2 * mini-posix.c: POSIX signal handling support for Mono.
5 * Mono Team (mono-list@lists.ximian.com)
7 * Copyright 2001-2003 Ximian, Inc.
8 * Copyright 2003-2008 Ximian, Inc.
9 * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
11 * See LICENSE for licensing information.
12 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
23 #ifdef HAVE_SYS_TIME_H
26 #ifdef HAVE_SYS_SYSCALL_H
27 #include <sys/syscall.h>
32 #include <mono/metadata/assembly.h>
33 #include <mono/metadata/loader.h>
34 #include <mono/metadata/tabledefs.h>
35 #include <mono/metadata/class.h>
36 #include <mono/metadata/object.h>
37 #include <mono/metadata/tokentype.h>
38 #include <mono/metadata/tabledefs.h>
39 #include <mono/metadata/threads.h>
40 #include <mono/metadata/appdomain.h>
41 #include <mono/metadata/debug-helpers.h>
42 #include <mono/io-layer/io-layer.h>
43 #include "mono/metadata/profiler.h"
44 #include <mono/metadata/profiler-private.h>
45 #include <mono/metadata/mono-config.h>
46 #include <mono/metadata/environment.h>
47 #include <mono/metadata/mono-debug.h>
48 #include <mono/metadata/gc-internals.h>
49 #include <mono/metadata/threads-types.h>
50 #include <mono/metadata/verify.h>
51 #include <mono/metadata/verify-internals.h>
52 #include <mono/metadata/mempool-internals.h>
53 #include <mono/metadata/attach.h>
54 #include <mono/utils/mono-math.h>
55 #include <mono/utils/mono-compiler.h>
56 #include <mono/utils/mono-counters.h>
57 #include <mono/utils/mono-logger-internals.h>
58 #include <mono/utils/mono-mmap.h>
59 #include <mono/utils/dtrace.h>
60 #include <mono/utils/mono-signal-handler.h>
61 #include <mono/utils/mono-threads.h>
62 #include <mono/utils/mono-threads-posix-signals.h>
69 #include "debugger-agent.h"
71 #include "jit-icalls.h"
73 #ifdef PLATFORM_MACOSX
74 #include <mach/mach.h>
75 #include <mach/mach_time.h>
76 #include <mach/clock.h>
79 #if defined(__native_client__) || defined(HOST_WATCHOS)
82 mono_runtime_setup_stat_profiler (void)
84 printf("WARNING: mono_runtime_setup_stat_profiler() called!\n");
89 mono_runtime_shutdown_stat_profiler (void)
95 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
100 #ifndef PLATFORM_MACOSX
102 mono_runtime_install_handlers (void)
108 mono_runtime_posix_install_handlers(void)
110 /* we still need to ignore SIGPIPE */
111 signal (SIGPIPE, SIG_IGN);
115 mono_runtime_shutdown_handlers (void)
120 mono_runtime_cleanup_handlers (void)
124 #if !defined(PLATFORM_MACOSX)
126 mono_runtime_syscall_fork (void)
128 g_assert_not_reached();
133 mono_gdb_render_native_backtraces (pid_t crashed_pid)
140 static GHashTable *mono_saved_signal_handlers = NULL;
142 static struct sigaction *
143 get_saved_signal_handler (int signo)
145 if (mono_saved_signal_handlers)
146 /* The hash is only modified during startup, so no need for locking */
147 return (struct sigaction *)g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
152 save_old_signal_handler (int signo, struct sigaction *old_action)
154 struct sigaction *handler_to_save = (struct sigaction *)g_malloc (sizeof (struct sigaction));
156 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
157 "Saving old signal handler for signal %d.", signo);
159 if (! (old_action->sa_flags & SA_SIGINFO)) {
160 handler_to_save->sa_handler = old_action->sa_handler;
162 #ifdef MONO_ARCH_USE_SIGACTION
163 handler_to_save->sa_sigaction = old_action->sa_sigaction;
164 #endif /* MONO_ARCH_USE_SIGACTION */
166 handler_to_save->sa_mask = old_action->sa_mask;
167 handler_to_save->sa_flags = old_action->sa_flags;
169 if (!mono_saved_signal_handlers)
170 mono_saved_signal_handlers = g_hash_table_new_full (NULL, NULL, NULL, g_free);
171 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
175 free_saved_signal_handlers (void)
177 if (mono_saved_signal_handlers) {
178 g_hash_table_destroy (mono_saved_signal_handlers);
179 mono_saved_signal_handlers = NULL;
186 * Call the original signal handler for the signal given by the arguments, which
187 * should be the same as for a signal handler. Returns TRUE if the original handler
188 * was called, false otherwise.
