v8/src/counters-inl.h
Ulan Degenbaev 42ac7fe04b [runtime] Make access to FLAG_runtime_stats atomic.
Background tasks read this flag, which creates a data race. This patch
works around the data races by making the access to the flag atomic.

The actual fix will be to not mutate the flag.

Bug: chromium:794911
Change-Id: Idcf03b7a1037e876036918418ce989b420784428
Reviewed-on: https://chromium-review.googlesource.com/834508
Reviewed-by: Fadi Meawad <fmeawad@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50215}
2017-12-19 19:01:50 +00:00

68 lines
1.8 KiB
C++

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_COUNTERS_INL_H_
#define V8_COUNTERS_INL_H_
#include "src/counters.h"
namespace v8 {
namespace internal {
void RuntimeCallTimer::Start(RuntimeCallCounter* counter,
RuntimeCallTimer* parent) {
DCHECK(!IsStarted());
counter_ = counter;
parent_.SetValue(parent);
if (base::AsAtomic32::Relaxed_Load(&FLAG_runtime_stats) ==
v8::tracing::TracingCategoryObserver::ENABLED_BY_SAMPLING) {
return;
}
base::TimeTicks now = RuntimeCallTimer::Now();
if (parent) parent->Pause(now);
Resume(now);
DCHECK(IsStarted());
}
void RuntimeCallTimer::Pause(base::TimeTicks now) {
DCHECK(IsStarted());
elapsed_ += (now - start_ticks_);
start_ticks_ = base::TimeTicks();
}
void RuntimeCallTimer::Resume(base::TimeTicks now) {
DCHECK(!IsStarted());
start_ticks_ = now;
}
RuntimeCallTimer* RuntimeCallTimer::Stop() {
if (!IsStarted()) return parent();
base::TimeTicks now = RuntimeCallTimer::Now();
Pause(now);
counter_->Increment();
CommitTimeToCounter();
RuntimeCallTimer* parent_timer = parent();
if (parent_timer) {
parent_timer->Resume(now);
}
return parent_timer;
}
void RuntimeCallTimer::CommitTimeToCounter() {
counter_->Add(elapsed_);
elapsed_ = base::TimeDelta();
}
bool RuntimeCallTimer::IsStarted() { return start_ticks_ != base::TimeTicks(); }
RuntimeCallTimerScope::RuntimeCallTimerScope(HeapObject* heap_object,
RuntimeCallCounterId counter_id)
: RuntimeCallTimerScope(heap_object->GetIsolate(), counter_id) {}
} // namespace internal
} // namespace v8
#endif // V8_COUNTERS_INL_H_