER_RESUMED); /* skip CREATED */
th->ec = &fib->cont.saved_ec;
/* NOTE: On WIN32, fib_handle is not allocated yet. */
}
void
rb_threadptr_root_fiber_release(rb_thread_t *th)
{
if (th->root_fiber) {
/* ignore. A root fiber object will free th->ec */
}
else {
VM_ASSERT(th->ec->fiber_ptr->cont.type == ROOT_FIBER_CONTEXT);
VM_ASSERT(th->ec->fiber_ptr->cont.self == 0);
fiber_free(th->ec->fiber_ptr);
if (th->ec == ruby_current_execution_context_ptr) {
ruby_current_execution_context_ptr = NULL;
}
th->ec = NULL;
}
}
static inline rb_fiber_t*
fiber_current(void)
{
rb_execution_context_t *ec = GET_EC();
if (ec->fiber_ptr->cont.self == 0) {
root_fiber_alloc(rb_ec_thread_ptr(ec));
}
return ec->fiber_ptr;
}
static inline rb_fiber_t*
return_fiber(void)
{
rb_fiber_t *fib = fiber_current();
rb_fiber_t *prev = fib->prev;
if (!prev) {
rb_thread_t *th = GET_THREAD();
rb_fiber_t *root_fiber = th->root_fiber;
VM_ASSERT(root_fiber != NULL);
if (root_fiber == fib) {
rb_raise(rb_eFiberError, "can't yield from root fiber");
}
return root_fiber;
}
else {
fib->prev = NULL;
return prev;
}
}
VALUE
rb_fiber_current(void)
{
return fiber_current()->cont.self;
}
static inline VALUE
fiber_store(rb_fiber_t *next_fib, rb_thread_t *th)
{
rb_fiber_t *fib;
if (th->ec->fiber_ptr != NULL) {
fib = th->ec->fiber_ptr;
}
else {
/* create root fiber */
fib = root_fiber_alloc(th);
}
VM_ASSERT(FIBER_RESUMED_P(fib) || FIBER_TERMINATED_P(fib));
VM_ASSERT(FIBER_RUNNABLE_P(next_fib));
#if FIBER_USE_NATIVE
if (FIBER_CREATED_P(next_fib)) {
fiber_initialize_machine_stack_context(next_fib, th->vm->default_params.fiber_machine_stack_size);
}
#endif
if (FIBER_RESUMED_P(fib)) fiber_status_set(fib, FIBER_SUSPENDED);
#if FIBER_USE_NATIVE == 0
/* should (re-)allocate stack are before fib->status change to pass fiber_verify() */
cont_save_machine_stack(th, &fib->cont);
#endif
fiber_status_set(next_fib, FIBER_RESUMED);
#if FIBER_USE_NATIVE
fiber_setcontext(next_fib, fib);
/* restored */
#ifndef _WIN32
if (terminated_machine_stack.ptr) {
if (machine_stack_cache_index < MAX_MACHINE_STACK_CACHE) {
machine_stack_cache[machine_stack_cache_index].ptr = terminated_machine_stack.ptr;
machine_stack_cache[machine_stack_cache_index].size = terminated_machine_stack.size;
machine_stack_cache_index++;
}
else {
if (terminated_machine_stack.ptr != fib->cont.machine.stack) {
munmap((void*)terminated_machine_stack.ptr, terminated_machine_stack.size * sizeof(VALUE));
}
else {
rb_bug("terminated fiber resumed");
}
}
terminated_machine_stack.ptr = NULL;
terminated_machine_stack.size = 0;
}
#endif /* not _WIN32 */
fib = th->ec->fiber_ptr;
if (fib->cont.argc == -1) rb_exc_raise(fib->cont.value);
return fib->cont.value;
#else /* FIBER_USE_NATIVE */
if (ruby_setjmp(fib->cont.jmpbuf)) {
/* restored */
fib = th->ec->fiber_ptr;
if (fib->cont.argc == -1) rb_exc_raise(fib->cont.value);
if (next_fib->cont.value == Qundef) {
cont_restore_0(&next_fib->cont, &next_fib->cont.value);
VM_UNREACHABLE(fiber_store);
}
return fib->cont.value;
}
else {
VALUE undef = Qundef;
cont_restore_0(&next_fib->cont, &undef);
VM_UNREACHABLE(fiber_store);