191 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
193 int signal = MONO_SIG_HANDLER_GET_SIGNO ();
194 struct sigaction *saved_handler = (struct sigaction *)get_saved_signal_handler (signal);
196 if (saved_handler && saved_handler->sa_handler) {
197 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
198 saved_handler->sa_handler (signal);
200 #ifdef MONO_ARCH_USE_SIGACTION
201 saved_handler->sa_sigaction (MONO_SIG_HANDLER_PARAMS);
202 #endif /* MONO_ARCH_USE_SIGACTION */
209 MONO_SIG_HANDLER_FUNC (static, sigabrt_signal_handler)
211 MonoJitInfo *ji = NULL;
212 MONO_SIG_HANDLER_INFO_TYPE *info = MONO_SIG_HANDLER_GET_INFO ();
213 MONO_SIG_HANDLER_GET_CONTEXT;
215 if (mono_thread_internal_current ())
216 ji = mono_jit_info_table_find_internal (mono_domain_get (), (char *)mono_arch_ip_from_context (ctx), TRUE, TRUE);
218 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
220 mono_handle_native_sigsegv (SIGABRT, ctx, info);
224 #if defined(__i386__) || defined(__x86_64__)
225 #define FULL_STAT_PROFILER_BACKTRACE 1
226 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
227 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
228 #if MONO_ARCH_STACK_GROWS_UP
229 #define IS_BEFORE_ON_STACK <
230 #define IS_AFTER_ON_STACK >
232 #define IS_BEFORE_ON_STACK >
233 #define IS_AFTER_ON_STACK <
236 #define FULL_STAT_PROFILER_BACKTRACE 0
239 #if (defined (USE_POSIX_BACKEND) && defined (SIGRTMIN)) || defined (SIGPROF)
240 #define HAVE_PROFILER_SIGNAL
243 #ifdef HAVE_PROFILER_SIGNAL
246 per_thread_profiler_hit (void *ctx)
248 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
249 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
251 if (call_chain_depth == 0) {
252 mono_profiler_stat_hit ((guchar *)mono_arch_ip_from_context (ctx), ctx);
254 MonoJitTlsData *jit_tls = (MonoJitTlsData *)mono_native_tls_get_value (mono_jit_tls_id);
255 int current_frame_index = 1;
256 MonoContext mono_context;
257 guchar *ips [call_chain_depth + 1];
259 mono_sigctx_to_monoctx (ctx, &mono_context);
260 ips [0] = (guchar *)MONO_CONTEXT_GET_IP (&mono_context);
262 if (jit_tls != NULL) {
263 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
264 #if FULL_STAT_PROFILER_BACKTRACE
265 guchar *current_frame;
266 guchar *stack_bottom;
269 stack_bottom = (guchar *)jit_tls->end_of_stack;
270 stack_top = (guchar *)MONO_CONTEXT_GET_SP (&mono_context);
271 current_frame = (guchar *)MONO_CONTEXT_GET_BP (&mono_context);
273 while ((current_frame_index <= call_chain_depth) &&
274 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
275 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
276 ips [current_frame_index] = (guchar *)CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
277 current_frame_index ++;
278 stack_top = current_frame;
279 current_frame = (guchar *)CURRENT_FRAME_GET_BASE_POINTER (current_frame);
282 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
286 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
287 #if GLIBC_PROFILER_BACKTRACE
288 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
290 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
294 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
295 MonoDomain *domain = mono_domain_get ();
296 if (domain != NULL) {
300 MonoContext new_mono_context;
302 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
303 &new_mono_context, NULL, &lmf, &native_offset, NULL);
304 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
305 ips [current_frame_index] = (guchar *)MONO_CONTEXT_GET_IP (&new_mono_context);
306 current_frame_index ++;
307 mono_context = new_mono_context;
308 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
309 &new_mono_context, NULL, &lmf, &native_offset, NULL);
315 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
319 static MonoNativeThreadId sampling_thread;
321 static gint32 profiler_signals_sent;
322 static gint32 profiler_signals_received;
323 static gint32 profiler_signals_accepted;
324 static gint32 profiler_interrupt_signals_received;
