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src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp
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rev 47675 : [mq]: 8149127-rename-concurrentrefine-a
rev 47676 : imported patch 8149127-rename-concurrentrefine-b
rev 47677 : [mq]: 8149127-rename-concurrentrefine-b-stefanj-review
rev 47678 : imported patch 8140255-move-sampling-thread
rev 47679 : [mq]: 8140255-update
rev 47680 : [mq]: 8190426-lazy-init-refinement-threads
@@ -31,10 +31,83 @@
#include "utilities/debug.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/pair.hpp"
#include <math.h>
+G1ConcurrentRefineThreadControl::G1ConcurrentRefineThreadControl() :
+ _cg1r(NULL),
+ _threads(NULL),
+ _num_max_threads(0)
+{
+}
+
+G1ConcurrentRefineThreadControl::~G1ConcurrentRefineThreadControl() {
+ for (uint i = 0; i < _num_max_threads; i++) {
+ G1ConcurrentRefineThread* t = _threads[i];
+ if (t != NULL) {
+ delete t;
+ }
+ }
+ FREE_C_HEAP_ARRAY(G1ConcurrentRefineThread*, _threads);
+}
+
+void G1ConcurrentRefineThreadControl::initialize(G1ConcurrentRefine* cg1r, uint num_max_threads) {
+ assert(cg1r != NULL, "Passed g1ConcurrentRefine must not be NULL");
+ _cg1r = cg1r;
+ _num_max_threads = num_max_threads;
+ _threads = NEW_C_HEAP_ARRAY(G1ConcurrentRefineThread*, num_max_threads, mtGC);
+ for (uint i = 0; i < num_max_threads; i++) {
+ if (UseDynamicNumberOfGCThreads) {
+ _threads[i] = NULL;
+ } else {
+ _threads[i] = new G1ConcurrentRefineThread(_cg1r, i);
+ }
+ }
+}
+
+void G1ConcurrentRefineThreadControl::maybe_activate_next(uint cur_worker_id) {
+ assert(cur_worker_id < _num_max_threads, "Tried to activate from impossible thread %u", cur_worker_id);
+ if (cur_worker_id == (_num_max_threads - 1)) {
+ // Already the last thread, there is no more thread to activate.
+ return;
+ }
+
+ uint worker_id = cur_worker_id + 1;
+ G1ConcurrentRefineThread* thread_to_activate = _threads[worker_id];
+ if (thread_to_activate == NULL) {
+ // Still need to create the thread...
+ _threads[worker_id] = new G1ConcurrentRefineThread(_cg1r, worker_id);
+ thread_to_activate = _threads[worker_id];
+ }
+ thread_to_activate->activate();
+}
+
+void G1ConcurrentRefineThreadControl::print_on(outputStream* st) const {
+ for (uint i = 0; i < _num_max_threads; ++i) {
+ if (_threads[i] != NULL) {
+ _threads[i]->print_on(st);
+ st->cr();
+ }
+ }
+}
+
+void G1ConcurrentRefineThreadControl::worker_threads_do(ThreadClosure* tc) {
+ for (uint i = 0; i < _num_max_threads; i++) {
+ if (_threads[i] != NULL) {
+ tc->do_thread(_threads[i]);
+ }
+ }
+}
+
+void G1ConcurrentRefineThreadControl::stop() {
+ for (uint i = 0; i < _num_max_threads; i++) {
+ if (_threads[i] != NULL) {
+ _threads[i]->stop();
+ }
+ }
+}
+
// Arbitrary but large limits, to simplify some of the zone calculations.
// The general idea is to allow expressions like
// MIN2(x OP y, max_XXX_zone)
// without needing to check for overflow in "x OP y", because the
// ranges for x and y have been restricted.
@@ -94,11 +167,11 @@
static Thresholds calc_thresholds(size_t green_zone,
size_t yellow_zone,
uint worker_i) {
double yellow_size = yellow_zone - green_zone;
- double step = yellow_size / G1ConcurrentRefine::thread_num();
+ double step = yellow_size / G1ConcurrentRefine::max_num_threads();
if (worker_i == 0) {
// Potentially activate worker 0 more aggressively, to keep
// available buffers near green_zone value. When yellow_size is
// large we don't want to allow a full step to accumulate before
// doing any processing, as that might lead to significantly more
@@ -113,23 +186,23 @@
G1ConcurrentRefine::G1ConcurrentRefine(size_t green_zone,
size_t yellow_zone,
size_t red_zone,
size_t min_yellow_zone_size) :
- _threads(NULL),
- _n_worker_threads(thread_num()),
+ _thread_control(),
_green_zone(green_zone),
_yellow_zone(yellow_zone),
_red_zone(red_zone),
_min_yellow_zone_size(min_yellow_zone_size)
{
assert_zone_constraints_gyr(green_zone, yellow_zone, red_zone);
+ _thread_control.initialize(this, max_num_threads());
}
static size_t calc_min_yellow_zone_size() {
size_t step = G1ConcRefinementThresholdStep;
- uint n_workers = G1ConcurrentRefine::thread_num();
+ uint n_workers = G1ConcurrentRefine::max_num_threads();
if ((max_yellow_zone / step) < n_workers) {
return max_yellow_zone;
} else {
return step * n_workers;
}
@@ -189,81 +262,31 @@
*ecode = JNI_ENOMEM;
vm_shutdown_during_initialization("Could not create G1ConcurrentRefine");
return NULL;
}
