1 // Copyright 2012 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "src/heap/sweeper-thread.h" 6 7 #include "src/v8.h" 8 9 #include "src/isolate.h" 10 #include "src/v8threads.h" 11 12 namespace v8 { 13 namespace internal { 14 15 static const int kSweeperThreadStackSize = 64 * KB; 16 17 SweeperThread::SweeperThread(Isolate* isolate) 18 : Thread(Thread::Options("v8:SweeperThread", kSweeperThreadStackSize)), 19 isolate_(isolate), 20 heap_(isolate->heap()), 21 collector_(heap_->mark_compact_collector()), 22 start_sweeping_semaphore_(0), 23 end_sweeping_semaphore_(0), 24 stop_semaphore_(0) { 25 DCHECK(!FLAG_job_based_sweeping); 26 base::NoBarrier_Store(&stop_thread_, static_cast<base::AtomicWord>(false)); 27 } 28 29 30 void SweeperThread::Run() { 31 Isolate::SetIsolateThreadLocals(isolate_, NULL); 32 DisallowHeapAllocation no_allocation; 33 DisallowHandleAllocation no_handles; 34 DisallowHandleDereference no_deref; 35 36 while (true) { 37 start_sweeping_semaphore_.Wait(); 38 39 if (base::Acquire_Load(&stop_thread_)) { 40 stop_semaphore_.Signal(); 41 return; 42 } 43 44 collector_->SweepInParallel(heap_->old_data_space(), 0); 45 collector_->SweepInParallel(heap_->old_pointer_space(), 0); 46 end_sweeping_semaphore_.Signal(); 47 } 48 } 49 50 51 void SweeperThread::Stop() { 52 base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(true)); 53 start_sweeping_semaphore_.Signal(); 54 stop_semaphore_.Wait(); 55 Join(); 56 } 57 58 59 void SweeperThread::StartSweeping() { start_sweeping_semaphore_.Signal(); } 60 61 62 void SweeperThread::WaitForSweeperThread() { end_sweeping_semaphore_.Wait(); } 63 64 65 bool SweeperThread::SweepingCompleted() { 66 bool value = end_sweeping_semaphore_.WaitFor(base::TimeDelta::FromSeconds(0)); 67 if (value) { 68 end_sweeping_semaphore_.Signal(); 69 } 70 return value; 71 } 72 73 74 int SweeperThread::NumberOfThreads(int max_available) { 75 if (!FLAG_concurrent_sweeping && !FLAG_parallel_sweeping) return 0; 76 if (FLAG_sweeper_threads > 0) return FLAG_sweeper_threads; 77 if (FLAG_concurrent_sweeping) return max_available - 1; 78 DCHECK(FLAG_parallel_sweeping); 79 return max_available; 80 } 81 } 82 } // namespace v8::internal 83