326 MONO_SIG_HANDLER_FUNC (static, profiler_signal_handler)
328 int old_errno = errno;
330 MONO_SIG_HANDLER_GET_CONTEXT;
332 /* See the comment in mono_runtime_shutdown_stat_profiler (). */
333 if (mono_native_thread_id_get () == sampling_thread) {
334 #ifdef HAVE_CLOCK_NANOSLEEP
335 if (mono_profiler_get_sampling_mode () == MONO_PROFILER_STAT_MODE_PROCESS) {
336 InterlockedIncrement (&profiler_interrupt_signals_received);
341 g_error ("%s: Unexpected profiler signal received by the sampler thread", __func__);
344 InterlockedIncrement (&profiler_signals_received);
346 if (mono_thread_info_get_small_id () == -1)
347 return; //an non-attached thread got the signal
349 if (!mono_domain_get () || !mono_native_tls_get_value (mono_jit_tls_id))
350 return; //thread in the process of dettaching
352 InterlockedIncrement (&profiler_signals_accepted);
354 hp_save_index = mono_hazard_pointer_save_for_signal_handler ();
356 mono_thread_info_set_is_async_context (TRUE);
357 per_thread_profiler_hit (ctx);
358 mono_thread_info_set_is_async_context (FALSE);
360 mono_hazard_pointer_restore_for_signal_handler (hp_save_index);
363 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
368 MONO_SIG_HANDLER_FUNC (static, sigquit_signal_handler)
372 /* We use this signal to start the attach agent too */
373 res = mono_attach_start ();
377 mono_threads_request_thread_dump ();
379 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
382 MONO_SIG_HANDLER_FUNC (static, sigusr2_signal_handler)
384 gboolean enabled = mono_trace_is_enabled ();
386 mono_trace_enable (!enabled);
388 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
392 add_signal_handler (int signo, gpointer handler, int flags)
395 struct sigaction previous_sa;
397 #ifdef MONO_ARCH_USE_SIGACTION
398 sa.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;
399 sigemptyset (&sa.sa_mask);
400 sa.sa_flags = SA_SIGINFO | flags;
401 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
403 /*Apple likes to deliver SIGBUS for *0 */
404 #ifdef PLATFORM_MACOSX
405 if (signo == SIGSEGV || signo == SIGBUS) {
407 if (signo == SIGSEGV) {
409 sa.sa_flags |= SA_ONSTACK;
412 * libgc will crash when trying to do stack marking for threads which are on
413 * an altstack, so delay the suspend signal after the signal handler has
416 if (mono_gc_get_suspend_signal () != -1)
417 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
420 if (signo == SIGSEGV) {
422 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
426 sigemptyset (&block_mask);
429 sa.sa_handler = handler;
430 sigemptyset (&sa.sa_mask);
433 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
435 /* if there was already a handler in place for this signal, store it */
436 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
437 (SIG_DFL == previous_sa.sa_handler)) {
438 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
440 if (mono_do_signal_chaining)
441 save_old_signal_handler (signo, &previous_sa);
446 remove_signal_handler (int signo)
449 struct sigaction *saved_action = get_saved_signal_handler (signo);
452 sa.sa_handler = SIG_DFL;
453 sigemptyset (&sa.sa_mask);
456 sigaction (signo, &sa, NULL);
458 g_assert (sigaction (signo, saved_action, NULL) != -1);
463 mono_runtime_posix_install_handlers (void)
468 if (mini_get_debug_options ()->handle_sigint)
469 add_signal_handler (SIGINT, mono_sigint_signal_handler, SA_RESTART);
471 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler, 0);
472 add_signal_handler (SIGQUIT, sigquit_signal_handler, SA_RESTART);
473 add_signal_handler (SIGILL, mono_sigill_signal_handler, 0);
474 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler, 0);
475 if (mono_jit_trace_calls != NULL)
476 add_signal_handler (SIGUSR2, sigusr2_signal_handler, SA_RESTART);
478 /* it seems to have become a common bug for some programs that run as parents
479 * of many processes to block signal delivery for real time signals.
480 * We try to detect and work around their breakage here.
