| /* |
| * Copyright (c) 1998, 2016, 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 "compiler/compileBroker.hpp" |
| #include "gc/shared/collectedHeap.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/method.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "oops/verifyOopClosure.hpp" |
| #include "runtime/interfaceSupport.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/os.hpp" |
| #include "runtime/safepoint.hpp" |
| #include "runtime/thread.inline.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "runtime/vm_operations.hpp" |
| #include "services/runtimeService.hpp" |
| #include "trace/tracing.hpp" |
| #include "utilities/dtrace.hpp" |
| #include "utilities/events.hpp" |
| #include "utilities/xmlstream.hpp" |
| |
| // Dummy VM operation to act as first element in our circular double-linked list |
| class VM_Dummy: public VM_Operation { |
| VMOp_Type type() const { return VMOp_Dummy; } |
| void doit() {}; |
| }; |
| |
| VMOperationQueue::VMOperationQueue() { |
| // The queue is a circular doubled-linked list, which always contains |
| // one element (i.e., one element means empty). |
| for(int i = 0; i < nof_priorities; i++) { |
| _queue_length[i] = 0; |
| _queue_counter = 0; |
| _queue[i] = new VM_Dummy(); |
| _queue[i]->set_next(_queue[i]); |
| _queue[i]->set_prev(_queue[i]); |
| } |
| _drain_list = NULL; |
| } |
| |
| |
| bool VMOperationQueue::queue_empty(int prio) { |
| // It is empty if there is exactly one element |
| bool empty = (_queue[prio] == _queue[prio]->next()); |
| assert( (_queue_length[prio] == 0 && empty) || |
| (_queue_length[prio] > 0 && !empty), "sanity check"); |
| return _queue_length[prio] == 0; |
| } |
| |
| // Inserts an element to the right of the q element |
| void VMOperationQueue::insert(VM_Operation* q, VM_Operation* n) { |
| assert(q->next()->prev() == q && q->prev()->next() == q, "sanity check"); |
| n->set_prev(q); |
| n->set_next(q->next()); |
| q->next()->set_prev(n); |
| q->set_next(n); |
| } |
| |
| void VMOperationQueue::queue_add_front(int prio, VM_Operation *op) { |
| _queue_length[prio]++; |
| insert(_queue[prio]->next(), op); |
| } |
| |
| void VMOperationQueue::queue_add_back(int prio, VM_Operation *op) { |
| _queue_length[prio]++; |
| insert(_queue[prio]->prev(), op); |
| } |
| |
| |
| void VMOperationQueue::unlink(VM_Operation* q) { |
| assert(q->next()->prev() == q && q->prev()->next() == q, "sanity check"); |
| q->prev()->set_next(q->next()); |
| q->next()->set_prev(q->prev()); |
| } |
| |
| VM_Operation* VMOperationQueue::queue_remove_front(int prio) { |
| if (queue_empty(prio)) return NULL; |
| assert(_queue_length[prio] >= 0, "sanity check"); |
| _queue_length[prio]--; |
| VM_Operation* r = _queue[prio]->next(); |
| assert(r != _queue[prio], "cannot remove base element"); |
| unlink(r); |
| return r; |
| } |
| |
| VM_Operation* VMOperationQueue::queue_drain(int prio) { |
| if (queue_empty(prio)) return NULL; |
| DEBUG_ONLY(int length = _queue_length[prio];); |
| assert(length >= 0, "sanity check"); |
| _queue_length[prio] = 0; |
| VM_Operation* r = _queue[prio]->next(); |
| assert(r != _queue[prio], "cannot remove base element"); |
| // remove links to base element from head and tail |
| r->set_prev(NULL); |
| _queue[prio]->prev()->set_next(NULL); |
| // restore queue to empty state |
| _queue[prio]->set_next(_queue[prio]); |
| _queue[prio]->set_prev(_queue[prio]); |
| assert(queue_empty(prio), "drain corrupted queue"); |
| #ifdef ASSERT |
| int len = 0; |
| VM_Operation* cur; |
| for(cur = r; cur != NULL; cur=cur->next()) len++; |
| assert(len == length, "drain lost some ops"); |
| #endif |
| return r; |
| } |
| |
| void VMOperationQueue::queue_oops_do(int queue, OopClosure* f) { |
| VM_Operation* cur = _queue[queue]; |
| cur = cur->next(); |
| while (cur != _queue[queue]) { |
| cur->oops_do(f); |
