--- /dev/null
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS 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.
+ */
+#include <stdlib.h>
+#include <errno.h>
+#include <pthread.h>
+#include <sys/queue.h>
+
+static pthread_mutex_t handler_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER;
+
+struct atfork_t
+{
+ CIRCLEQ_ENTRY(atfork_t) entries;
+
+ void (*prepare)(void);
+ void (*child)(void);
+ void (*parent)(void);
+};
+static CIRCLEQ_HEAD(atfork_head_t, atfork_t) atfork_head = \
+ CIRCLEQ_HEAD_INITIALIZER(atfork_head);
+
+void __bionic_atfork_run_prepare()
+{
+ struct atfork_t *cursor;
+
+ /* We will lock this here, and unlock it in the parent and child functions.
+ * This ensures that nobody can modify the handler array between the calls
+ * to the prepare and parent/child handlers.
+ *
+ * TODO: If a handler mucks with the list, it could cause problems. Right
+ * now it's ok because all they can do is add new items to the end
+ * of the list, but if/when we implement cleanup in dlclose() things
+ * will get more interesting...
+ */
+ pthread_mutex_lock(&handler_mutex);
+
+ /* Call pthread_atfork() prepare handlers. Posix states that the prepare
+ * handlers should be called in the reverse order of the parent/child
+ * handlers, so we iterate backwards.
+ */
+ for (cursor = atfork_head.cqh_last;
+ cursor != (void*)&atfork_head;
+ cursor = cursor->entries.cqe_prev) {
+ if (cursor->prepare != NULL) {
+ cursor->prepare();
+ }
+ }
+}
+
+void __bionic_atfork_run_child()
+{
+ struct atfork_t *cursor;
+
+ /* Call pthread_atfork() child handlers */
+ for (cursor = atfork_head.cqh_first;
+ cursor != (void*)&atfork_head;
+ cursor = cursor->entries.cqe_next) {
+ if (cursor->child != NULL) {
+ cursor->child();
+ }
+ }
+
+ pthread_mutex_unlock(&handler_mutex);
+}
+
+void __bionic_atfork_run_parent()
+{
+ struct atfork_t *cursor;
+
+ /* Call pthread_atfork() parent handlers */
+ for (cursor = atfork_head.cqh_first;
+ cursor != (void*)&atfork_head;
+ cursor = cursor->entries.cqe_next) {
+ if (cursor->parent != NULL) {
+ cursor->parent();
+ }
+ }
+
+ pthread_mutex_unlock(&handler_mutex);
+}
+
+int pthread_atfork(void (*prepare)(void), void (*parent)(void), void(*child)(void))
+{
+ struct atfork_t *entry = malloc(sizeof(struct atfork_t));
+
+ if (entry == NULL) {
+ return ENOMEM;
+ }
+
+ entry->prepare = prepare;
+ entry->parent = parent;
+ entry->child = child;
+
+ pthread_mutex_lock(&handler_mutex);
+ CIRCLEQ_INSERT_TAIL(&atfork_head, entry, entries);
+ pthread_mutex_unlock(&handler_mutex);
+
+ return 0;
+}
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