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-rw-r--r--libpthread/nptl/sysdeps/unix/sysv/linux/or1k/pthread_once.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/or1k/pthread_once.c b/libpthread/nptl/sysdeps/unix/sysv/linux/or1k/pthread_once.c
new file mode 100644
index 0000000..ce68ce6
--- /dev/null
+++ b/libpthread/nptl/sysdeps/unix/sysv/linux/or1k/pthread_once.c
@@ -0,0 +1,92 @@
+/* Copyright (C) 2003-2013 Free Software Foundation, Inc.
+ 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 "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)
+strong_alias (__pthread_once, __pthread_once_internal)