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alpha: Remove alpha-linux pthread_once.c

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Richard Henderson 2014-04-16 21:36:33 -07:00
parent d77c0899db
commit ddb04724ed
2 changed files with 2 additions and 95 deletions
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ChangeLog
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@ -1,5 +1,7 @@
2014-04-16 Richard Henderson <rth@redhat.com>
* sysdeps/unix/sysv/linux/alpha/nptl/pthread_once.c: Remove.
* sysdeps/alpha/Makefile [debug] (CFLAGS-backtrace.c): Enable
unwind tables.

95
sysdeps/unix/sysv/linux/alpha/nptl/pthread_once.c
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@ -1,95 +0,0 @@
/* Copyright (C) 2003-2014 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
<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 (pthread_once_t *once_control, void (*init_routine) (void))
{
for (;;)
{
int oldval;
int newval;
int tmp;
/* Pseudo code:
newval = __fork_generation | 1;
oldval = *once_control;
if ((oldval & 2) == 0)
*once_control = newval;
Do this atomically.
*/
newval = __fork_generation | 1;
__asm __volatile (
"1: ldl_l %0, %2\n"
" and %0, 2, %1\n"
" bne %1, 2f\n"
" mov %3, %1\n"
" stl_c %1, %2\n"
" beq %1, 1b\n"
"2: mb"
: "=&r" (oldval), "=&r" (tmp), "=m" (*once_control)
: "r" (newval), "m" (*once_control));
/* Check if the initializer has already been done. */
if ((oldval & 2) != 0)
return 0;
/* Check if another thread already runs the initializer. */
if ((oldval & 1) == 0)
break;
/* Check whether the initializer execution was interrupted by a fork. */
if (oldval != newval)
break;
/* Same generation, some other thread was faster. Wait. */
lll_futex_wait (once_control, oldval, LLL_PRIVATE);
}
/* 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 to take the bottom 2 bits from 01 to 10. */
atomic_increment (once_control);
/* Wake up all other threads. */
lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
return 0;
}
weak_alias (__pthread_once, pthread_once)
hidden_def (__pthread_once)