int
sgen_thread_handshake (BOOL suspend)
{
int count, result;
SgenThreadInfo *info;
int signum = suspend ? suspend_signal_num : restart_signal_num;
MonoNativeThreadId me = mono_native_thread_id_get ();
count = 0;
mono_thread_info_current ()->client_info.suspend_done = TRUE;
FOREACH_THREAD_SAFE (info) {
if (mono_native_thread_id_equals (mono_thread_info_get_tid (info), me)) {
continue;
}
info->client_info.suspend_done = FALSE;
if (info->client_info.gc_disabled)
continue;
/*if (signum == suspend_signal_num && info->stop_count == global_stop_count)
continue;*/
result = mono_threads_pthread_kill (info, signum);
if (result == 0) {
count++;
} else {
info->client_info.skip = 1;
}
} END_FOREACH_THREAD_SAFE
sgen_wait_for_suspend_ack (count);
SGEN_LOG (4, "%s handshake for %d threads\n", suspend ? "suspend" : "resume", count);
return count;
}
void
mono_threads_suspend_abort_syscall (MonoThreadInfo *info)
{
/* We signal a thread to break it from the current syscall.
* This signal should not be interpreted as a suspend request. */
info->syscall_break_signal = TRUE;
if (!mono_threads_pthread_kill (info, mono_threads_posix_get_abort_signal ()))
mono_threads_add_to_pending_operation_set (info);
}
gboolean
mono_threads_core_suspend (MonoThreadInfo *info)
{
/*FIXME, check return value*/
mono_threads_pthread_kill (info, mono_thread_get_abort_signal ());
while (MONO_SEM_WAIT (&info->begin_suspend_semaphore) != 0) {
/* g_assert (errno == EINTR); */
}
return info->suspend_can_continue;
}
void
mono_threads_core_abort_syscall (MonoThreadInfo *info)
{
/*
We signal a thread to break it from the urrent syscall.
This signal should not be interpreted as a suspend request.
*/
info->syscall_break_signal = TRUE;
mono_threads_pthread_kill (info, mono_thread_get_abort_signal ());
}
gboolean
mono_threads_core_begin_async_suspend (MonoThreadInfo *info, gboolean interrupt_kernel)
{
int sig = interrupt_kernel ? abort_signal_num : suspend_signal_num;
if (!mono_threads_pthread_kill (info, sig)) {
mono_threads_add_to_pending_operation_set (info);
return TRUE;
}
return FALSE;
}
/*
This begins async resume. This function must do the following:
- Install an async target if one was requested.
- Notify the target to resume.
*/
gboolean
mono_threads_suspend_begin_async_resume (MonoThreadInfo *info)
{
int sig = mono_threads_suspend_get_restart_signal ();
if (!mono_threads_pthread_kill (info, sig)) {
mono_threads_add_to_pending_operation_set (info);
return TRUE;
}
return FALSE;
}
void
mono_runtime_shutdown_stat_profiler (void)
{
mono_atomic_store_i32 (&sampling_thread_running, 0);
mono_profiler_sampling_thread_post ();
#ifndef HOST_DARWIN
/*
* There is a slight problem when we're using CLOCK_PROCESS_CPUTIME_ID: If
* we're shutting down and there's largely no activity in the process other
* than waiting for the sampler thread to shut down, it can take upwards of
* 20 seconds (depending on a lot of factors) for us to shut down because
* the sleep progresses very slowly as a result of the low CPU activity.
*
* We fix this by repeatedly sending the profiler signal to the sampler
* thread in order to interrupt the sleep. clock_sleep_ns_abs () will check
* sampling_thread_running upon an interrupt and return immediately if it's
* zero. profiler_signal_handler () has a special case to ignore the signal
* for the sampler thread.
*/
MonoThreadInfo *info;
// Did it shut down already?
if ((info = mono_thread_info_lookup (sampling_thread))) {
while (!mono_atomic_load_i32 (&sampling_thread_exiting)) {
mono_threads_pthread_kill (info, profiler_signal);
mono_thread_info_usleep (10 * 1000 /* 10ms */);
}
// Make sure info can be freed.
mono_hazard_pointer_clear (mono_hazard_pointer_get (), 1);
}
#endif
mono_os_event_wait_one (&sampling_thread_exited, MONO_INFINITE_WAIT, FALSE);
mono_os_event_destroy (&sampling_thread_exited);
/*
* We can't safely remove the signal handler because we have no guarantee
* that all pending signals have been delivered at this point. This should
* not really be a problem anyway.
