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Diffstat (limited to 'libpthread/linuxthreads/specific.c')
| -rw-r--r-- | libpthread/linuxthreads/specific.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/specific.c b/libpthread/linuxthreads/specific.c new file mode 100644 index 000000000..92eec3d99 --- /dev/null +++ b/libpthread/linuxthreads/specific.c @@ -0,0 +1,241 @@ +/* Linuxthreads - a simple clone()-based implementation of Posix */ +/* threads for Linux. */ +/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */ +/* */ +/* This program is free software; you can redistribute it and/or */ +/* modify it under the terms of the GNU Library General Public License */ +/* as published by the Free Software Foundation; either version 2 */ +/* 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 Library General Public License for more details. */ + +/* Thread-specific data */ + +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> +#include "pthread.h" +#include "internals.h" +#include "spinlock.h" +#include "restart.h" +#include <bits/libc-lock.h> +#include <not-cancel.h> + +/* Table of keys. */ + +static struct pthread_key_struct pthread_keys[PTHREAD_KEYS_MAX] = + { { 0, NULL } }; + +/* For debugging purposes put the maximum number of keys in a variable. */ +const int __linuxthreads_pthread_keys_max = PTHREAD_KEYS_MAX; +const int __linuxthreads_pthread_key_2ndlevel_size = PTHREAD_KEY_2NDLEVEL_SIZE; + +/* Mutex to protect access to pthread_keys */ + +static pthread_mutex_t pthread_keys_mutex = PTHREAD_MUTEX_INITIALIZER; + +/* Create a new key */ + +int __pthread_key_create(pthread_key_t * key, destr_function destr) +{ + int i; + + pthread_mutex_lock(&pthread_keys_mutex); + for (i = 0; i < PTHREAD_KEYS_MAX; i++) { + if (! pthread_keys[i].in_use) { + /* Mark key in use */ + pthread_keys[i].in_use = 1; + pthread_keys[i].destr = destr; + pthread_mutex_unlock(&pthread_keys_mutex); + *key = i; + return 0; + } + } + pthread_mutex_unlock(&pthread_keys_mutex); + return EAGAIN; +} +strong_alias (__pthread_key_create, pthread_key_create) + +/* Reset deleted key's value to NULL in each live thread. + * NOTE: this executes in the context of the thread manager! */ + +struct pthread_key_delete_helper_args { + /* Damn, we need lexical closures in C! ;) */ + unsigned int idx1st, idx2nd; + pthread_descr self; +}; + +static void pthread_key_delete_helper(void *arg, pthread_descr th) +{ + struct pthread_key_delete_helper_args *args = arg; + unsigned int idx1st = args->idx1st; + unsigned int idx2nd = args->idx2nd; + pthread_descr self = args->self; + + if (self == 0) + self = args->self = thread_self(); + + if (!th->p_terminated) { + /* pthread_exit() may try to free th->p_specific[idx1st] concurrently. */ + __pthread_lock(th->p_lock, self); + if (th->p_specific[idx1st] != NULL) + th->p_specific[idx1st][idx2nd] = NULL; + __pthread_unlock(th->p_lock); + } +} + +/* Delete a key */ +int pthread_key_delete(pthread_key_t key) +{ + pthread_descr self = thread_self(); + + pthread_mutex_lock(&pthread_keys_mutex); + if (key >= PTHREAD_KEYS_MAX || !pthread_keys[key].in_use) { + pthread_mutex_unlock(&pthread_keys_mutex); + return EINVAL; + } + pthread_keys[key].in_use = 0; + pthread_keys[key].destr = NULL; + + /* Set the value of the key to NULL in all running threads, so + that if the key is reallocated later by pthread_key_create, its + associated values will be NULL in all threads. + + If no threads have been created yet, clear it just in the + current thread. */ + + struct pthread_key_delete_helper_args