--- old/src/share/vm/utilities/workgroup.cpp 2015-05-13 13:59:02.422580981 +0200 +++ /dev/null 2015-03-18 17:10:38.111854831 +0100 @@ -1,655 +0,0 @@ -/* - * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -#include "precompiled.hpp" -#include "memory/allocation.hpp" -#include "memory/allocation.inline.hpp" -#include "runtime/atomic.inline.hpp" -#include "runtime/os.hpp" -#include "utilities/workgroup.hpp" - -// Definitions of WorkGang methods. - -AbstractWorkGang::AbstractWorkGang(const char* name, - bool are_GC_task_threads, - bool are_ConcurrentGC_threads) : - _name(name), - _are_GC_task_threads(are_GC_task_threads), - _are_ConcurrentGC_threads(are_ConcurrentGC_threads) { - - assert(!(are_GC_task_threads && are_ConcurrentGC_threads), - "They cannot both be STW GC and Concurrent threads" ); - - // Other initialization. - _monitor = new Monitor(/* priority */ Mutex::leaf, - /* name */ "WorkGroup monitor", - /* allow_vm_block */ are_GC_task_threads, - Monitor::_safepoint_check_sometimes); - assert(monitor() != NULL, "Failed to allocate monitor"); - _terminate = false; - _task = NULL; - _sequence_number = 0; - _started_workers = 0; - _finished_workers = 0; -} - -WorkGang::WorkGang(const char* name, - uint workers, - bool are_GC_task_threads, - bool are_ConcurrentGC_threads) : - AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) { - _total_workers = workers; -} - -GangWorker* WorkGang::allocate_worker(uint which) { - GangWorker* new_worker = new GangWorker(this, which); - return new_worker; -} - -// The current implementation will exit if the allocation -// of any worker fails. Still, return a boolean so that -// a future implementation can possibly do a partial -// initialization of the workers and report such to the -// caller. -bool WorkGang::initialize_workers() { - - if (TraceWorkGang) { - tty->print_cr("Constructing work gang %s with %d threads", - name(), - total_workers()); - } - _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers(), mtInternal); - if (gang_workers() == NULL) { - vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GangWorker array."); - return false; - } - os::ThreadType worker_type; - if (are_ConcurrentGC_threads()) { - worker_type = os::cgc_thread; - } else { - worker_type = os::pgc_thread; - } - for (uint worker = 0; worker < total_workers(); worker += 1) { - GangWorker* new_worker = allocate_worker(worker); - assert(new_worker != NULL, "Failed to allocate GangWorker"); - _gang_workers[worker] = new_worker; - if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) { - vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, - "Cannot create worker GC thread. Out of system resources."); - return false; - } - if (!DisableStartThread) { - os::start_thread(new_worker); - } - } - return true; -} - -AbstractWorkGang::~AbstractWorkGang() { - if (TraceWorkGang) { - tty->print_cr("Destructing work gang %s", name()); - } - stop(); // stop all the workers - for (uint worker = 0; worker < total_workers(); worker += 1) { - delete gang_worker(worker); - } - delete gang_workers(); - delete monitor(); -} - -GangWorker* AbstractWorkGang::gang_worker(uint i) const { - // Array index bounds checking. - GangWorker* result = NULL; - assert(gang_workers() != NULL, "No workers for indexing"); - assert(i < total_workers(), "Worker index out of bounds"); - result = _gang_workers[i]; - assert(result != NULL, "Indexing to null worker"); - return result; -} - -void WorkGang::run_task(AbstractGangTask* task) { - run_task(task, total_workers()); -} - -void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) { - task->set_for_termination(no_of_parallel_workers); - - // This thread is executed by the VM thread which does not block - // on ordinary MutexLocker's. - MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); - if (TraceWorkGang) { - tty->print_cr("Running work gang %s task %s", name(), task->name()); - } - // Tell all the workers to run a task. - assert(task != NULL, "Running a null task"); - // Initialize. - _task = task; - _sequence_number += 1; - _started_workers = 0; - _finished_workers = 0; - // Tell the workers to get to work. - monitor()->notify_all(); - // Wait for them to be finished - while (finished_workers() < no_of_parallel_workers) { - if (TraceWorkGang) { - tty->print_cr("Waiting in work gang %s: %u/%u finished sequence %d", - name(), finished_workers(), no_of_parallel_workers, - _sequence_number); - } - monitor()->wait(/* no_safepoint_check */ true); - } - _task = NULL; - if (TraceWorkGang) { - tty->print_cr("\nFinished work gang %s: %u/%u sequence %d", - name(), finished_workers(), no_of_parallel_workers, - _sequence_number); - Thread* me = Thread::current(); - tty->print_cr(" T: " PTR_FORMAT " VM_thread: %d", p2i(me), me->is_VM_thread()); - } -} - -void FlexibleWorkGang::run_task(AbstractGangTask* task) { - // If active_workers() is passed, _finished_workers - // must only be incremented for workers that find non_null - // work (as opposed to all those that just check that the - // task is not null). - WorkGang::run_task(task, (uint) active_workers()); -} - -void AbstractWorkGang::stop() { - // Tell all workers to terminate, then wait for them to become inactive. - MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); - if (TraceWorkGang) { - tty->print_cr("Stopping work gang %s task %s", name(), task()->name()); - } - _task = NULL; - _terminate = true; - monitor()->notify_all(); - while (finished_workers() < active_workers()) { - if (TraceWorkGang) { - tty->print_cr("Waiting in work gang %s: %u/%u finished", - name(), finished_workers(), active_workers()); - } - monitor()->wait(/* no_safepoint_check */ true); - } -} - -void AbstractWorkGang::internal_worker_poll(WorkData* data) const { - assert(monitor()->owned_by_self(), "worker_poll is an internal method"); - assert(data != NULL, "worker data is null"); - data->set_terminate(terminate()); - data->set_task(task()); - data->set_sequence_number(sequence_number()); -} - -void AbstractWorkGang::internal_note_start() { - assert(monitor()->owned_by_self(), "note_finish is an internal method"); - _started_workers += 1; -} - -void AbstractWorkGang::internal_note_finish() { - assert(monitor()->owned_by_self(), "note_finish is an internal method"); - _finished_workers += 1; -} - -void AbstractWorkGang::print_worker_threads_on(outputStream* st) const { - uint num_thr = total_workers(); - for (uint i = 0; i < num_thr; i++) { - gang_worker(i)->print_on(st); - st->cr(); - } -} - -void AbstractWorkGang::threads_do(ThreadClosure* tc) const { - assert(tc != NULL, "Null ThreadClosure"); - uint num_thr = total_workers(); - for (uint i = 0; i < num_thr; i++) { - tc->do_thread(gang_worker(i)); - } -} - -// GangWorker methods. - -GangWorker::GangWorker(AbstractWorkGang* gang, uint id) { - _gang = gang; - set_id(id); - set_name("%s#%d", gang->name(), id); -} - -void GangWorker::run() { - initialize(); - loop(); -} - -void GangWorker::initialize() { - this->initialize_thread_local_storage(); - this->record_stack_base_and_size(); - this->initialize_named_thread(); - assert(_gang != NULL, "No gang to run in"); - os::set_priority(this, NearMaxPriority); - if (TraceWorkGang) { - tty->print_cr("Running gang worker for gang %s id %u", - gang()->name(), id()); - } - // The VM thread should not execute here because MutexLocker's are used - // as (opposed to MutexLockerEx's). - assert(!Thread::current()->is_VM_thread(), "VM thread should not be part" - " of a work gang"); -} - -void GangWorker::loop() { - int previous_sequence_number = 0; - Monitor* gang_monitor = gang()->monitor(); - for ( ; /* !terminate() */; ) { - WorkData data; - int part; // Initialized below. - { - // Grab the gang mutex. - MutexLocker ml(gang_monitor); - // Wait for something to do. - // Polling outside the while { wait } avoids missed notifies - // in the outer loop. - gang()->internal_worker_poll(&data); - if (TraceWorkGang) { - tty->print("Polled outside for work in gang %s worker %u", - gang()->name(), id()); - tty->print(" terminate: %s", - data.terminate() ? "true" : "false"); - tty->print(" sequence: %d (prev: %d)", - data.sequence_number(), previous_sequence_number); - if (data.task() != NULL) { - tty->print(" task: %s", data.task()->name()); - } else { - tty->print(" task: NULL"); - } - tty->cr(); - } - for ( ; /* break or return */; ) { - // Terminate if requested. - if (data.terminate()) { - gang()->internal_note_finish(); - gang_monitor->notify_all(); - return; - } - // Check for new work. - if ((data.task() != NULL) && - (data.sequence_number() != previous_sequence_number)) { - if (gang()->needs_more_workers()) { - gang()->internal_note_start(); - gang_monitor->notify_all(); - part = gang()->started_workers() - 1; - break; - } - } - // Nothing