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// 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 <stdlib.h>
#include <string.h>
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "base/no_destructor.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/threading/thread_local.h"
#include "base/trace_event/heap_profiler_allocation_context_tracker.h"
namespace base {
namespace {
static const char kDefaultName[] = "";
static std::string* g_default_name;
ThreadLocalStorage::Slot& GetThreadNameTLS() {
static base::NoDestructor<base::ThreadLocalStorage::Slot> 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<ThreadIdNameManager,
LeakySingletonTraits<ThreadIdNameManager> >::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<char*>(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<const char*>(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);
}
} // namespace base