htl: Move __register_atfork from forward to own file

Since we need it also in the static linking case.

1 files changed, 157 insertions, 0 deletions

diff --git a/htl/register-atfork.c b/htl/register-atfork.c
new file mode 100644
index 0000000000..256b1148ac
--- /dev/null
+++ b/htl/register-atfork.c
@@ -0,0 +1,157 @@
+/* Atfork handling.  Hurd pthread version.
+   Copyright (C) 2002-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library;  if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <libc-lock.h>
+#include <fork.h>
+
+struct atfork
+{
+  void (*prepare) (void);
+  void (*parent) (void);
+  void (*child) (void);
+  void *dso_handle;
+  struct atfork *prev;
+  struct atfork *next;
+};
+
+/* TODO: better locking */
+__libc_lock_define_initialized (static, atfork_lock);
+static struct atfork *fork_handlers, *fork_last_handler;
+
+static void
+atfork_pthread_prepare (void)
+{
+  struct atfork *handlers, *last_handler;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  last_handler = fork_last_handler;
+  __libc_lock_unlock (atfork_lock);
+
+  if (last_handler == NULL)
+    return;
+
+  while (1)
+    {
+      if (last_handler->prepare != NULL)
+	last_handler->prepare ();
+      if (last_handler == handlers)
+	break;
+      last_handler = last_handler->prev;
+    }
+}
+text_set_element (_hurd_atfork_prepare_hook, atfork_pthread_prepare);
+
+static void
+atfork_pthread_parent (void)
+{
+  struct atfork *handlers;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  __libc_lock_unlock (atfork_lock);
+
+  while (handlers != NULL)
+    {
+      if (handlers->parent != NULL)
+	handlers->parent ();
+      handlers = handlers->next;
+    }
+}
+text_set_element (_hurd_atfork_parent_hook, atfork_pthread_parent);
+
+static void
+atfork_pthread_child (void)
+{
+  struct atfork *handlers;
+
+  __libc_lock_lock (atfork_lock);
+  handlers = fork_handlers;
+  __libc_lock_unlock (atfork_lock);
+
+  while (handlers != NULL)
+    {
+      if (handlers->child != NULL)
+	handlers->child ();
+      handlers = handlers->next;
+    }
+}
+text_set_element (_hurd_atfork_child_hook, atfork_pthread_child);
+
+int
+__register_atfork (void (*prepare) (void),
+		   void (*parent) (void),
+		   void (*child) (void),
+		   void *dso_handle)
+{
+  struct atfork *new = malloc (sizeof (*new));
+  if (new == NULL)
+    return errno;
+
+  new->prepare = prepare;
+  new->parent = parent;
+  new->child = child;
+  new->dso_handle = dso_handle;
+  new->prev = NULL;
+
+  __libc_lock_lock (atfork_lock);
+  new->next = fork_handlers;
+  if (fork_handlers != NULL)
+    fork_handlers->prev = new;
+  fork_handlers = new;
+  if (fork_last_handler == NULL)
+    fork_last_handler = new;
+  __libc_lock_unlock (atfork_lock);
+
+  return 0;
+}
+libc_hidden_def (__register_atfork)
+
+void
+__unregister_atfork (void *dso_handle)
+{
+  struct atfork **handlers, *prev = NULL, *next;
+  __libc_lock_lock (atfork_lock);
+  handlers = &fork_handlers;
+  while (*handlers != NULL)
+    {
+      if ((*handlers)->dso_handle == dso_handle)
+	{
+	  /* Drop this handler from the list.  */
+	  if (*handlers == fork_last_handler)
+	    {
+	      /* Was last, new last is prev, if any.  */
+	      fork_last_handler = prev;
+	    }
+
+	  next = (*handlers)->next;
+	  if (next != NULL)
+	    next->prev = prev;
+	  *handlers = next;
+	}
+      else
+	{
+	  /* Just proceed to next handler.  */
+	  prev = *handlers;
+	  handlers = &prev->next;
+	}
+    }
+  __libc_lock_unlock (atfork_lock);
+}