1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/threading/thread_id_name_manager.h"
6
7 #include <stdlib.h>
8 #include <string.h>
9
10 #include "base/check.h"
11 #include "base/containers/contains.h"
12 #include "base/memory/singleton.h"
13 #include "base/strings/string_util.h"
14 #include "base/trace_event/heap_profiler_allocation_context_tracker.h" // no-presubmit-check
15 #include "third_party/abseil-cpp/absl/base/attributes.h"
16
17 namespace base {
18 namespace {
19
20 static const char kDefaultName[] = "";
21 static std::string* g_default_name;
22
23 ABSL_CONST_INIT thread_local const char* thread_name = kDefaultName;
24 }
25
26 ThreadIdNameManager::Observer::~Observer() = default;
27
ThreadIdNameManager()28 ThreadIdNameManager::ThreadIdNameManager()
29 : main_process_name_(nullptr), main_process_id_(kInvalidThreadId) {
30 g_default_name = new std::string(kDefaultName);
31
32 AutoLock locked(lock_);
33 name_to_interned_name_[kDefaultName] = g_default_name;
34 }
35
36 ThreadIdNameManager::~ThreadIdNameManager() = default;
37
GetInstance()38 ThreadIdNameManager* ThreadIdNameManager::GetInstance() {
39 return Singleton<ThreadIdNameManager,
40 LeakySingletonTraits<ThreadIdNameManager> >::get();
41 }
42
GetDefaultInternedString()43 const char* ThreadIdNameManager::GetDefaultInternedString() {
44 return g_default_name->c_str();
45 }
46
RegisterThread(PlatformThreadHandle::Handle handle,PlatformThreadId id)47 void ThreadIdNameManager::RegisterThread(PlatformThreadHandle::Handle handle,
48 PlatformThreadId id) {
49 AutoLock locked(lock_);
50 thread_id_to_handle_[id] = handle;
51 thread_handle_to_interned_name_[handle] =
52 name_to_interned_name_[kDefaultName];
53 }
54
AddObserver(Observer * obs)55 void ThreadIdNameManager::AddObserver(Observer* obs) {
56 AutoLock locked(lock_);
57 DCHECK(!base::Contains(observers_, obs));
58 observers_.push_back(obs);
59 }
60
RemoveObserver(Observer * obs)61 void ThreadIdNameManager::RemoveObserver(Observer* obs) {
62 AutoLock locked(lock_);
63 DCHECK(base::Contains(observers_, obs));
64 std::erase(observers_, obs);
65 }
66
SetName(const std::string & name)67 void ThreadIdNameManager::SetName(const std::string& name) {
68 PlatformThreadId id = PlatformThread::CurrentId();
69 std::string* leaked_str = nullptr;
70 {
71 AutoLock locked(lock_);
72 auto iter = name_to_interned_name_.find(name);
73 if (iter != name_to_interned_name_.end()) {
74 leaked_str = iter->second;
75 } else {
76 leaked_str = new std::string(name);
77 name_to_interned_name_[name] = leaked_str;
78 }
79
80 auto id_to_handle_iter = thread_id_to_handle_.find(id);
81
82 thread_name = leaked_str->c_str();
83 for (Observer* obs : observers_)
84 obs->OnThreadNameChanged(leaked_str->c_str());
85
86 // The main thread of a process will not be created as a Thread object which
87 // means there is no PlatformThreadHandler registered.
88 if (id_to_handle_iter == thread_id_to_handle_.end()) {
89 main_process_name_ = leaked_str;
90 main_process_id_ = id;
91 return;
92 }
93 thread_handle_to_interned_name_[id_to_handle_iter->second] = leaked_str;
94 }
95
96 // Add the leaked thread name to heap profiler context tracker. The name added
97 // is valid for the lifetime of the process. AllocationContextTracker cannot
98 // call GetName(which holds a lock) during the first allocation because it can
99 // cause a deadlock when the first allocation happens in the
100 // ThreadIdNameManager itself when holding the lock.
101 trace_event::AllocationContextTracker::SetCurrentThreadName(
102 leaked_str->c_str());
103 }
104
GetName(PlatformThreadId id)105 const char* ThreadIdNameManager::GetName(PlatformThreadId id) {
106 AutoLock locked(lock_);
107
108 if (id == main_process_id_)
109 return main_process_name_->c_str();
110
111 auto id_to_handle_iter = thread_id_to_handle_.find(id);
112 if (id_to_handle_iter == thread_id_to_handle_.end())
113 return name_to_interned_name_[kDefaultName]->c_str();
114
115 auto handle_to_name_iter =
116 thread_handle_to_interned_name_.find(id_to_handle_iter->second);
117 return handle_to_name_iter->second->c_str();
118 }
119
GetNameForCurrentThread()120 const char* ThreadIdNameManager::GetNameForCurrentThread() {
121 return thread_name;
122 }
123
RemoveName(PlatformThreadHandle::Handle handle,PlatformThreadId id)124 void ThreadIdNameManager::RemoveName(PlatformThreadHandle::Handle handle,
125 PlatformThreadId id) {
126 AutoLock locked(lock_);
127 auto handle_to_name_iter = thread_handle_to_interned_name_.find(handle);
128
129 CHECK(handle_to_name_iter != thread_handle_to_interned_name_.end(),
130 base::NotFatalUntil::M125);
131 thread_handle_to_interned_name_.erase(handle_to_name_iter);
132
133 auto id_to_handle_iter = thread_id_to_handle_.find(id);
134 CHECK(id_to_handle_iter != thread_id_to_handle_.end(),
135 base::NotFatalUntil::M125);
136 // The given |id| may have been re-used by the system. Make sure the
137 // mapping points to the provided |handle| before removal.
138 if (id_to_handle_iter->second != handle)
139 return;
140
141 thread_id_to_handle_.erase(id_to_handle_iter);
142 }
143
GetIds()144 std::vector<PlatformThreadId> ThreadIdNameManager::GetIds() {
145 AutoLock locked(lock_);
146
147 std::vector<PlatformThreadId> ids;
148 ids.reserve(thread_id_to_handle_.size());
149 for (const auto& iter : thread_id_to_handle_)
150 ids.push_back(iter.first);
151
152 return ids;
153 }
154
155 } // namespace base
156