/**
* Acquires the lock over threading subsystem.
*
* The lock blocks new thread creation and thread exit operations.
*/
IDATA VMCALL hythread_global_lock() {
IDATA status;
hythread_t self = hythread_self();
// we need not care about suspension if the thread
// is not even attached to hythread
if (self == NULL) {
return port_mutex_lock(&TM_LIBRARY->TM_LOCK);
}
// disable_count must be 0 on potentially
// blocking operation to prevent suspension deadlocks,
// meaning that the thread is safe for suspension
assert(hythread_is_suspend_enabled());
status = port_mutex_lock(&TM_LIBRARY->TM_LOCK);
assert(status == TM_ERROR_NONE);
// make sure we do not get a global thread lock
// while being requested to suspend
while (self->suspend_count) {
// give up global thread lock before safepoint,
// because this thread can be suspended at a safepoint
status = port_mutex_unlock(&TM_LIBRARY->TM_LOCK);
assert(status == TM_ERROR_NONE);
hythread_safe_point();
status = port_mutex_lock(&TM_LIBRARY->TM_LOCK);
assert(status == TM_ERROR_NONE);
}
return TM_ERROR_NONE;
}
/**
* Releases the ownership over monitor.
*
* @param[in] mon_ptr monitor
*/
IDATA VMCALL jthread_raw_monitor_exit(jrawMonitorID mon_ptr)
{
hythread_monitor_t monitor =
(hythread_monitor_t)array_get(jvmti_monitor_table, (UDATA)mon_ptr);
if (!monitor) {
return TM_ERROR_INVALID_MONITOR;
}
IDATA status = hythread_monitor_exit(monitor);
hythread_safe_point();
hythread_exception_safe_point();
return status;
} // jthread_raw_monitor_exit
/*
this method is called before STW gc start, there is a big lock outside
*/
void gc_wait_con_finish( GC* gc ) {
int64 time_collection_start = time_now();
unsigned int partial_type; //for time measuring and debugging
/* cocurrent gc is idle */
if( state_transformation( gc, GC_CON_NIL, GC_CON_DISABLE ) ) { // for the race condition of con schduling and STW gc
Con_Collection_Statistics *con_collection_stat = gc_ms_get_con_collection_stat((GC_MS*)gc);
con_collection_stat->gc_start_time = time_now();
con_collection_stat->pause_start_time = con_collection_stat->gc_start_time;
partial_type = GC_PARTIAL_PSTW;
gc_partial_con_PSTW( gc );
} else {
while(gc->gc_concurrent_status == GC_CON_STW_ENUM ) { //wait concurrent gc finish enumeration
hythread_safe_point();
vm_thread_yield();
}
if( gc_is_kind(ALGO_CON_MOSTLY) )
partial_type = gc_con_heap_full_mostly_con(gc);
else if( gc_is_kind(ALGO_CON_OTF_OBJ) || gc_is_kind(ALGO_CON_OTF_REF) ) {
partial_type = gc_con_heap_full_otf(gc);
if(gc->gc_concurrent_status == GC_CON_RESET) {
while( gc->gc_concurrent_status == GC_CON_RESET ) { //wait concurrent to finish
hythread_safe_point();
vm_thread_yield();
}
}
}
else
RAISE_ERROR;
}
int64 pause_time = time_now()-time_collection_start;
gc_con_stat_information_out(gc);
if(GC_CAUSE_RUNTIME_FORCE_GC == gc->cause) {
INFO2("gc.con.time","[GC][Con]pause( Forcing GC ): "<<(unsigned int)(pause_time)<<" us ");
} else {
partial_stop_the_world_info( partial_type, (unsigned int)pause_time );
}
}
IDATA monitor_wait_impl(hythread_monitor_t mon_ptr, I_64 ms, IDATA nano, IDATA interruptable) {
IDATA status;
int saved_recursion;
//int saved_disable_count;
hythread_t self = tm_self_tls;
if (mon_ptr->owner != self) {
return TM_ERROR_ILLEGAL_STATE;
}
saved_recursion = mon_ptr->recursion_count;
assert(saved_recursion>=0);
mon_ptr->owner = NULL;
mon_ptr->recursion_count =0;
mon_ptr->wait_count++;
port_mutex_lock(&self->mutex);
self->state |= TM_THREAD_STATE_IN_MONITOR_WAIT;
self->waited_monitor = mon_ptr;
port_mutex_unlock(&self->mutex);
do {
apr_time_t start;
assert(mon_ptr->notify_count >= 0);
