diff options
Diffstat (limited to 'absl/base/internal/thread_identity.cc')
| -rw-r--r-- | absl/base/internal/thread_identity.cc | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/absl/base/internal/thread_identity.cc b/absl/base/internal/thread_identity.cc index dbec326a..d63a04ae 100644 --- a/absl/base/internal/thread_identity.cc +++ b/absl/base/internal/thread_identity.cc @@ -28,7 +28,7 @@ #include "absl/base/internal/spinlock.h" namespace absl { -inline namespace lts_2019_08_08 { +ABSL_NAMESPACE_BEGIN namespace base_internal { #if ABSL_THREAD_IDENTITY_MODE != ABSL_THREAD_IDENTITY_MODE_USE_CPP11 @@ -56,7 +56,12 @@ void AllocateThreadIdentityKey(ThreadIdentityReclaimerFunction reclaimer) { #ifdef __GNUC__ __attribute__((visibility("protected"))) #endif // __GNUC__ - ABSL_PER_THREAD_TLS_KEYWORD ThreadIdentity* thread_identity_ptr; +#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( @@ -70,8 +75,8 @@ void SetCurrentThreadIdentity( absl::call_once(init_thread_identity_key_once, AllocateThreadIdentityKey, reclaimer); -#ifdef __EMSCRIPTEN__ - // Emscripten PThread implementation does not support signals. +#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, @@ -90,7 +95,7 @@ void SetCurrentThreadIdentity( pthread_setspecific(thread_identity_pthread_key, reinterpret_cast<void*>(identity)); pthread_sigmask(SIG_SETMASK, &curr_signals, nullptr); -#endif // !__EMSCRIPTEN__ +#endif // !__EMSCRIPTEN__ && !__MINGW32__ #elif ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_TLS // NOTE: Not async-safe. But can be open-coded. @@ -108,6 +113,18 @@ void SetCurrentThreadIdentity( #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 @@ -131,5 +148,5 @@ ThreadIdentity* CurrentThreadIdentityIfPresent() { #endif } // namespace base_internal -} // inline namespace lts_2019_08_08 +ABSL_NAMESPACE_END } // namespace absl |