to do. - gang_monitor->wait(/* no_safepoint_check */ true); - gang()->internal_worker_poll(&data); - if (TraceWorkGang) { - tty->print("Polled inside for work in gang %s worker %u", - gang()->name(), id()); - tty->print(" terminate: %s", - data.terminate() ? "true" : "false"); - tty->print(" sequence: %d (prev: %d)", - data.sequence_number(), previous_sequence_number); - if (data.task() != NULL) { - tty->print(" task: %s", data.task()->name()); - } else { - tty->print(" task: NULL"); - } - tty->cr(); - } - } - // Drop gang mutex. - } - if (TraceWorkGang) { - tty->print("Work for work gang %s id %u task %s part %d", - gang()->name(), id(), data.task()->name(), part); - } - assert(data.task() != NULL, "Got null task"); - data.task()->work(part); - { - if (TraceWorkGang) { - tty->print("Finish for work gang %s id %u task %s part %d", - gang()->name(), id(), data.task()->name(), part); - } - // Grab the gang mutex. - MutexLocker ml(gang_monitor); - gang()->internal_note_finish(); - // Tell the gang you are done. - gang_monitor->notify_all(); - // Drop the gang mutex. - } - previous_sequence_number = data.sequence_number(); - } -} - -bool GangWorker::is_GC_task_thread() const { - return gang()->are_GC_task_threads(); -} - -bool GangWorker::is_ConcurrentGC_thread() const { - return gang()->are_ConcurrentGC_threads(); -} - -void GangWorker::print_on(outputStream* st) const { - st->print("\"%s\" ", name()); - Thread::print_on(st); - st->cr(); -} - -// Printing methods - -const char* AbstractWorkGang::name() const { - return _name; -} - -#ifndef PRODUCT - -const char* AbstractGangTask::name() const { - return _name; -} - -#endif /* PRODUCT */ - -// FlexibleWorkGang - - -// *** WorkGangBarrierSync - -WorkGangBarrierSync::WorkGangBarrierSync() - : _monitor(Mutex::safepoint, "work gang barrier sync", true, - Monitor::_safepoint_check_never), - _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) { -} - -WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name) - : _monitor(Mutex::safepoint, name, true, Monitor::_safepoint_check_never), - _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) { -} - -void WorkGangBarrierSync::set_n_workers(uint n_workers) { - _n_workers = n_workers; - _n_completed = 0; - _should_reset = false; - _aborted = false; -} - -bool WorkGangBarrierSync::enter() { - MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); - if (should_reset()) { - // The should_reset() was set and we are the first worker to enter - // the sync barrier. We will zero the n_completed() count which - // effectively resets the barrier. - zero_completed(); - set_should_reset(false); - } - inc_completed(); - if (n_completed() == n_workers()) { - // At this point we would like to reset the barrier to be ready in - // case it is used again. However, we cannot set n_completed() to - // 0, even after the notify_all(), given that some other workers - // might still be waiting for n_completed() to become == - // n_workers(). So, if we set n_completed() to 0, those workers - // will get stuck (as they will wake up, see that n_completed() != - // n_workers() and go back to sleep). Instead, we raise the - // should_reset() flag and the barrier will be reset the first - // time a worker enters it again. - set_should_reset(true); - monitor()->notify_all(); - } else { - while (n_completed() != n_workers() && !aborted()) { - monitor()->wait(/* no_safepoint_check */ true); - } - } - return !aborted(); -} - -void WorkGangBarrierSync::abort() { - MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); - set_aborted(); - monitor()->notify_all(); -} - -// SubTasksDone functions. - -SubTasksDone::SubTasksDone(uint n) : - _n_tasks(n), _n_threads(1), _tasks(NULL) { - _tasks = NEW_C_HEAP_ARRAY(uint, n, mtInternal); - guarantee(_tasks != NULL, "alloc failure"); - clear(); -} - -bool SubTasksDone::valid() { - return _tasks != NULL; -} - -void SubTasksDone::set_n_threads(uint t) { - assert(_claimed == 0 || _threads_completed == _n_threads, - "should not be called while tasks are being processed!"); - _n_threads = (t == 0 ? 