482 sigemptyset (&signal_set);
483 if (mono_gc_get_suspend_signal () != -1)
484 sigaddset (&signal_set, mono_gc_get_suspend_signal ());
485 if (mono_gc_get_restart_signal () != -1)
486 sigaddset (&signal_set, mono_gc_get_restart_signal ());
487 sigaddset (&signal_set, SIGCHLD);
488 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
490 signal (SIGPIPE, SIG_IGN);
492 add_signal_handler (SIGABRT, sigabrt_signal_handler, 0);
495 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler, 0);
498 #ifndef PLATFORM_MACOSX
500 mono_runtime_install_handlers (void)
502 mono_runtime_posix_install_handlers ();
507 mono_runtime_cleanup_handlers (void)
509 if (mini_get_debug_options ()->handle_sigint)
510 remove_signal_handler (SIGINT);
512 remove_signal_handler (SIGFPE);
513 remove_signal_handler (SIGQUIT);
514 remove_signal_handler (SIGILL);
515 remove_signal_handler (SIGBUS);
516 if (mono_jit_trace_calls != NULL)
517 remove_signal_handler (SIGUSR2);
519 remove_signal_handler (SIGABRT);
521 remove_signal_handler (SIGSEGV);
523 free_saved_signal_handlers ();
526 #ifdef HAVE_PROFILER_SIGNAL
528 static volatile gint32 sampling_thread_running;
530 #ifdef PLATFORM_MACOSX
532 static clock_serv_t sampling_clock_service;
540 ret = host_get_clock_service (mach_host_self (), SYSTEM_CLOCK, &sampling_clock_service);
541 } while (ret == KERN_ABORTED);
543 if (ret != KERN_SUCCESS)
544 g_error ("%s: host_get_clock_service () returned %d", __func__, ret);
553 ret = mach_port_deallocate (mach_task_self (), sampling_clock_service);
554 } while (ret == KERN_ABORTED);
556 if (ret != KERN_SUCCESS)
557 g_error ("%s: mach_port_deallocate () returned %d", __func__, ret);
561 clock_get_time_ns (void)
564 mach_timespec_t mach_ts;
567 ret = clock_get_time (sampling_clock_service, &mach_ts);
568 } while (ret == KERN_ABORTED);
570 if (ret != KERN_SUCCESS)
571 g_error ("%s: clock_get_time () returned %d", __func__, ret);
573 return ((guint64) mach_ts.tv_sec * 1000000000) + (guint64) mach_ts.tv_nsec;
577 clock_sleep_ns_abs (guint64 ns_abs)
580 mach_timespec_t then, remain_unused;
582 then.tv_sec = ns_abs / 1000000000;
583 then.tv_nsec = ns_abs % 1000000000;
586 ret = clock_sleep (sampling_clock_service, TIME_ABSOLUTE, then, &remain_unused);
588 if (ret != KERN_SUCCESS && ret != KERN_ABORTED)
589 g_error ("%s: clock_sleep () returned %d", __func__, ret);
590 } while (ret == KERN_ABORTED && InterlockedRead (&sampling_thread_running));
595 clockid_t sampling_posix_clock;
600 switch (mono_profiler_get_sampling_mode ()) {
601 case MONO_PROFILER_STAT_MODE_PROCESS:
602 #ifdef HAVE_CLOCK_NANOSLEEP
604 * If we don't have clock_nanosleep (), measuring the process time
605 * makes very little sense as we can only use nanosleep () to sleep on
608 sampling_posix_clock = CLOCK_PROCESS_CPUTIME_ID;
611 case MONO_PROFILER_STAT_MODE_REAL: sampling_posix_clock = CLOCK_MONOTONIC; break;
612 default: g_assert_not_reached (); break;
622 clock_get_time_ns (void)
626 if (clock_gettime (sampling_posix_clock, &ts) == -1)
627 g_error ("%s: clock_gettime () returned -1, errno = %d", __func__, errno);
629 return ((guint64) ts.tv_sec * 1000000000) + (guint64) ts.tv_nsec;
633 clock_sleep_ns_abs (guint64 ns_abs)
635 #ifdef HAVE_CLOCK_NANOSLEEP
637 struct timespec then;
639 then.tv_sec = ns_abs / 1000000000;
640 then.tv_nsec = ns_abs % 1000000000;
643 ret = clock_nanosleep (sampling_posix_clock, TIMER_ABSTIME, &then, NULL);
645 if (ret != 0 && ret != EINTR)
646 g_error ("%s: clock_nanosleep () returned %d", __func__, ret);
647 } while (ret == EINTR && InterlockedRead (&sampling_thread_running));
654 * What follows is a crude attempt at emulating clock_nanosleep () on OSs
655 * which don't provide it (e.g. FreeBSD).
