/********************************************************************** mjit.c - MRI method JIT compiler functions for Ruby's main thread Copyright (C) 2017 Vladimir Makarov . **********************************************************************/ /* We utilize widely used C compilers (GCC and LLVM Clang) to implement MJIT. We feed them a C code generated from ISEQ. The industrial C compilers are slower than regular JIT engines. Generated code performance of the used C compilers has a higher priority over the compilation speed. So our major goal is to minimize the ISEQ compilation time when we use widely optimization level (-O2). It is achieved by o Using a precompiled version of the header o Keeping all files in `/tmp`. On modern Linux `/tmp` is a file system in memory. So it is pretty fast o Implementing MJIT as a multi-threaded code because we want to compile ISEQs in parallel with iseq execution to speed up Ruby code execution. MJIT has one thread (*worker*) to do parallel compilations: o It prepares a precompiled code of the minimized header. It starts at the MRI execution start o It generates PIC object files of ISEQs o It takes one JIT unit from a priority queue unless it is empty. o It translates the JIT unit ISEQ into C-code using the precompiled header, calls CC and load PIC code when it is ready o Currently MJIT put ISEQ in the queue when ISEQ is called o MJIT can reorder ISEQs in the queue if some ISEQ has been called many times and its compilation did not start yet o MRI reuses the machine code if it already exists for ISEQ o The machine code we generate can stop and switch to the ISEQ interpretation if some condition is not satisfied as the machine code can be speculative or some exception raises o Speculative machine code can be canceled. Here is a diagram showing the MJIT organization: _______ |header | |_______| | MRI building --------------|---------------------------------------- | MRI execution | _____________|_____ | | | | ___V__ | CC ____________________ | | |----------->| precompiled header | | | | | |____________________| | | | | | | | MJIT | | | | | | | | | | | | ____V___ CC __________ | |______|----------->| C code |--->| .so file | | | |________| |__________| | | | | | | | MRI machine code |<----------------------------- |___________________| loading */ #include "ruby/internal/config.h" // defines USE_MJIT #if USE_MJIT #include "constant.h" #include "id_table.h" #include "internal.h" #include "internal/class.h" #include "internal/cmdlineopt.h" #include "internal/cont.h" #include "internal/file.h" #include "internal/hash.h" #include "internal/process.h" #include "internal/warnings.h" #include "vm_sync.h" #include "ractor_core.h" #ifdef __sun #define __EXTENSIONS__ 1 #endif #include "vm_core.h" #include "vm_callinfo.h" #include "mjit.h" #include "mjit_unit.h" #include "gc.h" #include "ruby_assert.h" #include "ruby/debug.h" #include "ruby/thread.h" #include "ruby/version.h" #include "builtin.h" #include "insns.inc" #include "insns_info.inc" #include "internal/compile.h" #include #include #include #include #ifdef HAVE_FCNTL_H #include #endif #ifdef HAVE_SYS_PARAM_H # include #endif #include "dln.h" #include "ruby/util.h" #undef strdup // ruby_strdup may trigger GC #ifndef MAXPATHLEN # define MAXPATHLEN 1024 #endif // Atomically set function pointer if possible. #define MJIT_ATOMIC_SET(var, val) (void)ATOMIC_PTR_EXCHANGE(var, val) #define MJIT_TMP_PREFIX "_ruby_mjit_" // Linked list of struct rb_mjit_unit. struct rb_mjit_unit_list { struct ccan_list_head head; int length; // the list length }; extern void rb_native_mutex_lock(rb_nativethread_lock_t *lock); extern void rb_native_mutex_unlock(rb_nativethread_lock_t *lock); extern void rb_native_mutex_initialize(rb_nativethread_lock_t *lock); extern void rb_native_mutex_destroy(rb_nativethread_lock_t *lock); extern void rb_native_cond_initialize(rb_nativethread_cond_t *cond); extern void rb_native_cond_destroy(rb_nativethread_cond_t *cond); extern void rb_native_cond_signal(rb_nativethread_cond_t *cond); extern void rb_native_cond_broadcast(rb_nativethread_cond_t *cond); extern void rb_native_cond_wait(rb_nativethread_cond_t *cond, rb_nativethread_lock_t *mutex); // process.c extern void mjit_add_waiting_pid(rb_vm_t *vm, rb_pid_t pid); // A copy of MJIT portion of MRI options since MJIT initialization. We // need them as MJIT threads still can work when the most MRI data were // freed. struct mjit_options mjit_opts; // true if MJIT is enabled. bool mjit_enabled = false; // true if JIT-ed code should be called. When `ruby_vm_event_enabled_global_flags & ISEQ_TRACE_EVENTS` // and `mjit_call_p == false`, any JIT-ed code execution is cancelled as soon as possible. bool mjit_call_p = false; // Priority queue of iseqs waiting for JIT compilation. // This variable is a pointer to head unit of the queue. static struct rb_mjit_unit_list unit_queue = { CCAN_LIST_HEAD_INIT(unit_queue.head) }; // List of units which are successfully compiled. static struct rb_mjit_unit_list active_units = { CCAN_LIST_HEAD_INIT(active_units.head) }; // List of compacted so files which will be cleaned up by `free_list()` in `mjit_finish()`. static struct rb_mjit_unit_list compact_units = { CCAN_LIST_HEAD_INIT(compact_units.head) }; // List of units before recompilation and just waiting for dlclose(). static struct rb_mjit_unit_list stale_units = { CCAN_LIST_HEAD_INIT(stale_units.head) }; // The number of so far processed ISEQs, used to generate unique id. static int current_unit_num; // A mutex for conitionals and critical sections. static rb_nativethread_lock_t mjit_engine_mutex; // A thread conditional to wake up `mjit_finish` at the end of PCH thread. static rb_nativethread_cond_t mjit_pch_wakeup; // A thread conditional to wake up the client if there is a change in // executed unit status. static rb_nativethread_cond_t mjit_client_wakeup; // A thread conditional to wake up a worker if there we have something // to add or we need to stop MJIT engine. static rb_nativethread_cond_t mjit_worker_wakeup; // A thread conditional to wake up workers if at the end of GC. static rb_nativethread_cond_t mjit_gc_wakeup; // The times when unload_units is requested. unload_units is called after some requests. static int unload_requests = 0; // The total number of unloaded units. static int total_unloads = 0; // Set to true to stop worker. static bool stop_worker_p; // Set to true if worker is stopped. static bool worker_stopped = true; // Path of "/tmp", which is different on Windows or macOS. See: system_default_tmpdir() static char *tmp_dir; // Used C compiler path. static const char *cc_path; // Used C compiler flags. static const char **cc_common_args; // Used C compiler flags added by --mjit-debug=... static char **cc_added_args; // Name of the precompiled header file. static char *pch_file; // The process id which should delete the pch_file on mjit_finish. static rb_pid_t pch_owner_pid; // Status of the precompiled header creation. The status is // shared by the workers and the pch thread. static enum {PCH_NOT_READY, PCH_FAILED, PCH_SUCCESS} pch_status; // The start timestamp of current compilation static double current_cc_ms = 0.0; // TODO: make this part of unit? // Currently compiling MJIT unit static struct rb_mjit_unit *current_cc_unit = NULL; // PID of currently running C compiler process. 