void
mono_thread_info_self_suspend (void)
{
gboolean ret;
MonoThreadInfo *info = mono_thread_info_current ();
if (!info)
return;
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->suspend_semaphore);
THREADS_DEBUG ("self suspend IN COUNT %d\n", info->suspend_count);
g_assert (info->suspend_count == 0);
++info->suspend_count;
info->thread_state |= STATE_SELF_SUSPENDED;
ret = mono_threads_get_runtime_callbacks ()->thread_state_init_from_sigctx (&info->suspend_state, NULL);
g_assert (ret);
MONO_SEM_POST (&info->suspend_semaphore);
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->resume_semaphore);
g_assert (!info->async_target); /*FIXME this should happen normally for suspend. */
MONO_SEM_POST (&info->finish_resume_semaphore);
}
gboolean
mono_thread_info_resume (MonoNativeThreadId tid)
{
gboolean result = TRUE;
MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
MonoThreadInfo *info = mono_thread_info_lookup (tid); /*info on HP1*/
if (!info)
return FALSE;
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->suspend_semaphore);
THREADS_DEBUG ("resume %x IN COUNT %d\n",tid, info->suspend_count);
if (info->suspend_count <= 0) {
MONO_SEM_POST (&info->suspend_semaphore);
mono_hazard_pointer_clear (hp, 1);
return FALSE;
}
/*
* The theory here is that if we manage to suspend the thread it means it did not
* start cleanup since it take the same lock.
*/
g_assert (mono_thread_info_get_tid (info));
if (--info->suspend_count == 0)
result = mono_thread_info_resume_internal (info);
MONO_SEM_POST (&info->suspend_semaphore);
mono_hazard_pointer_clear (hp, 1);
mono_atomic_store_release (&mono_thread_info_current ()->inside_critical_region, FALSE);
return result;
}
/*
The suspend lock is held during any suspend in progress.
A GC that has safepoints must take this lock as part of its
STW to make sure no unsafe pending suspend is in progress.
*/
void
mono_thread_info_suspend_lock (void)
{
MONO_TRY_BLOCKING;
MONO_SEM_WAIT_UNITERRUPTIBLE (&global_suspend_semaphore);
MONO_FINISH_TRY_BLOCKING;
}
static gboolean
mono_thread_info_core_resume (MonoThreadInfo *info)
{
gboolean result;
MonoNativeThreadId tid = mono_thread_info_get_tid (info);
if (info->create_suspended) {
/* Have to special case this, as the normal suspend/resume pair are racy, they don't work if he resume is received before the suspend */
info->create_suspended = FALSE;
mono_threads_core_resume_created (info, tid);
return TRUE;
}
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->suspend_semaphore);
THREADS_DEBUG ("resume %x IN COUNT %d\n", tid, info->suspend_count);
if (info->suspend_count <= 0) {
MONO_SEM_POST (&info->suspend_semaphore);
return FALSE;
}
/*
* The theory here is that if we manage to suspend the thread it means it did not
* start cleanup since it take the same lock.
*/
g_assert (mono_thread_info_get_tid (info));
if (--info->suspend_count == 0) {
if (mono_thread_info_suspend_state (info) == STATE_SELF_SUSPENDED) {
MONO_SEM_POST (&info->resume_semaphore);
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->finish_resume_semaphore);
result = TRUE;
} else {
result = mono_threads_core_resume (info);
}
info->thread_state &= ~SUSPEND_STATE_MASK;
} else {
result = TRUE;
}
MONO_SEM_POST (&info->suspend_semaphore);
return result;
}
static gboolean
mono_thread_info_resume_internal (MonoThreadInfo *info)
{
gboolean result;
if (mono_thread_info_suspend_state (info) == STATE_SELF_SUSPENDED) {
MONO_SEM_POST (&info->resume_semaphore);
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->finish_resume_semaphore);
result = TRUE;
} else {
result = mono_threads_core_resume (info);
}
info->thread_state &= ~SUSPEND_STATE_MASK;
return result;
}
/*
The return value is only valid until a matching mono_thread_info_resume is called
*/
static MonoThreadInfo*
mono_thread_info_suspend_sync (MonoNativeThreadId tid, gboolean interrupt_kernel, const char **error_condition)
{
MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
MonoThreadInfo *info = mono_thread_info_lookup (tid); /*info on HP1*/
if (!info) {
*error_condition = "Thread not found";
return NULL;
}
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->suspend_semaphore);
/*thread is on the process of detaching*/
if (mono_thread_info_run_state (info) > STATE_RUNNING) {
mono_hazard_pointer_clear (hp, 1);
*error_condition = "Thread is detaching";
return NULL;
}
THREADS_DEBUG ("suspend %x IN COUNT %d\n", tid, info->suspend_count);
if (info->suspend_count) {
++info->suspend_count;
mono_hazard_pointer_clear (hp, 1);
MONO_SEM_POST (&info->suspend_semaphore);
return info;
}
if (!mono_threads_core_suspend (info)) {
MONO_SEM_POST (&info->suspend_semaphore);
mono_hazard_pointer_clear (hp, 1);
*error_condition = "Could not suspend thread";
return NULL;
}
if (interrupt_kernel)
mono_threads_core_interrupt (info);
++info->suspend_count;
info->thread_state |= STATE_SUSPENDED;
MONO_SEM_POST (&info->suspend_semaphore);
return info;
}
/*
The suspend lock is held during any suspend in progress.
A GC that has safepoints must take this lock as part of its
STW to make sure no unsafe pending suspend is in progress.
*/
void
mono_thread_info_suspend_lock (void)
{
MONO_SEM_WAIT_UNITERRUPTIBLE (&global_suspend_semaphore);
}
void
mono_thread_info_wait_for_resume (MonoThreadInfo* info)
{
THREADS_SUSPEND_DEBUG ("**WAIT self-resume %p\n", mono_thread_info_get_tid (info));
MONO_SEM_WAIT_UNITERRUPTIBLE (&info->resume_semaphore);
}
