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 (NULL, NULL);
171 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
175 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
181 free_saved_signal_handlers (void)
183 if (mono_saved_signal_handlers) {
184 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
185 g_hash_table_destroy (mono_saved_signal_handlers);
186 mono_saved_signal_handlers = NULL;
193 * Call the original signal handler for the signal given by the arguments, which
194 * should be the same as for a signal handler. Returns TRUE if the original handler
195 * was called, false otherwise.
198 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
200 int signal = MONO_SIG_HANDLER_GET_SIGNO ();
201 struct sigaction *saved_handler = (struct sigaction *)get_saved_signal_handler (signal);
203 if (saved_handler && saved_handler->sa_handler) {
204 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
205 saved_handler->sa_handler (signal);
207 #ifdef MONO_ARCH_USE_SIGACTION
208 saved_handler->sa_sigaction (MONO_SIG_HANDLER_PARAMS);
209 #endif /* MONO_ARCH_USE_SIGACTION */
216 MONO_SIG_HANDLER_FUNC (static, sigabrt_signal_handler)
218 MonoJitInfo *ji = NULL;
219 MONO_SIG_HANDLER_INFO_TYPE *info = MONO_SIG_HANDLER_GET_INFO ();
220 MONO_SIG_HANDLER_GET_CONTEXT;
222 if (mono_thread_internal_current ())
223 ji = mono_jit_info_table_find_internal (mono_domain_get (), (char *)mono_arch_ip_from_context (ctx), TRUE, TRUE);
225 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
227 mono_handle_native_sigsegv (SIGABRT, ctx, info);
231 #if defined(__i386__) || defined(__x86_64__)
232 #define FULL_STAT_PROFILER_BACKTRACE 1
233 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
234 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
235 #if MONO_ARCH_STACK_GROWS_UP
236 #define IS_BEFORE_ON_STACK <
237 #define IS_AFTER_ON_STACK >
239 #define IS_BEFORE_ON_STACK >
240 #define IS_AFTER_ON_STACK <
243 #define FULL_STAT_PROFILER_BACKTRACE 0
246 #if (defined (USE_POSIX_BACKEND) && defined (SIGRTMIN)) || defined (SIGPROF)
247 #define HAVE_PROFILER_SIGNAL
250 #ifdef HAVE_PROFILER_SIGNAL
253 per_thread_profiler_hit (void *ctx)
255 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
256 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
258 if (call_chain_depth == 0) {
259 mono_profiler_stat_hit ((guchar *)mono_arch_ip_from_context (ctx), ctx);
261 MonoJitTlsData *jit_tls = (MonoJitTlsData *)mono_native_tls_get_value (mono_jit_tls_id);
262 int current_frame_index = 1;
263 MonoContext mono_context;
264 guchar *ips [call_chain_depth + 1];
266 mono_sigctx_to_monoctx (ctx, &mono_context);
267 ips [0] = (guchar *)MONO_CONTEXT_GET_IP (&mono_context);
269 if (jit_tls != NULL) {
270 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
271 #if FULL_STAT_PROFILER_BACKTRACE
272 guchar *current_frame;
273 guchar *stack_bottom;
276 stack_bottom = (guchar *)jit_tls->end_of_stack;
277 stack_top = (guchar *)MONO_CONTEXT_GET_SP (&mono_context);
278 current_frame = (guchar *)MONO_CONTEXT_GET_BP (&mono_context);
280 while ((current_frame_index <= call_chain_depth) &&
281 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
282 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
283 ips [current_frame_index] = (guchar *)CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
284 current_frame_index ++;
285 stack_top = current_frame;
286 current_frame = (guchar *)CURRENT_FRAME_GET_BASE_POINTER (current_frame);
289 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
293 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
294 #if GLIBC_PROFILER_BACKTRACE
295 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
297 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
301 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
302 MonoDomain *domain = mono_domain_get ();
303 if (domain != NULL) {
307 MonoContext new_mono_context;
309 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
310 &new_mono_context, NULL, &lmf, &native_offset, NULL);
311 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
312 ips [current_frame_index] = (guchar *)MONO_CONTEXT_GET_IP (&new_mono_context);
313 current_frame_index ++;
314 mono_context = new_mono_context;
315 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