args; + args.idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE; + args.idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE; + if (__pthread_manager_request != -1) + { + struct pthread_request request; + + args.self = 0; + + request.req_thread = self; + request.req_kind = REQ_FOR_EACH_THREAD; + request.req_args.for_each.arg = &args; + request.req_args.for_each.fn = pthread_key_delete_helper; + + TEMP_FAILURE_RETRY(write_not_cancel(__pthread_manager_request, + (char *) &request, sizeof(request))); + suspend(self); + } + else + { + if (self->p_specific[args.idx1st] != NULL) + self->p_specific[args.idx1st][args.idx2nd] = NULL; + } + + pthread_mutex_unlock(&pthread_keys_mutex); + return 0; +} + +/* Set the value of a key */ + +int __pthread_setspecific(pthread_key_t key, const void * pointer) +{ + pthread_descr self = thread_self(); + unsigned int idx1st, idx2nd; + + if (key >= PTHREAD_KEYS_MAX || !pthread_keys[key].in_use) + return EINVAL; + idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE; + idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE; + if (THREAD_GETMEM_NC(self, p_specific[idx1st]) == NULL) { + void *newp = calloc(PTHREAD_KEY_2NDLEVEL_SIZE, sizeof (void *)); + if (newp == NULL) + return ENOMEM; + THREAD_SETMEM_NC(self, p_specific[idx1st], newp); + } + THREAD_GETMEM_NC(self, p_specific[idx1st])[idx2nd] = (void *) pointer; + return 0; +} +strong_alias (__pthread_setspecific, pthread_setspecific) + +/* Get the value of a key */ + +void * __pthread_getspecific(pthread_key_t key) +{ + pthread_descr self = thread_self(); + unsigned int idx1st, idx2nd; + + if (key >= PTHREAD_KEYS_MAX) + return NULL; + idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE; + idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE; + if (THREAD_GETMEM_NC(self, p_specific[idx1st]) == NULL + || !pthread_keys[key].in_use) + return NULL; + return THREAD_GETMEM_NC(self, p_specific[idx1st])[idx2nd]; +} +strong_alias (__pthread_getspecific, pthread_getspecific) + +/* Call the destruction routines on all keys */ + +void __pthread_destroy_specifics() +{ + pthread_descr self = thread_self(); + int i, j, round, found_nonzero; + destr_function destr; + void * data; + + for (round = 0, found_nonzero = 1; + found_nonzero && round < PTHREAD_DESTRUCTOR_ITERATIONS; + round++) { + found_nonzero = 0; + for (i = 0; i < PTHREAD_KEY_1STLEVEL_SIZE; i++) + if (THREAD_GETMEM_NC(self, p_specific[i]) != NULL) + for (j = 0; j < PTHREAD_KEY_2NDLEVEL_SIZE; j++) { + destr = pthread_keys[i * PTHREAD_KEY_2NDLEVEL_SIZE + j].destr; + data = THREAD_GETMEM_NC(self, p_specific[i])[j]; + if (destr != NULL && data != NULL) { + THREAD_GETMEM_NC(self, p_specific[i])[j] = NULL; + destr(data); + found_nonzero = 1; + } + } + } + __pthread_lock(THREAD_GETMEM(self, p_lock), self); + for (i = 0; i < PTHREAD_KEY_1STLEVEL_SIZE; i++) { + if (THREAD_GETMEM_NC(self, p_specific[i]) != NULL) { + free(THREAD_GETMEM_NC(self, p_specific[i])); + THREAD_SETMEM_NC(self, p_specific[i], NULL); + } + } + __pthread_unlock(THREAD_GETMEM(self, p_lock)); +} + +#if !(USE_TLS && HAVE___THREAD) + +/* Thread-specific data for libc. */ + +int +__pthread_internal_tsd_set (int key, const void * pointer) +{ + pthread_descr self = thread_self(); + + THREAD_SETMEM_NC(self, p_libc_specific[key], (void *) pointer); + return 0; +} + +void * +__pthread_internal_tsd_get (int key) +{ + pthread_descr self = thread_self(); + + return THREAD_GETMEM_NC(self, p_libc_specific[key]); +} + +void ** __attribute__ ((__const__)) +__pthread_internal_tsd_address (int key) +{ + pthread_descr self = thread_self(); + return &self->p_libc_specific[key]; +} + +#endif |