1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154


base / threading / thread_id_name_manager.cc [blame]

// Copyright 2012 The Chromium Authors
// 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/check.h"
#include "base/containers/contains.h"
#include "base/memory/singleton.h"
#include "base/strings/string_util.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;

constinit thread_local const char* thread_name = kDefaultName;
}

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));
  std::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);

    thread_name = 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() {
  return thread_name;
}

void ThreadIdNameManager::RemoveName(PlatformThreadHandle::Handle handle,
                                     PlatformThreadId id) {
  AutoLock locked(lock_);
  auto handle_to_name_iter = thread_handle_to_interned_name_.find(handle);

  CHECK(handle_to_name_iter != thread_handle_to_interned_name_.end(),
        base::NotFatalUntil::M125);
  thread_handle_to_interned_name_.erase(handle_to_name_iter);

  auto id_to_handle_iter = thread_id_to_handle_.find(id);
  CHECK(id_to_handle_iter != thread_id_to_handle_.end(),
        base::NotFatalUntil::M125);
  // 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<PlatformThreadId> ThreadIdNameManager::GetIds() {
  AutoLock locked(lock_);

  std::vector<PlatformThreadId> 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