}
#endif /* FIBER_USE_NATIVE */
}
static inline VALUE
fiber_switch(rb_fiber_t *fib, int argc, const VALUE *argv, int is_resume)
{
VALUE value;
rb_context_t *cont = &fib->cont;
rb_thread_t *th = GET_THREAD();
/* make sure the root_fiber object is available */
if (th->root_fiber == NULL) root_fiber_alloc(th);
if (th->ec->fiber_ptr == fib) {
/* ignore fiber context switch
* because destination fiber is same as current fiber
*/
return make_passing_arg(argc, argv);
}
if (cont_thread_value(cont) != th->self) {
rb_raise(rb_eFiberError, "fiber called across threads");
}
else if (cont->saved_ec.protect_tag != th->ec->protect_tag) {
rb_raise(rb_eFiberError, "fiber called across stack rewinding barrier");
}
else if (FIBER_TERMINATED_P(fib)) {
value = rb_exc_new2(rb_eFiberError, "dead fiber called");
if (!FIBER_TERMINATED_P(th->ec->fiber_ptr)) {
rb_exc_raise(value);
VM_UNREACHABLE(fiber_switch);
}
else {
/* th->ec->fiber_ptr is also dead => switch to root fiber */
/* (this means we're being called from rb_fiber_terminate, */
/* and the terminated fiber's return_fiber() is already dead) */
VM_ASSERT(FIBER_SUSPENDED_P(th->root_fiber));
cont = &th->root_fiber->cont;
cont->argc = -1;
cont->value = value;
#if FIBER_USE_NATIVE
fiber_setcontext(th->root_fiber, th->ec->fiber_ptr);
#else
cont_restore_0(cont, &value);
#endif
VM_UNREACHABLE(fiber_switch);
}
}
if (is_resume) {
fib->prev = fiber_current();
}
VM_ASSERT(FIBER_RUNNABLE_P(fib));
cont->argc = argc;
cont->value = make_passing_arg(argc, argv);
value = fiber_store(fib, th);
RUBY_VM_CHECK_INTS(th->ec);
EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
return value;
}
VALUE
rb_fiber_transfer(VALUE fibval, int argc, const VALUE *argv)
{
rb_fiber_t *fib;
GetFiberPtr(fibval, fib);
return fiber_switch(fib, argc, argv, 0);
}
void
rb_fiber_close(rb_fiber_t *fib)
{
VALUE *vm_stack = fib->cont.saved_ec.vm_stack;
fiber_status_set(fib, FIBER_TERMINATED);
if (fib->cont.type == ROOT_FIBER_CONTEXT) {
rb_thread_recycle_stack_release(vm_stack);
}
else {
ruby_xfree(vm_stack);
}
ec_set_vm_stack(&fib->cont.saved_ec, NULL, 0);
#if !FIBER_USE_NATIVE
/* should not mark machine stack any more */
fib->cont.saved_ec.machine.stack_end = NULL;
#endif
}
static void
rb_fiber_terminate(rb_fiber_t *fib, int need_interrupt)
{
VALUE value = fib->cont.value;
rb_fiber_t *ret_fib;
VM_ASSERT(FIBER_RESUMED_P(fib));
rb_fiber_close(fib);
#if FIBER_USE_NATIVE && !defined(_WIN32)
/* Ruby must not switch to other thread until storing terminated_machine_stack */
terminated_machine_stack.ptr = fib->ss_sp;
terminated_machine_stack.size = fib->ss_size / sizeof(VALUE);
fib->ss_sp = NULL;
fib->context.uc_stack.ss_sp = NULL;
fib->cont.machine.stack = NULL;
fib->cont.machine.stack_size = 0;
#endif
ret_fib = return_fiber();
if (need_interrupt) RUBY_VM_SET_INTERRUPT(&ret_fib->cont.saved_ec);
fiber_switch(ret_fib, 1, &value, 0);
}
VALUE
rb_fiber_resume(VALUE fibval, int argc, const VALUE *argv)
{
rb_fiber_t *fib;
GetFiberPtr(fibval, fib);
if (fib->prev != 0 || fib->cont.type == ROOT_FIBER_CONTEXT) {
rb_raise(rb_eFiberError, "double resume");
}
