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Diffstat (limited to 'gnulib-tests/glthread/thread.h')
| -rw-r--r-- | gnulib-tests/glthread/thread.h | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/gnulib-tests/glthread/thread.h b/gnulib-tests/glthread/thread.h new file mode 100644 index 0000000..6d98f2d --- /dev/null +++ b/gnulib-tests/glthread/thread.h @@ -0,0 +1,338 @@ +/* Creating and controlling threads. + Copyright (C) 2005-2022 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. + Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-win32.h. */ + +/* This file contains primitives for creating and controlling threads. + + Thread data type: gl_thread_t. + + Creating a thread: + thread = gl_thread_create (func, arg); + Or with control of error handling: + err = glthread_create (&thread, func, arg); + extern int glthread_create (gl_thread_t *result, + void *(*func) (void *), void *arg); + + Querying and changing the signal mask of a thread (not supported on all + platforms): + gl_thread_sigmask (how, newmask, oldmask); + Or with control of error handling: + err = glthread_sigmask (how, newmask, oldmask); + extern int glthread_sigmask (int how, const sigset_t *newmask, sigset_t *oldmask); + + Waiting for termination of another thread: + gl_thread_join (thread, &return_value); + Or with control of error handling: + err = glthread_join (thread, &return_value); + extern int glthread_join (gl_thread_t thread, void **return_value_ptr); + + Getting a reference to the current thread: + current = gl_thread_self (); + extern gl_thread_t gl_thread_self (void); + + Getting a reference to the current thread as a pointer, for debugging: + ptr = gl_thread_self_pointer (); + extern void * gl_thread_self_pointer (void); + + Terminating the current thread: + gl_thread_exit (return_value); + extern _Noreturn void gl_thread_exit (void *return_value); + + Requesting custom code to be executed at fork() time (not supported on all + platforms): + gl_thread_atfork (prepare_func, parent_func, child_func); + Or with control of error handling: + err = glthread_atfork (prepare_func, parent_func, child_func); + extern int glthread_atfork (void (*prepare_func) (void), + void (*parent_func) (void), + void (*child_func) (void)); + Note that even on platforms where this is supported, use of fork() and + threads together is problematic, see + <https://lists.gnu.org/r/bug-gnulib/2008-08/msg00062.html> + */ + + +#ifndef _GLTHREAD_THREAD_H +#define _GLTHREAD_THREAD_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 the ISO C threads library. */ + +# include <threads.h> + +# ifdef __cplusplus +extern "C" { +# endif + +/* -------------------------- gl_thread_t datatype -------------------------- */ + +typedef struct thrd_with_exitvalue *gl_thread_t; +extern int glthread_create (gl_thread_t *threadp, + void *(*func) (void *), void *arg); +# define glthread_sigmask(HOW, SET, OSET) \ + pthread_sigmask (HOW, SET, OSET) +extern int glthread_join (gl_thread_t thread, void **return_value_ptr); +extern gl_thread_t gl_thread_self (void); +# define gl_thread_self_pointer() \ + (void *) gl_thread_self () +extern _Noreturn void gl_thread_exit (void *return_value); +# define glthread_atfork(PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) 0 + +# ifdef __cplusplus +} +# endif + +#endif + +/* ========================================================================= */ + +#if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS + +/* Use the POSIX threads library. */ + +# include <pthread.h> + +/* On IRIX, pthread_atfork is declared in <unistd.h>, not in <pthread.h>. */ +# if defined __sgi +# include <unistd.h> +# endif + +# if USE_POSIX_THREADS_WEAK +/* Compilers other than GCC need to see the declaration of pthread_sigmask + before the "#pragma weak pthread_sigmask" below. */ +# include <signal.h> +# endif + +# ifdef __cplusplus +extern "C" { +# endif + +# 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. */ + +/* Weak references avoid dragging in external libraries if the other parts + of the program don't use them. Here we use them, because we don't want + every program that uses libintl to depend on libpthread. This assumes + that libpthread would not be loaded after libintl; i.e. if libintl is + loaded first, by an executable that does not depend on libpthread, and + then a module is dynamically loaded that depends on libpthread, libintl + will not be multithread-safe. */ + +/* The way to test at runtime whether libpthread is present is to test + whether a function pointer's value, such as &pthread_mutex_init, is + non-NULL. However, some versions of GCC have a bug through which, in + PIC mode, &foo != NULL always evaluates to true if there is a direct + call to foo(...) in the same function. To