0 if nothing is running. static pid_t current_cc_pid = 0; // TODO: make this part of unit? // Name of the header file. static char *header_file; #include "mjit_config.h" #if defined(__GNUC__) && \ (!defined(__clang__) || \ (defined(__clang__) && (defined(__FreeBSD__) || defined(__GLIBC__)))) # define GCC_PIC_FLAGS "-Wfatal-errors", "-fPIC", "-shared", "-w", "-pipe", # define MJIT_CFLAGS_PIPE 1 #else # define GCC_PIC_FLAGS /* empty */ # define MJIT_CFLAGS_PIPE 0 #endif // Use `-nodefaultlibs -nostdlib` for GCC where possible, which does not work on cygwin, AIX, and OpenBSD. // This seems to improve MJIT performance on GCC. #if defined __GNUC__ && !defined __clang__ && !defined(__CYGWIN__) && !defined(_AIX) && !defined(__OpenBSD__) # define GCC_NOSTDLIB_FLAGS "-nodefaultlibs", "-nostdlib", #else # define GCC_NOSTDLIB_FLAGS // empty #endif static const char *const CC_COMMON_ARGS[] = { MJIT_CC_COMMON MJIT_CFLAGS GCC_PIC_FLAGS NULL }; static const char *const CC_DEBUG_ARGS[] = {MJIT_DEBUGFLAGS NULL}; static const char *const CC_OPTIMIZE_ARGS[] = {MJIT_OPTFLAGS NULL}; static const char *const CC_LDSHARED_ARGS[] = {MJIT_LDSHARED MJIT_CFLAGS GCC_PIC_FLAGS NULL}; static const char *const CC_DLDFLAGS_ARGS[] = {MJIT_DLDFLAGS NULL}; // `CC_LINKER_ARGS` are linker flags which must be passed to `-c` as well. static const char *const CC_LINKER_ARGS[] = { #if defined __GNUC__ && !defined __clang__ && !defined(__OpenBSD__) "-nostartfiles", #endif GCC_NOSTDLIB_FLAGS NULL }; static const char *const CC_LIBS[] = { #if defined(__CYGWIN__) MJIT_LIBS // mswin, cygwin #endif #if defined __GNUC__ && !defined __clang__ "-lgcc", // cygwin, and GCC platforms using `-nodefaultlibs -nostdlib` #endif #if defined __ANDROID__ "-lm", // to avoid 'cannot locate symbol "modf" referenced by .../_ruby_mjit_XXX.so"' #endif NULL }; #define CC_CODEFLAG_ARGS (mjit_opts.debug ? CC_DEBUG_ARGS : CC_OPTIMIZE_ARGS) // Print the arguments according to FORMAT to stderr only if MJIT // verbose option value is more or equal to LEVEL. PRINTF_ARGS(static void, 2, 3) verbose(int level, const char *format, ...) { if (mjit_opts.verbose >= level) { va_list args; size_t len = strlen(format); char *full_format = alloca(sizeof(char) * (len + 2)); // Creating `format + '\n'` to atomically print format and '\n'. memcpy(full_format, format, len); full_format[len] = '\n'; full_format[len+1] = '\0'; va_start(args, format); vfprintf(stderr, full_format, args); va_end(args); } } PRINTF_ARGS(static void, 1, 2) mjit_warning(const char *format, ...) { if (mjit_opts.warnings || mjit_opts.verbose) { va_list args; fprintf(stderr, "MJIT warning: "); va_start(args, format); vfprintf(stderr, format, args); va_end(args); fprintf(stderr, "\n"); } } // Add unit node to the tail of doubly linked `list`. It should be not in // the list before. static void add_to_list(struct rb_mjit_unit *unit, struct rb_mjit_unit_list *list) { (void)RB_DEBUG_COUNTER_INC_IF(mjit_length_unit_queue, list == &unit_queue); (void)RB_DEBUG_COUNTER_INC_IF(mjit_length_active_units, list == &active_units); (void)RB_DEBUG_COUNTER_INC_IF(mjit_length_compact_units, list == &compact_units); (void)RB_DEBUG_COUNTER_INC_IF(mjit_length_stale_units, list == &stale_units); ccan_list_add_tail(&list->head, &unit->unode); list->length++; } static void remove_from_list(struct rb_mjit_unit *unit, struct rb_mjit_unit_list *list) { #if USE_DEBUG_COUNTER rb_debug_counter_add(RB_DEBUG_COUNTER_mjit_length_unit_queue, -1, list == &unit_queue); rb_debug_counter_add(RB_DEBUG_COUNTER_mjit_length_active_units, -1, list == &active_units); rb_debug_counter_add(RB_DEBUG_COUNTER_mjit_length_compact_units, -1, list == &compact_units); rb_debug_counter_add(RB_DEBUG_COUNTER_mjit_length_stale_units, -1, list == &stale_units); #endif ccan_list_del(&unit->unode); list->length--; } static void remove_file(const char *filename) { if (remove(filename)) { mjit_warning("failed to remove \"%s\": %s", filename, strerror(errno)); } } // This is called in the following situations: // 1) On dequeue or `unload_units()`, associated ISeq is already GCed. // 2) The unit is not called often and unloaded by `unload_units()`. // 3) Freeing lists on `mjit_finish()`. // // `jit_func` value does not matter for 1 and 3 since the unit won't be used anymore. // For the situation 2, this sets the ISeq's JIT state to NOT_COMPILED_JIT_ISEQ_FUNC // to prevent the situation that the same methods are continuously compiled. static void free_unit(struct rb_mjit_unit *unit) { if (unit->iseq) { // ISeq is not GCed ISEQ_BODY(unit->iseq)->jit_func = (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC; ISEQ_BODY(unit->iseq)->jit_unit = NULL; } if (unit->cc_entries) { void *entries = (void *)unit->cc_entries; free(entries); } if (unit->handle && dlclose(unit->handle)) { // handle is NULL if it's in queue mjit_warning("failed to close handle for u%d: %s", unit->id, dlerror()); } free(unit); } // Start a critical section. Use message `msg` to print debug info at `level`. static inline void CRITICAL_SECTION_START(int level, const char *msg) { verbose(level, "Locking %s", msg); rb_native_mutex_lock(&mjit_engine_mutex); verbose(level, "Locked %s", msg); } // Finish the current critical section. Use message `msg` to print // debug info at `level`. static inline void CRITICAL_SECTION_FINISH(int level, const char *msg) { verbose(level, "Unlocked %s", msg); rb_native_mutex_unlock(&mjit_engine_mutex); } static pid_t mjit_pid = 0; static int sprint_uniq_filename(char *str, size_t size, unsigned long id, const char *prefix, const char *suffix) { return snprintf(str, size, "%s/%sp%"PRI_PIDT_PREFIX"uu%lu%s", tmp_dir, prefix, mjit_pid, id, suffix); } // Return time in milliseconds as a double. #ifdef __APPLE__ double ruby_real_ms_time(void); # define real_ms_time() ruby_real_ms_time() #else static double real_ms_time(void) { # ifdef HAVE_CLOCK_GETTIME struct timespec tv; # ifdef CLOCK_MONOTONIC const clockid_t c = CLOCK_MONOTONIC; # else const clockid_t c = CLOCK_REALTIME; # endif clock_gettime(c, &tv); return tv.tv_nsec / 1000000.0 + tv.tv_sec * 1000.0; # else struct timeval tv; gettimeofday(&tv, NULL); return tv.tv_usec / 1000.0 + tv.tv_sec * 1000.0; # endif } #endif // Return the best unit from list. The best is the first // high priority unit or the unit whose iseq has the biggest number // of calls so far. static struct rb_mjit_unit * get_from_list(struct rb_mjit_unit_list *list) { // Find iseq with max total_calls struct rb_mjit_unit *unit = NULL, *next, *best = NULL; ccan_list_for_each_safe(&list->head, unit, next, unode) { if (unit->iseq == NULL) { // ISeq is GCed. remove_from_list(unit, list); free_unit(unit); continue; } if (best == NULL || ISEQ_BODY(best->iseq)->total_calls < ISEQ_BODY(unit->iseq)->total_calls) { best = unit; } } if (best) { remove_from_list(best, list); } return best; } // Return length of NULL-terminated array `args` excluding the NULL marker. static size_t args_len(char *const *args) { size_t i; for (i = 0; (args[i]) != NULL;i++) ; return i; } // Concatenate `num` passed NULL-terminated arrays of strings, put the // result (with NULL end marker) into the heap, and return the result. static char ** form_args(int num, ...) { va_list argp; size_t len, n; int i; char **args, **res, **tmp; va_start(argp, num); res = NULL; for (i = len = 0; i < num; i++) { args = va_arg(argp, char **); n = args_len(args); if ((tmp = (char **)realloc(res, sizeof(char *) * (len + n + 1))) == NULL) { free(res); res = NULL; break; } res = tmp; MEMCPY(res + len, args, char *, n + 1); len += n; } va_end(argp); return res; } COMPILER_WARNING_PUSH #if __has_warning("-Wdeprecated-declarations") || RBIMPL_COMPILER_IS(GCC) COMPILER_WARNING_IGNORED(-Wdeprecated-declarations) #endif // Start an