duke@435: /*
trims@1907:  * Copyright (c) 2002, 2007, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: #include "incls/_precompiled.incl"
duke@435: #include "incls/_gcTaskManager.cpp.incl"
duke@435: 
duke@435: //
duke@435: // GCTask
duke@435: //
duke@435: 
duke@435: const char* GCTask::Kind::to_string(kind value) {
duke@435:   const char* result = "unknown GCTask kind";
duke@435:   switch (value) {
duke@435:   default:
duke@435:     result = "unknown GCTask kind";
duke@435:     break;
duke@435:   case unknown_task:
duke@435:     result = "unknown task";
duke@435:     break;
duke@435:   case ordinary_task:
duke@435:     result = "ordinary task";
duke@435:     break;
duke@435:   case barrier_task:
duke@435:     result = "barrier task";
duke@435:     break;
duke@435:   case noop_task:
duke@435:     result = "noop task";
duke@435:     break;
duke@435:   }
duke@435:   return result;
duke@435: };
duke@435: 
duke@435: GCTask::GCTask() :
duke@435:   _kind(Kind::ordinary_task),
duke@435:   _affinity(GCTaskManager::sentinel_worker()){
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: GCTask::GCTask(Kind::kind kind) :
duke@435:   _kind(kind),
duke@435:   _affinity(GCTaskManager::sentinel_worker()) {
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: GCTask::GCTask(uint affinity) :
duke@435:   _kind(Kind::ordinary_task),
duke@435:   _affinity(affinity) {
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: GCTask::GCTask(Kind::kind kind, uint affinity) :
duke@435:   _kind(kind),
duke@435:   _affinity(affinity) {
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: void GCTask::initialize() {
duke@435:   _older = NULL;
duke@435:   _newer = NULL;
duke@435: }
duke@435: 
duke@435: void GCTask::destruct() {
duke@435:   assert(older() == NULL, "shouldn't have an older task");
duke@435:   assert(newer() == NULL, "shouldn't have a newer task");
duke@435:   // Nothing to do.
duke@435: }
duke@435: 
duke@435: NOT_PRODUCT(
duke@435: void GCTask::print(const char* message) const {
duke@435:   tty->print(INTPTR_FORMAT " <- " INTPTR_FORMAT "(%u) -> " INTPTR_FORMAT,
duke@435:              newer(), this, affinity(), older());
duke@435: }
duke@435: )
duke@435: 
duke@435: //
duke@435: // GCTaskQueue
duke@435: //
duke@435: 
duke@435: GCTaskQueue* GCTaskQueue::create() {
duke@435:   GCTaskQueue* result = new GCTaskQueue(false);
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("GCTaskQueue::create()"
duke@435:                   " returns " INTPTR_FORMAT, result);
duke@435:   }
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: GCTaskQueue* GCTaskQueue::create_on_c_heap() {
duke@435:   GCTaskQueue* result = new(ResourceObj::C_HEAP) GCTaskQueue(true);
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("GCTaskQueue::create_on_c_heap()"
duke@435:                   " returns " INTPTR_FORMAT,
duke@435:                   result);
duke@435:   }
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: GCTaskQueue::GCTaskQueue(bool on_c_heap) :
duke@435:   _is_c_heap_obj(on_c_heap) {
duke@435:   initialize();
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::GCTaskQueue() constructor",
duke@435:                   this);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void GCTaskQueue::destruct() {
duke@435:   // Nothing to do.
duke@435: }
duke@435: 
duke@435: void GCTaskQueue::destroy(GCTaskQueue* that) {
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::destroy()"
duke@435:                   "  is_c_heap_obj:  %s",
duke@435:                   that,
duke@435:                   that->is_c_heap_obj() ? "true" : "false");
duke@435:   }
duke@435:   // That instance may have been allocated as a CHeapObj,
duke@435:   // in which case we have to free it explicitly.
duke@435:   if (that != NULL) {
duke@435:     that->destruct();
duke@435:     assert(that->is_empty(), "should be empty");
duke@435:     if (that->is_c_heap_obj()) {
duke@435:       FreeHeap(that);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void GCTaskQueue::initialize() {
duke@435:   set_insert_end(NULL);
duke@435:   set_remove_end(NULL);
duke@435:   set_length(0);
duke@435: }
duke@435: 
duke@435: // Enqueue one task.
