/* * Copyright (c) 2008 - 2009 * Jonathan Schleifer <js@webkeks.org> * * All rights reserved. * * This file is part of ObjFW. It may be distributed under the terms of the * Q Public License 1.0, which can be found in the file LICENSE included in * the packaging of this file. */ #include "config.h" #include <stdio.h> #include <stdlib.h> #include <assert.h> #import <objc/objc.h> #import "threading.h" /// \cond internal struct locks_s { id obj; size_t count; size_t recursion; of_thread_t thread; of_mutex_t mutex; }; /// \endcond static of_mutex_t mutex; static struct locks_s *locks = NULL; static size_t num_locks = 0; #define SYNC_ERR(f) \ { \ fprintf(stderr, "WARNING: %s failed in line %d!\n" \ "WARNING: This might result in a race " \ "condition!\n", f, __LINE__); \ return 1; \ } BOOL objc_sync_init() { return (of_mutex_new(&mutex) ? YES : NO); } int objc_sync_enter(id obj) { int i; if (obj == nil) return 0; if (!of_mutex_lock(&mutex)) SYNC_ERR("of_mutex_lock(&mutex)"); for (i = num_locks - 1; i >= 0; i--) { if (locks[i].obj == obj) { if (of_thread_is_current(locks[i].thread)) locks[i].recursion++; else { /* Make sure objc_sync_exit doesn't free it */ locks[i].count++; /* Unlock so objc_sync_exit can return */ if (!of_mutex_unlock(&mutex)) SYNC_ERR("of_mutex_unlock(&mutex)"); if (!of_mutex_lock(&locks[i].mutex)) { of_mutex_unlock(&mutex); SYNC_ERR( "of_mutex_lock(&locks[i].mutex"); } if (!of_mutex_lock(&mutex)) SYNC_ERR("of_mutex_lock(&mutex)"); assert(locks[i].recursion == 0); /* Update lock's active thread */ locks[i].thread = of_thread_current(); } if (!of_mutex_unlock(&mutex)) SYNC_ERR("of_mutex_unlock(&mutex)"); return 0; } } if (locks == NULL) { if ((locks = malloc(sizeof(struct locks_s))) == NULL) { of_mutex_unlock(&mutex); SYNC_ERR("malloc(...)"); } } else { struct locks_s *new_locks; if ((new_locks = realloc(locks, (num_locks + 1) * sizeof(struct locks_s))) == NULL) { of_mutex_unlock(&mutex); SYNC_ERR("realloc(...)"); } locks = new_locks; } locks[num_locks].obj = obj; locks[num_locks].count = 1; locks[num_locks].recursion = 0; locks[num_locks].thread = of_thread_current(); if (!of_mutex_new(&locks[num_locks].mutex)) { of_mutex_unlock(&mutex); SYNC_ERR("of_mutex_new(&locks[num_locks].mutex"); } if (!of_mutex_lock(&locks[num_locks].mutex)) { of_mutex_unlock(&mutex); SYNC_ERR("of_mutex_lock(&locks[num_locks].mutex"); } num_locks++; if (!of_mutex_unlock(&mutex)) SYNC_ERR("of_mutex_unlock(&mutex)"); return 0; } int objc_sync_exit(id obj) { int i; if (obj == nil) return 0; if (!of_mutex_lock(&mutex)) SYNC_ERR("of_mutex_lock(&mutex)"); for (i = num_locks - 1; i >= 0; i--) { if (locks[i].obj == obj) { if (locks[i].recursion > 0 && of_thread_is_current(locks[i].thread)) { locks[i].recursion--; if (!of_mutex_unlock(&mutex)) SYNC_ERR("of_mutex_unlock(&mutex)"); return 0; } if (!of_mutex_unlock(&locks[i].mutex)) { of_mutex_unlock(&mutex); SYNC_ERR("of_mutex_unlock(&locks[i].mutex)"); } locks[i].count--; if (locks[i].count == 0) { struct locks_s *new_locks = NULL; if (!of_mutex_free(&locks[i].mutex)) { of_mutex_unlock(&mutex); SYNC_ERR( "of_mutex_free(&locks[i].mutex"); } num_locks--; locks[i] = locks[num_locks]; if (num_locks == 0) { free(locks); new_locks = NULL; } else if ((new_locks = realloc(locks, num_locks * sizeof(struct locks_s))) == NULL) { of_mutex_unlock(&mutex); SYNC_ERR("realloc(...)"); } locks = new_locks; } if (!of_mutex_unlock(&mutex)) SYNC_ERR("of_mutex_unlock(&mutex)"); return 0; } } of_mutex_unlock(&mutex); SYNC_ERR("objc_sync_exit()"); }