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
SweeperThread(Isolate * isolate)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
Run()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
Stop()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
StartSweeping()59 void SweeperThread::StartSweeping() { start_sweeping_semaphore_.Signal(); }
60
61
WaitForSweeperThread()62 void SweeperThread::WaitForSweeperThread() { end_sweeping_semaphore_.Wait(); }
63
64
SweepingCompleted()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
NumberOfThreads(int max_available)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