1 : t); -} - -void SubTasksDone::clear() { - for (uint i = 0; i < _n_tasks; i++) { - _tasks[i] = 0; - } - _threads_completed = 0; -#ifdef ASSERT - _claimed = 0; -#endif -} - -bool SubTasksDone::is_task_claimed(uint t) { - assert(t < _n_tasks, "bad task id."); - uint old = _tasks[t]; - if (old == 0) { - old = Atomic::cmpxchg(1, &_tasks[t], 0); - } - assert(_tasks[t] == 1, "What else?"); - bool res = old != 0; -#ifdef ASSERT - if (!res) { - assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?"); - Atomic::inc((volatile jint*) &_claimed); - } -#endif - return res; -} - -void SubTasksDone::all_tasks_completed() { - jint observed = _threads_completed; - jint old; - do { - old = observed; - observed = Atomic::cmpxchg(old+1, &_threads_completed, old); - } while (observed != old); - // If this was the last thread checking in, clear the tasks. - if (observed+1 == (jint)_n_threads) clear(); -} - - -SubTasksDone::~SubTasksDone() { - if (_tasks != NULL) FREE_C_HEAP_ARRAY(jint, _tasks); -} - -// *** SequentialSubTasksDone - -void SequentialSubTasksDone::clear() { - _n_tasks = _n_claimed = 0; - _n_threads = _n_completed = 0; -} - -bool SequentialSubTasksDone::valid() { - return _n_threads > 0; -} - -bool SequentialSubTasksDone::is_task_claimed(uint& t) { - uint* n_claimed_ptr = &_n_claimed; - t = *n_claimed_ptr; - while (t < _n_tasks) { - jint res = Atomic::cmpxchg(t+1, n_claimed_ptr, t); - if (res == (jint)t) { - return false; - } - t = *n_claimed_ptr; - } - return true; -} - -bool SequentialSubTasksDone::all_tasks_completed() { - uint* n_completed_ptr = &_n_completed; - uint complete = *n_completed_ptr; - while (true) { - uint res = Atomic::cmpxchg(complete+1, n_completed_ptr, complete); - if (res == complete) { - break; - } - complete = res; - } - if (complete+1 == _n_threads) { - clear(); - return true; - } - return false; -} - -bool FreeIdSet::_stat_init = false; -FreeIdSet* FreeIdSet::_sets[NSets]; -bool FreeIdSet::_safepoint; - -FreeIdSet::FreeIdSet(int sz, Monitor* mon) : - _sz(sz), _mon(mon), _hd(0), _waiters(0), _index(-1), _claimed(0) -{ - _ids = NEW_C_HEAP_ARRAY(int, sz, mtInternal); - for (int i = 0; i < sz; i++) _ids[i] = i+1; - _ids[sz-1] = end_of_list; // end of list. - if (_stat_init) { - for (int j = 0; j < NSets; j++) _sets[j] = NULL; - _stat_init = true; - } - // Add to sets. (This should happen while the system is still single-threaded.) - for (int j = 0; j < NSets; j++) { - if (_sets[j] == NULL) { - _sets[j] = this; - _index = j; - break; - } - } - guarantee(_index != -1, "Too many FreeIdSets in use!"); -} - -FreeIdSet::~FreeIdSet() { - _sets[_index] = NULL; - FREE_C_HEAP_ARRAY(int, _ids); -} - -void FreeIdSet::set_safepoint(bool b) { - _safepoint = b; - if (b) { - for (int j = 0; j < NSets; j++) { - if (_sets[j] != NULL && _sets[j]->_waiters > 0) { - Monitor* mon = _sets[j]->_mon; - mon->lock_without_safepoint_check(); - mon->notify_all(); - mon->unlock(); - } - } - } -} - -#define FID_STATS 0 - -int FreeIdSet::claim_par_id() { -#if FID_STATS - thread_t tslf = thr_self(); - tty->print("claim_par_id[%d]: sz = %d, claimed = %d\n", tslf, _sz, _claimed); -#endif - MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); - while (!_safepoint && _hd == end_of_list) { - _waiters++; -#if FID_STATS - if (_waiters > 5) { - tty->print("claim_par_id waiting[%d]: %d waiters, %d claimed.\n", - tslf, _waiters, _claimed); - } -#endif - _mon->wait(Mutex::_no_safepoint_check_flag); - _waiters--; - } - if (_hd == end_of_list) { -#if FID_STATS - tty->print("claim_par_id[%d]: returning EOL.\n", tslf); -#endif - return -1; - } else { - int res = _hd; - _hd = _ids[res]; - _ids[res] = claimed; // For debugging. - _claimed++; -#if FID_STATS - tty->print("claim_par_id[%d]: returning %d, claimed = %d.\n", - tslf, res, _claimed); -#endif - return res; - } -} - -bool FreeIdSet::claim_perm_id(int i) { - assert(0 <= i && i < _sz, "Out of range."); - MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); - int prev = end_of_list; - int cur = _hd; - while (cur != end_of_list) { - if (cur == i) { - if (prev == end_of_list) { - _hd = _ids[cur]; - } else { - _ids[prev] = _ids[cur]; - } - _ids[cur] = claimed; - _claimed++; - return true; - } else { - prev = cur; - cur = _ids[cur]; - } - } - return false; - -} - -void FreeIdSet::release_par_id(int id) { - MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); - assert(_ids[id] == claimed, "Precondition."); - _ids[id] = _hd; - _hd = id; - _claimed--; -#if FID_STATS - tty->print("[%d] release_par_id(%d), waiters =%d, claimed = %d.