316 &new_mono_context, NULL, &lmf, &native_offset, NULL);
322 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
326 static MonoNativeThreadId sampling_thread;
328 static gint32 profiler_signals_sent;
329 static gint32 profiler_signals_received;
330 static gint32 profiler_signals_accepted;
331 static gint32 profiler_interrupt_signals_received;
333 MONO_SIG_HANDLER_FUNC (static, profiler_signal_handler)
335 int old_errno = errno;
337 MONO_SIG_HANDLER_GET_CONTEXT;
339 /* See the comment in mono_runtime_shutdown_stat_profiler (). */
340 if (mono_native_thread_id_get () == sampling_thread) {
341 #ifdef HAVE_CLOCK_NANOSLEEP
342 if (mono_profiler_get_sampling_mode () == MONO_PROFILER_STAT_MODE_PROCESS) {
343 InterlockedIncrement (&profiler_interrupt_signals_received);
348 g_error ("%s: Unexpected profiler signal received by the sampler thread", __func__);
351 InterlockedIncrement (&profiler_signals_received);
353 if (mono_thread_info_get_small_id () == -1)
354 return; //an non-attached thread got the signal
356 if (!mono_domain_get () || !mono_native_tls_get_value (mono_jit_tls_id))
357 return; //thread in the process of dettaching
359 InterlockedIncrement (&profiler_signals_accepted);
361 hp_save_index = mono_hazard_pointer_save_for_signal_handler ();
363 mono_thread_info_set_is_async_context (TRUE);
364 per_thread_profiler_hit (ctx);
365 mono_thread_info_set_is_async_context (FALSE);
367 mono_hazard_pointer_restore_for_signal_handler (hp_save_index);
370 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
375 MONO_SIG_HANDLER_FUNC (static, sigquit_signal_handler)
379 /* We use this signal to start the attach agent too */
380 res = mono_attach_start ();
384 mono_threads_request_thread_dump ();
386 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
389 MONO_SIG_HANDLER_FUNC (static, sigusr2_signal_handler)
391 gboolean enabled = mono_trace_is_enabled ();
393 mono_trace_enable (!enabled);
395 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
399 add_signal_handler (int signo, gpointer handler, int flags)
402 struct sigaction previous_sa;
404 #ifdef MONO_ARCH_USE_SIGACTION
405 sa.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;
406 sigemptyset (&sa.sa_mask);
407 sa.sa_flags = SA_SIGINFO | flags;
408 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
410 /*Apple likes to deliver SIGBUS for *0 */
411 #ifdef PLATFORM_MACOSX
412 if (signo == SIGSEGV || signo == SIGBUS) {
414 if (signo == SIGSEGV) {
416 sa.sa_flags |= SA_ONSTACK;
419 * libgc will crash when trying to do stack marking for threads which are on
420 * an altstack, so delay the suspend signal after the signal handler has
423 if (mono_gc_get_suspend_signal () != -1)
424 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
427 if (signo == SIGSEGV) {
429 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
433 sigemptyset (&block_mask);
436 sa.sa_handler = handler;
437 sigemptyset (&sa.sa_mask);
440 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
442 /* if there was already a handler in place for this signal, store it */
443 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
444 (SIG_DFL == previous_sa.sa_handler)) {
445 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
447 if (mono_do_signal_chaining)
448 save_old_signal_handler (signo, &previous_sa);
453 remove_signal_handler (int signo)
456 struct sigaction *saved_action = get_saved_signal_handler (signo);
459 sa.sa_handler = SIG_DFL;
460 sigemptyset (&sa.sa_mask);
463 sigaction (signo, &sa, NULL);
465 g_assert (sigaction (signo, saved_action, NULL) != -1);
470 mono_runtime_posix_install_handlers (void)
475 if (mini_get_debug_options ()->handle_sigint)
476 add_signal_handler (SIGINT, mono_sigint_signal_handler, SA_RESTART);
478 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler, 0);
479 add_signal_handler (SIGQUIT, sigquit_signal_handler, SA_RESTART);
480 add_signal_handler (SIGILL, mono_sigill_signal_handler, 0);
481 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler, 0);
482 if (mono_jit_trace_calls != NULL)
483 add_signal_handler (SIGUSR2, sigusr2_signal_handler, SA_RESTART);
485 /* it seems to have become a common bug for some programs that run as parents
486 * of many processes to block signal delivery for real time signals.
487 * We try to detect and work around their breakage here.