657 * The problem with nanosleep () is that if it is interrupted by a signal,
658 * time will drift as a result of having to restart the call after the
659 * signal handler has finished. For this reason, we avoid using the rem
660 * argument of nanosleep (). Instead, before every nanosleep () call, we
661 * check if enough time has passed to satisfy the sleep request. If yes, we
662 * simply return. If not, we calculate the difference and do another sleep.
664 * This should reduce the amount of drift that happens because we account
665 * for the time spent executing the signal handler, which nanosleep () is
666 * not guaranteed to do for the rem argument.
668 * The downside to this approach is that it is slightly expensive: We have
669 * to make an extra system call to retrieve the current time whenever we're
670 * going to restart a nanosleep () call. This is unlikely to be a problem
671 * in practice since the sampling thread won't be receiving many signals in
672 * the first place (it's a tools thread, so no STW), and because typical
673 * sleep periods for the thread are many orders of magnitude bigger than
674 * the time it takes to actually perform that system call (just a few
678 diff = (gint64) ns_abs - (gint64) clock_get_time_ns ();
683 req.tv_sec = diff / 1000000000;
684 req.tv_nsec = diff % 1000000000;
686 if ((ret = nanosleep (&req, NULL)) == -1 && errno != EINTR)
687 g_error ("%s: nanosleep () returned -1, errno = %d", __func__, errno);
688 } while (ret == -1 && InterlockedRead (&sampling_thread_running));
694 static int profiler_signal;
695 static volatile gint32 sampling_thread_exiting;
697 static mono_native_thread_return_t
698 sampling_thread_func (void *data)
700 mono_threads_attach_tools_thread ();
701 mono_native_thread_set_name (mono_native_thread_id_get (), "Profiler sampler");
703 gint64 rate = 1000000000 / mono_profiler_get_sampling_rate ();
706 struct sched_param old_sched;
707 pthread_getschedparam (pthread_self (), &old_policy, &old_sched);
710 * Attempt to switch the thread to real time scheduling. This will not
711 * necessarily work on all OSs; for example, most Linux systems will give
712 * us EPERM here unless configured to allow this.
714 * TODO: This does not work on Mac (and maybe some other OSs). On Mac, we
715 * have to use the Mach thread policy routines to switch to real-time
716 * scheduling. This is quite tricky as we need to specify how often we'll
717 * be doing work (easy), the normal processing time needed (also easy),
718 * and the maximum amount of processing time needed (hard). This is
719 * further complicated by the fact that if we misbehave and take too long
720 * to do our work, the kernel may knock us back down to the normal thread
721 * scheduling policy without telling us.
723 struct sched_param sched = { .sched_priority = sched_get_priority_max (SCHED_FIFO) };
724 pthread_setschedparam (pthread_self (), SCHED_FIFO, &sched);
728 guint64 sleep = clock_get_time_ns ();
730 while (InterlockedRead (&sampling_thread_running)) {
733 FOREACH_THREAD_SAFE (info) {
734 /* info should never be this thread as we're a tools thread. */
735 g_assert (mono_thread_info_get_tid (info) != mono_native_thread_id_get ());
737 mono_threads_pthread_kill (info, profiler_signal);
738 InterlockedIncrement (&profiler_signals_sent);
739 } FOREACH_THREAD_SAFE_END
741 clock_sleep_ns_abs (sleep);
744 InterlockedWrite (&sampling_thread_exiting, 1);
748 pthread_setschedparam (pthread_self (), old_policy, &old_sched);
750 mono_thread_info_detach ();
756 mono_runtime_shutdown_stat_profiler (void)
758 InterlockedWrite (&sampling_thread_running, 0);
760 #ifdef HAVE_CLOCK_NANOSLEEP
762 * There is a slight problem when we're using CLOCK_PROCESS_CPUTIME_ID: If
763 * we're shutting down and there's largely no activity in the process other
764 * than waiting for the sampler thread to shut down, it can take upwards of
765 * 20 seconds (depending on a lot of factors) for us to shut down because
766 * the sleep progresses very slowly as a result of the low CPU activity.
768 * We fix this by repeatedly sending the profiler signal to the sampler
769 * thread in order to interrupt the sleep. clock_sleep_ns_abs () will check
770 * sampling_thread_running upon an interrupt and return immediately if it's
771 * zero. profiler_signal_handler () has a special case to ignore the signal
772 * for the sampler thread.