duke@435: void GCTaskQueue::enqueue(GCTask* task) {
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::enqueue(task: "
duke@435:                   INTPTR_FORMAT ")",
duke@435:                   this, task);
duke@435:     print("before:");
duke@435:   }
duke@435:   assert(task != NULL, "shouldn't have null task");
duke@435:   assert(task->older() == NULL, "shouldn't be on queue");
duke@435:   assert(task->newer() == NULL, "shouldn't be on queue");
duke@435:   task->set_newer(NULL);
duke@435:   task->set_older(insert_end());
duke@435:   if (is_empty()) {
duke@435:     set_remove_end(task);
duke@435:   } else {
duke@435:     insert_end()->set_newer(task);
duke@435:   }
duke@435:   set_insert_end(task);
duke@435:   increment_length();
duke@435:   if (TraceGCTaskQueue) {
duke@435:     print("after:");
duke@435:   }
duke@435: }
duke@435: 
duke@435: // Enqueue a whole list of tasks.  Empties the argument list.
duke@435: void GCTaskQueue::enqueue(GCTaskQueue* list) {
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::enqueue(list: "
duke@435:                   INTPTR_FORMAT ")",
duke@435:                   this);
duke@435:     print("before:");
duke@435:     list->print("list:");
duke@435:   }
duke@435:   if (list->is_empty()) {
duke@435:     // Enqueuing the empty list: nothing to do.
duke@435:     return;
duke@435:   }
duke@435:   uint list_length = list->length();
duke@435:   if (is_empty()) {
duke@435:     // Enqueuing to empty list: just acquire elements.
duke@435:     set_insert_end(list->insert_end());
duke@435:     set_remove_end(list->remove_end());
duke@435:     set_length(list_length);
duke@435:   } else {
duke@435:     // Prepend argument list to our queue.
duke@435:     list->remove_end()->set_older(insert_end());
duke@435:     insert_end()->set_newer(list->remove_end());
duke@435:     set_insert_end(list->insert_end());
duke@435:     // empty the argument list.
duke@435:   }
duke@435:   set_length(length() + list_length);
duke@435:   list->initialize();
duke@435:   if (TraceGCTaskQueue) {
duke@435:     print("after:");
duke@435:     list->print("list:");
duke@435:   }
duke@435: }
duke@435: 
duke@435: // Dequeue one task.
duke@435: GCTask* GCTaskQueue::dequeue() {
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::dequeue()", this);
duke@435:     print("before:");
duke@435:   }
duke@435:   assert(!is_empty(), "shouldn't dequeue from empty list");
duke@435:   GCTask* result = remove();
duke@435:   assert(result != NULL, "shouldn't have NULL task");
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("    return: " INTPTR_FORMAT, result);
duke@435:     print("after:");
duke@435:   }
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: // Dequeue one task, preferring one with affinity.
duke@435: GCTask* GCTaskQueue::dequeue(uint affinity) {
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " GCTaskQueue::dequeue(%u)", this, affinity);
duke@435:     print("before:");
duke@435:   }
duke@435:   assert(!is_empty(), "shouldn't dequeue from empty list");
duke@435:   // Look down to the next barrier for a task with this affinity.
duke@435:   GCTask* result = NULL;
duke@435:   for (GCTask* element = remove_end();
duke@435:        element != NULL;
duke@435:        element = element->newer()) {
duke@435:     if (element->is_barrier_task()) {
duke@435:       // Don't consider barrier tasks, nor past them.
duke@435:       result = NULL;
duke@435:       break;
duke@435:     }
duke@435:     if (element->affinity() == affinity) {
duke@435:       result = remove(element);
duke@435:       break;
duke@435:     }
duke@435:   }
duke@435:   // If we didn't find anything with affinity, just take the next task.
duke@435:   if (result == NULL) {
duke@435:     result = remove();
duke@435:   }
duke@435:   if (TraceGCTaskQueue) {
duke@435:     tty->print_cr("    return: " INTPTR_FORMAT, result);
duke@435:     print("after:");
duke@435:   }
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: GCTask* GCTaskQueue::remove() {
duke@435:   // Dequeue from remove end.
duke@435:   GCTask* result = remove_end();
duke@435:   assert(result != NULL, "shouldn't have null task");
duke@435:   assert(result->older() == NULL, "not the remove_end");
duke@435:   set_remove_end(result->newer());
duke@435:   if (remove_end() == NULL) {
duke@435:     assert(insert_end() == result, "not a singleton");
duke@435:     set_insert_end(NULL);
duke@435:   } else {
duke@435:     remove_end()->set_older(NULL);
duke@435:   }
duke@435:   result->set_newer(NULL);
duke@435:   decrement_length();
duke@435:   assert(result->newer() == NULL, "shouldn't be on queue");
duke@435:   assert(result->older() == NULL, "shouldn't be on queue");
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: GCTask* GCTaskQueue::remove(GCTask* task) {
duke@435:   // This is slightly more work, and has slightly fewer asserts
duke@435:   // than removing from the remove end.
