summaryrefslogtreecommitdiffstats
path: root/base/debug/trace_event_synthetic_delay.cc
diff options
context:
space:
mode:
Diffstat (limited to 'base/debug/trace_event_synthetic_delay.cc')
-rw-r--r--base/debug/trace_event_synthetic_delay.cc217
1 files changed, 0 insertions, 217 deletions
diff --git a/base/debug/trace_event_synthetic_delay.cc b/base/debug/trace_event_synthetic_delay.cc
deleted file mode 100644
index 505fe5d..0000000
--- a/base/debug/trace_event_synthetic_delay.cc
+++ /dev/null
@@ -1,217 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "base/debug/trace_event_synthetic_delay.h"
-#include "base/memory/singleton.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/platform_thread.h"
-
-namespace {
-const int kMaxSyntheticDelays = 32;
-} // namespace
-
-namespace base {
-namespace debug {
-
-TraceEventSyntheticDelayClock::TraceEventSyntheticDelayClock() {}
-TraceEventSyntheticDelayClock::~TraceEventSyntheticDelayClock() {}
-
-class TraceEventSyntheticDelayRegistry : public TraceEventSyntheticDelayClock {
- public:
- static TraceEventSyntheticDelayRegistry* GetInstance();
-
- TraceEventSyntheticDelay* GetOrCreateDelay(const char* name);
-
- // TraceEventSyntheticDelayClock implementation.
- virtual base::TimeTicks Now() OVERRIDE;
-
- private:
- TraceEventSyntheticDelayRegistry();
-
- friend struct DefaultSingletonTraits<TraceEventSyntheticDelayRegistry>;
-
- Lock lock_;
- TraceEventSyntheticDelay delays_[kMaxSyntheticDelays];
- TraceEventSyntheticDelay dummy_delay_;
- base::subtle::Atomic32 delay_count_;
-
- DISALLOW_COPY_AND_ASSIGN(TraceEventSyntheticDelayRegistry);
-};
-
-TraceEventSyntheticDelay::TraceEventSyntheticDelay()
- : mode_(STATIC), generation_(0), clock_(NULL) {}
-
-TraceEventSyntheticDelay::~TraceEventSyntheticDelay() {}
-
-TraceEventSyntheticDelay* TraceEventSyntheticDelay::Lookup(
- const std::string& name) {
- return TraceEventSyntheticDelayRegistry::GetInstance()->GetOrCreateDelay(
- name.c_str());
-}
-
-void TraceEventSyntheticDelay::Initialize(
- const std::string& name,
- TraceEventSyntheticDelayClock* clock) {
- DCHECK(!thread_state_.Get());
- name_ = name;
- clock_ = clock;
-}
-
-void TraceEventSyntheticDelay::SetTargetDuration(
- base::TimeDelta target_duration) {
- AutoLock lock(lock_);
- target_duration_ = target_duration;
- generation_++;
-}
-
-void TraceEventSyntheticDelay::SetMode(Mode mode) {
- AutoLock lock(lock_);
- mode_ = mode;
- generation_++;
-}
-
-void TraceEventSyntheticDelay::SetClock(TraceEventSyntheticDelayClock* clock) {
- AutoLock lock(lock_);
- clock_ = clock;
- generation_++;
-}
-
-TraceEventSyntheticDelay::ThreadState::ThreadState()
- : trigger_count(0u), generation(0) {}
-
-void TraceEventSyntheticDelay::Activate() {
- // Note that we check for a non-zero target duration without locking to keep
- // things quick for the common case when delays are disabled. Since the delay
- // calculation is done with a lock held, it will always be correct. The only
- // downside of this is that we may fail to apply some delays when the target
- // duration changes.
- ANNOTATE_BENIGN_RACE(&target_duration_, "Synthetic delay duration");
- if (!target_duration_.ToInternalValue())
- return;
-
- // Store the start time in a thread local struct so the same delay can be
- // applied to multiple threads simultaneously. Note that the structs are
- // leaked at program exit.