OS process of absolute executable path with arguments `argv`. // Return PID of the process. static pid_t start_process(const char *abspath, char *const *argv) { // Not calling non-async-signal-safe functions between vfork // and execv for safety int dev_null = rb_cloexec_open(ruby_null_device, O_WRONLY, 0); if (dev_null < 0) { verbose(1, "MJIT: Failed to open a null device: %s", strerror(errno)); return -1; } if (mjit_opts.verbose >= 2) { const char *arg; fprintf(stderr, "Starting process: %s", abspath); for (int i = 0; (arg = argv[i]) != NULL; i++) fprintf(stderr, " %s", arg); fprintf(stderr, "\n"); } pid_t pid; if ((pid = vfork()) == 0) { /* TODO: reuse some function in process.c */ umask(0077); if (mjit_opts.verbose == 0) { // CC can be started in a thread using a file which has been // already removed while MJIT is finishing. Discard the // messages about missing files. dup2(dev_null, STDERR_FILENO); dup2(dev_null, STDOUT_FILENO); } (void)close(dev_null); pid = execv(abspath, argv); // Pid will be negative on an error // Even if we successfully found CC to compile PCH we still can // fail with loading the CC in very rare cases for some reasons. // Stop the forked process in this case. verbose(1, "MJIT: Error in execv: %s", abspath); _exit(1); } (void)close(dev_null); return pid; } COMPILER_WARNING_POP // Execute an OS process of executable PATH with arguments ARGV. // Return -1 or -2 if failed to execute, otherwise exit code of the process. // TODO: Use a similar function in process.c static int exec_process(const char *path, char *const argv[]) { int stat, exit_code = -2; pid_t pid = start_process(path, argv); for (;pid > 0;) { pid_t r = waitpid(pid, &stat, 0); if (r == -1) { if (errno == EINTR) continue; fprintf(stderr, "[%"PRI_PIDT_PREFIX"d] waitpid(%lu): %s (SIGCHLD=%d,%u)\n", getpid(), (unsigned long)pid, strerror(errno), RUBY_SIGCHLD, SIGCHLD_LOSSY); break; } else if (r == pid) { if (WIFEXITED(stat)) { exit_code = WEXITSTATUS(stat); break; } else if (WIFSIGNALED(stat)) { exit_code = -1; break; } } } return exit_code; } static void remove_so_file(const char *so_file, struct rb_mjit_unit *unit) { remove_file(so_file); } // Print _mjitX, but make a human-readable funcname when --mjit-debug is used static void sprint_funcname(char *funcname, const struct rb_mjit_unit *unit) { const rb_iseq_t *iseq = unit->iseq; if (iseq == NULL || (!mjit_opts.debug && !mjit_opts.debug_flags)) { sprintf(funcname, "_mjit%d", unit->id); return; } // Generate a short path const char *path = RSTRING_PTR(rb_iseq_path(iseq)); const char *lib = "/lib/"; const char *version = "/" STRINGIZE(RUBY_API_VERSION_MAJOR) "." STRINGIZE(RUBY_API_VERSION_MINOR) "." STRINGIZE(RUBY_API_VERSION_TEENY) "/"; while (strstr(path, lib)) // skip "/lib/" path = strstr(path, lib) + strlen(lib); while (strstr(path, version)) // skip "/x.y.z/" path = strstr(path, version) + strlen(version); // Annotate all-normalized method names const char *method = RSTRING_PTR(ISEQ_BODY(iseq)->location.label); if (!strcmp(method, "[]")) method = "AREF"; if (!strcmp(method, "[]=")) method = "ASET"; // Print and normalize sprintf(funcname, "_mjit%d_%s_%s", unit->id, path, method); for (size_t i = 0; i < strlen(funcname); i++) { char c = funcname[i]; if (!(('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || c == '_')) { funcname[i] = '_'; } } } static const int c_file_access_mode = #ifdef O_BINARY O_BINARY| #endif O_WRONLY|O_EXCL|O_CREAT; #define append_str2(p, str, len) ((char *)memcpy((p), str, (len))+(len)) #define append_str(p, str) append_str2(p, str, sizeof(str)-1) #define append_lit(p, str) append_str2(p, str, rb_strlen_lit(str)) // The function producing the pre-compiled header. static void make_pch(void) { const char *rest_args[] = { # ifdef __clang__ "-emit-pch", "-c", # endif // -nodefaultlibs is a linker flag, but it may affect cc1 behavior on Gentoo, which should NOT be changed on pch: // https://gitweb.gentoo.org/proj/gcc-patches.git/tree/7.3.0/gentoo/13_all_default-ssp-fix.patch GCC_NOSTDLIB_FLAGS "-o", pch_file, header_file, NULL, }; verbose(2, "Creating precompiled header"); char **args = form_args(4, cc_common_args, CC_CODEFLAG_ARGS, cc_added_args, rest_args); if (args == NULL) { mjit_warning("making precompiled header failed on forming args"); pch_status = PCH_FAILED; return; } int exit_code = exec_process(cc_path, args); free(args); if (exit_code == 0) { pch_status = PCH_SUCCESS; } else { mjit_warning("Making precompiled header failed on compilation. Stopping MJIT worker..."); pch_status = PCH_FAILED; } } static int compile_c_to_so(const char *c_file, const char *so_file) { const char *so_args[] = { "-o", so_file, # ifdef __clang__ "-include-pch", pch_file, # endif c_file, NULL }; # if defined(__MACH__) extern VALUE rb_libruby_selfpath; const char *loader_args[] = {"-bundle_loader", StringValuePtr(rb_libruby_selfpath), NULL}; # else const char *loader_args[] = {NULL}; # endif char **args = form_args(8, CC_LDSHARED_ARGS, CC_CODEFLAG_ARGS, cc_added_args, so_args, loader_args, CC_LIBS, CC_DLDFLAGS_ARGS, CC_LINKER_ARGS); if (args == NULL) return 1; int exit_code = exec_process(cc_path, args); if (!mjit_opts.save_temps) remove_file(c_file); free(args); return exit_code; } static void compile_prelude(FILE *f); // Compile all JIT code into a single .c file static bool mjit_compact(char* c_file) { FILE *f; int fd = rb_cloexec_open(c_file, c_file_access_mode, 0600); if (fd < 0 || (f = fdopen(fd, "w")) == NULL) { int e = errno; if (fd >= 0) (void)close(fd); verbose(1, "Failed to fopen '%s', giving up JIT for it (%s)", c_file, strerror(e)); return false; } compile_prelude(f); // This entire loop lock GC so that we do not need to consider a case that // ISeq is GC-ed in a middle of re-compilation. It takes 3~4ms with 100 methods // on my machine. It's not too bad compared to compilation time of C (7200~8000ms), // but it might be larger if we use a larger --jit-max-cache. // // TODO: Consider using a more granular lock after we implement inlining across // compacted functions (not done yet). bool success = true; struct rb_mjit_unit *child_unit = 0; ccan_list_for_each(&active_units.head, child_unit, unode) { if (!success) continue; if (ISEQ_BODY(child_unit->iseq)->jit_unit == NULL) continue; // Sometimes such units are created. TODO: Investigate why char funcname[MAXPATHLEN]; sprint_funcname(funcname, child_unit); long iseq_lineno = 0; if (FIXNUM_P(ISEQ_BODY(child_unit->iseq)->location.first_lineno)) // FIX2INT may fallback to rb_num2long(), which is a method call and dangerous in MJIT worker. So using only FIX2LONG. iseq_lineno = FIX2LONG(ISEQ_BODY(child_unit->iseq)->location.first_lineno); const char *sep = "@"; const char *iseq_label = RSTRING_PTR(ISEQ_BODY(child_unit->iseq)->location.label); const char *iseq_path = RSTRING_PTR(rb_iseq_path(child_unit->iseq)); if (!iseq_label) iseq_label = sep = ""; fprintf(f, "\n/* %s%s%s:%ld */\n", iseq_label, sep, iseq_path, iseq_lineno); success &= mjit_compile(f, child_unit->iseq, funcname, child_unit->id); } fclose(f); return success; } // Compile all cached .c files and build a single .so file. Reload all JIT func from it. // This improves the code locality for better performance in terms of iTLB and iCache. static int mjit_compact_unit(struct rb_mjit_unit *unit) { static const char c_ext[] = ".c"; static const char so_ext[] = DLEXT; char c_file[MAXPATHLEN], so_file[MAXPATHLEN]; sprint_uniq_filename(c_file, (int)sizeof(c_file), unit->id, MJIT_TMP_PREFIX, c_ext); sprint_uniq_filename(so_file, (int)sizeof(so_file), unit->id, MJIT_TMP_PREFIX, so_ext); bool