libpthread/nptl: core of the "Native Posix Threading Library" for uClibc

targetting arm,sh,i386,mips,sparc for now

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

1 files changed, 108 insertions, 0 deletions

diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c
new file mode 100644
index 000000000..18b9893d9
--- /dev/null
+++ b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c
@@ -0,0 +1,108 @@
+/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "fork.h"
+
+
+/* Lock to protect allocation and deallocation of fork handlers.  */
+lll_lock_t __fork_lock = LLL_LOCK_INITIALIZER;
+
+
+/* Number of pre-allocated handler entries.  */
+#define NHANDLER 48
+
+/* Memory pool for fork handler structures.  */
+static struct fork_handler_pool
+{
+  struct fork_handler_pool *next;
+  struct fork_handler mem[NHANDLER];
+} fork_handler_pool;
+
+
+static struct fork_handler *
+fork_handler_alloc (void)
+{
+  struct fork_handler_pool *runp = &fork_handler_pool;
+  struct fork_handler *result = NULL;
+  unsigned int i;
+
+  do
+    {
+      /* Search for an empty entry.  */
+      for (i = 0; i < NHANDLER; ++i)
+	if (runp->mem[i].refcntr == 0)
+	  goto found;
+    }
+  while ((runp = runp->next) != NULL);
+
+  /* We have to allocate a new entry.  */
+  runp = (struct fork_handler_pool *) calloc (1, sizeof (*runp));
+  if (runp != NULL)
+    {
+      /* Enqueue the new memory pool into the list.  */
+      runp->next = fork_handler_pool.next;
+      fork_handler_pool.next = runp;
+
+      /* We use the last entry on the page.  This means when we start
+	 searching from the front the next time we will find the first
+	 entry unused.  */
+      i = NHANDLER - 1;
+
+    found:
+      result = &runp->mem[i];
+      result->refcntr = 1;
+      result->need_signal = 0;
+    }
+
+  return result;
+}
+
+
+int
+__register_atfork (prepare, parent, child, dso_handle)
+     void (*prepare) (void);
+     void (*parent) (void);
+     void (*child) (void);
+     void *dso_handle;
+{
+  /* Get the lock to not conflict with other allocations.  */
+  lll_lock (__fork_lock);
+
+  struct fork_handler *newp = fork_handler_alloc ();
+
+  if (newp != NULL)
+    {
+      /* Initialize the new record.  */
+      newp->prepare_handler = prepare;
+      newp->parent_handler = parent;
+      newp->child_handler = child;
+      newp->dso_handle = dso_handle;
+
+      newp->next = __fork_handlers;
+      __fork_handlers = newp;
+    }
+
+  /* Release the lock.  */
+  lll_unlock (__fork_lock);
+
+  return newp == NULL ? ENOMEM : 0;
+}