774 * We do not need to do this on platforms where we use a regular sleep
775 * based on a monotonic clock. The sleep will return in a reasonable amount
776 * of time in those cases.
778 if (mono_profiler_get_sampling_mode () == MONO_PROFILER_STAT_MODE_PROCESS) {
779 MonoThreadInfo *info;
781 // Did it shut down already?
782 if ((info = mono_thread_info_lookup (sampling_thread))) {
783 while (!InterlockedRead (&sampling_thread_exiting)) {
784 mono_threads_pthread_kill (info, profiler_signal);
785 mono_thread_info_usleep (10 * 1000 /* 10ms */);
788 // Make sure info can be freed.
789 mono_hazard_pointer_clear (mono_hazard_pointer_get (), 1);
794 pthread_join (sampling_thread, NULL);
797 * We can't safely remove the signal handler because we have no guarantee
798 * that all pending signals have been delivered at this point. This should
799 * not really be a problem anyway.
801 //remove_signal_handler (profiler_signal);
805 mono_runtime_setup_stat_profiler (void)
808 * Use a real-time signal when possible. This gives us roughly a 99% signal
809 * delivery rate in all cases. On the other hand, using a regular signal
810 * tends to result in awful delivery rates when the application is heavily
813 * We avoid real-time signals on Android as they're super broken in certain
814 * API levels (too small sigset_t, nonsensical SIGRTMIN/SIGRTMAX values,
817 * TODO: On Mac, we should explore using the Mach thread suspend/resume
818 * functions and doing the stack walk from the sampling thread. This would
819 * get us a 100% sampling rate. However, this may interfere with the GC's
820 * STW logic. Could perhaps be solved by taking the suspend lock.
822 #if defined (USE_POSIX_BACKEND) && defined (SIGRTMIN) && !defined (PLATFORM_ANDROID)
823 /* Just take the first real-time signal we can get. */
824 profiler_signal = mono_threads_posix_signal_search_alternative (-1);
826 profiler_signal = SIGPROF;
829 add_signal_handler (profiler_signal, profiler_signal_handler, SA_RESTART);
831 mono_counters_register ("Sampling signals sent", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_sent);
832 mono_counters_register ("Sampling signals received", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_received);
833 mono_counters_register ("Sampling signals accepted", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_accepted);
834 mono_counters_register ("Shutdown signals received", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_interrupt_signals_received);
836 InterlockedWrite (&sampling_thread_running, 1);
837 mono_native_thread_create (&sampling_thread, sampling_thread_func, NULL);
843 mono_runtime_shutdown_stat_profiler (void)
848 mono_runtime_setup_stat_profiler (void)
854 #if !defined(PLATFORM_MACOSX)
856 mono_runtime_syscall_fork ()
858 #if defined(PLATFORM_ANDROID)
859 /* SYS_fork is defined to be __NR_fork which is not defined in some ndk versions */
860 g_assert_not_reached ();
862 #elif defined(SYS_fork)
863 return (pid_t) syscall (SYS_fork);
865 g_assert_not_reached ();
871 mono_gdb_render_native_backtraces (pid_t crashed_pid)
873 const char *argv [9];
874 char template_ [] = "/tmp/mono-lldb-commands.XXXXXX";
877 gboolean using_lldb = FALSE;
879 argv [0] = g_find_program_in_path ("gdb");
880 if (argv [0] == NULL) {
881 argv [0] = g_find_program_in_path ("lldb");
885 if (argv [0] == NULL)
889 if (mkstemp (template_) == -1)
892 commands = fopen (template_, "w");
894 fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
895 fprintf (commands, "thread list\n");
896 fprintf (commands, "thread backtrace all\n");
897 fprintf (commands, "detach\n");
898 fprintf (commands, "quit\n");
903 argv [1] = "--source";
904 argv [2] = template_;
908 sprintf (buf1, "attach %ld", (long) crashed_pid);
911 argv [4] = "info threads";
913 argv [6] = "thread apply all bt";
914 argv [7] = "--batch";
918 execv (argv [0], (char**)argv);
924 #endif /* __native_client__ */
926 #if !defined (__MACH__)
929 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoThreadInfo *info)
931 g_error ("Posix systems don't support mono_thread_state_init_from_handle");