success = mjit_compact(c_file); if (success) { return compile_c_to_so(c_file, so_file); } return 1; } extern pid_t rb_mjit_fork(); static pid_t start_mjit_compact(struct rb_mjit_unit *unit) { pid_t pid = rb_mjit_fork(); if (pid == 0) { int exit_code = mjit_compact_unit(unit); exit(exit_code); } else { return pid; } } static void load_compact_funcs_from_so(struct rb_mjit_unit *unit, char *c_file, char *so_file) { struct rb_mjit_unit *cur = 0; double end_time = real_ms_time(); void *handle = dlopen(so_file, RTLD_NOW); if (handle == NULL) { mjit_warning("failure in loading code from compacted '%s': %s", so_file, dlerror()); free(unit); return; } unit->handle = handle; // lazily dlclose handle (and .so file for win32) on `mjit_finish()`. add_to_list(unit, &compact_units); if (!mjit_opts.save_temps) remove_so_file(so_file, unit); ccan_list_for_each(&active_units.head, cur, unode) { void *func; char funcname[MAXPATHLEN]; sprint_funcname(funcname, cur); if ((func = dlsym(handle, funcname)) == NULL) { mjit_warning("skipping to reload '%s' from '%s': %s", funcname, so_file, dlerror()); continue; } if (cur->iseq) { // Check whether GCed or not // Usage of jit_code might be not in a critical section. MJIT_ATOMIC_SET(ISEQ_BODY(cur->iseq)->jit_func, (mjit_func_t)func); } } verbose(1, "JIT compaction (%.1fms): Compacted %d methods %s -> %s", end_time - current_cc_ms, active_units.length, c_file, so_file); } static void * load_func_from_so(const char *so_file, const char *funcname, struct rb_mjit_unit *unit) { void *handle, *func; handle = dlopen(so_file, RTLD_NOW); if (handle == NULL) { mjit_warning("failure in loading code from '%s': %s", so_file, dlerror()); return (void *)NOT_COMPILED_JIT_ISEQ_FUNC; } func = dlsym(handle, funcname); unit->handle = handle; return func; } #ifndef __clang__ static const char * header_name_end(const char *s) { const char *e = s + strlen(s); # ifdef __GNUC__ // don't chomp .pch for mswin static const char suffix[] = ".gch"; // chomp .gch suffix if (e > s+sizeof(suffix)-1 && strcmp(e-sizeof(suffix)+1, suffix) == 0) { e -= sizeof(suffix)-1; } # endif return e; } #endif // Print platform-specific prerequisites in generated code. static void compile_prelude(FILE *f) { #ifndef __clang__ // -include-pch is used for Clang const char *s = pch_file; const char *e = header_name_end(s); fprintf(f, "#include \""); // print pch_file except .gch for gcc, but keep .pch for mswin for (; s < e; s++) { switch (*s) { case '\\': case '"': fputc('\\', f); } fputc(*s, f); } fprintf(f, "\"\n"); #endif } // Compile ISeq in UNIT and return function pointer of JIT-ed code. // It may return NOT_COMPILED_JIT_ISEQ_FUNC if something went wrong. static int mjit_compile_unit(struct rb_mjit_unit *unit) { static const char c_ext[] = ".c"; static const char so_ext[] = DLEXT; char c_file[MAXPATHLEN], so_file[MAXPATHLEN], funcname[MAXPATHLEN]; sprint_uniq_filename(c_file, (int)sizeof(c_file), unit->id, MJIT_TMP_PREFIX, c_ext); sprint_uniq_filename(so_file, (int)sizeof(so_file), unit->id, MJIT_TMP_PREFIX, so_ext); sprint_funcname(funcname, unit); FILE *f; int fd = rb_cloexec_open(c_file, c_file_access_mode, 0600); if (fd < 0 || (f = fdopen(fd, "w")) == NULL) { int e = errno; if (fd >= 0) (void)close(fd); verbose(1, "Failed to fopen '%s', giving up JIT for it (%s)", c_file, strerror(e)); return 1; } // print #include of MJIT header, etc. compile_prelude(f); // To make MJIT worker thread-safe against GC.compact, copy ISeq values while `in_jit` is true. long iseq_lineno = 0; if (FIXNUM_P(ISEQ_BODY(unit->iseq)->location.first_lineno)) // FIX2INT may fallback to rb_num2long(), which is a method call and dangerous in MJIT worker. So using only FIX2LONG. iseq_lineno = FIX2LONG(ISEQ_BODY(unit->iseq)->location.first_lineno); char *iseq_label = alloca(RSTRING_LEN(ISEQ_BODY(unit->iseq)->location.label) + 1); char *iseq_path = alloca(RSTRING_LEN(rb_iseq_path(unit->iseq)) + 1); strcpy(iseq_label, RSTRING_PTR(ISEQ_BODY(unit->iseq)->location.label)); strcpy(iseq_path, RSTRING_PTR(rb_iseq_path(unit->iseq))); verbose(2, "start compilation: %s@%s:%ld -> %s", iseq_label, iseq_path, iseq_lineno, c_file); fprintf(f, "/* %s@%s:%ld */\n\n", iseq_label, iseq_path, iseq_lineno); bool success = mjit_compile(f, unit->iseq, funcname, unit->id); fclose(f); if (!success) { if (!mjit_opts.save_temps) remove_file(c_file); verbose(1, "JIT failure: %s@%s:%ld -> %s", iseq_label, iseq_path, iseq_lineno, c_file); return 1; } return compile_c_to_so(c_file, so_file); } static pid_t start_mjit_compile(struct rb_mjit_unit *unit) { pid_t pid = rb_mjit_fork(); if (pid == 0) { int exit_code = mjit_compile_unit(unit); exit(exit_code); } else { return pid; } } // Capture cc entries of `captured_iseq` and append them to `compiled_iseq->jit_unit->cc_entries`. // This is needed when `captured_iseq` is inlined by `compiled_iseq` and GC needs to mark inlined cc. // // Index to refer to `compiled_iseq->jit_unit->cc_entries` is returned instead of the address // because old addresses may be invalidated by `realloc` later. -1 is returned on failure. // // This assumes that it's safe to reference cc without acquiring GVL. int mjit_capture_cc_entries(const struct rb_iseq_constant_body *compiled_iseq, const struct rb_iseq_constant_body *captured_iseq) { VM_ASSERT(compiled_iseq != NULL); VM_ASSERT(compiled_iseq->jit_unit != NULL); VM_ASSERT(captured_iseq != NULL); struct rb_mjit_unit *unit = compiled_iseq->jit_unit; unsigned int new_entries_size = unit->cc_entries_size + captured_iseq->ci_size; VM_ASSERT(captured_iseq->ci_size > 0); // Allocate new cc_entries and append them to unit->cc_entries const struct rb_callcache **cc_entries; int cc_entries_index = unit->cc_entries_size; if (unit->cc_entries_size == 0) { VM_ASSERT(unit->cc_entries == NULL); unit->cc_entries = cc_entries = malloc(sizeof(struct rb_callcache *) * new_entries_size); if (cc_entries == NULL) return -1; } else { void *cc_ptr = (void *)unit->cc_entries; // get rid of bogus warning by VC cc_entries = realloc(cc_ptr, sizeof(struct rb_callcache *) * new_entries_size); if (cc_entries == NULL) return -1; unit->cc_entries = cc_entries; cc_entries += cc_entries_index; } unit->cc_entries_size = new_entries_size; // Capture cc to cc_enties for (unsigned int i = 0; i < captured_iseq->ci_size; i++) { cc_entries[i] = captured_iseq->call_data[i].cc; } return cc_entries_index; } // Set up field `used_code_p` for unit iseqs whose iseq on the stack of ec. static void mark_ec_units(rb_execution_context_t *ec) { const rb_control_frame_t *cfp; if (ec->vm_stack == NULL) return; for (cfp = RUBY_VM_END_CONTROL_FRAME(ec) - 1; ; cfp = RUBY_VM_NEXT_CONTROL_FRAME(cfp)) { const rb_iseq_t *iseq; if (cfp->pc && (iseq = cfp->iseq) != NULL && imemo_type((VALUE) iseq) == imemo_iseq && (ISEQ_BODY(iseq)->jit_unit) != NULL) { ISEQ_BODY(iseq)->jit_unit->used_code_p = true; } if (cfp == ec->cfp) break; // reached the most recent cfp } } // MJIT info related to an existing continutaion. struct mjit_cont { rb_execution_context_t *ec; // continuation ec struct mjit_cont *prev, *next; // used to form lists }; // Double linked list of registered continuations. This is used to detect // units which are in use in unload_units. static struct mjit_cont *first_cont; // Unload JIT code of some units to satisfy the maximum permitted // number of units with a loaded code. static void unload_units(void) { struct rb_mjit_unit *unit = 0, *next; struct mjit_cont *cont; int units_num = active_units.length; // For now, we don't unload units when ISeq