duke@435:   assert(task != NULL, "shouldn't have null task");
duke@435:   GCTask* result = task;
duke@435:   if (result->newer() != NULL) {
duke@435:     result->newer()->set_older(result->older());
duke@435:   } else {
duke@435:     assert(insert_end() == result, "not youngest");
duke@435:     set_insert_end(result->older());
duke@435:   }
duke@435:   if (result->older() != NULL) {
duke@435:     result->older()->set_newer(result->newer());
duke@435:   } else {
duke@435:     assert(remove_end() == result, "not oldest");
duke@435:     set_remove_end(result->newer());
duke@435:   }
duke@435:   result->set_newer(NULL);
duke@435:   result->set_older(NULL);
duke@435:   decrement_length();
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: NOT_PRODUCT(
duke@435: void GCTaskQueue::print(const char* message) const {
duke@435:   tty->print_cr("[" INTPTR_FORMAT "] GCTaskQueue:"
duke@435:                 "  insert_end: " INTPTR_FORMAT
duke@435:                 "  remove_end: " INTPTR_FORMAT
duke@435:                 "  %s",
duke@435:                 this, insert_end(), remove_end(), message);
duke@435:   for (GCTask* element = insert_end();
duke@435:        element != NULL;
duke@435:        element = element->older()) {
duke@435:     element->print("    ");
duke@435:     tty->cr();
duke@435:   }
duke@435: }
duke@435: )
duke@435: 
duke@435: //
duke@435: // SynchronizedGCTaskQueue
duke@435: //
duke@435: 
duke@435: SynchronizedGCTaskQueue::SynchronizedGCTaskQueue(GCTaskQueue* queue_arg,
duke@435:                                                  Monitor *       lock_arg) :
duke@435:   _unsynchronized_queue(queue_arg),
duke@435:   _lock(lock_arg) {
duke@435:   assert(unsynchronized_queue() != NULL, "null queue");
duke@435:   assert(lock() != NULL, "null lock");
duke@435: }
duke@435: 
duke@435: SynchronizedGCTaskQueue::~SynchronizedGCTaskQueue() {
duke@435:   // Nothing to do.
duke@435: }
duke@435: 
duke@435: //
duke@435: // GCTaskManager
duke@435: //
duke@435: GCTaskManager::GCTaskManager(uint workers) :
duke@435:   _workers(workers),
duke@435:   _ndc(NULL) {
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: GCTaskManager::GCTaskManager(uint workers, NotifyDoneClosure* ndc) :
duke@435:   _workers(workers),
duke@435:   _ndc(ndc) {
duke@435:   initialize();
duke@435: }
duke@435: 
duke@435: void GCTaskManager::initialize() {
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("GCTaskManager::initialize: workers: %u", workers());
duke@435:   }
duke@435:   assert(workers() != 0, "no workers");
duke@435:   _monitor = new Monitor(Mutex::barrier,                // rank
duke@435:                          "GCTaskManager monitor",       // name
duke@435:                          Mutex::_allow_vm_block_flag);  // allow_vm_block
duke@435:   // The queue for the GCTaskManager must be a CHeapObj.
duke@435:   GCTaskQueue* unsynchronized_queue = GCTaskQueue::create_on_c_heap();
duke@435:   _queue = SynchronizedGCTaskQueue::create(unsynchronized_queue, lock());
duke@435:   _noop_task = NoopGCTask::create_on_c_heap();
duke@435:   _resource_flag = NEW_C_HEAP_ARRAY(bool, workers());
duke@435:   {
duke@435:     // Set up worker threads.
duke@435:     //     Distribute the workers among the available processors,
duke@435:     //     unless we were told not to, or if the os doesn't want to.