if (fib->transferred != 0) {
rb_raise(rb_eFiberError, "cannot resume transferred Fiber");
}
return fiber_switch(fib, argc, argv, 1);
}
VALUE
rb_fiber_yield(int argc, const VALUE *argv)
{
return fiber_switch(return_fiber(), argc, argv, 0);
}
void
rb_fiber_reset_root_local_storage(VALUE thval)
{
rb_thread_t *th = rb_thread_ptr(thval);
if (th->root_fiber && th->root_fiber != th->ec->fiber_ptr) {
th->ec->local_storage = th->root_fiber->cont.saved_ec.local_storage;
}
}
/*
* call-seq:
* fiber.alive? -> true or false
*
* Returns true if the fiber can still be resumed (or transferred
* to). After finishing execution of the fiber block this method will
* always return false. You need to <code>require 'fiber'</code>
* before using this method.
*/
VALUE
rb_fiber_alive_p(VALUE fibval)
{
const rb_fiber_t *fib;
GetFiberPtr(fibval, fib);
return FIBER_TERMINATED_P(fib) ? Qfalse : Qtrue;
}
/*
* call-seq:
* fiber.resume(args, ...) -> obj
*
* Resumes the fiber from the point at which the last <code>Fiber.yield</code>
* was called, or starts running it if it is the first call to
* <code>resume</code>. Arguments passed to resume will be the value of
* the <code>Fiber.yield</code> expression or will be passed as block
* parameters to the fiber's block if this is the first <code>resume</code>.
*
* Alternatively, when resume is called it evaluates to the arguments passed
* to the next <code>Fiber.yield</code> statement inside the fiber's block
* or to the block value if it runs to completion without any
* <code>Fiber.yield</code>
*/
static VALUE
rb_fiber_m_resume(int argc, VALUE *argv, VALUE fib)
{
return rb_fiber_resume(fib, argc, argv);
}
/*
* call-seq:
* fiber.transfer(args, ...) -> obj
*
* Transfer control to another fiber, resuming it from where it last
* stopped or starting it if it was not resumed before. The calling
* fiber will be suspended much like in a call to
* <code>Fiber.yield</code>. You need to <code>require 'fiber'</code>
* before using this method.
*
* The fiber which receives the transfer call is treats it much like
* a resume call. Arguments passed to transfer are treated like those
* passed to resume.
*
* You cannot resume a fiber that transferred control to another one.
* This will cause a double resume error. You need to transfer control
* back to this fiber before it can yield and resume.
*
* Example:
*
* fiber1 = Fiber.new do
* puts "In Fiber 1"
* Fiber.yield
* end
*
* fiber2 = Fiber.new do
* puts "In Fiber 2"
* fiber1.transfer
* puts "Never see this message"
* end
*
* fiber3 = Fiber.new do
* puts "In Fiber 3"
* end
*
* fiber2.resume
* fiber3.resume
*
* <em>produces</em>
*
* In fiber 2
* In fiber 1
* In fiber 3
*
*/
static VALUE
rb_fiber_m_transfer(int argc, VALUE *argv, VALUE fibval)
{
rb_fiber_t *fib;
GetFiberPtr(fibval, fib);
fib->transferred = 1;
return fiber_switch(fib, argc, argv, 0);
}
/*
* call-seq:
* Fiber.yield(args, ...) -> obj
*
* Yields control back to the context that resumed the fiber, passing
* along any arguments that were passed to it. The fiber will resume
* processing at this point when <code>resume</code> is called next.