is GCed. We should // unload such ISeqs first here. ccan_list_for_each_safe(&active_units.head, unit, next, unode) { if (unit->iseq == NULL) { // ISeq is GCed. remove_from_list(unit, &active_units); free_unit(unit); } } // Detect units which are in use and can't be unloaded. ccan_list_for_each(&active_units.head, unit, unode) { VM_ASSERT(unit->iseq != NULL && unit->handle != NULL); unit->used_code_p = false; } // All threads have a root_fiber which has a mjit_cont. Other normal fibers also // have a mjit_cont. Thus we can check ISeqs in use by scanning ec of mjit_conts. for (cont = first_cont; cont != NULL; cont = cont->next) { mark_ec_units(cont->ec); } // TODO: check stale_units and unload unused ones! (note that the unit is not associated to ISeq anymore) // Unload units whose total_calls is smaller than any total_calls in unit_queue. // TODO: make the algorithm more efficient long unsigned prev_queue_calls = -1; while (true) { // Calculate the next max total_calls in unit_queue long unsigned max_queue_calls = 0; ccan_list_for_each(&unit_queue.head, unit, unode) { if (unit->iseq != NULL && max_queue_calls < ISEQ_BODY(unit->iseq)->total_calls && ISEQ_BODY(unit->iseq)->total_calls < prev_queue_calls) { max_queue_calls = ISEQ_BODY(unit->iseq)->total_calls; } } prev_queue_calls = max_queue_calls; bool unloaded_p = false; ccan_list_for_each_safe(&active_units.head, unit, next, unode) { if (unit->used_code_p) // We can't unload code on stack. continue; if (max_queue_calls > ISEQ_BODY(unit->iseq)->total_calls) { verbose(2, "Unloading unit %d (calls=%lu, threshold=%lu)", unit->id, ISEQ_BODY(unit->iseq)->total_calls, max_queue_calls); VM_ASSERT(unit->handle != NULL); remove_from_list(unit, &active_units); free_unit(unit); unloaded_p = true; } } if (!unloaded_p) break; } if (units_num > active_units.length) { verbose(1, "Too many JIT code -- %d units unloaded", units_num - active_units.length); total_unloads += units_num - active_units.length; } } static void mjit_add_iseq_to_process(const rb_iseq_t *iseq, const struct rb_mjit_compile_info *compile_info, bool worker_p); // Return an unique file name in /tmp with PREFIX and SUFFIX and // number ID. Use getpid if ID == 0. The return file name exists // until the next function call. static char * get_uniq_filename(unsigned long id, const char *prefix, const char *suffix) { char buff[70], *str = buff; int size = sprint_uniq_filename(buff, sizeof(buff), id, prefix, suffix); str = 0; ++size; str = xmalloc(size); if (size <= (int)sizeof(buff)) { memcpy(str, buff, size); } else { sprint_uniq_filename(str, size, id, prefix, suffix); } return str; } // Prohibit calling JIT-ed code and let existing JIT-ed frames exit before the next insn. void mjit_cancel_all(const char *reason) { if (!mjit_enabled) return; mjit_call_p = false; if (mjit_opts.warnings || mjit_opts.verbose) { fprintf(stderr, "JIT cancel: Disabled JIT-ed code because %s\n", reason); } } // Deal with ISeq movement from compactor void mjit_update_references(const rb_iseq_t *iseq) { if (!mjit_enabled) return; CRITICAL_SECTION_START(4, "mjit_update_references"); if (ISEQ_BODY(iseq)->jit_unit) { ISEQ_BODY(iseq)->jit_unit->iseq = (rb_iseq_t *)rb_gc_location((VALUE)ISEQ_BODY(iseq)->jit_unit->iseq); // We need to invalidate JIT-ed code for the ISeq because it embeds pointer addresses. // To efficiently do that, we use the same thing as TracePoint and thus everything is cancelled for now. // See mjit.h and tool/ruby_vm/views/_mjit_compile_insn.erb for how `mjit_call_p` is used. mjit_cancel_all("GC.compact is used"); // TODO: instead of cancelling all, invalidate only this one and recompile it with some threshold. } // Units in stale_units (list of over-speculated and invalidated code) are not referenced from // `ISEQ_BODY(iseq)->jit_unit` anymore (because new one replaces that). So we need to check them too. // TODO: we should be able to reduce the number of units checked here. struct rb_mjit_unit *unit = NULL; ccan_list_for_each(&stale_units.head, unit, unode) { if (unit->iseq == iseq) { unit->iseq = (rb_iseq_t *)rb_gc_location((VALUE)unit->iseq); } } CRITICAL_SECTION_FINISH(4, "mjit_update_references"); } // Iseqs can be garbage collected. This function should call when it // happens. It removes iseq from the unit. void mjit_free_iseq(const rb_iseq_t *iseq) { if (!mjit_enabled) return; if (ISEQ_BODY(iseq)->jit_unit) { // jit_unit is not freed here because it may be referred by multiple // lists of units. `get_from_list` and `mjit_finish` do the job. ISEQ_BODY(iseq)->jit_unit->iseq = NULL; } // Units in stale_units (list of over-speculated and invalidated code) are not referenced from // `ISEQ_BODY(iseq)->jit_unit` anymore (because new one replaces that). So we need to check them too. // TODO: we should be able to reduce the number of units checked here. struct rb_mjit_unit *unit = NULL; ccan_list_for_each(&stale_units.head, unit, unode) { if (unit->iseq == iseq) { unit->iseq = NULL; } } } // Free unit list. This should be called only when worker is finished // because node of unit_queue and one of active_units may have the same unit // during proceeding unit. static void free_list(struct rb_mjit_unit_list *list, bool close_handle_p) { struct rb_mjit_unit *unit = 0, *next; ccan_list_for_each_safe(&list->head, unit, next, unode) { ccan_list_del(&unit->unode); if (!close_handle_p) unit->handle = NULL; /* Skip dlclose in free_unit() */ if (list == &stale_units) { // `free_unit(unit)` crashes after GC.compact on `stale_units` /* * TODO: REVERT THIS BRANCH * Debug the crash on stale_units w/ GC.compact and just use `free_unit(unit)`!! */ if (unit->handle && dlclose(unit->handle)) { mjit_warning("failed to close handle for u%d: %s", unit->id, dlerror()); } free(unit); } else { free_unit(unit); } } list->length = 0; } // Register a new continuation with execution context `ec`. Return MJIT info about // the continuation. struct mjit_cont * mjit_cont_new(rb_execution_context_t *ec) { struct mjit_cont *cont; // We need to use calloc instead of something like ZALLOC to avoid triggering GC here. // When this function is called from rb_thread_alloc through rb_threadptr_root_fiber_setup, // the thread is still being prepared and marking it causes SEGV. cont = calloc(1, sizeof(struct mjit_cont)); if (cont == NULL) rb_memerror(); cont->ec = ec; CRITICAL_SECTION_START(3, "in mjit_cont_new"); if (first_cont == NULL) { cont->next = cont->prev = NULL; } else { cont->prev = NULL; cont->next = first_cont; first_cont->prev = cont; } first_cont = cont; CRITICAL_SECTION_FINISH(3, "in mjit_cont_new"); return cont; } // Unregister continuation `cont`. void mjit_cont_free(struct mjit_cont *cont) { CRITICAL_SECTION_START(3, "in mjit_cont_new"); if (cont == first_cont) { first_cont = cont->next; if (first_cont != NULL) first_cont->prev = NULL; } else { cont->prev->next = cont->next; if (cont->next != NULL) cont->next->prev = cont->prev; } CRITICAL_SECTION_FINISH(3, "in mjit_cont_new"); free(cont); } // Finish work with continuation info. static void finish_conts(void) { struct mjit_cont *cont, *next; for (cont = first_cont; cont != NULL; cont = next) { next = cont->next; xfree(cont); } } static void mjit_wait(struct rb_iseq_constant_body *body); // Check the unit queue and start mjit_compile if nothing is in progress. static void check_unit_queue(void) { if (worker_stopped) return; if (current_cc_pid != 0) return; // still compiling // Run unload_units after it's requested `max_cache_size / 10` (default: 10) times. // This throttles the call to mitigate