| cur = cur->next(); |
| } |
| } |
| |
| void VMOperationQueue::drain_list_oops_do(OopClosure* f) { |
| VM_Operation* cur = _drain_list; |
| while (cur != NULL) { |
| cur->oops_do(f); |
| cur = cur->next(); |
| } |
| } |
| |
| //----------------------------------------------------------------- |
| // High-level interface |
| bool VMOperationQueue::add(VM_Operation *op) { |
| |
| HOTSPOT_VMOPS_REQUEST( |
| (char *) op->name(), strlen(op->name()), |
| op->evaluation_mode()); |
| |
| // Encapsulates VM queue policy. Currently, that |
| // only involves putting them on the right list |
| if (op->evaluate_at_safepoint()) { |
| queue_add_back(SafepointPriority, op); |
| return true; |
| } |
| |
| queue_add_back(MediumPriority, op); |
| return true; |
| } |
| |
| VM_Operation* VMOperationQueue::remove_next() { |
| // Assuming VMOperation queue is two-level priority queue. If there are |
| // more than two priorities, we need a different scheduling algorithm. |
| assert(SafepointPriority == 0 && MediumPriority == 1 && nof_priorities == 2, |
| "current algorithm does not work"); |
| |
| // simple counter based scheduling to prevent starvation of lower priority |
| // queue. -- see 4390175 |
| int high_prio, low_prio; |
| if (_queue_counter++ < 10) { |
| high_prio = SafepointPriority; |
| low_prio = MediumPriority; |
| } else { |
| _queue_counter = 0; |
| high_prio = MediumPriority; |
| low_prio = SafepointPriority; |
| } |
| |
| return queue_remove_front(queue_empty(high_prio) ? low_prio : high_prio); |
| } |
| |
| void VMOperationQueue::oops_do(OopClosure* f) { |
| for(int i = 0; i < nof_priorities; i++) { |
| queue_oops_do(i, f); |
| } |
| drain_list_oops_do(f); |
| } |
| |
| |
| //------------------------------------------------------------------------------------------------------------------ |
| // Implementation of VMThread stuff |
| |
| bool VMThread::_should_terminate = false; |
| bool VMThread::_terminated = false; |
| Monitor* VMThread::_terminate_lock = NULL; |
| VMThread* VMThread::_vm_thread = NULL; |
| VM_Operation* VMThread::_cur_vm_operation = NULL; |
| VMOperationQueue* VMThread::_vm_queue = NULL; |
| PerfCounter* VMThread::_perf_accumulated_vm_operation_time = NULL; |
| |
| |
| void VMThread::create() { |
| assert(vm_thread() == NULL, "we can only allocate one VMThread"); |
| _vm_thread = new VMThread(); |
| |
| // Create VM operation queue |
| _vm_queue = new VMOperationQueue(); |
| guarantee(_vm_queue != NULL, "just checking"); |
| |
| _terminate_lock = new Monitor(Mutex::safepoint, "VMThread::_terminate_lock", true, |
| Monitor::_safepoint_check_never); |
| |
| if (UsePerfData) { |
| // jvmstat performance counters |
| Thread* THREAD = Thread::current(); |
| _perf_accumulated_vm_operation_time = |
| PerfDataManager::create_counter(SUN_THREADS, "vmOperationTime", |
| PerfData::U_Ticks, CHECK); |
| } |
| } |
| |
| |
| VMThread::VMThread() : NamedThread() { |
| set_name("VM Thread"); |
| } |
| |
| void VMThread::destroy() { |
| if (_vm_thread != NULL) { |
| delete _vm_thread; |
| _vm_thread = NULL; // VM thread is gone |
| } |
| } |
| |
| void VMThread::run() { |
| assert(this == vm_thread(), "check"); |
| |
| this->initialize_named_thread(); |
| this->record_stack_base_and_size(); |
| // Notify_lock wait checks on active_handles() to rewait in |
| // case of spurious wakeup, it should wait on the last |
| // value set prior to the notify |
| this->set_active_handles(JNIHandleBlock::allocate_block()); |
| |
| { |
| MutexLocker ml(Notify_lock); |
| Notify_lock->notify(); |
| } |
| // Notify_lock is destroyed by Threads::create_vm() |
| |
| int prio = (VMThreadPriority == -1) |
| ? os::java_to_os_priority[NearMaxPriority] |
| : VMThreadPriority; |
| // Note that I cannot call os::set_priority because it expects Java |
| // priorities and I am *explicitly* using OS priorities so that it's |