* Any arguments passed to the next <code>resume</code> will be the
* value that this <code>Fiber.yield</code> expression evaluates to.
*/
static VALUE
rb_fiber_s_yield(int argc, VALUE *argv, VALUE klass)
{
return rb_fiber_yield(argc, argv);
}
/*
* call-seq:
* Fiber.current() -> fiber
*
* Returns the current fiber. You need to <code>require 'fiber'</code>
* before using this method. If you are not running in the context of
* a fiber this method will return the root fiber.
*/
static VALUE
rb_fiber_s_current(VALUE klass)
{
return rb_fiber_current();
}
/*
* call-seq:
* fiber.to_s -> string
*
* Returns fiber information string.
*
*/
static VALUE
fiber_to_s(VALUE fibval)
{
const rb_fiber_t *fib;
const rb_proc_t *proc;
char status_info[0x10];
GetFiberPtr(fibval, fib);
snprintf(status_info, 0x10, " (%s)", fiber_status_name(fib->status));
if (!rb_obj_is_proc(fib->first_proc)) {
VALUE str = rb_any_to_s(fibval);
strlcat(status_info, ">", sizeof(status_info));
rb_str_set_len(str, RSTRING_LEN(str)-1);
rb_str_cat_cstr(str, status_info);
return str;
}
GetProcPtr(fib->first_proc, proc);
return rb_block_to_s(fibval, &proc->block, status_info);
}
/*
* Document-class: FiberError
*
* Raised when an invalid operation is attempted on a Fiber, in
* particular when attempting to call/resume a dead fiber,
* attempting to yield from the root fiber, or calling a fiber across
* threads.
*
* fiber = Fiber.new{}
* fiber.resume #=> nil
* fiber.resume #=> FiberError: dead fiber called
*/
void
Init_Cont(void)
{
#if FIBER_USE_NATIVE
rb_thread_t *th = GET_THREAD();
#ifdef _WIN32
SYSTEM_INFO info;
GetSystemInfo(&info);
pagesize = info.dwPageSize;
#else /* not WIN32 */
pagesize = sysconf(_SC_PAGESIZE);
#endif
SET_MACHINE_STACK_END(&th->ec->machine.stack_end);
#endif
rb_cFiber = rb_define_class("Fiber", rb_cObject);
rb_define_alloc_func(rb_cFiber, fiber_alloc);
rb_eFiberError = rb_define_class("FiberError", rb_eStandardError);
rb_define_singleton_method(rb_cFiber, "yield", rb_fiber_s_yield, -1);
rb_define_method(rb_cFiber, "initialize", rb_fiber_init, 0);
rb_define_method(rb_cFiber, "resume", rb_fiber_m_resume, -1);
rb_define_method(rb_cFiber, "to_s", fiber_to_s, 0);
rb_define_alias(rb_cFiber, "inspect", "to_s");
}
RUBY_SYMBOL_EXPORT_BEGIN
void
ruby_Init_Continuation_body(void)
{
rb_cContinuation = rb_define_class("Continuation", rb_cObject);
rb_undef_alloc_func(rb_cContinuation);
rb_undef_method(CLASS_OF(rb_cContinuation), "new");
rb_define_method(rb_cContinuation, "call", rb_cont_call, -1);
rb_define_method(rb_cContinuation, "[]", rb_cont_call, -1);
rb_define_global_function("callcc", rb_callcc, 0);
}
void
ruby_Init_Fiber_as_Coroutine(void)
{
rb_define_method(rb_cFiber, "transfer", rb_fiber_m_transfer, -1);
rb_define_method(rb_cFiber, "alive?", rb_fiber_alive_p, 0);
rb_define_singleton_method(rb_cFiber, "current", rb_fiber_s_current, 0);
}
RUBY_SYMBOL_EXPORT_END
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