248 lines
7.6 KiB
C
248 lines
7.6 KiB
C
/* Linuxthreads - a simple clone()-based implementation of Posix */
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/* threads for Linux. */
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/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
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/* */
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/* This program is free software; you can redistribute it and/or */
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/* modify it under the terms of the GNU Library General Public License */
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/* as published by the Free Software Foundation; either version 2 */
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/* of the License, or (at your option) any later version. */
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/* */
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/* This program is distributed in the hope that it will be useful, */
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/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
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/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
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/* GNU Library General Public License for more details. */
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/* Thread-specific data */
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#include <errno.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include "pthread.h"
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#include "internals.h"
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#include "spinlock.h"
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#include "restart.h"
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#include <bits/libc-lock.h>
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/* Table of keys. */
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static struct pthread_key_struct pthread_keys[PTHREAD_KEYS_MAX] =
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{ { 0, NULL } };
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/* For debugging purposes put the maximum number of keys in a variable. */
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const int __linuxthreads_pthread_keys_max = PTHREAD_KEYS_MAX;
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const int __linuxthreads_pthread_key_2ndlevel_size = PTHREAD_KEY_2NDLEVEL_SIZE;
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/* Mutex to protect access to pthread_keys */
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static pthread_mutex_t pthread_keys_mutex = PTHREAD_MUTEX_INITIALIZER;
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/* Create a new key */
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int __pthread_key_create(pthread_key_t * key, destr_function destr)
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{
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int i;
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pthread_mutex_lock(&pthread_keys_mutex);
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for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
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if (! pthread_keys[i].in_use) {
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/* Mark key in use */
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pthread_keys[i].in_use = 1;
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pthread_keys[i].destr = destr;
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pthread_mutex_unlock(&pthread_keys_mutex);
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*key = i;
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return 0;
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}
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}
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pthread_mutex_unlock(&pthread_keys_mutex);
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return EAGAIN;
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}
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strong_alias (__pthread_key_create, pthread_key_create)
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/* Reset deleted key's value to NULL in each live thread.
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* NOTE: this executes in the context of the thread manager! */
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struct pthread_key_delete_helper_args {
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/* Damn, we need lexical closures in C! ;) */
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unsigned int idx1st, idx2nd;
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pthread_descr self;
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};
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static void pthread_key_delete_helper(void *arg, pthread_descr th)
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{
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struct pthread_key_delete_helper_args *args = arg;
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unsigned int idx1st = args->idx1st;
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unsigned int idx2nd = args->idx2nd;
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pthread_descr self = args->self;
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if (self == 0)
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self = args->self = thread_self();
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if (!th->p_terminated) {
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/* pthread_exit() may try to free th->p_specific[idx1st] concurrently. */
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__pthread_lock(THREAD_GETMEM(th, p_lock), self);
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if (th->p_specific[idx1st] != NULL)
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th->p_specific[idx1st][idx2nd] = NULL;
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__pthread_unlock(THREAD_GETMEM(th, p_lock));
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}
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}
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/* Delete a key */
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int pthread_key_delete(pthread_key_t key)
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{
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pthread_descr self = thread_self();
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pthread_mutex_lock(&pthread_keys_mutex);
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if (key >= PTHREAD_KEYS_MAX || !pthread_keys[key].in_use) {
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pthread_mutex_unlock(&pthread_keys_mutex);
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return EINVAL;
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}
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pthread_keys[key].in_use = 0;
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pthread_keys[key].destr = NULL;
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/* Set the value of the key to NULL in all running threads, so
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that if the key is reallocated later by pthread_key_create, its
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associated values will be NULL in all threads.