| // possible to set the VM thread priority higher than any Java thread. |
| os::set_native_priority( this, prio ); |
| |
| // Wait for VM_Operations until termination |
| this->loop(); |
| |
| // Note the intention to exit before safepointing. |
| // 6295565 This has the effect of waiting for any large tty |
| // outputs to finish. |
| if (xtty != NULL) { |
| ttyLocker ttyl; |
| xtty->begin_elem("destroy_vm"); |
| xtty->stamp(); |
| xtty->end_elem(); |
| assert(should_terminate(), "termination flag must be set"); |
| } |
| |
| // 4526887 let VM thread exit at Safepoint |
| SafepointSynchronize::begin(); |
| |
| if (VerifyBeforeExit) { |
| HandleMark hm(VMThread::vm_thread()); |
| // Among other things, this ensures that Eden top is correct. |
| Universe::heap()->prepare_for_verify(); |
| os::check_heap(); |
| // Silent verification so as not to pollute normal output, |
| // unless we really asked for it. |
| Universe::verify(); |
| } |
| |
| CompileBroker::set_should_block(); |
| |
| // wait for threads (compiler threads or daemon threads) in the |
| // _thread_in_native state to block. |
| VM_Exit::wait_for_threads_in_native_to_block(); |
| |
| // signal other threads that VM process is gone |
| { |
| // Note: we must have the _no_safepoint_check_flag. Mutex::lock() allows |
| // VM thread to enter any lock at Safepoint as long as its _owner is NULL. |
| // If that happens after _terminate_lock->wait() has unset _owner |
| // but before it actually drops the lock and waits, the notification below |
| // may get lost and we will have a hang. To avoid this, we need to use |
| // Mutex::lock_without_safepoint_check(). |
| MutexLockerEx ml(_terminate_lock, Mutex::_no_safepoint_check_flag); |
| _terminated = true; |
| _terminate_lock->notify(); |
| } |
| |
| // Deletion must be done synchronously by the JNI DestroyJavaVM thread |
| // so that the VMThread deletion completes before the main thread frees |
| // up the CodeHeap. |
| |
| } |
| |
| |
| // Notify the VMThread that the last non-daemon JavaThread has terminated, |
| // and wait until operation is performed. |
| void VMThread::wait_for_vm_thread_exit() { |
| { MutexLocker mu(VMOperationQueue_lock); |
| _should_terminate = true; |
| VMOperationQueue_lock->notify(); |
| } |
| |
| // Note: VM thread leaves at Safepoint. We are not stopped by Safepoint |
| // because this thread has been removed from the threads list. But anything |
| // that could get blocked by Safepoint should not be used after this point, |
| // otherwise we will hang, since there is no one can end the safepoint. |
| |
| // Wait until VM thread is terminated |
| // Note: it should be OK to use Terminator_lock here. But this is called |
| // at a very delicate time (VM shutdown) and we are operating in non- VM |
| // thread at Safepoint. It's safer to not share lock with other threads. |
| { MutexLockerEx ml(_terminate_lock, Mutex::_no_safepoint_check_flag); |
| while(!VMThread::is_terminated()) { |
| _terminate_lock->wait(Mutex::_no_safepoint_check_flag); |
| } |
| } |
| } |
| |
| void VMThread::evaluate_operation(VM_Operation* op) { |
| ResourceMark rm; |
| |
| { |
| PerfTraceTime vm_op_timer(perf_accumulated_vm_operation_time()); |
| HOTSPOT_VMOPS_BEGIN( |
| (char *) op->name(), strlen(op->name()), |
| op->evaluation_mode()); |
| |
| EventExecuteVMOperation event; |
| |
| op->evaluate(); |
| |
| if (event.should_commit()) { |
| const bool is_concurrent = op->evaluate_concurrently(); |
| const bool evaluate_at_safepoint = op->evaluate_at_safepoint(); |
| event.set_operation(op->type()); |
| event.set_safepoint(evaluate_at_safepoint); |
| event.set_blocking(!is_concurrent); |
| // Only write caller thread information for non-concurrent vm operations. |
| // For concurrent vm operations, the thread id is set to 0 indicating thread is unknown. |