locking in unload_units. It also throttles JIT compaction. int throttle_threshold = mjit_opts.max_cache_size / 10; if (unload_requests >= throttle_threshold) { unload_units(); unload_requests = 0; if (active_units.length == mjit_opts.max_cache_size && mjit_opts.wait) { // Sometimes all methods may be in use mjit_opts.max_cache_size++; // avoid infinite loop on `rb_mjit_wait_call`. Note that --jit-wait is just for testing. verbose(1, "No units can be unloaded -- incremented max-cache-size to %d for --jit-wait", mjit_opts.max_cache_size); } } if (active_units.length >= mjit_opts.max_cache_size) return; // wait until unload_units makes a progress // Dequeue a unit struct rb_mjit_unit *unit = get_from_list(&unit_queue); if (unit == NULL) return; current_cc_ms = real_ms_time(); current_cc_unit = unit; current_cc_pid = start_mjit_compile(unit); // JIT failure if (current_cc_pid == -1) { current_cc_pid = 0; current_cc_unit->iseq->body->jit_func = (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC; // TODO: consider unit->compact_p current_cc_unit = NULL; return; } if (mjit_opts.wait) { mjit_wait(unit->iseq->body); } } // Create unit for `iseq`. This function may be called from an MJIT worker. static struct rb_mjit_unit* create_unit(const rb_iseq_t *iseq) { // To prevent GC, don't use ZALLOC // TODO: just use ZALLOC struct rb_mjit_unit *unit = calloc(1, sizeof(struct rb_mjit_unit)); if (unit == NULL) return NULL; unit->id = current_unit_num++; if (iseq == NULL) { // Compact unit unit->compact_p = true; } else { // Normal unit unit->iseq = (rb_iseq_t *)iseq; ISEQ_BODY(iseq)->jit_unit = unit; } return unit; } // Check if it should compact all JIT code and start it as needed static void check_compaction(void) { // Allow only `max_cache_size / 100` times (default: 100) of compaction. // Note: GC of compacted code has not been implemented yet. int max_compact_size = mjit_opts.max_cache_size / 100; if (max_compact_size < 10) max_compact_size = 10; // Run unload_units after it's requested `max_cache_size / 10` (default: 10) times. // This throttles the call to mitigate locking in unload_units. It also throttles JIT compaction. int throttle_threshold = mjit_opts.max_cache_size / 10; if (compact_units.length < max_compact_size && ((!mjit_opts.wait && unit_queue.length == 0 && active_units.length > 1) || (active_units.length == mjit_opts.max_cache_size && compact_units.length * throttle_threshold <= total_unloads))) { // throttle compaction by total_unloads struct rb_mjit_unit *unit = create_unit(NULL); if (unit != NULL) { // TODO: assert unit is null current_cc_ms = real_ms_time(); current_cc_unit = unit; current_cc_pid = start_mjit_compact(unit); // TODO: check -1 } } } // Check the current CC process if any, and start a next C compiler process as needed. void mjit_notify_waitpid(int status) { // TODO: check current_cc_pid? current_cc_pid = 0; // Delete .c file char c_file[MAXPATHLEN]; sprint_uniq_filename(c_file, (int)sizeof(c_file), current_cc_unit->id, MJIT_TMP_PREFIX, ".c"); // Check the result bool success = false; if (WIFEXITED(status)) { success = (WEXITSTATUS(status) == 0); } if (!success) { verbose(2, "Failed to generate so"); if (!current_cc_unit->compact_p) { current_cc_unit->iseq->body->jit_func = (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC; } free_unit(current_cc_unit); current_cc_unit = NULL; return; } // Load .so file char so_file[MAXPATHLEN]; sprint_uniq_filename(so_file, (int)sizeof(so_file), current_cc_unit->id, MJIT_TMP_PREFIX, DLEXT); if (current_cc_unit->compact_p) { // Compact unit load_compact_funcs_from_so(current_cc_unit, c_file, so_file); current_cc_unit = NULL; } else { // Normal unit // Load the function from so char funcname[MAXPATHLEN]; sprint_funcname(funcname, current_cc_unit); void *func = load_func_from_so(so_file, funcname, current_cc_unit); // Delete .so file if (!mjit_opts.save_temps) remove_file(so_file); // Set the jit_func if successful if (current_cc_unit->iseq != NULL) { // mjit_free_iseq could nullify this rb_iseq_t *iseq = current_cc_unit->iseq; if ((uintptr_t)func > (uintptr_t)LAST_JIT_ISEQ_FUNC) { double end_time = real_ms_time(); verbose(1, "JIT success (%.1fms): %s@%s:%ld -> %s", end_time - current_cc_ms, RSTRING_PTR(ISEQ_BODY(iseq)->location.label), RSTRING_PTR(rb_iseq_path(iseq)), FIX2LONG(ISEQ_BODY(iseq)->location.first_lineno), c_file); add_to_list(current_cc_unit, &active_units); } MJIT_ATOMIC_SET(ISEQ_BODY(iseq)->jit_func, func); } // TODO: free unit on else? current_cc_unit = NULL; // Run compaction if it should if (!stop_worker_p) { check_compaction(); } } // Skip further compilation if mjit_finish is trying to stop it if (!stop_worker_p) { // Start the next one as needed check_unit_queue(); } } // Return true if given ISeq body should be compiled by MJIT static inline int mjit_target_iseq_p(const rb_iseq_t *iseq) { struct rb_iseq_constant_body *body = ISEQ_BODY(iseq); return (body->type == ISEQ_TYPE_METHOD || body->type == ISEQ_TYPE_BLOCK) && !body->builtin_inline_p && strcmp("", RSTRING_PTR(rb_iseq_path(iseq))); } // If recompile_p is true, the call is initiated by mjit_recompile. // This assumes the caller holds CRITICAL_SECTION when recompile_p is true. static void mjit_add_iseq_to_process(const rb_iseq_t *iseq, const struct rb_mjit_compile_info *compile_info, bool recompile_p) { // TODO: Support non-main Ractors if (!mjit_enabled || pch_status == PCH_FAILED || !rb_ractor_main_p()) return; if (!mjit_target_iseq_p(iseq)) { ISEQ_BODY(iseq)->jit_func = (mjit_func_t)NOT_COMPILED_JIT_ISEQ_FUNC; // skip mjit_wait return; } RB_DEBUG_COUNTER_INC(mjit_add_iseq_to_process); ISEQ_BODY(iseq)->jit_func = (mjit_func_t)NOT_READY_JIT_ISEQ_FUNC; create_unit(iseq); if (ISEQ_BODY(iseq)->jit_unit == NULL) // Failure in creating the unit. return; if (compile_info != NULL) ISEQ_BODY(iseq)->jit_unit->compile_info = *compile_info; add_to_list(ISEQ_BODY(iseq)->jit_unit, &unit_queue); if (active_units.length >= mjit_opts.max_cache_size) { unload_requests++; } } // Add ISEQ to be JITed in parallel with the current thread. // Unload some JIT codes if there are too many of them. void rb_mjit_add_iseq_to_process(const rb_iseq_t *iseq) { mjit_add_iseq_to_process(iseq, NULL, false); check_unit_queue(); } // For this timeout seconds, --jit-wait will wait for JIT compilation finish. #define MJIT_WAIT_TIMEOUT_SECONDS 60 static void mjit_wait(struct rb_iseq_constant_body *body) { pid_t initial_pid = current_cc_pid; struct timeval tv; int tries = 0; tv.tv_sec = 0; tv.tv_usec = 1000; while (body == NULL ? current_cc_pid == initial_pid : body->jit_func == (mjit_func_t)NOT_READY_JIT_ISEQ_FUNC) { // TODO: refactor this tries++; if (tries / 1000 > MJIT_WAIT_TIMEOUT_SECONDS || pch_status == PCH_FAILED) { if (body != NULL) { body->jit_func = (mjit_func_t) NOT_COMPILED_JIT_ISEQ_FUNC; // JIT worker seems dead. Give up. } mjit_warning("timed out to wait for JIT finish"); break; } rb_thread_wait_for(tv); } } static void mjit_wait_unit(struct rb_mjit_unit *unit) { if (unit->compact_p) { mjit_wait(NULL); } else { mjit_wait(current_cc_unit->iseq->body); } } // Wait for JIT compilation finish for --jit-wait, and call the function pointer // if the compiled result is not NOT_COMPILED_JIT_ISEQ_FUNC. VALUE rb_mjit_wait_call(rb_execution_context_t *ec, struct rb_iseq_constant_body *body) { if (worker_stopped) return Qundef; mjit_wait(body); if ((uintptr_t)body->jit_func <= (uintptr_t)LAST_JIT_ISEQ_FUNC) { return Qundef; } return body->jit_func(ec, ec->cfp); } struct rb_mjit_compile_info* rb_mjit_iseq_compile_info(const