--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Fri Dec 11 09:30:48 2009 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp Wed Dec 16 15:12:51 2009 -0800
@@ -25,10 +25,6 @@
#include "incls/_precompiled.incl"
#include "incls/_concurrentG1RefineThread.cpp.incl"
-// ======= Concurrent Mark Thread ========
-
-// The CM thread is created when the G1 garbage collector is used
-
ConcurrentG1RefineThread::
ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread *next,
int worker_id_offset, int worker_id) :
@@ -37,19 +33,42 @@
_worker_id(worker_id),
_active(false),
_next(next),
+ _monitor(NULL),
_cg1r(cg1r),
- _vtime_accum(0.0),
- _interval_ms(5.0)
+ _vtime_accum(0.0)
{
+
+ // Each thread has its own monitor. The i-th thread is responsible for signalling
+ // to thread i+1 if the number of buffers in the queue exceeds a threashold for this
+ // thread. Monitors are also used to wake up the threads during termination.
+ // The 0th worker in notified by mutator threads and has a special monitor.
+ // The last worker is used for young gen rset size sampling.
+ if (worker_id > 0) {
+ _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true);
+ } else {
+ _monitor = DirtyCardQ_CBL_mon;
+ }
+ initialize();
create_and_start();
}
+void ConcurrentG1RefineThread::initialize() {
+ if (_worker_id < cg1r()->worker_thread_num()) {
+ // Current thread activation threshold
+ _threshold = MIN2<int>(cg1r()->thread_threshold_step() * (_worker_id + 1) + cg1r()->green_zone(),
+ cg1r()->yellow_zone());
+ // A thread deactivates once the number of buffer reached a deactivation threshold
+ _deactivation_threshold = MAX2<int>(_threshold - cg1r()->thread_threshold_step(), cg1r()->green_zone());
+ } else {
+ set_active(true);
+ }
+}
+
void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
G1CollectorPolicy* g1p = g1h->g1_policy();
if (g1p->adaptive_young_list_length()) {
int regions_visited = 0;
-
g1h->young_list_rs_length_sampling_init();
while (g1h->young_list_rs_length_sampling_more()) {
g1h->young_list_rs_length_sampling_next();
@@ -70,99 +89,121 @@
}
}
-void ConcurrentG1RefineThread::run() {
- initialize_in_thread();
+void ConcurrentG1RefineThread::run_young_rs_sampling() {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
_vtime_start = os::elapsedVTime();
- wait_for_universe_init();
+ while(!_should_terminate) {
+ _sts.join();
+ sample_young_list_rs_lengths();
+ _sts.leave();
- while (!_should_terminate) {
- DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
- // Wait for completed log buffers to exist.
- {
- MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
- while (((_worker_id == 0 && !dcqs.process_completed_buffers()) ||
- (_worker_id > 0 && !is_active())) &&
- !_should_terminate) {
- DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag);
- }
- }
-
- if (_should_terminate) {
- return;
+ if (os::supports_vtime()) {
+ _vtime_accum = (os::elapsedVTime() - _vtime_start);
+ } else {
+ _vtime_accum = 0.0;
}
- // Now we take them off (this doesn't hold locks while it applies
- // closures.) (If we did a full collection, then we'll do a full
- // traversal.
- _sts.join();
- int n_logs = 0;
- int lower_limit = 0;
- double start_vtime_sec; // only used when G1SmoothConcRefine is on
- int prev_buffer_num; // only used when G1SmoothConcRefine is on
- // This thread activation threshold
- int threshold = G1UpdateBufferQueueProcessingThreshold * _worker_id;
- // Next thread activation threshold
- int next_threshold = threshold + G1UpdateBufferQueueProcessingThreshold;
- int deactivation_threshold = MAX2<int>(threshold - G1UpdateBufferQueueProcessingThreshold / 2, 0);
+ MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
+ if (_should_terminate) {
+ break;
+ }
+ _monitor->wait(Mutex::_no_safepoint_check_flag, G1ConcRefineServiceInterval);
+ }
+}
- if (G1SmoothConcRefine) {
- lower_limit = 0;
- start_vtime_sec = os::elapsedVTime();
- prev_buffer_num = (int) dcqs.completed_buffers_num();
- } else {
- lower_limit = G1UpdateBufferQueueProcessingThreshold / 4; // For now.