\n", - thr_self(), id, _waiters, _claimed); -#endif - if (_waiters > 0) - // Notify all would be safer, but this is OK, right? - _mon->notify_all(); -} --- /dev/null 2015-03-18 17:10:38.111854831 +0100 +++ new/src/share/vm/gc/shared/workgroup.cpp 2015-05-13 13:59:02.212572255 +0200 @@ -0,0 +1,655 @@ +/* + * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc/shared/workgroup.hpp" +#include "memory/allocation.hpp" +#include "memory/allocation.inline.hpp" +#include "runtime/atomic.inline.hpp" +#include "runtime/os.hpp" + +// Definitions of WorkGang methods. + +AbstractWorkGang::AbstractWorkGang(const char* name, + bool are_GC_task_threads, + bool are_ConcurrentGC_threads) : + _name(name), + _are_GC_task_threads(are_GC_task_threads), + _are_ConcurrentGC_threads(are_ConcurrentGC_threads) { + + assert(!(are_GC_task_threads && are_ConcurrentGC_threads), + "They cannot both be STW GC and Concurrent threads" ); + + // Other initialization. + _monitor = new Monitor(/* priority */ Mutex::leaf, + /* name */ "WorkGroup monitor", + /* allow_vm_block */ are_GC_task_threads, + Monitor::_safepoint_check_sometimes); + assert(monitor() != NULL, "Failed to allocate monitor"); + _terminate = false; + _task = NULL; + _sequence_number = 0; + _started_workers = 0; + _finished_workers = 0; +} + +WorkGang::WorkGang(const char* name, + uint workers, + bool are_GC_task_threads, + bool are_ConcurrentGC_threads) : + AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) { + _total_workers = workers; +} + +GangWorker* WorkGang::allocate_worker(uint which) { + GangWorker* new_worker = new GangWorker(this, which); + return new_worker; +} + +// The current implementation will exit if the allocation +// of any worker fails. Still, return a boolean so that +// a future implementation can possibly do a partial +// initialization of the workers and report such to the +// caller. +bool WorkGang::initialize_workers() { + + if (TraceWorkGang) { + tty->print_cr("Constructing work gang %s with %d threads", + name(), + total_workers()); + } + _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers(), mtInternal); + if (gang_workers() == NULL) { + vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GangWorker array."); + return false; + } + os::ThreadType worker_type; + if (are_ConcurrentGC_threads()) { + worker_type = os::cgc_thread; + } else { + worker_type = os::pgc_thread; + } + for (uint worker = 0; worker < total_workers(); worker += 1) { + GangWorker* new_worker = allocate_worker(worker); + assert(new_worker != NULL, "Failed to allocate GangWorker"); + _gang_workers[worker] = new_worker; + if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) { + vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, + "Cannot create worker GC thread. Out of system resources."); + return false; + } + if (!DisableStartThread) { + os::start_thread(new_worker); + } + } + return true; +} + +AbstractWorkGang::~AbstractWorkGang() { + if (TraceWorkGang) { + tty->print_cr("Destructing work gang %s", name()); + } + stop(); // stop all the workers + for (uint worker = 0; worker < total_workers(); worker += 1) { + delete gang_worker(worker); + } + delete gang_workers(); + delete monitor(); +} + +GangWorker* AbstractWorkGang::gang_worker(uint i) const { + // Array index bounds checking. + GangWorker* result = NULL; + assert(gang_workers() != NULL, "No workers for indexing"); + assert(i < total_workers(), "Worker index out of bounds"); + result = _gang_workers[i]; + assert(result != NULL, "Indexing to null worker"); + return result; +} + +void WorkGang::run_task(AbstractGangTask* task) { + run_task(task, total_workers()); +} + +void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) { + task->set_for_termination(no_of_parallel_workers); + + // This thread is executed by the VM thread which does not block + // on ordinary MutexLocker's. + MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); + if (TraceWorkGang) { + tty->print_cr("Running work gang %s task %s", name(), task->name()); + } + // Tell all the workers to run a task. + assert(task != NULL, "Running a null task"); + // Initialize. + _task = task; + _sequence_number += 1; + _started_workers = 0; + _finished_workers = 0; + // Tell the workers to get to work. + monitor()->notify_all(); + // Wait for them to be finished + while (finished_workers() < no_of_parallel_workers) { + if (TraceWorkGang) { + tty->print_cr("Waiting in work gang %s: %u/%u finished sequence %d", + name(), finished_workers(), no_of_parallel_workers, + _sequence_number); + } + monitor()->wait(/* no_safepoint_check */ true); + } + _task = NULL; + if (TraceWorkGang) { + tty->print_cr("\nFinished work gang %s: %u/%u sequence %d", + name(), finished_workers(), no_of_parallel_workers, + _sequence_number); + Thread* me = Thread::current(); + tty->print_cr(" T: " PTR_FORMAT " VM_thread: %d", p2i(me), me->is_VM_thread()); + } +} + +void FlexibleWorkGang::run_task(AbstractGangTask* task) { + // If active_workers() is passed, _finished_workers + // must only be incremented for workers that find non_null + // work (as opposed to all those that just check that the + // task is not null). + WorkGang::run_task(task, (uint) active_workers()); +} + +void AbstractWorkGang::stop() { + // Tell all workers to terminate, then wait for them to become inactive. + MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); + if (TraceWorkGang) { + tty->print_cr("Stopping work gang %s task %s", name(), task()->name()); + } + _task = NULL; + _terminate = true; + monitor()->notify_all(); + while (finished_workers() < active_workers()) { + if (TraceWorkGang) { + tty->print_cr("Waiting in work gang %s: %u/%u finished", + name(), finished_workers(), active_workers()); + } + monitor()->wait(/* no_safepoint_check */ true); + } +} + +void AbstractWorkGang::internal_worker_poll(WorkData* data) const { + assert(monitor()->owned_by_self(), "worker_poll is an internal method"); + assert(data != NULL, "worker data is null"); + data->set_terminate(terminate()); + data->set_task(task()); + data->set_sequence_number(sequence_number()); +} + +void AbstractWorkGang::internal_note_start() { + assert(monitor()->owned_by_self(), "note_finish is an internal method"); + _started_workers += 1; +} + +void AbstractWorkGang::internal_note_finish() { + assert(monitor()->owned_by_self(), "note_finish is an internal method"); + _finished_workers += 1; +} + +void AbstractWorkGang::print_worker_threads_on(outputStream* st) const { + uint num_thr = total_workers(); + for (uint i = 0; i < num_thr; i++) { + gang_worker(i)->print_on(st); + st->cr(); + } +} + +void AbstractWorkGang::threads_do(ThreadClosure* tc) const { + assert(tc != NULL, "Null ThreadClosure"); + uint num_thr = total_workers(); + for (uint i = 0; i < num_thr; i++) { + tc->do_thread(gang_worker(i)); + } +} + +// GangWorker methods. + +GangWorker::GangWorker(AbstractWorkGang* gang, uint id) { + _gang = gang; + set_id(id); + set_name("%s#%d", gang->name(), id); +} + +void GangWorker::run() { + initialize(); + loop(); +} + +void GangWorker::initialize() { + this->initialize_thread_local_storage(); + this->record_stack_base_and_size(); + this->initialize_named_thread(); + assert(_gang != NULL, "No gang to run in"); + os::set_priority(this, NearMaxPriority); + if (TraceWorkGang) { + tty->print_cr("Running gang worker for gang %s id %u", + gang()->name(), id()); + } + // The VM thread should not execute here because MutexLocker's are used + // as (opposed to MutexLockerEx's). + assert(!Thread::current()->is_VM_thread(), "VM thread should not be part" + " of a work gang"); +} + +void GangWorker::loop() { + int previous_sequence_number = 0; + Monitor* gang_monitor = gang()->monitor(); + for ( ; /* !terminate() */; ) { + WorkData data; + int part; // Initialized below. + { + // Grab the gang mutex. + MutexLocker ml(gang_monitor); + // Wait for something to do. + // Polling outside the while { wait } avoids missed notifies + // in the outer loop. + gang()->internal_worker_poll(&data); + if (TraceWorkGang) { + tty->print("Polled outside for work in gang %s worker %u", + gang()->name(), id()); + tty->print(" terminate: %s", + data.terminate() ? "true" : "false"); + tty->print(" sequence: %d (prev: %d)", + data.sequence_number(), previous_sequence_number); + if (data.task() != NULL) { + tty->print(" task: %s", data.task()->name()); + } else { + tty->print(" task: NULL"); + } + tty->cr(); + } + for ( ; /* break or return */; ) { + // Terminate if requested. + if (data.terminate()) { + gang()->internal_note_finish(); + gang_monitor->notify_all(); + return; + } + // Check for new work. + if ((data.task() != NULL) && + (data.sequence_number() != previous_sequence_number)) { + if (gang()->needs_more_workers()) { + gang()->internal_note_start(); + gang_monitor->notify_all(); + part = gang()->started_workers() - 1; + break; + } + } + // Nothing to