| // This is because the caller thread could have exited already. |
| event.set_caller(is_concurrent ? 0 : THREAD_TRACE_ID(op->calling_thread())); |
| event.set_safepointId(evaluate_at_safepoint ? SafepointSynchronize::safepoint_counter() : 0); |
| event.commit(); |
| } |
| |
| HOTSPOT_VMOPS_END( |
| (char *) op->name(), strlen(op->name()), |
| op->evaluation_mode()); |
| } |
| |
| // Last access of info in _cur_vm_operation! |
| bool c_heap_allocated = op->is_cheap_allocated(); |
| |
| // Mark as completed |
| if (!op->evaluate_concurrently()) { |
| op->calling_thread()->increment_vm_operation_completed_count(); |
| } |
| // It is unsafe to access the _cur_vm_operation after the 'increment_vm_operation_completed_count' call, |
| // since if it is stack allocated the calling thread might have deallocated |
| if (c_heap_allocated) { |
| delete _cur_vm_operation; |
| } |
| } |
| |
| |
| void VMThread::loop() { |
| assert(_cur_vm_operation == NULL, "no current one should be executing"); |
| |
| while(true) { |
| VM_Operation* safepoint_ops = NULL; |
| // |
| // Wait for VM operation |
| // |
| // use no_safepoint_check to get lock without attempting to "sneak" |
| { MutexLockerEx mu_queue(VMOperationQueue_lock, |
| Mutex::_no_safepoint_check_flag); |
| |
| // Look for new operation |
| assert(_cur_vm_operation == NULL, "no current one should be executing"); |
| _cur_vm_operation = _vm_queue->remove_next(); |
| |
| // Stall time tracking code |
| if (PrintVMQWaitTime && _cur_vm_operation != NULL && |
| !_cur_vm_operation->evaluate_concurrently()) { |
| long stall = os::javaTimeMillis() - _cur_vm_operation->timestamp(); |
| if (stall > 0) |
| tty->print_cr("%s stall: %ld", _cur_vm_operation->name(), stall); |
| } |
| |
| while (!should_terminate() && _cur_vm_operation == NULL) { |
| // wait with a timeout to guarantee safepoints at regular intervals |
| bool timedout = |
| VMOperationQueue_lock->wait(Mutex::_no_safepoint_check_flag, |
| GuaranteedSafepointInterval); |
| |
| // Support for self destruction |
| if ((SelfDestructTimer != 0) && !is_error_reported() && |
| (os::elapsedTime() > (double)SelfDestructTimer * 60.0)) { |
| tty->print_cr("VM self-destructed"); |
| exit(-1); |
| } |
| |
| if (timedout && (SafepointALot || |
| SafepointSynchronize::is_cleanup_needed())) { |
| MutexUnlockerEx mul(VMOperationQueue_lock, |
| Mutex::_no_safepoint_check_flag); |
| // Force a safepoint since we have not had one for at least |
| // 'GuaranteedSafepointInterval' milliseconds. This will run all |
| // the clean-up processing that needs to be done regularly at a |
| // safepoint |
| SafepointSynchronize::begin(); |
| #ifdef ASSERT |
| if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot(); |
| #endif |
| SafepointSynchronize::end(); |
| } |
| _cur_vm_operation = _vm_queue->remove_next(); |
| |
| // If we are at a safepoint we will evaluate all the operations that |
| // follow that also require a safepoint |
| if (_cur_vm_operation != NULL && |
| _cur_vm_operation->evaluate_at_safepoint()) { |
| safepoint_ops = _vm_queue->drain_at_safepoint_priority(); |
| } |
| } |
| |
| if (should_terminate()) break; |
| } // Release mu_queue_lock |
| |
| // |
| // Execute VM operation |
| // |
| { HandleMark hm(VMThread::vm_thread()); |
| |
| EventMark em("Executing VM operation: %s", vm_operation()->name()); |
| assert(_cur_vm_operation != NULL, "we should have found an operation to execute"); |
| |
| // Give the VM thread an extra quantum. Jobs tend to be bursty and this |
| // helps the VM thread to finish up the job. |
| // FIXME: When this is enabled and there are many threads, this can degrade |
| // performance significantly. |
| if( VMThreadHintNoPreempt ) |
| os::hint_no_preempt(); |
| |
| // If we are at a safepoint we will evaluate all the operations that |
| // follow that also require a safepoint |
