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Diffstat (limited to 'mit-pthreads/pthreads/specific.c')
| -rw-r--r-- | mit-pthreads/pthreads/specific.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/specific.c b/mit-pthreads/pthreads/specific.c new file mode 100644 index 00000000000..898f9b0cd1b --- /dev/null +++ b/mit-pthreads/pthreads/specific.c @@ -0,0 +1,198 @@ +/* ==== specific.c ======================================================= + * Copyright (c) 1994 by Chris Provenzano, proven@mit.edu + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Chris Provenzano. + * 4. The name of Chris Provenzano may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Description : Pthread thread specific data management. + * + * 1.20 94/03/30 proven + * -Started coding this file. + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include <errno.h> +#include <pthread.h> +#include <stdlib.h> +#include <string.h> + +static struct pthread_key key_table[PTHREAD_DATAKEYS_MAX]; +static pthread_mutex_t key_mutex = PTHREAD_MUTEX_INITIALIZER; + +/* ========================================================================== + * pthread_key_create() + */ +int pthread_key_create(pthread_key_t *key, void (*destructor)(void *)) +{ + pthread_mutex_lock(&key_mutex); + for ((*key) = 0; (*key) < PTHREAD_DATAKEYS_MAX; (*key)++) { + if (key_table[(*key)].count == 0) { + key_table[(*key)].count++; + key_table[(*key)].destructor = destructor; + pthread_mutex_init(&(key_table[(*key)].mutex), NULL); + pthread_mutex_unlock(&key_mutex); + return(OK); + } + } + pthread_mutex_unlock(&key_mutex); + return(EAGAIN); +} + +/* ========================================================================== + * pthread_key_delete() + */ +int pthread_key_delete(pthread_key_t key) +{ + int ret; + + if (key < PTHREAD_DATAKEYS_MAX) { + pthread_mutex_lock(&(key_table[key].mutex)); + switch (key_table[key].count) { + case 1: + pthread_mutex_destroy(&(key_table[key].mutex)); + key_table[key].destructor = NULL; + key_table[key].count = 0; + case 0: + ret = OK; + break; + default: + ret = EBUSY; + } + pthread_mutex_unlock(&(key_table[key].mutex)); + } else { + ret = EINVAL; + } + return(ret); +} + +/* ========================================================================== + * pthread_cleanupspecific() + */ +void pthread_cleanupspecific(void) +{ + void * data; + int key; + int itr; + + pthread_mutex_lock(&key_mutex); + for (itr = 0; itr < _POSIX_THREAD_DESTRUTOR_ITERATIONS; itr++) { + for (key = 0; key < PTHREAD_DATAKEYS_MAX; key++) { + if (pthread_run->specific_data_count) { + if (pthread_run->specific_data[key]) { + data = (void *)pthread_run->specific_data[key]; + pthread_run->specific_data[key] = NULL; + pthread_run->specific_data_count--; + if (key_table[key].destructor) { + pthread_mutex_unlock(&key_mutex); + key_table[key].destructor(data); + pthread_mutex_lock(&key_mutex); + } + key_table[key].count--; + } + } else { + free(pthread_run->specific_data); + pthread_mutex_unlock(&key_mutex); + return; + } + } + } + free(pthread_run->specific_data); + pthread_mutex_unlock(&key_mutex); +} + +static inline const void ** pthread_key_allocate_data(void) +{ + const void ** new_data; + if(new_data = (const void**)malloc(sizeof(void *) * PTHREAD_DATAKEYS_MAX)) { + memset((void *)new_data, 0, sizeof(void *) * PTHREAD_DATAKEYS_MAX); + } + return(new_data); +} + +/* ========================================================================== + * pthread_setspecific() + */ +int pthread_setspecific(pthread_key_t key, const void * value) +{ + int ret; + + if ((pthread_run->specific_data) || + (pthread_run->specific_data = pthread_key_allocate_data())) { + if ((key < PTHREAD_DATAKEYS_MAX) && (key_table)) { + pthread_mutex_lock(&(key_table[key].mutex)); + if (key_table[key].count) { + if (pthread_run->specific_data[key] == NULL) { + if (value != NULL) { + pthread_run->specific_data_count++; + key_table[key].count++; + } + } else { + if (value == NULL) { + pthread_run->specific_data_count--; + key_table[key].count--; + } + } + pthread_run->specific_data[key] = value; + ret = OK; + } else { + ret = EINVAL; + } + pthread_mutex_unlock(&(key_table[key].mutex)); + } else { + ret = EINVAL; + } + } else { + ret = ENOMEM; + } + return(ret); +} + +/* ========================================================================== + * pthread_getspecific() + */ +void * pthread_getspecific(pthread_key_t key) +{ + void *ret; + + if ((pthread_run->specific_data) && (key < PTHREAD_DATAKEYS_MAX) + && (key_table)) { + pthread_mutex_lock(&(key_table[key].mutex)); + if (key_table[key].count) { + ret = (void *)pthread_run->specific_data[key]; + } else { + ret = NULL; + } + pthread_mutex_unlock(&(key_table[key].mutex)); + } else { + ret = NULL; + } + return(ret); +} |