2 * Copyright 2017 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <folly/ThreadName.h>
19 #include <type_traits>
21 #include <folly/Portability.h>
22 #include <folly/Traits.h>
23 #include <folly/portability/PThread.h>
27 // This looks a bit weird, but it's necessary to avoid
28 // having an undefined compiler function called.
29 #if defined(__GLIBC__) && !defined(__APPLE__) && !defined(__ANDROID__)
30 #if __GLIBC_PREREQ(2, 12)
31 // has pthread_setname_np(pthread_t, const char*) (2 params)
32 #define FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME 1
36 #if defined(__APPLE__) && defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
37 #if __MAC_OS_X_VERSION_MIN_REQUIRED >= 1060
38 // has pthread_setname_np(const char*) (1 param)
39 #define FOLLY_HAS_PTHREAD_SETNAME_NP_NAME 1
43 bool canSetCurrentThreadName() {
44 #if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME || \
45 FOLLY_HAS_PTHREAD_SETNAME_NP_NAME
52 bool canSetOtherThreadName() {
53 #if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME
60 static constexpr size_t kMaxThreadNameLength = 16;
62 Optional<std::string> getCurrentThreadName() {
63 #if !FOLLY_HAVE_PTHREAD
64 return Optional<std::string>();
66 #if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME
67 std::array<char, kMaxThreadNameLength> buf;
68 if (pthread_getname_np(pthread_self(), buf.data(), buf.size()) != 0) {
69 return Optional<std::string>();
71 return make_optional(std::string(buf.data()));
72 #elif FOLLY_HAS_PTHREAD_SETNAME_NP_NAME
73 std::array<char, kMaxThreadNameLength> buf;
74 if (pthread_getname_np(buf.data(), buf.size()) != 0) {
75 return Optional<std::string>();
77 return make_optional(std::string(buf.data()));
79 return Optional<std::string>();
84 bool setThreadName(std::thread::id tid, StringPiece name) {
85 #if !FOLLY_HAVE_PTHREAD || _WIN32
89 std::is_same<pthread_t, std::thread::native_handle_type>::value,
90 "This assumes that the native handle type is pthread_t");
92 sizeof(std::thread::native_handle_type) == sizeof(std::thread::id),
93 "This assumes std::thread::id is a thin wrapper around "
94 "std::thread::native_handle_type, but that doesn't appear to be true.");
95 // In most implementations, std::thread::id is a thin wrapper around
96 // std::thread::native_handle_type, which means we can do unsafe things to
99 std::memcpy(&id, &tid, sizeof(id));
100 auto trimmedName = name.fbstr().substr(0, kMaxThreadNameLength - 1);
101 #if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME
102 return 0 == pthread_setname_np(id, trimmedName.c_str());
103 #elif FOLLY_HAS_PTHREAD_SETNAME_NP_NAME
104 // Since OS X 10.6 it is possible for a thread to set its own name,
105 // but not that of some other thread.
106 if (pthread_equal(pthread_self(), id)) {
107 return 0 == pthread_setname_np(trimmedName.c_str());
116 #if FOLLY_HAVE_PTHREAD
117 bool setThreadName(pthread_t pid, StringPiece name) {
119 // Not currently supported on Windows.
123 std::is_same<pthread_t, std::thread::native_handle_type>::value,
124 "This assumes that the native handle type is pthread_t");
126 sizeof(std::thread::native_handle_type) == sizeof(std::thread::id),
127 "This assumes std::thread::id is a thin wrapper around "
128 "std::thread::native_handle_type, but that doesn't appear to be true.");
129 // In most implementations, std::thread::id is a thin wrapper around
130 // std::thread::native_handle_type, which means we can do unsafe things to
133 std::memcpy(&id, &pid, sizeof(id));
134 return setThreadName(id, name);
139 bool setThreadName(StringPiece name) {
140 return setThreadName(std::this_thread::get_id(), name);