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Do nothing if no threads have been created yet. */
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if (__pthread_manager_request != -1)
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{
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struct pthread_key_delete_helper_args args;
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struct pthread_request request;
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args.idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
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args.idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;
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args.self = 0;
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request.req_thread = self;
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request.req_kind = REQ_FOR_EACH_THREAD;
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request.req_args.for_each.arg = &args;
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request.req_args.for_each.fn = pthread_key_delete_helper;
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TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,
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(char *) &request, sizeof(request)));
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suspend(self);
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}
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pthread_mutex_unlock(&pthread_keys_mutex);
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return 0;
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}
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/* Set the value of a key */
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int __pthread_setspecific(pthread_key_t key, const void * pointer)
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{
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pthread_descr self = thread_self();
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unsigned int idx1st, idx2nd;
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if (key >= PTHREAD_KEYS_MAX || !pthread_keys[key].in_use)
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return EINVAL;
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idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
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idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;
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if (THREAD_GETMEM_NC(self, p_specific[idx1st]) == NULL) {
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void *newp = calloc(PTHREAD_KEY_2NDLEVEL_SIZE, sizeof (void *));
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if (newp == NULL)
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return ENOMEM;
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THREAD_SETMEM_NC(self, p_specific[idx1st], newp);
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}
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THREAD_GETMEM_NC(self, p_specific[idx1st])[idx2nd] = (void *) pointer;
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return 0;
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}
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strong_alias (__pthread_setspecific, pthread_setspecific)
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/* Get the value of a key */
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void * __pthread_getspecific(pthread_key_t key)
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{
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pthread_descr self = thread_self();
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unsigned int idx1st, idx2nd;
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if (key >= PTHREAD_KEYS_MAX)
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return NULL;
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idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
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idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;
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if (THREAD_GETMEM_NC(self, p_specific[idx1st]) == NULL
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|| !pthread_keys[key].in_use)
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return NULL;
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return THREAD_GETMEM_NC(self, p_specific[idx1st])[idx2nd];
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}
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strong_alias (__pthread_getspecific, pthread_getspecific)
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/* Call the destruction routines on all keys */
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void __pthread_destroy_specifics()
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{
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pthread_descr self = thread_self();
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int i, j, round, found_nonzero;
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destr_function destr;
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void * data;
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for (round = 0, found_nonzero = 1;
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found_nonzero && round < PTHREAD_DESTRUCTOR_ITERATIONS;
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round++) {
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found_nonzero = 0;
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for (i = 0; i < PTHREAD_KEY_1STLEVEL_SIZE; i++)
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if (THREAD_GETMEM_NC(self, p_specific[i]) != NULL)
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for (j = 0; j < PTHREAD_KEY_2NDLEVEL_SIZE; j++) {
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destr = pthread_keys[i * PTHREAD_KEY_2NDLEVEL_SIZE + j].destr;
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data = THREAD_GETMEM_NC(self, p_specific[i])[j];
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if (destr != NULL && data != NULL) {
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THREAD_GETMEM_NC(self, p_specific[i])[j] = NULL;
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destr(data);
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found_nonzero = 1;
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}
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}
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}
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__pthread_lock(THREAD_GETMEM(self, p_lock), self);
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for (i = 0; i < PTHREAD_KEY_1STLEVEL_SIZE; i++) {
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if (THREAD_GETMEM_NC(self, p_specific[i]) != NULL) {
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free(THREAD_GETMEM_NC(self, p_specific[i]));
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THREAD_SETMEM_NC(self, p_specific[i], NULL);
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}
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}
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__pthread_unlock(THREAD_GETMEM(self, p_lock));
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}
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#if !(USE_TLS && HAVE___THREAD)
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/* Thread-specific data for libc. */
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static int
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libc_internal_tsd_set(enum __libc_tsd_key_t key, const void * pointer)
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{
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pthread_descr self = thread_self();
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THREAD_SETMEM_NC(self, p_libc_specific[key], (void *) pointer);
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return 0;
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}
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int (*__libc_internal_tsd_set)(enum __libc_tsd_key_t key, const void * pointer)
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= libc_internal_tsd_set;
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static void *
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libc_internal_tsd_get(enum __libc_tsd_key_t key)
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{
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pthread_descr self = thread_self();
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return THREAD_GETMEM_NC(self, p_libc_specific[key]);
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}
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void * (*__libc_internal_tsd_get)(enum __libc_tsd_key_t key)
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= libc_internal_tsd_get;
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static void ** __attribute__ ((__const__))
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libc_internal_tsd_address (enum __libc_tsd_key_t key)
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{
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pthread_descr self = thread_self();
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return &self->p_libc_specific[key];
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}
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void **(*const __libc_internal_tsd_address) (enum __libc_tsd_key_t key)
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__THROW __attribute__ ((__const__)) = libc_internal_tsd_address;
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#endif
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int __libc_alloca_cutoff (size_t size)
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{
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pthread_descr self = thread_self();
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return size <= THREAD_GETMEM_NC(self, p_alloca_cutoff);
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}
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