diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/thread_identity.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/base/internal/thread_identity.cc | 155 |
1 files changed, 0 insertions, 155 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/thread_identity.cc b/third_party/abseil_cpp/absl/base/internal/thread_identity.cc deleted file mode 100644 index 6ea010ed0d31..000000000000 --- a/third_party/abseil_cpp/absl/base/internal/thread_identity.cc +++ /dev/null @@ -1,155 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// 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 -// -// https://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 "absl/base/internal/thread_identity.h" - -#ifndef _WIN32 -#include <pthread.h> -#include <signal.h> -#endif - -#include <atomic> -#include <cassert> -#include <memory> - -#include "absl/base/attributes.h" -#include "absl/base/call_once.h" -#include "absl/base/internal/raw_logging.h" -#include "absl/base/internal/spinlock.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace base_internal { - -#if ABSL_THREAD_IDENTITY_MODE != ABSL_THREAD_IDENTITY_MODE_USE_CPP11 -namespace { -// Used to co-ordinate one-time creation of our pthread_key -absl::once_flag init_thread_identity_key_once; -pthread_key_t thread_identity_pthread_key; -std::atomic<bool> pthread_key_initialized(false); - -void AllocateThreadIdentityKey(ThreadIdentityReclaimerFunction reclaimer) { - pthread_key_create(&thread_identity_pthread_key, reclaimer); - pthread_key_initialized.store(true, std::memory_order_release); -} -} // namespace -#endif - -#if ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_TLS || \ - ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11 -// The actual TLS storage for a thread's currently associated ThreadIdentity. -// This is referenced by inline accessors in the header. -// "protected" visibility ensures that if multiple instances of Abseil code -// exist within a process (via dlopen() or similar), references to -// thread_identity_ptr from each instance of the code will refer to -// *different* instances of this ptr. -// Apple platforms have the visibility attribute, but issue a compile warning -// that protected visibility is unsupported. -#if ABSL_HAVE_ATTRIBUTE(visibility) && !defined(__APPLE__) -__attribute__((visibility("protected"))) -#endif // ABSL_HAVE_ATTRIBUTE(visibility) && !defined(__APPLE__) -#if ABSL_PER_THREAD_TLS -// Prefer __thread to thread_local as benchmarks indicate it is a bit faster. -ABSL_PER_THREAD_TLS_KEYWORD ThreadIdentity* thread_identity_ptr = nullptr; -#elif defined(ABSL_HAVE_THREAD_LOCAL) -thread_local ThreadIdentity* thread_identity_ptr = nullptr; -#endif // ABSL_PER_THREAD_TLS -#endif // TLS or CPP11 - -void SetCurrentThreadIdentity( - ThreadIdentity* identity, ThreadIdentityReclaimerFunction reclaimer) { - assert(CurrentThreadIdentityIfPresent() == nullptr); - // Associate our destructor. - // NOTE: This call to pthread_setspecific is currently the only immovable - // barrier to CurrentThreadIdentity() always being async signal safe. -#if ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC - // NOTE: Not async-safe. But can be open-coded. - absl::call_once(init_thread_identity_key_once, AllocateThreadIdentityKey, - reclaimer); - -#if defined(__EMSCRIPTEN__) || defined(__MINGW32__) - // Emscripten and MinGW pthread implementations does not support signals. - // See https://kripken.github.io/emscripten-site/docs/porting/pthreads.html - // for more information. - pthread_setspecific(thread_identity_pthread_key, - reinterpret_cast<void*>(identity)); -#else - // We must mask signals around the call to setspecific as with current glibc, - // a concurrent getspecific (needed for GetCurrentThreadIdentityIfPresent()) - // may zero our value. - // - // While not officially async-signal safe, getspecific within a signal handler - // is otherwise OK. - sigset_t all_signals; - sigset_t curr_signals; - sigfillset(&all_signals); - pthread_sigmask(SIG_SETMASK, &all_signals, &curr_signals); - pthread_setspecific(thread_identity_pthread_key, - reinterpret_cast<void*>(identity)); - pthread_sigmask(SIG_SETMASK, &curr_signals, nullptr); -#endif // !__EMSCRIPTEN__ && !__MINGW32__ - -#elif ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_TLS - // NOTE: Not async-safe. But can be open-coded. - absl::call_once(init_thread_identity_key_once, AllocateThreadIdentityKey, - reclaimer); - pthread_setspecific(thread_identity_pthread_key, - reinterpret_cast<void*>(identity)); - thread_identity_ptr = identity; -#elif ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11 - thread_local std::unique_ptr<ThreadIdentity, ThreadIdentityReclaimerFunction> - holder(identity, reclaimer); - thread_identity_ptr = identity; -#else -#error Unimplemented ABSL_THREAD_IDENTITY_MODE -#endif -} - -#if ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_TLS || \ - ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11 - -// Please see the comment on `CurrentThreadIdentityIfPresent` in -// thread_identity.h. Because DLLs cannot expose thread_local variables in -// headers, we opt for the correct-but-slower option of placing the definition -// of this function only in a translation unit inside DLL. -#if defined(ABSL_BUILD_DLL) || defined(ABSL_CONSUME_DLL) -ThreadIdentity* CurrentThreadIdentityIfPresent() { return thread_identity_ptr; } -#endif -#endif - -void ClearCurrentThreadIdentity() { -#if ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_TLS || \ - ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11 - thread_identity_ptr = nullptr; -#elif ABSL_THREAD_IDENTITY_MODE == \ - ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC - // pthread_setspecific expected to clear value on destruction - assert(CurrentThreadIdentityIfPresent() == nullptr); -#endif -} - -#if ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC -ThreadIdentity* CurrentThreadIdentityIfPresent() { - bool initialized = pthread_key_initialized.load(std::memory_order_acquire); - if (!initialized) { - return nullptr; - } - return reinterpret_cast<ThreadIdentity*>( - pthread_getspecific(thread_identity_pthread_key)); -} -#endif - -} // namespace base_internal -ABSL_NAMESPACE_END -} // namespace absl |