avoid this, we test the + address of a function in libpthread that we don't use. */ + +# ifndef pthread_sigmask /* Do not declare rpl_pthread_sigmask weak. */ +# pragma weak pthread_sigmask +# endif + +# pragma weak pthread_join +# ifndef pthread_self +# pragma weak pthread_self +# endif +# pragma weak pthread_exit +# if HAVE_PTHREAD_ATFORK +# pragma weak pthread_atfork +# 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_thread_t datatype -------------------------- */ + +/* This choice of gl_thread_t assumes that + pthread_equal (a, b) is equivalent to ((a) == (b)). + This is the case on all platforms in use in 2008. */ +typedef pthread_t gl_thread_t; +# define glthread_create(THREADP, FUNC, ARG) \ + (pthread_in_use () ? pthread_create (THREADP, NULL, FUNC, ARG) : ENOSYS) +# define glthread_sigmask(HOW, SET, OSET) \ + (pthread_in_use () ? pthread_sigmask (HOW, SET, OSET) : 0) +# define glthread_join(THREAD, RETVALP) \ + (pthread_in_use () ? pthread_join (THREAD, RETVALP) : 0) +# ifdef PTW32_VERSION + /* In pthreads-win32, pthread_t is a struct with a pointer field 'p' and + other fields. */ +# define gl_thread_self() \ + (pthread_in_use () ? pthread_self () : gl_null_thread) +# define gl_thread_self_pointer() \ + (pthread_in_use () ? pthread_self ().p : NULL) +extern const gl_thread_t gl_null_thread; +# elif defined __MVS__ + /* On IBM z/OS, pthread_t is a struct with an 8-byte '__' field. + The first three bytes of this field appear to uniquely identify a + pthread_t, though not necessarily representing a pointer. */ +# define gl_thread_self() \ + (pthread_in_use () ? pthread_self () : gl_null_thread) +# define gl_thread_self_pointer() \ + (pthread_in_use () ? *((void **) pthread_self ().__) : NULL) +extern const gl_thread_t gl_null_thread; +# else +# define gl_thread_self() \ + (pthread_in_use () ? pthread_self () : (pthread_t) 0) +# define gl_thread_self_pointer() \ + (pthread_in_use () ? (void *) pthread_self () : NULL) +# endif +# define gl_thread_exit(RETVAL) \ + (void) (pthread_in_use () ? (pthread_exit (RETVAL), 0) : 0) + +# if HAVE_PTHREAD_ATFORK +# define glthread_atfork(PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) \ + (pthread_in_use () ? pthread_atfork (PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) : 0) +# else +# define glthread_atfork(PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) 0 +# endif + +# ifdef __cplusplus +} +# endif + +#endif + +/* ========================================================================= */ + +#if USE_WINDOWS_THREADS + +# define WIN32_LEAN_AND_MEAN /* avoid including junk */ +# include <windows.h> + +# include "windows-thread.h" + +# ifdef __cplusplus +extern "C" { +# endif + +/* -------------------------- gl_thread_t datatype -------------------------- */ + +typedef glwthread_thread_t gl_thread_t; +# define glthread_create(THREADP, FUNC, ARG) \ + glwthread_thread_create (THREADP, 0, FUNC, ARG) +# define glthread_sigmask(HOW, SET, OSET) \ + /* unsupported */ 0 +# define glthread_join(THREAD, RETVALP) \ + glwthread_thread_join (THREAD, RETVALP) +# define gl_thread_self() \ + glwthread_thread_self () +# define gl_thread_self_pointer() \ + gl_thread_self () +# define gl_thread_exit(RETVAL) \ + glwthread_thread_exit (RETVAL) +# define glthread_atfork(PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) 0 + +# ifdef __cplusplus +} +# endif + +#endif + +/* ========================================================================= */ + +#if !(USE_ISOC_THREADS || USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS || USE_WINDOWS_THREADS) + +/* Provide dummy implementation if threads are not supported. */ + +typedef int gl_thread_t; +# define glthread_create(THREADP, FUNC, ARG) ENOSYS +# define glthread_sigmask(HOW, SET, OSET) 0 +# define glthread_join(THREAD, RETVALP) 0 +# define gl_thread_self() 0 +# define gl_thread_self_pointer() \ + ((void *) gl_thread_self ()) +# define gl_thread_exit(RETVAL) (void)0 +# define glthread_atfork(PREPARE_FUNC, PARENT_FUNC, CHILD_FUNC) 0 + +#endif + +/* ========================================================================= */ + +/* Macros with built-in error handling. */ + +#ifdef __cplusplus +extern "C" { +#endif + +extern gl_thread_t gl_thread_create (void *(*func) (void *arg), void *arg); +#define gl_thread_sigmask(HOW, SET, OSET) \ + do \ + { \ + if (glthread_sigmask (HOW, SET, OSET)) \ + abort (); \ + } \ + while (0) +#define gl_thread_join(THREAD, RETVAL) \ + do \ + { \ + if (glthread_join (THREAD, RETVAL)) \ + abort (); \ + } \ + while (0) +#define gl_thread_atfork(PREPARE, PARENT, CHILD) \ + do \ + { \ + if (glthread_atfork (PREPARE, PARENT, CHILD)) \ + abort (); \ + } \ + while (0) + +#ifdef __cplusplus +} +#endif + +#endif /* _GLTHREAD_THREAD_H */ |