- cr->_threads = NEW_C_HEAP_ARRAY_RETURN_NULL(G1ConcurrentRefineThread*, cr->_n_worker_threads, mtGC);
- if (cr->_threads == NULL) {
- *ecode = JNI_ENOMEM;
- vm_shutdown_during_initialization("Could not allocate an array for G1ConcurrentRefineThread");
- return NULL;
- }
-
- uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
-
- G1ConcurrentRefineThread *next = NULL;
- for (uint i = cr->_n_worker_threads - 1; i != UINT_MAX; i--) {
- Thresholds thresholds = calc_thresholds(green_zone, yellow_zone, i);
- G1ConcurrentRefineThread* t =
- new G1ConcurrentRefineThread(cr,
- next,
- worker_id_offset,
- i,
- activation_level(thresholds),
- deactivation_level(thresholds));
- assert(t != NULL, "Conc refine should have been created");
- if (t->osthread() == NULL) {
- *ecode = JNI_ENOMEM;
- vm_shutdown_during_initialization("Could not create G1ConcurrentRefineThread");
- return NULL;
- }
-
- assert(t->cr() == cr, "Conc refine thread should refer to this");
- cr->_threads[i] = t;
- next = t;
- }
-
*ecode = JNI_OK;
return cr;
}
void G1ConcurrentRefine::stop() {
- for (uint i = 0; i < _n_worker_threads; i++) {
- _threads[i]->stop();
- }
-}
-
-void G1ConcurrentRefine::update_thread_thresholds() {
- for (uint i = 0; i < _n_worker_threads; i++) {
- Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, i);
- _threads[i]->update_thresholds(activation_level(thresholds),
- deactivation_level(thresholds));
- }
+ _thread_control.stop();
}
G1ConcurrentRefine::~G1ConcurrentRefine() {
- for (uint i = 0; i < _n_worker_threads; i++) {
- delete _threads[i];
- }
- FREE_C_HEAP_ARRAY(G1ConcurrentRefineThread*, _threads);
}
void G1ConcurrentRefine::threads_do(ThreadClosure *tc) {
- for (uint i = 0; i < _n_worker_threads; i++) {
- tc->do_thread(_threads[i]);
- }
+ _thread_control.worker_threads_do(tc);
}
-uint G1ConcurrentRefine::thread_num() {
+uint G1ConcurrentRefine::max_num_threads() {
return G1ConcRefinementThreads;
}
void G1ConcurrentRefine::print_threads_on(outputStream* st) const {
- for (uint i = 0; i < _n_worker_threads; ++i) {
- _threads[i]->print_on(st);
- st->cr();
- }
+ _thread_control.print_on(st);
}
static size_t calc_new_green_zone(size_t green,
double update_rs_time,
size_t update_rs_processed_buffers,
@@ -324,20 +347,19 @@
double goal_ms) {
DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
if (G1UseAdaptiveConcRefinement) {
update_zones(update_rs_time, update_rs_processed_buffers, goal_ms);
- update_thread_thresholds();
// Change the barrier params
- if (_n_worker_threads == 0) {
+ if (max_num_threads() == 0) {
// Disable dcqs notification when there are no threads to notify.
dcqs.set_process_completed_threshold(INT_MAX);
} else {
// Worker 0 is the primary; wakeup is via dcqs notification.
STATIC_ASSERT(max_yellow_zone <= INT_MAX);
- size_t activate = _threads[0]->activation_threshold();
+ size_t activate = activation_threshold(0);
dcqs.set_process_completed_threshold((int)activate);
}
dcqs.set_max_completed_queue((int)red_zone());
}
@@ -347,5 +369,44 @@
} else {
dcqs.set_completed_queue_padding(0);
}
dcqs.notify_if_necessary();
}
+
+size_t G1ConcurrentRefine::activation_threshold(uint worker_id) const {
+ Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, worker_id);
+ return activation_level(thresholds);
+}
+
+size_t G1ConcurrentRefine::deactivation_threshold(uint worker_id) const {
+ Thresholds thresholds = calc_thresholds(_green_zone, _yellow_zone, worker_id);
+ return deactivation_level(thresholds);
+}
+
+uint G1ConcurrentRefine::worker_id_offset() {
+ return DirtyCardQueueSet::num_par_ids();
+}
+
+void G1ConcurrentRefine::maybe_activate_more_threads(uint worker_id, size_t num_cur_buffers) {
+ if (activation_threshold(worker_id + 1) > num_cur_buffers) {
+ _thread_control.maybe_activate_next(worker_id);
+ }
+}
+
+bool G1ConcurrentRefine::do_refinement_step(uint worker_id) {
+ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+
+ size_t curr_buffer_num = 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.
+ // Since the value written to the DCQS is the same for all threads, there is no
+ // need to synchronize.
+ if (dcqs.completed_queue_padding() > 0 && curr_buffer_num <= yellow_zone()) {
+ dcqs.set_completed_queue_padding(0);
+ }
+
+ maybe_activate_more_threads(worker_id, curr_buffer_num);
+
+ // Process the next buffer, if there are enough left.
+ return dcqs.refine_completed_buffer_concurrently(worker_id + worker_id_offset(),
+ deactivation_threshold(worker_id));
+}
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