| if (_cur_vm_operation->evaluate_at_safepoint()) { |
| |
| _vm_queue->set_drain_list(safepoint_ops); // ensure ops can be scanned |
| |
| SafepointSynchronize::begin(); |
| evaluate_operation(_cur_vm_operation); |
| // now process all queued safepoint ops, iteratively draining |
| // the queue until there are none left |
| do { |
| _cur_vm_operation = safepoint_ops; |
| if (_cur_vm_operation != NULL) { |
| do { |
| // evaluate_operation deletes the op object so we have |
| // to grab the next op now |
| VM_Operation* next = _cur_vm_operation->next(); |
| _vm_queue->set_drain_list(next); |
| evaluate_operation(_cur_vm_operation); |
| _cur_vm_operation = next; |
| if (PrintSafepointStatistics) { |
| SafepointSynchronize::inc_vmop_coalesced_count(); |
| } |
| } while (_cur_vm_operation != NULL); |
| } |
| // There is a chance that a thread enqueued a safepoint op |
| // since we released the op-queue lock and initiated the safepoint. |
| // So we drain the queue again if there is anything there, as an |
| // optimization to try and reduce the number of safepoints. |
| // As the safepoint synchronizes us with JavaThreads we will see |
| // any enqueue made by a JavaThread, but the peek will not |
| // necessarily detect a concurrent enqueue by a GC thread, but |
| // that simply means the op will wait for the next major cycle of the |
| // VMThread - just as it would if the GC thread lost the race for |
| // the lock. |
| if (_vm_queue->peek_at_safepoint_priority()) { |
| // must hold lock while draining queue |
| MutexLockerEx mu_queue(VMOperationQueue_lock, |
| Mutex::_no_safepoint_check_flag); |
| safepoint_ops = _vm_queue->drain_at_safepoint_priority(); |
| } else { |
| safepoint_ops = NULL; |
| } |
| } while(safepoint_ops != NULL); |
| |
| _vm_queue->set_drain_list(NULL); |
| |
| // Complete safepoint synchronization |
| SafepointSynchronize::end(); |
| |
| } else { // not a safepoint operation |
| if (TraceLongCompiles) { |
| elapsedTimer t; |
| t.start(); |
| evaluate_operation(_cur_vm_operation); |
| t.stop(); |
| double secs = t.seconds(); |
| if (secs * 1e3 > LongCompileThreshold) { |
| // XXX - _cur_vm_operation should not be accessed after |
| // the completed count has been incremented; the waiting |
| // thread may have already freed this memory. |
| tty->print_cr("vm %s: %3.7f secs]", _cur_vm_operation->name(), secs); |
| } |
| } else { |
| evaluate_operation(_cur_vm_operation); |
| } |
| |
| _cur_vm_operation = NULL; |
| } |
| } |
| |
| // |
| // Notify (potential) waiting Java thread(s) - lock without safepoint |
| // check so that sneaking is not possible |
| { MutexLockerEx mu(VMOperationRequest_lock, |
| Mutex::_no_safepoint_check_flag); |
| VMOperationRequest_lock->notify_all(); |
| } |
| |
| // |
| // We want to make sure that we get to a safepoint regularly. |
| // |
| if (SafepointALot || SafepointSynchronize::is_cleanup_needed()) { |
| long interval = SafepointSynchronize::last_non_safepoint_interval(); |
| bool max_time_exceeded = GuaranteedSafepointInterval != 0 && (interval > GuaranteedSafepointInterval); |
| if (SafepointALot || max_time_exceeded) { |
| HandleMark hm(VMThread::vm_thread()); |
| SafepointSynchronize::begin(); |
| SafepointSynchronize::end(); |
| } |
| } |
| } |
| } |
| |
| void VMThread::execute(VM_Operation* op) { |
| Thread* t = Thread::current(); |
| |
| if (!t->is_VM_thread()) { |
| SkipGCALot sgcalot(t); // avoid re-entrant attempts to gc-a-lot |
| // JavaThread or WatcherThread |
| bool concurrent = op->evaluate_concurrently(); |
| // only blocking VM operations need to verify the caller's safepoint state: |
| if (!concurrent) { |
| t->check_for_valid_safepoint_state(true); |
| } |
| |
| // New request from Java thread, evaluate prologue |
| if (!op->doit_prologue()) { |
| return; // op was cancelled |
| } |
| |
