| /* Thread-local storage in multithreaded situations. |
| Copyright (C) 2005, 2007-2021 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by Bruno Haible <bruno@clisp.org>, 2005. */ |
| |
| /* This file contains thread-local storage primitives for use with a given |
| thread library. It does not contain primitives for creating threads or |
| for other multithreading primitives. |
| |
| Type: gl_tls_key_t |
| Initialization: gl_tls_key_init (name, destructor); |
| Getting per-thread value: gl_tls_get (name) |
| Setting per-thread value: gl_tls_set (name, pointer); |
| De-initialization: gl_tls_key_destroy (name); |
| Equivalent functions with control of error handling: |
| Initialization: err = glthread_tls_key_init (&name, destructor); |
| Setting per-thread value: err = glthread_tls_set (&name, pointer); |
| De-initialization: err = glthread_tls_key_destroy (&name); |
| |
| A per-thread value is of type 'void *'. |
| |
| A destructor is a function pointer of type 'void (*) (void *)', called |
| when a thread exits, and taking the last per-thread value as argument. It |
| is unspecified whether the destructor function is called when the last |
| per-thread value is NULL. On some platforms, the destructor function is |
| not called at all. |
| */ |
| |
| |
| #ifndef _TLS_H |
| #define _TLS_H |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| |
| #if !defined c11_threads_in_use |
| # if HAVE_THREADS_H && USE_POSIX_THREADS_WEAK |
| # include <threads.h> |
| # pragma weak thrd_exit |
| # define c11_threads_in_use() (thrd_exit != NULL) |
| # else |
| # define c11_threads_in_use() 0 |
| # endif |
| #endif |
| |
| /* ========================================================================= */ |
| |
| #if USE_ISOC_THREADS || USE_ISOC_AND_POSIX_THREADS |
| |
| /* Use the ISO C threads library. */ |
| |
| # include <threads.h> |
| |
| /* ------------------------- gl_tls_key_t datatype ------------------------- */ |
| |
| typedef tss_t gl_tls_key_t; |
| # define glthread_tls_key_init(KEY, DESTRUCTOR) \ |
| (tss_create (KEY, DESTRUCTOR) != thrd_success ? EAGAIN : 0) |
| # define gl_tls_get(NAME) \ |
| tss_get (NAME) |
| # define glthread_tls_set(KEY, POINTER) \ |
| (tss_set (*(KEY), (POINTER)) != thrd_success ? ENOMEM : 0) |
| # define glthread_tls_key_destroy(KEY) \ |
| (tss_delete (*(KEY)), 0) |
| |
| #endif |
| |
| /* ========================================================================= */ |
| |
| #if USE_POSIX_THREADS |
| |
| /* Use the POSIX threads library. */ |
| |
| # include <pthread.h> |
| |
| # if PTHREAD_IN_USE_DETECTION_HARD |
| |
| /* The pthread_in_use() detection needs to be done at runtime. */ |
| # define pthread_in_use() \ |
| glthread_in_use () |
| extern int glthread_in_use (void); |
| |
| # endif |
| |
| # if USE_POSIX_THREADS_WEAK |
| |
| /* Use weak references to the POSIX threads library. */ |
| |
| # pragma weak pthread_key_create |
| # pragma weak pthread_getspecific |
| # pragma weak pthread_setspecific |
| # pragma weak pthread_key_delete |
| # ifndef pthread_self |
| # pragma weak pthread_self |
| # endif |
| |
| # if !PTHREAD_IN_USE_DETECTION_HARD |
| # pragma weak pthread_mutexattr_gettype |
| # define pthread_in_use() \ |
| (pthread_mutexattr_gettype != NULL || c11_threads_in_use ()) |
| # endif |
| |
| # else |
| |
| # if !PTHREAD_IN_USE_DETECTION_HARD |
| # define pthread_in_use() 1 |
| # endif |
| |
| # endif |
| |
| /* ------------------------- gl_tls_key_t datatype ------------------------- */ |
| |
| typedef union |
| { |
| void *singlethread_value; |
| pthread_key_t key; |
| } |
| gl_tls_key_t; |
| # define glthread_tls_key_init(KEY, DESTRUCTOR) \ |
| (pthread_in_use () \ |
| ? pthread_key_create (&(KEY)->key, DESTRUCTOR) \ |
| : ((KEY)->singlethread_value = NULL, 0)) |
| # define gl_tls_get(NAME) \ |
| (pthread_in_use () \ |
| ? pthread_getspecific ((NAME).key) \ |
| : (NAME).singlethread_value) |
| # define glthread_tls_set(KEY, POINTER) \ |
| (pthread_in_use () \ |
| ? pthread_setspecific ((KEY)->key, (POINTER)) \ |
| : ((KEY)->singlethread_value = (POINTER), 0)) |
| # define glthread_tls_key_destroy(KEY) \ |
| (pthread_in_use () ? pthread_key_delete ((KEY)->key) : 0) |
| |
| #endif |
| |
| /* ========================================================================= */ |
| |
| #if USE_WINDOWS_THREADS |
| |
| # define WIN32_LEAN_AND_MEAN /* avoid including junk */ |
| # include <windows.h> |
| |
| # include "windows-tls.h" |
| |
| /* ------------------------- gl_tls_key_t datatype ------------------------- */ |
| |
| typedef glwthread_tls_key_t gl_tls_key_t; |
| # define glthread_tls_key_init(KEY, DESTRUCTOR) \ |
| glwthread_tls_key_create (KEY, DESTRUCTOR) |
| # define gl_tls_get(NAME) \ |
| TlsGetValue (NAME) |
| # define glthread_tls_set(KEY, POINTER) \ |
| (!TlsSetValue (*(KEY), POINTER) ? EINVAL : 0) |
| # define glthread_tls_key_destroy(KEY) \ |
| glwthread_tls_key_delete (*(KEY)) |
| |
| #endif |
| |
| /* ========================================================================= */ |
| |
| #if !(USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS) |
| |
| /* Provide dummy implementation if threads are not supported. */ |
| |
| /* ------------------------- gl_tls_key_t datatype ------------------------- */ |
| |
| typedef struct |
| { |
| void *singlethread_value; |
| } |
| gl_tls_key_t; |
| # define glthread_tls_key_init(KEY, DESTRUCTOR) \ |
| ((KEY)->singlethread_value = NULL, \ |
| (void) (DESTRUCTOR), \ |
| 0) |
| # define gl_tls_get(NAME) \ |
| (NAME).singlethread_value |
| # define glthread_tls_set(KEY, POINTER) \ |
| ((KEY)->singlethread_value = (POINTER), 0) |
| # define glthread_tls_key_destroy(KEY) \ |
| 0 |
| |
| #endif |
| |
| /* ========================================================================= */ |
| |
| /* Macros with built-in error handling. */ |
| |
| /* ------------------------- gl_tls_key_t datatype ------------------------- */ |
| |
| #define gl_tls_key_init(NAME, DESTRUCTOR) \ |
| do \ |
| { \ |
| if (glthread_tls_key_init (&NAME, DESTRUCTOR)) \ |
| abort (); \ |
| } \ |
| while (0) |
| #define gl_tls_set(NAME, POINTER) \ |
| do \ |
| { \ |
| if (glthread_tls_set (&NAME, POINTER)) \ |
| abort (); \ |
| } \ |
| while (0) |
| #define gl_tls_key_destroy(NAME) \ |
| do \ |
| { \ |
| if (glthread_tls_key_destroy (&NAME)) \ |
| abort (); \ |
| } \ |
| while (0) |
| |
| /* ========================================================================= */ |
| |
| #endif /* _TLS_H */ |