// Copyright (c) 2012 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/thread_id_name_manager.h" #include #include #include "base/check.h" #include "base/containers/contains.h" #include "base/containers/cxx20_erase.h" #include "base/memory/singleton.h" #include "base/no_destructor.h" #include "base/strings/string_util.h" #include "base/threading/thread_local.h" #include "base/trace_event/heap_profiler_allocation_context_tracker.h" // no-presubmit-check namespace base { namespace { static const char kDefaultName[] = ""; static std::string* g_default_name; ThreadLocalStorage::Slot& GetThreadNameTLS() { static base::NoDestructor thread_name_tls; return *thread_name_tls; } } ThreadIdNameManager::Observer::~Observer() = default; ThreadIdNameManager::ThreadIdNameManager() : main_process_name_(nullptr), main_process_id_(kInvalidThreadId) { g_default_name = new std::string(kDefaultName); AutoLock locked(lock_); name_to_interned_name_[kDefaultName] = g_default_name; } ThreadIdNameManager::~ThreadIdNameManager() = default; ThreadIdNameManager* ThreadIdNameManager::GetInstance() { return Singleton >::get(); } const char* ThreadIdNameManager::GetDefaultInternedString() { return g_default_name->c_str(); } void ThreadIdNameManager::RegisterThread(PlatformThreadHandle::Handle handle, PlatformThreadId id) { AutoLock locked(lock_); thread_id_to_handle_[id] = handle; thread_handle_to_interned_name_[handle] = name_to_interned_name_[kDefaultName]; } void ThreadIdNameManager::AddObserver(Observer* obs) { AutoLock locked(lock_); DCHECK(!base::Contains(observers_, obs)); observers_.push_back(obs); } void ThreadIdNameManager::RemoveObserver(Observer* obs) { AutoLock locked(lock_); DCHECK(base::Contains(observers_, obs)); base::Erase(observers_, obs); } void ThreadIdNameManager::SetName(const std::string& name) { PlatformThreadId id = PlatformThread::CurrentId(); std::string* leaked_str = nullptr; { AutoLock locked(lock_); auto iter = name_to_interned_name_.find(name); if (iter != name_to_interned_name_.end()) { leaked_str = iter->second; } else { leaked_str = new std::string(name); name_to_interned_name_[name] = leaked_str; } auto id_to_handle_iter = thread_id_to_handle_.find(id); GetThreadNameTLS().Set(const_cast(leaked_str->c_str())); for (Observer* obs : observers_) obs->OnThreadNameChanged(leaked_str->c_str()); // The main thread of a process will not be created as a Thread object which // means there is no PlatformThreadHandler registered. if (id_to_handle_iter == thread_id_to_handle_.end()) { main_process_name_ = leaked_str; main_process_id_ = id; return; } thread_handle_to_interned_name_[id_to_handle_iter->second] = leaked_str; } // Add the leaked thread name to heap profiler context tracker. The name added // is valid for the lifetime of the process. AllocationContextTracker cannot // call GetName(which holds a lock) during the first allocation because it can // cause a deadlock when the first allocation happens in the // ThreadIdNameManager itself when holding the lock. trace_event::AllocationContextTracker::SetCurrentThreadName( leaked_str->c_str()); } const char* ThreadIdNameManager::GetName(PlatformThreadId id) { AutoLock locked(lock_); if (id == main_process_id_) return main_process_name_->c_str(); auto id_to_handle_iter = thread_id_to_handle_.find(id); if (id_to_handle_iter == thread_id_to_handle_.end()) return name_to_interned_name_[kDefaultName]->c_str(); auto handle_to_name_iter = thread_handle_to_interned_name_.find(id_to_handle_iter->second); return handle_to_name_iter->second->c_str(); } const char* ThreadIdNameManager::GetNameForCurrentThread() { const char* name = reinterpret_cast(GetThreadNameTLS().Get()); return name ? name : kDefaultName; } void ThreadIdNameManager::RemoveName(PlatformThreadHandle::Handle handle, PlatformThreadId id) { AutoLock locked(lock_); auto handle_to_name_iter = thread_handle_to_interned_name_.find(handle); DCHECK(handle_to_name_iter != thread_handle_to_interned_name_.end()); thread_handle_to_interned_name_.erase(handle_to_name_iter); auto id_to_handle_iter = thread_id_to_handle_.find(id); DCHECK((id_to_handle_iter!= thread_id_to_handle_.end())); // The given |id| may have been re-used by the system. Make sure the // mapping points to the provided |handle| before removal. if (id_to_handle_iter->second != handle) return; thread_id_to_handle_.erase(id_to_handle_iter); } std::vector ThreadIdNameManager::GetIds() { AutoLock locked(lock_); std::vector ids; ids.reserve(thread_id_to_handle_.size()); for (const auto& iter : thread_id_to_handle_) ids.push_back(iter.first); return ids; } } // namespace base