do. + gang_monitor->wait(/* no_safepoint_check */ true); + gang()->internal_worker_poll(&data); + if (TraceWorkGang) { + tty->print("Polled inside for work in gang %s worker %u", + gang()->name(), id()); + tty->print(" terminate: %s", + data.terminate() ? "true" : "false"); + tty->print(" sequence: %d (prev: %d)", + data.sequence_number(), previous_sequence_number); + if (data.task() != NULL) { + tty->print(" task: %s", data.task()->name()); + } else { + tty->print(" task: NULL"); + } + tty->cr(); + } + } + // Drop gang mutex. + } + if (TraceWorkGang) { + tty->print("Work for work gang %s id %u task %s part %d", + gang()->name(), id(), data.task()->name(), part); + } + assert(data.task() != NULL, "Got null task"); + data.task()->work(part); + { + if (TraceWorkGang) { + tty->print("Finish for work gang %s id %u task %s part %d", + gang()->name(), id(), data.task()->name(), part); + } + // Grab the gang mutex. + MutexLocker ml(gang_monitor); + gang()->internal_note_finish(); + // Tell the gang you are done. + gang_monitor->notify_all(); + // Drop the gang mutex. + } + previous_sequence_number = data.sequence_number(); + } +} + +bool GangWorker::is_GC_task_thread() const { + return gang()->are_GC_task_threads(); +} + +bool GangWorker::is_ConcurrentGC_thread() const { + return gang()->are_ConcurrentGC_threads(); +} + +void GangWorker::print_on(outputStream* st) const { + st->print("\"%s\" ", name()); + Thread::print_on(st); + st->cr(); +} + +// Printing methods + +const char* AbstractWorkGang::name() const { + return _name; +} + +#ifndef PRODUCT + +const char* AbstractGangTask::name() const { + return _name; +} + +#endif /* PRODUCT */ + +// FlexibleWorkGang + + +// *** WorkGangBarrierSync + +WorkGangBarrierSync::WorkGangBarrierSync() + : _monitor(Mutex::safepoint, "work gang barrier sync", true, + Monitor::_safepoint_check_never), + _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) { +} + +WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name) + : _monitor(Mutex::safepoint, name, true, Monitor::_safepoint_check_never), + _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) { +} + +void WorkGangBarrierSync::set_n_workers(uint n_workers) { + _n_workers = n_workers; + _n_completed = 0; + _should_reset = false; + _aborted = false; +} + +bool WorkGangBarrierSync::enter() { + MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); + if (should_reset()) { + // The should_reset() was set and we are the first worker to enter + // the sync barrier. We will zero the n_completed() count which + // effectively resets the barrier. + zero_completed(); + set_should_reset(false); + } + inc_completed(); + if (n_completed() == n_workers()) { + // At this point we would like to reset the barrier to be ready in + // case it is used again. However, we cannot set n_completed() to + // 0, even after the notify_all(), given that some other workers + // might still be waiting for n_completed() to become == + // n_workers(). So, if we set n_completed() to 0, those workers + // will get stuck (as they will wake up, see that n_completed() != + // n_workers() and go back to sleep). Instead, we raise the + // should_reset() flag and the barrier will be reset the first + // time a worker enters it again. + set_should_reset(true); + monitor()->notify_all(); + } else { + while (n_completed() != n_workers() && !aborted()) { + monitor()->wait(/* no_safepoint_check */ true); + } + } + return !aborted(); +} + +void WorkGangBarrierSync::abort() { + MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); + set_aborted(); + monitor()->notify_all(); +} + +// SubTasksDone functions. + +SubTasksDone::SubTasksDone(uint n) : + _n_tasks(n), _n_threads(1), _tasks(NULL) { + _tasks = NEW_C_HEAP_ARRAY(uint, n, mtInternal); + guarantee(_tasks != NULL, "alloc failure"); + clear(); +} + +bool SubTasksDone::valid() { + return _tasks != NULL; +} + +void SubTasksDone::set_n_threads(uint t) { + assert(_claimed == 0 || _threads_completed == _n_threads, + "should not be called while tasks are being processed!"); + _n_threads = (t == 0 ? 