duke@435:     uint* processor_assignment = NEW_C_HEAP_ARRAY(uint, workers());
duke@435:     if (!BindGCTaskThreadsToCPUs ||
duke@435:         !os::distribute_processes(workers(), processor_assignment)) {
duke@435:       for (uint a = 0; a < workers(); a += 1) {
duke@435:         processor_assignment[a] = sentinel_worker();
duke@435:       }
duke@435:     }
duke@435:     _thread = NEW_C_HEAP_ARRAY(GCTaskThread*, workers());
duke@435:     for (uint t = 0; t < workers(); t += 1) {
duke@435:       set_thread(t, GCTaskThread::create(this, t, processor_assignment[t]));
duke@435:     }
duke@435:     if (TraceGCTaskThread) {
duke@435:       tty->print("GCTaskManager::initialize: distribution:");
duke@435:       for (uint t = 0; t < workers(); t += 1) {
duke@435:         tty->print("  %u", processor_assignment[t]);
duke@435:       }
duke@435:       tty->cr();
duke@435:     }
duke@435:     FREE_C_HEAP_ARRAY(uint, processor_assignment);
duke@435:   }
duke@435:   reset_busy_workers();
duke@435:   set_unblocked();
duke@435:   for (uint w = 0; w < workers(); w += 1) {
duke@435:     set_resource_flag(w, false);
duke@435:   }
duke@435:   reset_delivered_tasks();
duke@435:   reset_completed_tasks();
duke@435:   reset_noop_tasks();
duke@435:   reset_barriers();
duke@435:   reset_emptied_queue();
duke@435:   for (uint s = 0; s < workers(); s += 1) {
duke@435:     thread(s)->start();
duke@435:   }
duke@435: }
duke@435: 
duke@435: GCTaskManager::~GCTaskManager() {
duke@435:   assert(busy_workers() == 0, "still have busy workers");
duke@435:   assert(queue()->is_empty(), "still have queued work");
duke@435:   NoopGCTask::destroy(_noop_task);
duke@435:   _noop_task = NULL;
duke@435:   if (_thread != NULL) {
duke@435:     for (uint i = 0; i < workers(); i += 1) {
duke@435:       GCTaskThread::destroy(thread(i));
duke@435:       set_thread(i, NULL);
duke@435:     }
duke@435:     FREE_C_HEAP_ARRAY(GCTaskThread*, _thread);
duke@435:     _thread = NULL;
duke@435:   }
duke@435:   if (_resource_flag != NULL) {
duke@435:     FREE_C_HEAP_ARRAY(bool, _resource_flag);
duke@435:     _resource_flag = NULL;
duke@435:   }
duke@435:   if (queue() != NULL) {
duke@435:     GCTaskQueue* unsynchronized_queue = queue()->unsynchronized_queue();
duke@435:     GCTaskQueue::destroy(unsynchronized_queue);
duke@435:     SynchronizedGCTaskQueue::destroy(queue());
duke@435:     _queue = NULL;
duke@435:   }
duke@435:   if (monitor() != NULL) {
duke@435:     delete monitor();
duke@435:     _monitor = NULL;
duke@435:   }
duke@435: }
duke@435: 
duke@435: void GCTaskManager::print_task_time_stamps() {
duke@435:   for(uint i=0; i<ParallelGCThreads; i++) {
duke@435:     GCTaskThread* t = thread(i);
duke@435:     t->print_task_time_stamps();
duke@435:   }
duke@435: }
duke@435: 
duke@435: void GCTaskManager::print_threads_on(outputStream* st) {
duke@435:   uint num_thr = workers();
duke@435:   for (uint i = 0; i < num_thr; i++) {
duke@435:     thread(i)->print_on(st);
duke@435:     st->cr();
duke@435:   }
duke@435: }
duke@435: 
duke@435: void GCTaskManager::threads_do(ThreadClosure* tc) {
duke@435:   assert(tc != NULL, "Null ThreadClosure");
duke@435:   uint num_thr = workers();
duke@435:   for (uint i = 0; i < num_thr; i++) {
duke@435:     tc->do_thread(thread(i));
duke@435:   }
duke@435: }
duke@435: 
duke@435: GCTaskThread* GCTaskManager::thread(uint which) {
duke@435:   assert(which < workers(), "index out of bounds");
duke@435:   assert(_thread[which] != NULL, "shouldn't have null thread");
duke@435:   return _thread[which];
duke@435: }
duke@435: 
duke@435: void GCTaskManager::set_thread(uint which, GCTaskThread* value) {
duke@435:   assert(which < workers(), "index out of bounds");
duke@435:   assert(value != NULL, "shouldn't have null thread");
duke@435:   _thread[which] = value;
duke@435: }
duke@435: 
duke@435: void GCTaskManager::add_task(GCTask* task) {
duke@435:   assert(task != NULL, "shouldn't have null task");
duke@435:   MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("GCTaskManager::add_task(" INTPTR_FORMAT " [%s])",
duke@435:                   task, GCTask::Kind::to_string(task->kind()));
duke@435:   }
duke@435:   queue()->enqueue(task);
duke@435:   // Notify with the lock held to avoid missed notifies.