+void ConcurrentG1RefineThread::wait_for_completed_buffers() {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
+ while (!_should_terminate && !is_active()) {
+ _monitor->wait(Mutex::_no_safepoint_check_flag);
+ }
+}
+
+bool ConcurrentG1RefineThread::is_active() {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ return _worker_id > 0 ? _active : dcqs.process_completed_buffers();
+}
+
+void ConcurrentG1RefineThread::activate() {
+ MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
+ if (_worker_id > 0) {
+ if (G1TraceConcurrentRefinement) {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ gclog_or_tty->print_cr("G1-Refine-activated worker %d, on threshold %d, current %d",
+ _worker_id, _threshold, (int)dcqs.completed_buffers_num());
}
- while (dcqs.apply_closure_to_completed_buffer(_worker_id + _worker_id_offset, lower_limit)) {
- double end_vtime_sec;
- double elapsed_vtime_sec;
- int elapsed_vtime_ms;
- int curr_buffer_num = (int) dcqs.completed_buffers_num();
+ set_active(true);
+ } else {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ dcqs.set_process_completed(true);
+ }
+ _monitor->notify();
+}
- if (G1SmoothConcRefine) {
- end_vtime_sec = os::elapsedVTime();
- elapsed_vtime_sec = end_vtime_sec - start_vtime_sec;
- elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0);
+void ConcurrentG1RefineThread::deactivate() {
+ MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
+ if (_worker_id > 0) {
+ if (G1TraceConcurrentRefinement) {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ gclog_or_tty->print_cr("G1-Refine-deactivated worker %d, off threshold %d, current %d",
+ _worker_id, _deactivation_threshold, (int)dcqs.completed_buffers_num());
+ }
+ set_active(false);
+ } else {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+ dcqs.set_process_completed(false);
+ }
+}
+
+void ConcurrentG1RefineThread::run() {
+ initialize_in_thread();
+ wait_for_universe_init();
- if (curr_buffer_num > prev_buffer_num ||
- curr_buffer_num > next_threshold) {
- decreaseInterval(elapsed_vtime_ms);
- } else if (curr_buffer_num < prev_buffer_num) {
- increaseInterval(elapsed_vtime_ms);
- }
+ if (_worker_id >= cg1r()->worker_thread_num()) {
+ run_young_rs_sampling();
+ terminate();
+ }
+
+ _vtime_start = os::elapsedVTime();
+ while (!_should_terminate) {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+
+ // Wait for work
+ wait_for_completed_buffers();
+
+ if (_should_terminate) {
+ break;
+ }
+
+ _sts.join();
+
+ do {
+ int curr_buffer_num = (int)dcqs.completed_buffers_num();
+ // If the number of the buffers falls down into the yellow zone,
+ // that means that the transition period after the evacuation pause has ended.
+ if (dcqs.completed_queue_padding() > 0 && curr_buffer_num <= cg1r()->yellow_zone()) {
+ dcqs.set_completed_queue_padding(0);
}
- if (_worker_id == 0) {
- sample_young_list_rs_lengths();
- } else if (curr_buffer_num < deactivation_threshold) {
+
+ if (_worker_id > 0 && curr_buffer_num <= _deactivation_threshold) {
// If the number of the buffer has fallen below our threshold
// we should deactivate. The predecessor will reactivate this
// thread should the number of the buffers cross the threshold again.
- MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
deactivate();
- if (G1TraceConcurrentRefinement) {
- gclog_or_tty->print_cr("G1-Refine-deactivated worker %d", _worker_id);
- }
break;
}
// Check if we need to activate the next thread.
- if (curr_buffer_num > next_threshold && _next != NULL && !_next->is_active()) {
- MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
+ if (_next != NULL && !_next->is_active() && curr_buffer_num > _next->_threshold) {
_next->activate();
- DirtyCardQ_CBL_mon->notify_all();
- if (G1TraceConcurrentRefinement) {
- gclog_or_tty->print_cr("G1-Refine-activated worker %d", _next->_worker_id);
- }
}
+ } while (dcqs.apply_closure_to_completed_buffer(_worker_id + _worker_id_offset, cg1r()->green_zone()));
- if (G1SmoothConcRefine) {
- prev_buffer_num = curr_buffer_num;
- _sts.leave();
- os::sleep(Thread::current(), (jlong) _interval_ms, false);
- _sts.join();
- start_vtime_sec = os::elapsedVTime();
- }
- n_logs++;
+ // We can exit the loop above while being active if there was a yield request.
+ if (is_active()) {
+ deactivate();
}
+
_sts.leave();
if (os::supports_vtime()) {
@@ -172,7 +213,6 @@
}
}
assert(_should_terminate, "just checking");
-
terminate();
}
@@ -191,8 +231,8 @@
}
{
- MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
- DirtyCardQ_CBL_mon->notify_all();
+ MutexLockerEx x(_monitor, Mutex::_no_safepoint_check_flag);
+ _monitor->notify();
}
{