assert(mon_ptr->notify_count < mon_ptr->wait_count);
start = apr_time_now();
status = condvar_wait_impl(&mon_ptr->condition, &mon_ptr->mutex, ms, nano, interruptable);
if (status != TM_ERROR_NONE || mon_ptr->notify_count) {
break;
}
// we should not change ms and nano if both are 0 (meaning "no timeout")
if (ms || nano) {
apr_interval_time_t elapsed;
elapsed = apr_time_now() - start; // microseconds
nano -= (IDATA)((elapsed % 1000) * 1000);
if (nano < 0) {
ms -= elapsed/1000 + 1;
nano += 1000000;
} else {
ms -= elapsed/1000;
}
if (ms < 0) {
assert(status == TM_ERROR_NONE);
status = TM_ERROR_TIMEOUT;
break;
}
assert(0 <= nano && nano < 1000000);
}
} while (1);
// consume the notify_count unless we got an error (or were interrupted)
if (mon_ptr->notify_count > 0
&& (status == TM_ERROR_NONE || mon_ptr->notify_count == mon_ptr->wait_count))
{
mon_ptr->notify_count--;
}
port_mutex_lock(&self->mutex);
self->state &= ~TM_THREAD_STATE_IN_MONITOR_WAIT;
self->waited_monitor = NULL;
port_mutex_unlock(&self->mutex);
mon_ptr->wait_count--;
assert(mon_ptr->notify_count <= mon_ptr->wait_count);
if (self->request) {
int save_count;
port_mutex_unlock(&mon_ptr->mutex);
hythread_safe_point();
hythread_exception_safe_point();
save_count = hythread_reset_suspend_disable();
port_mutex_lock(&mon_ptr->mutex);
hythread_set_suspend_disable(save_count);
}
mon_ptr->recursion_count = saved_recursion;
mon_ptr->owner = self;
assert(mon_ptr->owner);
return status;
}
IDATA thread_sleep_impl(I_64 millis, IDATA nanos, IDATA interruptable) {
IDATA status;
IDATA result;
hythread_t self;
hythread_monitor_t mon;
if (nanos == 0 && millis == 0) {
hythread_yield();
return TM_ERROR_NONE;
}
if (!(self = hythread_self())) {
// Report error in case current thread is not attached
return TM_ERROR_UNATTACHED_THREAD;
}
// Grab thread monitor
mon = self->monitor;
status = hythread_monitor_enter(mon);
assert(status == TM_ERROR_NONE);
assert(mon->recursion_count == 0);
mon->owner = NULL;
mon->wait_count++;
// Set thread state
status = port_mutex_lock(&self->mutex);
assert(status == TM_ERROR_NONE);
self->waited_monitor = mon;
self->state |= TM_THREAD_STATE_SLEEPING;
status = port_mutex_unlock(&self->mutex);
assert(status == TM_ERROR_NONE);
do {
apr_time_t start;
assert(mon->notify_count >= 0);
assert(mon->notify_count < mon->wait_count);
start = apr_time_now();
result = condvar_wait_impl(&mon->condition, &mon->mutex, millis, nanos, interruptable);
if (result != TM_ERROR_NONE) {
break;
}
// we should not change millis and nanos if both are 0 (meaning "no timeout")
if (millis || nanos) {
apr_interval_time_t elapsed = apr_time_now() - start;
nanos -= (IDATA)((elapsed % 1000) * 1000);
if (nanos < 0) {
millis -= elapsed/1000 + 1;
nanos += 1000000;
} else {
millis -= elapsed/1000;
}
if (millis < 0) {
assert(status == TM_ERROR_NONE);
status = TM_ERROR_TIMEOUT;
break;
}
assert(0 <= nanos && nanos < 1000000);
}
} while(1);
// Restore thread state
status = port_mutex_lock(&self->mutex);
assert(status == TM_ERROR_NONE);
self->state &= ~TM_THREAD_STATE_SLEEPING;
self->waited_monitor = NULL;
status = port_mutex_unlock(&self->mutex);
assert(status == TM_ERROR_NONE);
// Release thread monitor
mon->wait_count--;
mon->owner = self;
assert(mon->notify_count <= mon->wait_count);
status = hythread_monitor_exit(mon);
assert(status == TM_ERROR_NONE);
if (self->request) {
hythread_safe_point();
hythread_exception_safe_point();
}
return (result == TM_ERROR_INTERRUPT && interruptable)
? TM_ERROR_INTERRUPT : TM_ERROR_NONE;
}
/**
* Gains the ownership over monitor.
