1 files changed, 94 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c b/ports/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c
new file mode 100644
index 0000000000..93ac29b24c
--- /dev/null
+++ b/ports/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c
@@ -0,0 +1,94 @@
+/* Copyright (C) 2011-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
+   Based on work contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
+
+   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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <nptl/pthreadP.h>
+#include <lowlevellock.h>
+
+
+unsigned long int __fork_generation attribute_hidden;
+
+
+static void
+clear_once_control (void *arg)
+{
+  pthread_once_t *once_control = (pthread_once_t *) arg;
+
+  *once_control = 0;
+  lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
+}
+
+
+int
+__pthread_once (once_control, init_routine)
+     pthread_once_t *once_control;
+     void (*init_routine) (void);
+{
+  while (1)
+    {
+      int oldval, val, newval;
+
+      val = *once_control;
+      do
+	{
+	  /* Check if the initialized has already been done.  */
+	  if ((val & 2) != 0)
+	    return 0;
+
+	  oldval = val;
+	  newval = (oldval & 3) | __fork_generation | 1;
+	  val = atomic_compare_and_exchange_val_acq (once_control, newval,
+						     oldval);
+	}
+      while (__builtin_expect (val != oldval, 0));
+
+      /* Check if another thread already runs the initializer.	*/
+      if ((oldval & 1) != 0)
+	{
+	  /* Check whether the initializer execution was interrupted
+	     by a fork.	 */
+	  if (((oldval ^ newval) & -4) == 0)
+	    {
+	      /* Same generation, some other thread was faster. Wait.  */
+	      lll_futex_wait (once_control, newval, LLL_PRIVATE);
+	      continue;
+	    }
+	}
+
+      /* This thread is the first here.  Do the initialization.
+	 Register a cleanup handler so that in case the thread gets
+	 interrupted the initialization can be restarted.  */
+      pthread_cleanup_push (clear_once_control, once_control);
+
+      init_routine ();
+
+      pthread_cleanup_pop (0);
+
+
+      /* Add one to *once_control.  */
+      atomic_increment (once_control);
+
+      /* Wake up all other threads.  */
+      lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
+      break;
+    }
+
+  return 0;
+}
+weak_alias (__pthread_once, pthread_once)
+hidden_def (__pthread_once)