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Diffstat (limited to 'lib/glthread/tls.h')
| -rw-r--r-- | lib/glthread/tls.h | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/lib/glthread/tls.h b/lib/glthread/tls.h new file mode 100644 index 0000000..27b5bb2 --- /dev/null +++ b/lib/glthread/tls.h @@ -0,0 +1,230 @@ +/* Thread-local storage in multithreaded situations. + Copyright (C) 2005, 2007-2022 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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_FROM_LIBC +# define c11_threads_in_use() 1 +# elif 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 */ |