489 sigemptyset (&signal_set);
490 if (mono_gc_get_suspend_signal () != -1)
491 sigaddset (&signal_set, mono_gc_get_suspend_signal ());
492 if (mono_gc_get_restart_signal () != -1)
493 sigaddset (&signal_set, mono_gc_get_restart_signal ());
494 sigaddset (&signal_set, SIGCHLD);
495 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
497 signal (SIGPIPE, SIG_IGN);
499 add_signal_handler (SIGABRT, sigabrt_signal_handler, 0);
502 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler, 0);
505 #ifndef PLATFORM_MACOSX
507 mono_runtime_install_handlers (void)
509 mono_runtime_posix_install_handlers ();
514 mono_runtime_cleanup_handlers (void)
516 if (mini_get_debug_options ()->handle_sigint)
517 remove_signal_handler (SIGINT);
519 remove_signal_handler (SIGFPE);
520 remove_signal_handler (SIGQUIT);
521 remove_signal_handler (SIGILL);
522 remove_signal_handler (SIGBUS);
523 if (mono_jit_trace_calls != NULL)
524 remove_signal_handler (SIGUSR2);
526 remove_signal_handler (SIGABRT);
528 remove_signal_handler (SIGSEGV);
530 free_saved_signal_handlers ();
533 #ifdef HAVE_PROFILER_SIGNAL
535 static volatile gint32 sampling_thread_running;
537 #ifdef PLATFORM_MACOSX
539 static clock_serv_t sampling_clock_service;
547 ret = host_get_clock_service (mach_host_self (), SYSTEM_CLOCK, &sampling_clock_service);
548 } while (ret == KERN_ABORTED);
550 if (ret != KERN_SUCCESS)
551 g_error ("%s: host_get_clock_service () returned %d", __func__, ret);
560 ret = mach_port_deallocate (mach_task_self (), sampling_clock_service);
561 } while (ret == KERN_ABORTED);
563 if (ret != KERN_SUCCESS)
564 g_error ("%s: mach_port_deallocate () returned %d", __func__, ret);
568 clock_get_time_ns (void)
571 mach_timespec_t mach_ts;
574 ret = clock_get_time (sampling_clock_service, &mach_ts);
575 } while (ret == KERN_ABORTED);
577 if (ret != KERN_SUCCESS)
578 g_error ("%s: clock_get_time () returned %d", __func__, ret);
580 return ((guint64) mach_ts.tv_sec * 1000000000) + (guint64) mach_ts.tv_nsec;
584 clock_sleep_ns_abs (guint64 ns_abs)
587 mach_timespec_t then, remain_unused;
589 then.tv_sec = ns_abs / 1000000000;
590 then.tv_nsec = ns_abs % 1000000000;
593 ret = clock_sleep (sampling_clock_service, TIME_ABSOLUTE, then, &remain_unused);
595 if (ret != KERN_SUCCESS && ret != KERN_ABORTED)
596 g_error ("%s: clock_sleep () returned %d", __func__, ret);
597 } while (ret == KERN_ABORTED && InterlockedRead (&sampling_thread_running));
602 clockid_t sampling_posix_clock;
607 switch (mono_profiler_get_sampling_mode ()) {
608 case MONO_PROFILER_STAT_MODE_PROCESS:
609 #ifdef HAVE_CLOCK_NANOSLEEP
611 * If we don't have clock_nanosleep (), measuring the process time
612 * makes very little sense as we can only use nanosleep () to sleep on
615 sampling_posix_clock = CLOCK_PROCESS_CPUTIME_ID;
618 case MONO_PROFILER_STAT_MODE_REAL: sampling_posix_clock = CLOCK_MONOTONIC; break;
619 default: g_assert_not_reached (); break;
629 clock_get_time_ns (void)
633 if (clock_gettime (sampling_posix_clock, &ts) == -1)
634 g_error ("%s: clock_gettime () returned -1, errno = %d", __func__, errno);
636 return ((guint64) ts.tv_sec * 1000000000) + (guint64) ts.tv_nsec;
640 clock_sleep_ns_abs (guint64 ns_abs)
642 #ifdef HAVE_CLOCK_NANOSLEEP
644 struct timespec then;
646 then.tv_sec = ns_abs / 1000000000;
647 then.tv_nsec = ns_abs % 1000000000;
650 ret = clock_nanosleep (sampling_posix_clock, TIMER_ABSTIME, &then, NULL);
652 if (ret != 0 && ret != EINTR)
653 g_error ("%s: clock_nanosleep () returned %d", __func__, ret);
654 } while (ret == EINTR && InterlockedRead (&sampling_thread_running));
661 * What follows is a crude attempt at emulating clock_nanosleep () on OSs
662 * which don't provide it (e.g. FreeBSD).