- ThreadState* thread_state = EnsureThreadState();
- if (!thread_state->start_time.ToInternalValue())
- thread_state->start_time = clock_->Now();
-}
-
-TraceEventSyntheticDelay::ThreadState*
-TraceEventSyntheticDelay::EnsureThreadState() {
- ThreadState* thread_state = thread_state_.Get();
- if (!thread_state)
- thread_state_.Set((thread_state = new ThreadState()));
- return thread_state;
-}
-
-void TraceEventSyntheticDelay::Apply() {
- ANNOTATE_BENIGN_RACE(&target_duration_, "Synthetic delay duration");
- if (!target_duration_.ToInternalValue())
- return;
-
- ThreadState* thread_state = EnsureThreadState();
- if (!thread_state->start_time.ToInternalValue())
- return;
- base::TimeTicks now = clock_->Now();
- base::TimeTicks start_time = thread_state->start_time;
- base::TimeTicks end_time;
- thread_state->start_time = base::TimeTicks();
-
- {
- AutoLock lock(lock_);
- if (thread_state->generation != generation_) {
- thread_state->trigger_count = 0;
- thread_state->generation = generation_;
- }
-
- if (mode_ == ONE_SHOT && thread_state->trigger_count++)
- return;
- else if (mode_ == ALTERNATING && thread_state->trigger_count++ % 2)
- return;
-
- end_time = start_time + target_duration_;
- if (now >= end_time)
- return;
- }
- ApplyDelay(end_time);
-}
-
-void TraceEventSyntheticDelay::ApplyDelay(base::TimeTicks end_time) {
- TRACE_EVENT0("synthetic_delay", name_.c_str());
- while (clock_->Now() < end_time) {
- // Busy loop.
- }
-}
-
-TraceEventSyntheticDelayRegistry*
-TraceEventSyntheticDelayRegistry::GetInstance() {
- return Singleton<
- TraceEventSyntheticDelayRegistry,
- LeakySingletonTraits<TraceEventSyntheticDelayRegistry> >::get();
-}
-
-TraceEventSyntheticDelayRegistry::TraceEventSyntheticDelayRegistry()
- : delay_count_(0) {}
-
-TraceEventSyntheticDelay* TraceEventSyntheticDelayRegistry::GetOrCreateDelay(
- const char* name) {
- // Try to find an existing delay first without locking to make the common case
- // fast.
- int delay_count = base::subtle::Acquire_Load(&delay_count_);
- for (int i = 0; i < delay_count; ++i) {
- if (!strcmp(name, delays_[i].name_.c_str()))
- return &delays_[i];
- }
-
- AutoLock lock(lock_);
- delay_count = base::subtle::Acquire_Load(&delay_count_);
- for (int i = 0; i < delay_count; ++i) {
- if (!strcmp(name, delays_[i].name_.c_str()))
- return &delays_[i];
- }
-
- DCHECK(delay_count < kMaxSyntheticDelays)
- << "must increase kMaxSyntheticDelays";
- if (delay_count >= kMaxSyntheticDelays)
- return &dummy_delay_;
-
- delays_[delay_count].Initialize(std::string(name), this);
- base::subtle::Release_Store(&delay_count_, delay_count + 1);
- return &delays_[delay_count];
-}
-
-base::TimeTicks TraceEventSyntheticDelayRegistry::Now() {
- return base::TimeTicks::HighResNow();
-}
-
-} // namespace debug
-} // namespace base
-
-namespace trace_event_internal {
-
-ScopedSyntheticDelay::ScopedSyntheticDelay(const char* name,
- base::subtle::AtomicWord* impl_ptr)
- : delay_impl_(GetOrCreateDelay(name, impl_ptr)) {
- delay_impl_->Activate();
-}
-
-ScopedSyntheticDelay::~ScopedSyntheticDelay() { delay_impl_->Apply(); }
-
-base::debug::TraceEventSyntheticDelay* GetOrCreateDelay(
- const char* name,
- base::subtle::AtomicWord* impl_ptr) {
- base::debug::TraceEventSyntheticDelay* delay_impl =
- reinterpret_cast<base::debug::TraceEventSyntheticDelay*>(
- base::subtle::NoBarrier_Load(impl_ptr));
- if (!delay_impl) {
- delay_impl = base::debug::TraceEventSyntheticDelayRegistry::GetInstance()
- ->GetOrCreateDelay(name);
- base::subtle::NoBarrier_Store(
- impl_ptr, reinterpret_cast<base::subtle::AtomicWord>(delay_impl));
- }
- return delay_impl;
-}
-
-} // namespace trace_event_internal