MonoStringHandle
mono_string_new_handle (MonoDomain *domain, const char *data, MonoError *error)
{
return MONO_HANDLE_NEW (MonoString, mono_string_new_checked (domain, data, error));
}
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
}