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("    GCTaskManager::add_task (%s)->notify_all",
duke@435:                   monitor()->name());
duke@435:   }
duke@435:   (void) monitor()->notify_all();
duke@435:   // Release monitor().
duke@435: }
duke@435: 
duke@435: void GCTaskManager::add_list(GCTaskQueue* list) {
duke@435:   assert(list != NULL, "shouldn't have null task");
duke@435:   MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("GCTaskManager::add_list(%u)", list->length());
duke@435:   }
duke@435:   queue()->enqueue(list);
duke@435:   // Notify with the lock held to avoid missed notifies.
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("    GCTaskManager::add_list (%s)->notify_all",
duke@435:                   monitor()->name());
duke@435:   }
duke@435:   (void) monitor()->notify_all();
duke@435:   // Release monitor().
duke@435: }
duke@435: 
duke@435: GCTask* GCTaskManager::get_task(uint which) {
duke@435:   GCTask* result = NULL;
duke@435:   // Grab the queue lock.
duke@435:   MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:   // Wait while the queue is block or
duke@435:   // there is nothing to do, except maybe release resources.
duke@435:   while (is_blocked() ||
duke@435:          (queue()->is_empty() && !should_release_resources(which))) {
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("GCTaskManager::get_task(%u)"
duke@435:                     "  blocked: %s"
duke@435:                     "  empty: %s"
duke@435:                     "  release: %s",
duke@435:                     which,
duke@435:                     is_blocked() ? "true" : "false",
duke@435:                     queue()->is_empty() ? "true" : "false",
duke@435:                     should_release_resources(which) ? "true" : "false");
duke@435:       tty->print_cr("    => (%s)->wait()",
duke@435:                     monitor()->name());
duke@435:     }
duke@435:     monitor()->wait(Mutex::_no_safepoint_check_flag, 0);
duke@435:   }
duke@435:   // We've reacquired the queue lock here.
duke@435:   // Figure out which condition caused us to exit the loop above.
duke@435:   if (!queue()->is_empty()) {
duke@435:     if (UseGCTaskAffinity) {
duke@435:       result = queue()->dequeue(which);
duke@435:     } else {
duke@435:       result = queue()->dequeue();
duke@435:     }
duke@435:     if (result->is_barrier_task()) {
duke@435:       assert(which != sentinel_worker(),
duke@435:              "blocker shouldn't be bogus");
duke@435:       set_blocking_worker(which);
duke@435:     }
duke@435:   } else {
duke@435:     // The queue is empty, but we were woken up.
duke@435:     // Just hand back a Noop task,
duke@435:     // in case someone wanted us to release resources, or whatever.
duke@435:     result = noop_task();
duke@435:     increment_noop_tasks();
duke@435:   }
duke@435:   assert(result != NULL, "shouldn't have null task");
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("GCTaskManager::get_task(%u) => " INTPTR_FORMAT " [%s]",
duke@435:                   which, result, GCTask::Kind::to_string(result->kind()));
duke@435:     tty->print_cr("     %s", result->name());
duke@435:   }
duke@435:   increment_busy_workers();
duke@435:   increment_delivered_tasks();
duke@435:   return result;
duke@435:   // Release monitor().
duke@435: }
duke@435: 
duke@435: void GCTaskManager::note_completion(uint which) {
duke@435:   MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("GCTaskManager::note_completion(%u)", which);
duke@435:   }
duke@435:   // If we are blocked, check if the completing thread is the blocker.
duke@435:   if (blocking_worker() == which) {
duke@435:     assert(blocking_worker() != sentinel_worker(),
duke@435:            "blocker shouldn't be bogus");
duke@435:     increment_barriers();
duke@435:     set_unblocked();
duke@435:   }
duke@435:   increment_completed_tasks();
duke@435:   uint active = decrement_busy_workers();
duke@435:   if ((active == 0) && (queue()->is_empty())) {
duke@435:     increment_emptied_queue();
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("    GCTaskManager::note_completion(%u) done", which);
duke@435:     }
duke@435:     // Notify client that we are done.