struct rb_iseq_constant_body *body) { VM_ASSERT(body->jit_unit != NULL); return &body->jit_unit->compile_info; } static void mjit_recompile(const rb_iseq_t *iseq) { if ((uintptr_t)ISEQ_BODY(iseq)->jit_func <= (uintptr_t)LAST_JIT_ISEQ_FUNC) return; verbose(1, "JIT recompile: %s@%s:%d", RSTRING_PTR(ISEQ_BODY(iseq)->location.label), RSTRING_PTR(rb_iseq_path(iseq)), FIX2INT(ISEQ_BODY(iseq)->location.first_lineno)); VM_ASSERT(ISEQ_BODY(iseq)->jit_unit != NULL); mjit_add_iseq_to_process(iseq, &ISEQ_BODY(iseq)->jit_unit->compile_info, true); check_unit_queue(); } // Recompile iseq, disabling send optimization void rb_mjit_recompile_send(const rb_iseq_t *iseq) { rb_mjit_iseq_compile_info(ISEQ_BODY(iseq))->disable_send_cache = true; mjit_recompile(iseq); } // Recompile iseq, disabling ivar optimization void rb_mjit_recompile_ivar(const rb_iseq_t *iseq) { rb_mjit_iseq_compile_info(ISEQ_BODY(iseq))->disable_ivar_cache = true; mjit_recompile(iseq); } // Recompile iseq, disabling exivar optimization void rb_mjit_recompile_exivar(const rb_iseq_t *iseq) { rb_mjit_iseq_compile_info(ISEQ_BODY(iseq))->disable_exivar_cache = true; mjit_recompile(iseq); } // Recompile iseq, disabling method inlining void rb_mjit_recompile_inlining(const rb_iseq_t *iseq) { rb_mjit_iseq_compile_info(ISEQ_BODY(iseq))->disable_inlining = true; mjit_recompile(iseq); } // Recompile iseq, disabling getconstant inlining void rb_mjit_recompile_const(const rb_iseq_t *iseq) { rb_mjit_iseq_compile_info(ISEQ_BODY(iseq))->disable_const_cache = true; mjit_recompile(iseq); } extern VALUE ruby_archlibdir_path, ruby_prefix_path; // Initialize header_file, pch_file, libruby_pathflag. Return true on success. static bool init_header_filename(void) { int fd; #ifdef LOAD_RELATIVE // Root path of the running ruby process. Equal to RbConfig::TOPDIR. VALUE basedir_val; #endif const char *basedir = ""; size_t baselen = 0; char *p; #ifdef LOAD_RELATIVE basedir_val = ruby_prefix_path; basedir = StringValuePtr(basedir_val); baselen = RSTRING_LEN(basedir_val); #else if (getenv("MJIT_SEARCH_BUILD_DIR")) { // This path is not intended to be used on production, but using build directory's // header file here because people want to run `make test-all` without running // `make install`. Don't use $MJIT_SEARCH_BUILD_DIR except for test-all. struct stat st; const char *hdr = dlsym(RTLD_DEFAULT, "MJIT_HEADER"); if (!hdr) { verbose(1, "No MJIT_HEADER"); } else if (hdr[0] != '/') { verbose(1, "Non-absolute header file path: %s", hdr); } else if (stat(hdr, &st) || !S_ISREG(st.st_mode)) { verbose(1, "Non-file header file path: %s", hdr); } else if ((st.st_uid != getuid()) || (st.st_mode & 022) || !rb_path_check(hdr)) { verbose(1, "Unsafe header file: uid=%ld mode=%#o %s", (long)st.st_uid, (unsigned)st.st_mode, hdr); return FALSE; } else { // Do not pass PRELOADENV to child processes, on // multi-arch environment verbose(3, "PRELOADENV("PRELOADENV")=%s", getenv(PRELOADENV)); // assume no other PRELOADENV in test-all unsetenv(PRELOADENV); verbose(3, "MJIT_HEADER: %s", hdr); header_file = ruby_strdup(hdr); if (!header_file) return false; } } else #endif { // A name of the header file included in any C file generated by MJIT for iseqs. static const char header_name[] = MJIT_HEADER_INSTALL_DIR "/" MJIT_MIN_HEADER_NAME; const size_t header_name_len = sizeof(header_name) - 1; header_file = xmalloc(baselen + header_name_len + 1); p = append_str2(header_file, basedir, baselen); p = append_str2(p, header_name, header_name_len + 1); if ((fd = rb_cloexec_open(header_file, O_RDONLY, 0)) < 0) { verbose(1, "Cannot access header file: %s", header_file); xfree(header_file); header_file = NULL; return false; } (void)close(fd); } pch_file = get_uniq_filename(0, MJIT_TMP_PREFIX "h", ".h.gch"); return true; } static char * system_default_tmpdir(void) { // c.f. ext/etc/etc.c:etc_systmpdir() #if defined _CS_DARWIN_USER_TEMP_DIR char path[MAXPATHLEN]; size_t len = confstr(_CS_DARWIN_USER_TEMP_DIR, path, sizeof(path)); if (len > 0) { char *tmpdir = xmalloc(len); if (len > sizeof(path)) { confstr(_CS_DARWIN_USER_TEMP_DIR, tmpdir, len); } else { memcpy(tmpdir, path, len); } return tmpdir; } #endif return 0; } static int check_tmpdir(const char *dir) { struct stat st; if (!dir) return FALSE; if (stat(dir, &st)) return FALSE; #ifndef S_ISDIR # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR) #endif if (!S_ISDIR(st.st_mode)) return FALSE; #ifndef S_IWOTH # define S_IWOTH 002 #endif if (st.st_mode & S_IWOTH) { #ifdef S_ISVTX if (!(st.st_mode & S_ISVTX)) return FALSE; #else return FALSE; #endif } if (access(dir, W_OK)) return FALSE; return TRUE; } static char * system_tmpdir(void) { char *tmpdir; # define RETURN_ENV(name) \ if (check_tmpdir(tmpdir = getenv(name))) return ruby_strdup(tmpdir) RETURN_ENV("TMPDIR"); RETURN_ENV("TMP"); tmpdir = system_default_tmpdir(); if (check_tmpdir(tmpdir)) return tmpdir; return ruby_strdup("/tmp"); # undef RETURN_ENV } // Minimum value for JIT cache size. #define MIN_CACHE_SIZE 10 // Default permitted number of units with a JIT code kept in memory. #define DEFAULT_MAX_CACHE_SIZE 10000 // A default threshold used to add iseq to JIT. #define DEFAULT_MIN_CALLS_TO_ADD 10000 // Start MJIT worker. Return TRUE if worker is successfully started. static bool start_worker(void) { stop_worker_p = false; worker_stopped = false; return true; } // There's no strndup on Windows static char* ruby_strndup(const char *str, size_t n) { char *ret = xmalloc(n + 1); memcpy(ret, str, n); ret[n] = '\0'; return ret; } // Convert "foo bar" to {"foo", "bar", NULL} array. Caller is responsible for // freeing a returned buffer and its elements. static char ** split_flags(const char *flags) { char *buf[MAXPATHLEN]; int i = 0; char *next; for (; flags != NULL; flags = next) { next = strchr(flags, ' '); if (next == NULL) { if (strlen(flags) > 0) buf[i++] = strdup(flags); } else { if (next > flags) buf[i++] = ruby_strndup(flags, next - flags); next++; // skip space } } char **ret = xmalloc(sizeof(char *) * (i + 1)); memcpy(ret, buf, sizeof(char *) * i); ret[i] = NULL; return ret; } #define opt_match_noarg(s, l, name) \ opt_match(s, l, name) && (*(s) ? (rb_warn("argument to --mjit-" name " is ignored"), 1) : 1) #define opt_match_arg(s, l, name) \ opt_match(s, l, name) && (*(s) ? 1 : (rb_raise(rb_eRuntimeError, "--mjit-" name " needs an argument"), 0)) void mjit_setup_options(const char *s, struct mjit_options *mjit_opt) { const size_t l = strlen(s); if (l == 0) { return; } else if (opt_match_noarg(s, l, "warnings")) { mjit_opt->warnings = true; } else if (opt_match(s, l, "debug")) { if (*s) mjit_opt->debug_flags = strdup(s + 1); else mjit_opt->debug = true; } else if (opt_match_noarg(s, l, "wait")) { mjit_opt->wait = true; } else if (opt_match_noarg(s, l, "save-temps")) { mjit_opt->save_temps = true; } else if (opt_match(s, l, "verbose")) { mjit_opt->verbose = *s ? atoi(s + 1) : 1; } else if (opt_match_arg(s, l, "max-cache")) { mjit_opt->max_cache_size = atoi(s + 1); } else if (opt_match_arg(s, l, "min-calls")) { mjit_opt->min_calls = atoi(s + 1); } else { rb_raise(rb_eRuntimeError, "invalid MJIT option `%s' (--help will show valid MJIT options)", s); } } #define M(shortopt, longopt, desc) RUBY_OPT_MESSAGE(shortopt, longopt, desc) const struct ruby_opt_message mjit_option_messages[] = { M("--mjit-warnings", "", "Enable printing JIT warnings"), M("--mjit-debug", "", "Enable JIT debugging (very slow), or add cflags if specified"), M("--mjit-wait", "", "Wait until JIT compilation finishes every time (for