// Copyright 2021 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. #ifndef BASE_TRACING_TRACING_TLS_H_ #define BASE_TRACING_TRACING_TLS_H_ #include "base/base_export.h" #include "base/check.h" #include "base/memory/raw_ptr.h" #include "base/threading/thread_local.h" namespace base { namespace tracing { // Returns a thread-local flag that records whether the calling thread is // running trace event related code. This is used to avoid writing trace events // re-entrantly. BASE_EXPORT ThreadLocalBoolean* GetThreadIsInTraceEventTLS(); // A scoped class for automatically setting and clearing a thread-local boolean // flag. class BASE_EXPORT AutoThreadLocalBoolean { public: explicit AutoThreadLocalBoolean(ThreadLocalBoolean* thread_local_boolean) : thread_local_boolean_(thread_local_boolean) { DCHECK(!thread_local_boolean_->Get()); thread_local_boolean_->Set(true); } ~AutoThreadLocalBoolean() { thread_local_boolean_->Set(false); } AutoThreadLocalBoolean(const AutoThreadLocalBoolean&) = delete; AutoThreadLocalBoolean& operator=(const AutoThreadLocalBoolean&) = delete; private: raw_ptr thread_local_boolean_; }; } // namespace tracing } // namespace base #endif // BASE_TRACING_TRACING_TLS_H_