duke@435:     NotifyDoneClosure* ndc = notify_done_closure();
duke@435:     if (ndc != NULL) {
duke@435:       ndc->notify(this);
duke@435:     }
duke@435:   }
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("    GCTaskManager::note_completion(%u) (%s)->notify_all",
duke@435:                   which, monitor()->name());
duke@435:     tty->print_cr("  "
duke@435:                   "  blocked: %s"
duke@435:                   "  empty: %s"
duke@435:                   "  release: %s",
duke@435:                   is_blocked() ? "true" : "false",
duke@435:                   queue()->is_empty() ? "true" : "false",
duke@435:                   should_release_resources(which) ? "true" : "false");
duke@435:     tty->print_cr("  "
duke@435:                   "  delivered: %u"
duke@435:                   "  completed: %u"
duke@435:                   "  barriers: %u"
duke@435:                   "  emptied: %u",
duke@435:                   delivered_tasks(),
duke@435:                   completed_tasks(),
duke@435:                   barriers(),
duke@435:                   emptied_queue());
duke@435:   }
duke@435:   // Tell everyone that a task has completed.
duke@435:   (void) monitor()->notify_all();
duke@435:   // Release monitor().
duke@435: }
duke@435: 
duke@435: uint GCTaskManager::increment_busy_workers() {
duke@435:   assert(queue()->own_lock(), "don't own the lock");
duke@435:   _busy_workers += 1;
duke@435:   return _busy_workers;
duke@435: }
duke@435: 
duke@435: uint GCTaskManager::decrement_busy_workers() {
duke@435:   assert(queue()->own_lock(), "don't own the lock");
duke@435:   _busy_workers -= 1;
duke@435:   return _busy_workers;
duke@435: }
duke@435: 
duke@435: void GCTaskManager::release_all_resources() {
duke@435:   // If you want this to be done atomically, do it in a BarrierGCTask.
duke@435:   for (uint i = 0; i < workers(); i += 1) {
duke@435:     set_resource_flag(i, true);
duke@435:   }
duke@435: }
duke@435: 
duke@435: bool GCTaskManager::should_release_resources(uint which) {
duke@435:   // This can be done without a lock because each thread reads one element.
duke@435:   return resource_flag(which);
duke@435: }
duke@435: 
duke@435: void GCTaskManager::note_release(uint which) {
duke@435:   // This can be done without a lock because each thread writes one element.
duke@435:   set_resource_flag(which, false);
duke@435: }
duke@435: 
duke@435: void GCTaskManager::execute_and_wait(GCTaskQueue* list) {
duke@435:   WaitForBarrierGCTask* fin = WaitForBarrierGCTask::create();
duke@435:   list->enqueue(fin);
duke@435:   add_list(list);
duke@435:   fin->wait_for();
duke@435:   // We have to release the barrier tasks!
duke@435:   WaitForBarrierGCTask::destroy(fin);
duke@435: }
duke@435: 
duke@435: bool GCTaskManager::resource_flag(uint which) {
duke@435:   assert(which < workers(), "index out of bounds");
duke@435:   return _resource_flag[which];
duke@435: }
duke@435: 
duke@435: void GCTaskManager::set_resource_flag(uint which, bool value) {
duke@435:   assert(which < workers(), "index out of bounds");
duke@435:   _resource_flag[which] = value;
duke@435: }
duke@435: 
duke@435: //
duke@435: // NoopGCTask
duke@435: //
duke@435: 
duke@435: NoopGCTask* NoopGCTask::create() {
duke@435:   NoopGCTask* result = new NoopGCTask(false);
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: NoopGCTask* NoopGCTask::create_on_c_heap() {
duke@435:   NoopGCTask* result = new(ResourceObj::C_HEAP) NoopGCTask(true);
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: void NoopGCTask::destroy(NoopGCTask* that) {
duke@435:   if (that != NULL) {
duke@435:     that->destruct();
duke@435:     if (that->is_c_heap_obj()) {
duke@435:       FreeHeap(that);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void NoopGCTask::destruct() {
duke@435:   // This has to know it's superclass structure, just like the constructor.
duke@435:   this->GCTask::destruct();
duke@435:   // Nothing else to do.
duke@435: }
duke@435: 
duke@435: //
duke@435: // BarrierGCTask
duke@435: //
duke@435: 
duke@435: void BarrierGCTask::do_it(GCTaskManager* manager, uint which) {
duke@435:   // Wait for this to be the only busy worker.
duke@435:   // ??? I thought of having a StackObj class
duke@435:   //     whose constructor would grab the lock and come to the barrier,
duke@435:   //     and whose destructor would release the lock,
duke@435:   //     but that seems like too much mechanism for two lines of code.
duke@435:   MutexLockerEx ml(manager->lock(), Mutex::_no_safepoint_check_flag);
duke@435:   do_it_internal(manager, which);
duke@435:   // Release manager->lock().
