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Diffstat (limited to 'gnulib-tests/glthread/thread.c')
| -rw-r--r-- | gnulib-tests/glthread/thread.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/gnulib-tests/glthread/thread.c b/gnulib-tests/glthread/thread.c new file mode 100644 index 0000000..0b923c0 --- /dev/null +++ b/gnulib-tests/glthread/thread.c @@ -0,0 +1,216 @@ +/* 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. */ + +#include <config.h> + +/* Specification. */ +#include "glthread/thread.h" + +#include <stdlib.h> +#include "glthread/lock.h" + +/* ========================================================================= */ + +#if USE_ISOC_THREADS + +struct thrd_with_exitvalue +{ + thrd_t volatile tid; + void * volatile exitvalue; +}; + +/* The Thread-Specific Storage (TSS) key that allows to access each thread's + 'struct thrd_with_exitvalue *' pointer. */ +static tss_t thrd_with_exitvalue_key; + +/* Initializes thrd_with_exitvalue_key. + This function must only be called once. */ +static void +do_init_thrd_with_exitvalue_key (void) +{ + if (tss_create (&thrd_with_exitvalue_key, NULL) != thrd_success) + abort (); +} + +/* Initializes thrd_with_exitvalue_key. */ +static void +init_thrd_with_exitvalue_key (void) +{ + static once_flag once = ONCE_FLAG_INIT; + call_once (&once, do_init_thrd_with_exitvalue_key); +} + +typedef union + { + struct thrd_with_exitvalue t; + struct + { + thrd_t tid; /* reserve memory for t.tid */ + void *(*mainfunc) (void *); + void *arg; + } a; + } + main_arg_t; + +static int +thrd_main_func (void *pmarg) +{ + /* Unpack the object that combines mainfunc and arg. */ + main_arg_t *main_arg = (main_arg_t *) pmarg; + void *(*mainfunc) (void *) = main_arg->a.mainfunc; + void *arg = main_arg->a.arg; + + if (tss_set (thrd_with_exitvalue_key, &main_arg->t) != thrd_success) + abort (); + + /* Execute mainfunc, with arg as argument. */ + { + void *exitvalue = mainfunc (arg); + /* Store the exitvalue, for use by glthread_join(). */ + main_arg->t.exitvalue = exitvalue; + return 0; + } +} + +int +glthread_create (gl_thread_t *threadp, void *(*mainfunc) (void *), void *arg) +{ + init_thrd_with_exitvalue_key (); + { + /* Combine mainfunc and arg in a single object. + A stack-allocated object does not work, because it would be out of + existence when thrd_create returns before thrd_main_func is + entered. So, allocate it in the heap. */ + main_arg_t *main_arg = (main_arg_t *) malloc (sizeof (main_arg_t)); + if (main_arg == NULL) + return ENOMEM; + main_arg->a.mainfunc = mainfunc; + main_arg->a.arg = arg; + switch (thrd_create ((thrd_t *) &main_arg->t.tid, thrd_main_func, main_arg)) + { + case thrd_success: + break; + case thrd_nomem: + free (main_arg); + return ENOMEM; + default: + free (main_arg); + return EAGAIN; + } + *threadp = &main_arg->t; + return 0; + } +} + +gl_thread_t +gl_thread_self (void) +{ + init_thrd_with_exitvalue_key (); + { + gl_thread_t thread = + (struct thrd_with_exitvalue *) tss_get (thrd_with_exitvalue_key); + if (thread == NULL) + { + /* This happens only in threads that have not been created through + glthread_create(), such as the main thread. */ + for (;;) + { + thread = + (struct thrd_with_exitvalue *) + malloc (sizeof (struct thrd_with_exitvalue)); + if (thread != NULL) + break; + /* Memory allocation failed. There is not much we can do. Have to + busy-loop, waiting for the availability of memory. */ + { + struct timespec ts; + ts.tv_sec = 1; + ts.tv_nsec = 0; + thrd_sleep (&ts, NULL); + } + } + thread->tid = thrd_current (); + thread->exitvalue = NULL; /* just to be deterministic */ + if (tss_set (thrd_with_exitvalue_key, thread) != thrd_success) + abort (); + } + return thread; + } +} + +int +glthread_join (gl_thread_t thread, void **return_value_ptr) +{ + /* On Solaris 11.4, thrd_join crashes when the second argument we pass is + NULL. */ + int dummy; + + if (thread == gl_thread_self ()) + return EINVAL; + if (thrd_join (thread->tid, &dummy) != thrd_success) + return EINVAL; + if (return_value_ptr != NULL) + *return_value_ptr = thread->exitvalue; + free (thread); + return 0; +} + +_Noreturn void +gl_thread_exit (void *return_value) +{ + gl_thread_t thread = gl_thread_self (); + thread->exitvalue = return_value; + thrd_exit (0); +} + +#endif + +/* ========================================================================= */ + +#if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS + +#include <pthread.h> + +#if defined PTW32_VERSION || defined __MVS__ + +const gl_thread_t gl_null_thread /* = { .p = NULL } */; + +#endif + +#endif + +/* ========================================================================= */ + +#if USE_WINDOWS_THREADS + +#endif + +/* ========================================================================= */ + +gl_thread_t +gl_thread_create (void *(*func) (void *arg), void *arg) +{ + gl_thread_t thread; + int ret; + + ret = glthread_create (&thread, func, arg); + if (ret != 0) + abort (); + return thread; +} |