+/*
+ * Copyright 2017 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <folly/ThreadName.h>
+
+#include <type_traits>
+
+#include <folly/Portability.h>
+#include <folly/Traits.h>
+#include <folly/portability/PThread.h>
+
+namespace folly {
+
+// This looks a bit weird, but it's necessary to avoid
+// having an undefined compiler function called.
+#if defined(__GLIBC__) && !defined(__APPLE__) && !defined(__ANDROID__)
+#if __GLIBC_PREREQ(2, 12)
+// has pthread_setname_np(pthread_t, const char*) (2 params)
+#define FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME 1
+#endif
+#endif
+
+#if defined(__APPLE__) && defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
+#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 1060
+// has pthread_setname_np(const char*) (1 param)
+#define FOLLY_HAS_PTHREAD_SETNAME_NP_NAME 1
+#endif
+#endif
+
+bool canSetCurrentThreadName() {
+#if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME || \
+ FOLLY_HAS_PTHREAD_SETNAME_NP_NAME
+ return true;
+#else
+ return false;
+#endif
+}
+
+bool canSetOtherThreadName() {
+#if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME
+ return true;
+#else
+ return false;
+#endif
+}
+
+bool setThreadName(std::thread::id tid, StringPiece name) {
+#if !FOLLY_HAVE_PTHREAD
+ return false;
+#else
+ static_assert(
+ std::is_same<pthread_t, std::thread::native_handle_type>::value,
+ "This assumes that the native handle type is pthread_t");
+ static_assert(
+ sizeof(std::thread::native_handle_type) == sizeof(std::thread::id),
+ "This assumes std::thread::id is a thin wrapper around "
+ "std::thread::native_handle_type, but that doesn't appear to be true.");
+ // In most implementations, std::thread::id is a thin wrapper around
+ // std::thread::native_handle_type, which means we can do unsafe things to
+ // extract it.
+ pthread_t id;
+ std::memcpy(&id, &tid, sizeof(id));
+#if FOLLY_HAS_PTHREAD_SETNAME_NP_THREAD_NAME
+ return 0 == pthread_setname_np(id, name.fbstr().substr(0, 15).c_str());
+#elif FOLLY_HAS_PTHREAD_SETNAME_NP_NAME
+ // Since OS X 10.6 it is possible for a thread to set its own name,
+ // but not that of some other thread.
+ if (pthread_equal(pthread_self(), id)) {
+ return 0 == pthread_setname_np(name.fbstr().c_str());
+ }
+ return false;
+#else
+ return false;
+#endif
+#endif
+}
+
+#if FOLLY_HAVE_PTHREAD
+bool setThreadName(pthread_t pid, StringPiece name) {
+ static_assert(
+ std::is_same<pthread_t, std::thread::native_handle_type>::value,
+ "This assumes that the native handle type is pthread_t");
+ static_assert(
+ sizeof(std::thread::native_handle_type) == sizeof(std::thread::id),
+ "This assumes std::thread::id is a thin wrapper around "
+ "std::thread::native_handle_type, but that doesn't appear to be true.");
+ // In most implementations, std::thread::id is a thin wrapper around
+ // std::thread::native_handle_type, which means we can do unsafe things to
+ // extract it.
+ std::thread::id id;
+ std::memcpy(&id, &pid, sizeof(id));
+ return setThreadName(id, name);
+}
+#endif
+
+bool setThreadName(StringPiece name) {
+ return setThreadName(std::this_thread::get_id(), name);
+}
+}
projects / folly.git / commitdiff