duke@435: }
duke@435: 
duke@435: void BarrierGCTask::do_it_internal(GCTaskManager* manager, uint which) {
duke@435:   // Wait for this to be the only busy worker.
duke@435:   assert(manager->monitor()->owned_by_self(), "don't own the lock");
duke@435:   assert(manager->is_blocked(), "manager isn't blocked");
duke@435:   while (manager->busy_workers() > 1) {
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("BarrierGCTask::do_it(%u) waiting on %u workers",
duke@435:                     which, manager->busy_workers());
duke@435:     }
duke@435:     manager->monitor()->wait(Mutex::_no_safepoint_check_flag, 0);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void BarrierGCTask::destruct() {
duke@435:   this->GCTask::destruct();
duke@435:   // Nothing else to do.
duke@435: }
duke@435: 
duke@435: //
duke@435: // ReleasingBarrierGCTask
duke@435: //
duke@435: 
duke@435: void ReleasingBarrierGCTask::do_it(GCTaskManager* manager, uint which) {
duke@435:   MutexLockerEx ml(manager->lock(), Mutex::_no_safepoint_check_flag);
duke@435:   do_it_internal(manager, which);
duke@435:   manager->release_all_resources();
duke@435:   // Release manager->lock().
duke@435: }
duke@435: 
duke@435: void ReleasingBarrierGCTask::destruct() {
duke@435:   this->BarrierGCTask::destruct();
duke@435:   // Nothing else to do.
duke@435: }
duke@435: 
duke@435: //
duke@435: // NotifyingBarrierGCTask
duke@435: //
duke@435: 
duke@435: void NotifyingBarrierGCTask::do_it(GCTaskManager* manager, uint which) {
duke@435:   MutexLockerEx ml(manager->lock(), Mutex::_no_safepoint_check_flag);
duke@435:   do_it_internal(manager, which);
duke@435:   NotifyDoneClosure* ndc = notify_done_closure();
duke@435:   if (ndc != NULL) {
duke@435:     ndc->notify(manager);
duke@435:   }
duke@435:   // Release manager->lock().
duke@435: }
duke@435: 
duke@435: void NotifyingBarrierGCTask::destruct() {
duke@435:   this->BarrierGCTask::destruct();
duke@435:   // Nothing else to do.
duke@435: }
duke@435: 
duke@435: //
duke@435: // WaitForBarrierGCTask
duke@435: //
duke@435: WaitForBarrierGCTask* WaitForBarrierGCTask::create() {
duke@435:   WaitForBarrierGCTask* result = new WaitForBarrierGCTask(false);
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: WaitForBarrierGCTask* WaitForBarrierGCTask::create_on_c_heap() {
duke@435:   WaitForBarrierGCTask* result = new WaitForBarrierGCTask(true);
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: WaitForBarrierGCTask::WaitForBarrierGCTask(bool on_c_heap) :
duke@435:   _is_c_heap_obj(on_c_heap) {
duke@435:   _monitor = MonitorSupply::reserve();
duke@435:   set_should_wait(true);
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " WaitForBarrierGCTask::WaitForBarrierGCTask()"
duke@435:                   "  monitor: " INTPTR_FORMAT,
duke@435:                   this, monitor());
duke@435:   }
duke@435: }
duke@435: 
duke@435: void WaitForBarrierGCTask::destroy(WaitForBarrierGCTask* that) {
duke@435:   if (that != NULL) {
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                     " WaitForBarrierGCTask::destroy()"
duke@435:                     "  is_c_heap_obj: %s"
duke@435:                     "  monitor: " INTPTR_FORMAT,
duke@435:                     that,
duke@435:                     that->is_c_heap_obj() ? "true" : "false",
duke@435:                     that->monitor());
duke@435:     }
duke@435:     that->destruct();
duke@435:     if (that->is_c_heap_obj()) {
duke@435:       FreeHeap(that);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void WaitForBarrierGCTask::destruct() {
duke@435:   assert(monitor() != NULL, "monitor should not be NULL");
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " WaitForBarrierGCTask::destruct()"
duke@435:                   "  monitor: " INTPTR_FORMAT,
duke@435:                   this, monitor());
duke@435:   }
duke@435:   this->BarrierGCTask::destruct();
duke@435:   // Clean up that should be in the destructor,
duke@435:   // except that ResourceMarks don't call destructors.