testing)"), M("--mjit-save-temps", "", "Save JIT temporary files in $TMP or /tmp (for testing)"), M("--mjit-verbose=num", "", "Print JIT logs of level num or less to stderr (default: 0)"), M("--mjit-max-cache=num", "", "Max number of methods to be JIT-ed in a cache (default: " STRINGIZE(DEFAULT_MAX_CACHE_SIZE) ")"), M("--mjit-min-calls=num", "", "Number of calls to trigger JIT (for testing, default: " STRINGIZE(DEFAULT_MIN_CALLS_TO_ADD) ")"), {0} }; #undef M // Initialize MJIT. Start a thread creating the precompiled header and // processing ISeqs. The function should be called first for using MJIT. // If everything is successful, MJIT_INIT_P will be TRUE. void mjit_init(const struct mjit_options *opts) { mjit_opts = *opts; mjit_enabled = true; mjit_call_p = true; mjit_pid = getpid(); // Normalize options if (mjit_opts.min_calls == 0) mjit_opts.min_calls = DEFAULT_MIN_CALLS_TO_ADD; if (mjit_opts.max_cache_size <= 0) mjit_opts.max_cache_size = DEFAULT_MAX_CACHE_SIZE; if (mjit_opts.max_cache_size < MIN_CACHE_SIZE) mjit_opts.max_cache_size = MIN_CACHE_SIZE; // Initialize variables for compilation pch_status = PCH_NOT_READY; cc_path = CC_COMMON_ARGS[0]; verbose(2, "MJIT: CC defaults to %s", cc_path); cc_common_args = xmalloc(sizeof(CC_COMMON_ARGS)); memcpy((void *)cc_common_args, CC_COMMON_ARGS, sizeof(CC_COMMON_ARGS)); cc_added_args = split_flags(opts->debug_flags); xfree(opts->debug_flags); #if MJIT_CFLAGS_PIPE // eliminate a flag incompatible with `-pipe` for (size_t i = 0, j = 0; i < sizeof(CC_COMMON_ARGS) / sizeof(char *); i++) { if (CC_COMMON_ARGS[i] && strncmp("-save-temps", CC_COMMON_ARGS[i], strlen("-save-temps")) == 0) continue; // skip -save-temps flag cc_common_args[j] = CC_COMMON_ARGS[i]; j++; } #endif tmp_dir = system_tmpdir(); verbose(2, "MJIT: tmp_dir is %s", tmp_dir); if (!init_header_filename()) { mjit_enabled = false; verbose(1, "Failure in MJIT header file name initialization\n"); return; } pch_owner_pid = getpid(); // Initialize mutex rb_native_mutex_initialize(&mjit_engine_mutex); rb_native_cond_initialize(&mjit_pch_wakeup); rb_native_cond_initialize(&mjit_client_wakeup); rb_native_cond_initialize(&mjit_worker_wakeup); rb_native_cond_initialize(&mjit_gc_wakeup); // Make sure the saved_ec of the initial thread's root_fiber is scanned by mark_ec_units. // // rb_threadptr_root_fiber_setup for the initial thread is called before mjit_init, // meaning mjit_cont_new is skipped for the root_fiber. Therefore we need to call // rb_fiber_init_mjit_cont again with mjit_enabled=true to set the root_fiber's mjit_cont. rb_fiber_init_mjit_cont(GET_EC()->fiber_ptr); // Initialize worker thread start_worker(); // TODO: Consider running C compiler asynchronously make_pch(); } static void stop_worker(void) { stop_worker_p = true; if (current_cc_unit != NULL) { mjit_wait_unit(current_cc_unit); } worker_stopped = true; } // Stop JIT-compiling methods but compiled code is kept available. VALUE mjit_pause(bool wait_p) { if (!mjit_enabled) { rb_raise(rb_eRuntimeError, "MJIT is not enabled"); } if (worker_stopped) { return Qfalse; } // Flush all queued units with no option or `wait: true` if (wait_p) { while (current_cc_unit != NULL) { mjit_wait_unit(current_cc_unit); } } stop_worker(); return Qtrue; } // Restart JIT-compiling methods after mjit_pause. VALUE mjit_resume(void) { if (!mjit_enabled) { rb_raise(rb_eRuntimeError, "MJIT is not enabled"); } if (!worker_stopped) { return Qfalse; } if (!start_worker()) { rb_raise(rb_eRuntimeError, "Failed to resume MJIT worker"); } return Qtrue; } // This is called after fork initiated by Ruby's method to launch MJIT worker thread // for child Ruby process. // // In multi-process Ruby applications, child Ruby processes do most of the jobs. // Thus we want child Ruby processes to enqueue ISeqs to MJIT worker's queue and // call the JIT-ed code. // // But unfortunately current MJIT-generated code is process-specific. After the fork, // JIT-ed code created by parent Ruby process cannot be used in child Ruby process // because the code could rely on inline cache values (ivar's IC, send's CC) which // may vary between processes after fork or embed some process-specific addresses. // // So child Ruby process can't request parent process to JIT an ISeq and use the code. // Instead of that, MJIT worker thread is created for all child Ruby processes, even // while child processes would end up with compiling the same ISeqs. void mjit_child_after_fork(void) { if (!mjit_enabled) return; /* MJIT worker thread is not inherited on fork. Start it for this child process. */ start_worker(); } // Edit 0 to 1 to enable this feature for investigating hot methods #define MJIT_COUNTER 0 #if MJIT_COUNTER static void mjit_dump_total_calls(void) { struct rb_mjit_unit *unit; fprintf(stderr, "[MJIT_COUNTER] total_calls of active_units:\n"); ccan_list_for_each(&active_units.head, unit, unode) { const rb_iseq_t *iseq = unit->iseq; fprintf(stderr, "%8ld: %s@%s:%d\n", ISEQ_BODY(iseq)->total_calls, RSTRING_PTR(ISEQ_BODY(iseq)->location.label), RSTRING_PTR(rb_iseq_path(iseq)), FIX2INT(ISEQ_BODY(iseq)->location.first_lineno)); } } #endif // Finish the threads processing units and creating PCH, finalize // and free MJIT data. It should be called last during MJIT // life. // // If close_handle_p is true, it calls dlclose() for JIT-ed code. So it should be false // if the code can still be on stack. ...But it means to leak JIT-ed handle forever (FIXME). void mjit_finish(bool close_handle_p) { if (!mjit_enabled) return; // Stop worker verbose(2, "Stopping worker thread"); stop_worker(); rb_native_mutex_destroy(&mjit_engine_mutex); rb_native_cond_destroy(&mjit_pch_wakeup); rb_native_cond_destroy(&mjit_client_wakeup); rb_native_cond_destroy(&mjit_worker_wakeup); rb_native_cond_destroy(&mjit_gc_wakeup); #if MJIT_COUNTER mjit_dump_total_calls(); #endif if (!mjit_opts.save_temps && getpid() == pch_owner_pid) remove_file(pch_file); xfree(header_file); header_file = NULL; xfree((void *)cc_common_args); cc_common_args = NULL; for (char **flag = cc_added_args; *flag != NULL; flag++) xfree(*flag); xfree((void *)cc_added_args); cc_added_args = NULL; xfree(tmp_dir); tmp_dir = NULL; xfree(pch_file); pch_file = NULL; mjit_call_p = false; free_list(&unit_queue, close_handle_p); free_list(&active_units, close_handle_p); free_list(&compact_units, close_handle_p); free_list(&stale_units, close_handle_p); finish_conts(); mjit_enabled = false; verbose(1, "Successful MJIT finish"); } // Called by rb_vm_mark(). // // Mark active_units so that we do not GC ISeq which may still be // referenced by mjit_recompile() or mjit_compact(). void mjit_mark(void) { if (!mjit_enabled) return; RUBY_MARK_ENTER("mjit"); struct rb_mjit_unit *unit = NULL; ccan_list_for_each(&active_units.head, unit, unode) { rb_gc_mark((VALUE)unit->iseq); } RUBY_MARK_LEAVE("mjit"); } // Called by rb_iseq_mark() to mark cc_entries captured for MJIT void mjit_mark_cc_entries(const struct rb_iseq_constant_body *const body) { const struct rb_callcache **cc_entries; if (body->jit_unit && (cc_entries = body->jit_unit->cc_entries) != NULL) { // It must be `body->jit_unit->cc_entries_size` instead of `body->ci_size` to mark children's cc_entries for (unsigned int i = 0; i < body->jit_unit->cc_entries_size; i++) { const struct rb_callcache *cc = cc_entries[i]; if (cc != NULL && vm_cc_markable(cc)) { // Pin `cc` and `cc->cme` against GC.compact as their addresses may be written in JIT-ed code. rb_gc_mark((VALUE)cc); rb_gc_mark((VALUE)vm_cc_cme(cc)); } } } } #include "mjit.rbinc" #endif // USE_MJIT