| // Setup VM_operations for execution |
| op->set_calling_thread(t, Thread::get_priority(t)); |
| |
| // It does not make sense to execute the epilogue, if the VM operation object is getting |
| // deallocated by the VM thread. |
| bool execute_epilog = !op->is_cheap_allocated(); |
| assert(!concurrent || op->is_cheap_allocated(), "concurrent => cheap_allocated"); |
| |
| // Get ticket number for non-concurrent VM operations |
| int ticket = 0; |
| if (!concurrent) { |
| ticket = t->vm_operation_ticket(); |
| } |
| |
| // Add VM operation to list of waiting threads. We are guaranteed not to block while holding the |
| // VMOperationQueue_lock, so we can block without a safepoint check. This allows vm operation requests |
| // to be queued up during a safepoint synchronization. |
| { |
| VMOperationQueue_lock->lock_without_safepoint_check(); |
| bool ok = _vm_queue->add(op); |
| op->set_timestamp(os::javaTimeMillis()); |
| VMOperationQueue_lock->notify(); |
| VMOperationQueue_lock->unlock(); |
| // VM_Operation got skipped |
| if (!ok) { |
| assert(concurrent, "can only skip concurrent tasks"); |
| if (op->is_cheap_allocated()) delete op; |
| return; |
| } |
| } |
| |
| if (!concurrent) { |
| // Wait for completion of request (non-concurrent) |
| // Note: only a JavaThread triggers the safepoint check when locking |
| MutexLocker mu(VMOperationRequest_lock); |
| while(t->vm_operation_completed_count() < ticket) { |
| VMOperationRequest_lock->wait(!t->is_Java_thread()); |
| } |
| } |
| |
| if (execute_epilog) { |
| op->doit_epilogue(); |
| } |
| } else { |
| // invoked by VM thread; usually nested VM operation |
| assert(t->is_VM_thread(), "must be a VM thread"); |
| VM_Operation* prev_vm_operation = vm_operation(); |
| if (prev_vm_operation != NULL) { |
| // Check the VM operation allows nested VM operation. This normally not the case, e.g., the compiler |
| // does not allow nested scavenges or compiles. |
| if (!prev_vm_operation->allow_nested_vm_operations()) { |
| fatal("Nested VM operation %s requested by operation %s", |
| op->name(), vm_operation()->name()); |
| } |
| op->set_calling_thread(prev_vm_operation->calling_thread(), prev_vm_operation->priority()); |
| } |
| |
| EventMark em("Executing %s VM operation: %s", prev_vm_operation ? "nested" : "", op->name()); |
| |
| // Release all internal handles after operation is evaluated |
| HandleMark hm(t); |
| _cur_vm_operation = op; |
| |
| if (op->evaluate_at_safepoint() && !SafepointSynchronize::is_at_safepoint()) { |
| SafepointSynchronize::begin(); |
| op->evaluate(); |
| SafepointSynchronize::end(); |
| } else { |
| op->evaluate(); |
| } |
| |
| // Free memory if needed |
| if (op->is_cheap_allocated()) delete op; |
| |
| _cur_vm_operation = prev_vm_operation; |
| } |
| } |
| |
| |
| void VMThread::oops_do(OopClosure* f, CLDClosure* cld_f, CodeBlobClosure* cf) { |
| Thread::oops_do(f, cld_f, cf); |
| _vm_queue->oops_do(f); |
| } |
| |
| //------------------------------------------------------------------------------------------------------------------ |
| #ifndef PRODUCT |
| |
| void VMOperationQueue::verify_queue(int prio) { |
| // Check that list is correctly linked |
| int length = _queue_length[prio]; |
| VM_Operation *cur = _queue[prio]; |
| int i; |
| |
| // Check forward links |
| for(i = 0; i < length; i++) { |
| cur = cur->next(); |
| assert(cur != _queue[prio], "list to short (forward)"); |
| } |
| assert(cur->next() == _queue[prio], "list to long (forward)"); |
| |
| // Check backwards links |
| cur = _queue[prio]; |
| for(i = 0; i < length; i++) { |
| cur = cur->prev(); |
| assert(cur != _queue[prio], "list to short (backwards)"); |
| } |
| assert(cur->prev() == _queue[prio], "list to long (backwards)"); |
| } |
| |
| #endif |
| |
| void VMThread::verify() { |
| oops_do(&VerifyOopClosure::verify_oop, NULL, NULL); |
| } |