duke@435:    if (monitor() != NULL) {
duke@435:      MonitorSupply::release(monitor());
duke@435:   }
duke@435:   _monitor = (Monitor*) 0xDEAD000F;
duke@435: }
duke@435: 
duke@435: void WaitForBarrierGCTask::do_it(GCTaskManager* manager, uint which) {
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " WaitForBarrierGCTask::do_it() waiting for idle"
duke@435:                   "  monitor: " INTPTR_FORMAT,
duke@435:                   this, monitor());
duke@435:   }
duke@435:   {
duke@435:     // First, wait for the barrier to arrive.
duke@435:     MutexLockerEx ml(manager->lock(), Mutex::_no_safepoint_check_flag);
duke@435:     do_it_internal(manager, which);
duke@435:     // Release manager->lock().
duke@435:   }
duke@435:   {
duke@435:     // Then notify the waiter.
duke@435:     MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:     set_should_wait(false);
duke@435:     // Waiter doesn't miss the notify in the wait_for method
duke@435:     // since it checks the flag after grabbing the monitor.
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                     " WaitForBarrierGCTask::do_it()"
duke@435:                     "  [" INTPTR_FORMAT "] (%s)->notify_all()",
duke@435:                     this, monitor(), monitor()->name());
duke@435:     }
duke@435:     monitor()->notify_all();
duke@435:     // Release monitor().
duke@435:   }
duke@435: }
duke@435: 
duke@435: void WaitForBarrierGCTask::wait_for() {
duke@435:   if (TraceGCTaskManager) {
duke@435:     tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                   " WaitForBarrierGCTask::wait_for()"
duke@435:       "  should_wait: %s",
duke@435:       this, should_wait() ? "true" : "false");
duke@435:   }
duke@435:   {
duke@435:     // Grab the lock and check again.
duke@435:     MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag);
duke@435:     while (should_wait()) {
duke@435:       if (TraceGCTaskManager) {
duke@435:         tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                       " WaitForBarrierGCTask::wait_for()"
duke@435:           "  [" INTPTR_FORMAT "] (%s)->wait()",
duke@435:           this, monitor(), monitor()->name());
duke@435:       }
duke@435:       monitor()->wait(Mutex::_no_safepoint_check_flag, 0);
duke@435:     }
duke@435:     // Reset the flag in case someone reuses this task.
duke@435:     set_should_wait(true);
duke@435:     if (TraceGCTaskManager) {
duke@435:       tty->print_cr("[" INTPTR_FORMAT "]"
duke@435:                     " WaitForBarrierGCTask::wait_for() returns"
duke@435:         "  should_wait: %s",
duke@435:         this, should_wait() ? "true" : "false");
duke@435:     }
duke@435:     // Release monitor().
duke@435:   }
duke@435: }
duke@435: 
duke@435: Mutex*                   MonitorSupply::_lock     = NULL;
duke@435: GrowableArray<Monitor*>* MonitorSupply::_freelist = NULL;
duke@435: 
duke@435: Monitor* MonitorSupply::reserve() {
duke@435:   Monitor* result = NULL;
duke@435:   // Lazy initialization: possible race.
duke@435:   if (lock() == NULL) {
duke@435:     _lock = new Mutex(Mutex::barrier,                  // rank
duke@435:                       "MonitorSupply mutex",           // name
duke@435:                       Mutex::_allow_vm_block_flag);    // allow_vm_block
duke@435:   }
duke@435:   {
duke@435:     MutexLockerEx ml(lock());
duke@435:     // Lazy initialization.
duke@435:     if (freelist() == NULL) {
duke@435:       _freelist =
duke@435:         new(ResourceObj::C_HEAP) GrowableArray<Monitor*>(ParallelGCThreads,
duke@435:                                                          true);
duke@435:     }
duke@435:     if (! freelist()->is_empty()) {
duke@435:       result = freelist()->pop();
duke@435:     } else {
duke@435:       result = new Monitor(Mutex::barrier,                  // rank
duke@435:                            "MonitorSupply monitor",         // name
duke@435:                            Mutex::_allow_vm_block_flag);    // allow_vm_block
duke@435:     }
duke@435:     guarantee(result != NULL, "shouldn't return NULL");
duke@435:     assert(!result->is_locked(), "shouldn't be locked");
duke@435:     // release lock().
duke@435:   }
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: void MonitorSupply::release(Monitor* instance) {
duke@435:   assert(instance != NULL, "shouldn't release NULL");
duke@435:   assert(!instance->is_locked(), "shouldn't be locked");
duke@435:   {
duke@435:     MutexLockerEx ml(lock());
duke@435:     freelist()->push(instance);
duke@435:     // release lock().
duke@435:   }
duke@435: }