664 * The problem with nanosleep () is that if it is interrupted by a signal,
665 * time will drift as a result of having to restart the call after the
666 * signal handler has finished. For this reason, we avoid using the rem
667 * argument of nanosleep (). Instead, before every nanosleep () call, we
668 * check if enough time has passed to satisfy the sleep request. If yes, we
669 * simply return. If not, we calculate the difference and do another sleep.
671 * This should reduce the amount of drift that happens because we account
672 * for the time spent executing the signal handler, which nanosleep () is
673 * not guaranteed to do for the rem argument.
675 * The downside to this approach is that it is slightly expensive: We have
676 * to make an extra system call to retrieve the current time whenever we're
677 * going to restart a nanosleep () call. This is unlikely to be a problem
678 * in practice since the sampling thread won't be receiving many signals in
679 * the first place (it's a tools thread, so no STW), and because typical
680 * sleep periods for the thread are many orders of magnitude bigger than
681 * the time it takes to actually perform that system call (just a few
685 diff = (gint64) ns_abs - (gint64) clock_get_time_ns ();
690 req.tv_sec = diff / 1000000000;
691 req.tv_nsec = diff % 1000000000;
693 if ((ret = nanosleep (&req, NULL)) == -1 && errno != EINTR)
694 g_error ("%s: nanosleep () returned -1, errno = %d", __func__, errno);
695 } while (ret == -1 && InterlockedRead (&sampling_thread_running));
701 static int profiler_signal;
702 static volatile gint32 sampling_thread_exiting;
704 static mono_native_thread_return_t
705 sampling_thread_func (void *data)
707 mono_threads_attach_tools_thread ();
708 mono_native_thread_set_name (mono_native_thread_id_get (), "Profiler sampler");
710 gint64 rate = 1000000000 / mono_profiler_get_sampling_rate ();
713 struct sched_param old_sched;
714 pthread_getschedparam (pthread_self (), &old_policy, &old_sched);
717 * Attempt to switch the thread to real time scheduling. This will not
718 * necessarily work on all OSs; for example, most Linux systems will give
719 * us EPERM here unless configured to allow this.
721 * TODO: This does not work on Mac (and maybe some other OSs). On Mac, we
722 * have to use the Mach thread policy routines to switch to real-time
723 * scheduling. This is quite tricky as we need to specify how often we'll
724 * be doing work (easy), the normal processing time needed (also easy),
725 * and the maximum amount of processing time needed (hard). This is
726 * further complicated by the fact that if we misbehave and take too long
727 * to do our work, the kernel may knock us back down to the normal thread
728 * scheduling policy without telling us.
730 struct sched_param sched = { .sched_priority = sched_get_priority_max (SCHED_FIFO) };
731 pthread_setschedparam (pthread_self (), SCHED_FIFO, &sched);
735 guint64 sleep = clock_get_time_ns ();
737 while (InterlockedRead (&sampling_thread_running)) {
740 FOREACH_THREAD_SAFE (info) {
741 /* info should never be this thread as we're a tools thread. */
742 g_assert (mono_thread_info_get_tid (info) != mono_native_thread_id_get ());
744 mono_threads_pthread_kill (info, profiler_signal);
745 InterlockedIncrement (&profiler_signals_sent);
746 } FOREACH_THREAD_SAFE_END
748 clock_sleep_ns_abs (sleep);
751 InterlockedWrite (&sampling_thread_exiting, 1);
755 pthread_setschedparam (pthread_self (), old_policy, &old_sched);
757 mono_thread_info_detach ();
763 mono_runtime_shutdown_stat_profiler (void)
765 InterlockedWrite (&sampling_thread_running, 0);
767 #ifdef HAVE_CLOCK_NANOSLEEP
769 * There is a slight problem when we're using CLOCK_PROCESS_CPUTIME_ID: If
770 * we're shutting down and there's largely no activity in the process other
771 * than waiting for the sampler thread to shut down, it can take upwards of
772 * 20 seconds (depending on a lot of factors) for us to shut down because
773 * the sleep progresses very slowly as a result of the low CPU activity.
775 * We fix this by repeatedly sending the profiler signal to the sampler
776 * thread in order to interrupt the sleep. clock_sleep_ns_abs () will check
777 * sampling_thread_running upon an interrupt and return immediately if it's
778 * zero. profiler_signal_handler () has a special case to ignore the signal
779 * for the sampler thread.