1 : t); +} + +void SubTasksDone::clear() { + for (uint i = 0; i < _n_tasks; i++) { + _tasks[i] = 0; + } + _threads_completed = 0; +#ifdef ASSERT + _claimed = 0; +#endif +} + +bool SubTasksDone::is_task_claimed(uint t) { + assert(t < _n_tasks, "bad task id."); + uint old = _tasks[t]; + if (old == 0) { + old = Atomic::cmpxchg(1, &_tasks[t], 0); + } + assert(_tasks[t] == 1, "What else?"); + bool res = old != 0; +#ifdef ASSERT + if (!res) { + assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?"); + Atomic::inc((volatile jint*) &_claimed); + } +#endif + return res; +} + +void SubTasksDone::all_tasks_completed() { + jint observed = _threads_completed; + jint old; + do { + old = observed; + observed = Atomic::cmpxchg(old+1, &_threads_completed, old); + } while (observed != old); + // If this was the last thread checking in, clear the tasks. + if (observed+1 == (jint)_n_threads) clear(); +} + + +SubTasksDone::~SubTasksDone() { + if (_tasks != NULL) FREE_C_HEAP_ARRAY(jint, _tasks); +} + +// *** SequentialSubTasksDone + +void SequentialSubTasksDone::clear() { + _n_tasks = _n_claimed = 0; + _n_threads = _n_completed = 0; +} + +bool SequentialSubTasksDone::valid() { + return _n_threads > 0; +} + +bool SequentialSubTasksDone::is_task_claimed(uint& t) { + uint* n_claimed_ptr = &_n_claimed; + t = *n_claimed_ptr; + while (t < _n_tasks) { + jint res = Atomic::cmpxchg(t+1, n_claimed_ptr, t); + if (res == (jint)t) { + return false; + } + t = *n_claimed_ptr; + } + return true; +} + +bool SequentialSubTasksDone::all_tasks_completed() { + uint* n_completed_ptr = &_n_completed; + uint complete = *n_completed_ptr; + while (true) { + uint res = Atomic::cmpxchg(complete+1, n_completed_ptr, complete); + if (res == complete) { + break; + } + complete = res; + } + if (complete+1 == _n_threads) { + clear(); + return true; + } + return false; +} + +bool FreeIdSet::_stat_init = false; +FreeIdSet* FreeIdSet::_sets[NSets]; +bool FreeIdSet::_safepoint; + +FreeIdSet::FreeIdSet(int sz, Monitor* mon) : + _sz(sz), _mon(mon), _hd(0), _waiters(0), _index(-1), _claimed(0) +{ + _ids = NEW_C_HEAP_ARRAY(int, sz, mtInternal); + for (int i = 0; i < sz; i++) _ids[i] = i+1; + _ids[sz-1] = end_of_list; // end of list. + if (_stat_init) { + for (int j = 0; j < NSets; j++) _sets[j] = NULL; + _stat_init = true; + } + // Add to sets. (This should happen while the system is still single-threaded.) + for (int j = 0; j < NSets; j++) { + if (_sets[j] == NULL) { + _sets[j] = this; + _index = j; + break; + } + } + guarantee(_index != -1, "Too many FreeIdSets in use!"); +} + +FreeIdSet::~FreeIdSet() { + _sets[_index] = NULL; + FREE_C_HEAP_ARRAY(int, _ids); +} + +void FreeIdSet::set_safepoint(bool b) { + _safepoint = b; + if (b) { + for (int j = 0; j < NSets; j++) { + if (_sets[j] != NULL && _sets[j]->_waiters > 0) { + Monitor* mon = _sets[j]->_mon; + mon->lock_without_safepoint_check(); + mon->notify_all(); + mon->unlock(); + } + } + } +} + +#define FID_STATS 0 + +int FreeIdSet::claim_par_id() { +#if FID_STATS + thread_t tslf = thr_self(); + tty->print("claim_par_id[%d]: sz = %d, claimed = %d\n", tslf, _sz, _claimed); +#endif + MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); + while (!_safepoint && _hd == end_of_list) { + _waiters++; +#if FID_STATS + if (_waiters > 5) { + tty->print("claim_par_id waiting[%d]: %d waiters, %d claimed.\n", + tslf, _waiters, _claimed); + } +#endif + _mon->wait(Mutex::_no_safepoint_check_flag); + _waiters--; + } + if (_hd == end_of_list) { +#if FID_STATS + tty->print("claim_par_id[%d]: returning EOL.\n", tslf); +#endif + return -1; + } else { + int res = _hd; + _hd = _ids[res]; + _ids[res] = claimed; // For debugging. + _claimed++; +#if FID_STATS + tty->print("claim_par_id[%d]: returning %d, claimed = %d.\n", + tslf, res, _claimed); +#endif + return res; + } +} + +bool FreeIdSet::claim_perm_id(int i) { + assert(0 <= i && i < _sz, "Out of range."); + MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); + int prev = end_of_list; + int cur = _hd; + while (cur != end_of_list) { + if (cur == i) { + if (prev == end_of_list) { + _hd = _ids[cur]; + } else { + _ids[prev] = _ids[cur]; + } + _ids[cur] = claimed; + _claimed++; + return true; + } else { + prev = cur; + cur = _ids[cur]; + } + } + return false; + +} + +void FreeIdSet::release_par_id(int id) { + MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); + assert(_ids[id] == claimed, "Precondition."); + _ids[id] = _hd; + _hd = id; + _claimed--; +#if FID_STATS + tty->print("[%d] release_par_id(%d), waiters =%d, claimed = %d.\n", + thr_self(), id, _waiters, _claimed); +#endif + if (_waiters > 0) + // Notify all would be safer, but this is OK, right? + _mon->notify_all(); +}