*/
//remove_signal_handler (profiler_signal);
}
/*
This begins async resume. This function must do the following:
- Install an async target if one was requested.
- Notify the target to resume.
*/
gboolean
mono_threads_core_begin_async_resume (MonoThreadInfo *info)
{
mono_threads_add_to_pending_operation_set (info);
return mono_threads_pthread_kill (info, restart_signal_num) == 0;
}
gboolean
sgen_suspend_thread (SgenThreadInfo *info)
{
return mono_threads_pthread_kill (info, suspend_signal_num) == 0;
}
gboolean
sgen_resume_thread (SgenThreadInfo *info)
{
return mono_threads_pthread_kill (info, restart_signal_num) == 0;
}
static gsize
sampling_thread_func (gpointer unused)
{
MonoInternalThread *thread = mono_thread_internal_current ();
thread->flags |= MONO_THREAD_FLAG_DONT_MANAGE;
ERROR_DECL (error);
MonoString *name = mono_string_new_checked (mono_get_root_domain (), "Profiler Sampler", error);
mono_error_assert_ok (error);
mono_thread_set_name_internal (thread, name, FALSE, FALSE, error);
mono_error_assert_ok (error);
mono_thread_info_set_flags (MONO_THREAD_INFO_FLAGS_NO_GC | MONO_THREAD_INFO_FLAGS_NO_SAMPLE);
int old_policy;
struct sched_param old_sched;
pthread_getschedparam (pthread_self (), &old_policy, &old_sched);
/*
* Attempt to switch the thread to real time scheduling. This will not
* necessarily work on all OSs; for example, most Linux systems will give
* us EPERM here unless configured to allow this.
*
* TODO: This does not work on Mac (and maybe some other OSs). On Mac, we
* have to use the Mach thread policy routines to switch to real-time
* scheduling. This is quite tricky as we need to specify how often we'll
* be doing work (easy), the normal processing time needed (also easy),
* and the maximum amount of processing time needed (hard). This is
* further complicated by the fact that if we misbehave and take too long
* to do our work, the kernel may knock us back down to the normal thread
* scheduling policy without telling us.
*/
struct sched_param sched = { .sched_priority = sched_get_priority_max (SCHED_FIFO) };
pthread_setschedparam (pthread_self (), SCHED_FIFO, &sched);
MonoProfilerSampleMode mode;
init:
mono_profiler_get_sample_mode (NULL, &mode, NULL);
if (mode == MONO_PROFILER_SAMPLE_MODE_NONE) {
mono_profiler_sampling_thread_wait ();
if (!mono_atomic_load_i32 (&sampling_thread_running))
goto done;
goto init;
}
clock_init (mode);
for (guint64 sleep = clock_get_time_ns (); mono_atomic_load_i32 (&sampling_thread_running); clock_sleep_ns_abs (sleep)) {
uint32_t freq;
MonoProfilerSampleMode new_mode;
mono_profiler_get_sample_mode (NULL, &new_mode, &freq);
if (new_mode != mode) {
clock_cleanup ();
goto init;
}
sleep += 1000000000 / freq;
FOREACH_THREAD_SAFE_EXCLUDE (info, MONO_THREAD_INFO_FLAGS_NO_SAMPLE) {
g_assert (mono_thread_info_get_tid (info) != sampling_thread);
/*
* Require an ack for the last sampling signal sent to the thread
* so that we don't overflow the signal queue, leading to all sorts
* of problems (e.g. GC STW failing).
*/
if (profiler_signal != SIGPROF && !mono_atomic_cas_i32 (&info->profiler_signal_ack, 0, 1))
continue;
mono_threads_pthread_kill (info, profiler_signal);
mono_atomic_inc_i32 (&profiler_signals_sent);
} FOREACH_THREAD_SAFE_END
}