Nagram/TMessagesProj/jni/webrtc/base/threading/scoped_blocking_call_internal.cc
2020-08-14 19:58:22 +03:00

82 lines
3.0 KiB
C++

// Copyright 2020 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/threading/scoped_blocking_call_internal.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/scoped_clear_last_error.h"
#include "base/threading/scoped_blocking_call.h"
#include "base/threading/thread_local.h"
#include "build/build_config.h"
namespace base {
namespace internal {
namespace {
// The first 8 characters of sha1 of "ScopedBlockingCall".
// echo -n "ScopedBlockingCall" | sha1sum
constexpr uint32_t kActivityTrackerId = 0x11be9915;
LazyInstance<ThreadLocalPointer<internal::BlockingObserver>>::Leaky
tls_blocking_observer = LAZY_INSTANCE_INITIALIZER;
// Last ScopedBlockingCall instantiated on this thread.
LazyInstance<ThreadLocalPointer<internal::UncheckedScopedBlockingCall>>::Leaky
tls_last_scoped_blocking_call = LAZY_INSTANCE_INITIALIZER;
} // namespace
void SetBlockingObserverForCurrentThread(BlockingObserver* blocking_observer) {
DCHECK(!tls_blocking_observer.Get().Get());
tls_blocking_observer.Get().Set(blocking_observer);
}
void ClearBlockingObserverForCurrentThread() {
tls_blocking_observer.Get().Set(nullptr);
}
UncheckedScopedBlockingCall::UncheckedScopedBlockingCall(
const Location& from_here,
BlockingType blocking_type)
: blocking_observer_(tls_blocking_observer.Get().Get()),
previous_scoped_blocking_call_(tls_last_scoped_blocking_call.Get().Get()),
is_will_block_(blocking_type == BlockingType::WILL_BLOCK ||
(previous_scoped_blocking_call_ &&
previous_scoped_blocking_call_->is_will_block_)),
scoped_activity_(from_here, 0, kActivityTrackerId, 0) {
tls_last_scoped_blocking_call.Get().Set(this);
if (blocking_observer_) {
if (!previous_scoped_blocking_call_) {
blocking_observer_->BlockingStarted(blocking_type);
} else if (blocking_type == BlockingType::WILL_BLOCK &&
!previous_scoped_blocking_call_->is_will_block_) {
blocking_observer_->BlockingTypeUpgraded();
}
}
if (scoped_activity_.IsRecorded()) {
// Also record the data for extended crash reporting.
const base::TimeTicks now = base::TimeTicks::Now();
auto& user_data = scoped_activity_.user_data();
user_data.SetUint("timestamp_us", now.since_origin().InMicroseconds());
user_data.SetUint("blocking_type", static_cast<uint64_t>(blocking_type));
}
}
UncheckedScopedBlockingCall::~UncheckedScopedBlockingCall() {
// TLS affects result of GetLastError() on Windows. ScopedClearLastError
// prevents side effect.
base::internal::ScopedClearLastError save_last_error;
DCHECK_EQ(this, tls_last_scoped_blocking_call.Get().Get());
tls_last_scoped_blocking_call.Get().Set(previous_scoped_blocking_call_);
if (blocking_observer_ && !previous_scoped_blocking_call_)
blocking_observer_->BlockingEnded();
}
} // namespace internal
} // namespace base