*
* Current thread blocks if the specified monitor is owned by other thread.
*
* @param[in] monitor object where monitor is located
* @sa JNI::MonitorEnter()
*/
IDATA VMCALL jthread_monitor_enter(jobject monitor)
{
IDATA state;
hythread_t native_thread;
apr_time_t enter_begin;
assert(monitor);
hythread_suspend_disable();
hythread_thin_monitor_t *lockword = vm_object_get_lockword_addr(monitor);
IDATA status = hythread_thin_monitor_try_enter(lockword);
if (status != TM_ERROR_EBUSY) {
goto entered;
}
#ifdef LOCK_RESERVATION
// busy unreserve lock before blocking and inflating
while (TM_ERROR_NONE != hythread_unreserve_lock(lockword)) {
hythread_yield();
hythread_safe_point();
hythread_exception_safe_point();
lockword = vm_object_get_lockword_addr(monitor);
}
status = hythread_thin_monitor_try_enter(lockword);
if (status != TM_ERROR_EBUSY) {
goto entered;
}
#endif //LOCK_RESERVATION
native_thread = hythread_self();
hythread_thread_lock(native_thread);
state = hythread_get_state(native_thread);
state &= ~TM_THREAD_STATE_RUNNABLE;
state |= TM_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER;
status = hythread_set_state(native_thread, state);
assert(status == TM_ERROR_NONE);
hythread_thread_unlock(native_thread);
// should be moved to event handler
if (ti_is_enabled()) {
enter_begin = apr_time_now();
int disable_count = hythread_reset_suspend_disable();
jthread_set_owned_monitor(monitor);
if(jvmti_should_report_event(JVMTI_EVENT_MONITOR_CONTENDED_ENTER)) {
jvmti_send_contended_enter_or_entered_monitor_event(monitor, 1);
}
hythread_set_suspend_disable(disable_count);
}
// busy wait and inflate
// reload pointer after safepoints
lockword = vm_object_get_lockword_addr(monitor);
while ((status =
hythread_thin_monitor_try_enter(lockword)) == TM_ERROR_EBUSY)
{
hythread_safe_point();
hythread_exception_safe_point();
lockword = vm_object_get_lockword_addr(monitor);
if (hythread_is_fat_lock(*lockword)) {
status = hythread_thin_monitor_enter(lockword);
if (status != TM_ERROR_NONE) {
hythread_suspend_enable();
assert(0);
return status;
}
goto contended_entered;
}
hythread_yield();
}
assert(status == TM_ERROR_NONE);
if (!hythread_is_fat_lock(*lockword)) {
hythread_inflate_lock(lockword);
}
// do all ti staff here
contended_entered:
if (ti_is_enabled()) {
int disable_count = hythread_reset_suspend_disable();
if(jvmti_should_report_event(JVMTI_EVENT_MONITOR_CONTENDED_ENTERED)) {
jvmti_send_contended_enter_or_entered_monitor_event(monitor, 0);
}
hythread_set_suspend_disable(disable_count);
// should be moved to event handler
jvmti_thread_t jvmti_thread =
jthread_get_jvmti_thread(hythread_self());
jvmti_thread->blocked_time += apr_time_now() - enter_begin;
}
hythread_thread_lock(native_thread);
state = hythread_get_state(native_thread);
state &= ~TM_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER;
state |= TM_THREAD_STATE_RUNNABLE;
status = hythread_set_state(native_thread, state);
assert(status == TM_ERROR_NONE);
hythread_thread_unlock(native_thread);
entered:
if (ti_is_enabled()) {
jthread_add_owned_monitor(monitor);
}
hythread_suspend_enable();
return TM_ERROR_NONE;
} // jthread_monitor_enter