781 * We do not need to do this on platforms where we use a regular sleep
782 * based on a monotonic clock. The sleep will return in a reasonable amount
783 * of time in those cases.
785 if (mono_profiler_get_sampling_mode () == MONO_PROFILER_STAT_MODE_PROCESS) {
786 MonoThreadInfo *info;
788 // Did it shut down already?
789 if ((info = mono_thread_info_lookup (sampling_thread))) {
790 while (!InterlockedRead (&sampling_thread_exiting)) {
791 mono_threads_pthread_kill (info, profiler_signal);
792 mono_thread_info_usleep (10 * 1000 /* 10ms */);
795 // Make sure info can be freed.
796 mono_hazard_pointer_clear (mono_hazard_pointer_get (), 1);
801 pthread_join (sampling_thread, NULL);
804 * We can't safely remove the signal handler because we have no guarantee
805 * that all pending signals have been delivered at this point. This should
806 * not really be a problem anyway.
808 //remove_signal_handler (profiler_signal);
812 mono_runtime_setup_stat_profiler (void)
815 * Use a real-time signal when possible. This gives us roughly a 99% signal
816 * delivery rate in all cases. On the other hand, using a regular signal
817 * tends to result in awful delivery rates when the application is heavily
820 * We avoid real-time signals on Android as they're super broken in certain
821 * API levels (too small sigset_t, nonsensical SIGRTMIN/SIGRTMAX values,
824 * TODO: On Mac, we should explore using the Mach thread suspend/resume
825 * functions and doing the stack walk from the sampling thread. This would
826 * get us a 100% sampling rate. However, this may interfere with the GC's
827 * STW logic. Could perhaps be solved by taking the suspend lock.
829 #if defined (USE_POSIX_BACKEND) && defined (SIGRTMIN) && !defined (PLATFORM_ANDROID)
830 /* Just take the first real-time signal we can get. */
831 profiler_signal = mono_threads_posix_signal_search_alternative (-1);
833 profiler_signal = SIGPROF;
836 add_signal_handler (profiler_signal, profiler_signal_handler, SA_RESTART);
838 mono_counters_register ("Sampling signals sent", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_sent);
839 mono_counters_register ("Sampling signals received", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_received);
840 mono_counters_register ("Sampling signals accepted", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_signals_accepted);
841 mono_counters_register ("Shutdown signals received", MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, &profiler_interrupt_signals_received);
843 InterlockedWrite (&sampling_thread_running, 1);
844 mono_native_thread_create (&sampling_thread, sampling_thread_func, NULL);
850 mono_runtime_shutdown_stat_profiler (void)
855 mono_runtime_setup_stat_profiler (void)
861 #if !defined(PLATFORM_MACOSX)
863 mono_runtime_syscall_fork ()
865 #if defined(PLATFORM_ANDROID)
866 /* SYS_fork is defined to be __NR_fork which is not defined in some ndk versions */
867 g_assert_not_reached ();
869 #elif defined(SYS_fork)
870 return (pid_t) syscall (SYS_fork);
872 g_assert_not_reached ();
878 mono_gdb_render_native_backtraces (pid_t crashed_pid)
880 const char *argv [9];
881 char template_ [] = "/tmp/mono-lldb-commands.XXXXXX";
884 gboolean using_lldb = FALSE;
886 argv [0] = g_find_program_in_path ("gdb");
887 if (argv [0] == NULL) {
888 argv [0] = g_find_program_in_path ("lldb");
892 if (argv [0] == NULL)
896 if (mkstemp (template_) == -1)
899 commands = fopen (template_, "w");
901 fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
902 fprintf (commands, "thread list\n");
903 fprintf (commands, "thread backtrace all\n");
904 fprintf (commands, "detach\n");
905 fprintf (commands, "quit\n");
910 argv [1] = "--source";
911 argv [2] = template_;
915 sprintf (buf1, "attach %ld", (long) crashed_pid);
918 argv [4] = "info threads";
920 argv [6] = "thread apply all bt";
921 argv [7] = "--batch";
925 execv (argv [0], (char**)argv);
931 #endif /* __native_client__ */
933 #if !defined (__MACH__)
936 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoThreadInfo *info)
938 g_error ("Posix systems don't support mono_thread_state_init_from_handle");