1 files changed, 97 insertions, 0 deletions
diff --git a/linuxthreads/ptfork.c b/linuxthreads/ptfork.c
new file mode 100644
index 0000000000..8a7b7972a3
--- /dev/null
+++ b/linuxthreads/ptfork.c
@@ -0,0 +1,97 @@
+/* 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.                 */
+
+/* The "atfork" stuff */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "pthread.h"
+#include "internals.h"
+
+struct handler_list {
+  void (*handler)(void);
+  struct handler_list * next;
+};
+
+static pthread_mutex_t pthread_atfork_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct handler_list * pthread_atfork_prepare = NULL;
+static struct handler_list * pthread_atfork_parent = NULL;
+static struct handler_list * pthread_atfork_child = NULL;
+
+static void pthread_insert_list(struct handler_list ** list,
+                                void (*handler)(void),
+                                struct handler_list * newlist,
+                                int at_end)
+{
+  if (handler == NULL) return;
+  if (at_end) {
+    while(*list != NULL) list = &((*list)->next);
+  }
+  newlist->handler = handler;
+  newlist->next = *list;
+  *list = newlist;
+}
+
+struct handler_list_block {
+  struct handler_list prepare, parent, child;
+};
+
+int __pthread_atfork(void (*prepare)(void),
+		     void (*parent)(void),
+		     void (*child)(void))
+{
+  struct handler_list_block * block =
+    (struct handler_list_block *) malloc(sizeof(struct handler_list_block));
+  if (block == NULL) return ENOMEM;
+  pthread_mutex_lock(&pthread_atfork_lock);
+  /* "prepare" handlers are called in LIFO */
+  pthread_insert_list(&pthread_atfork_prepare, prepare, &block->prepare, 0);
+  /* "parent" handlers are called in FIFO */
+  pthread_insert_list(&pthread_atfork_parent, parent, &block->parent, 1);
+  /* "child" handlers are called in FIFO */
+  pthread_insert_list(&pthread_atfork_child, child, &block->child, 1);
+  pthread_mutex_unlock(&pthread_atfork_lock);
+  return 0;
+}
+weak_alias (__pthread_atfork, pthread_atfork)
+
+static inline void pthread_call_handlers(struct handler_list * list)
+{
+  for (/*nothing*/; list != NULL; list = list->next) (list->handler)();
+}
+
+extern int __fork(void);
+
+int fork(void)
+{
+  int pid;
+  struct handler_list * prepare, * child, * parent;
+
+  pthread_mutex_lock(&pthread_atfork_lock);
+  prepare = pthread_atfork_prepare;
+  child = pthread_atfork_child;
+  parent = pthread_atfork_parent;
+  pthread_mutex_unlock(&pthread_atfork_lock);
+  pthread_call_handlers(prepare);
+  pid = __fork();
+  if (pid == 0) {
+    __pthread_reset_main_thread();
+    __fresetlockfiles();
+    pthread_call_handlers(child);
+  } else {
+    pthread_call_handlers(parent);
+  }
+  return pid;
+}