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c6bfe5c4d7
I've moved the ARM port from ports to the main sysdeps hierarchy. Beyond the README update, the move of the files was simply git mv ports/sysdeps/arm sysdeps/arm git mv ports/sysdeps/unix/arm sysdeps/unix/arm git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm and in addition to the ChangeLog entries here, I put a note at the top of ports/ChangeLog.arm similar to that at the top of ChangeLog.powerpc. There is deliberately no NEWS change, as I think it makes the most sense to put in a general note above all ports having moved if we can achieve that for 2.20. Tested that disassembly of installed shared libraries for arm is the same before and after this patch, except for data (not instructions) in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the path by which that file is found, and so by which it appears in the assertion message, changes as a result of the move). * sysdeps/arm: Move directory from ports/sysdeps/arm. * sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm. * sysdeps/unix/sysv/linux/arm: Move directory from ports/sysdeps/unix/sysv/linux/arm. * README: Update listing for arm-*-linux-gnueabi. ports/ChangeLog.arm: * sysdeps/arm: Move directory to ../sysdeps/arm. * sysdeps/unix/arm: Move directory to ../sysdeps.arm. * sysdeps/unix/sysv/linux/arm: Move directory to ../sysdeps/unix/sysv/linux/arm.
90 lines
2.5 KiB
C
90 lines
2.5 KiB
C
/* Copyright (C) 2004-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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#include "pthreadP.h"
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#include <lowlevellock.h>
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unsigned long int __fork_generation attribute_hidden;
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static void
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clear_once_control (void *arg)
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{
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pthread_once_t *once_control = (pthread_once_t *) arg;
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*once_control = 0;
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lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
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}
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int
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__pthread_once (pthread_once_t *once_control, void (*init_routine) (void))
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{
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for (;;)
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{
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int oldval;
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int newval;
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/* Pseudo code:
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newval = __fork_generation | 1;
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oldval = *once_control;
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if ((oldval & 2) == 0)
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*once_control = newval;
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Do this atomically.
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*/
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do
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{
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newval = __fork_generation | 1;
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oldval = *once_control;
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if (oldval & 2)
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break;
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} while (atomic_compare_and_exchange_val_acq (once_control, newval, oldval) != oldval);
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/* Check if the initializer has already been done. */
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if ((oldval & 2) != 0)
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return 0;
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/* Check if another thread already runs the initializer. */
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if ((oldval & 1) == 0)
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break;
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/* Check whether the initializer execution was interrupted by a fork. */
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if (oldval != newval)
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break;
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/* Same generation, some other thread was faster. Wait. */
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lll_futex_wait (once_control, oldval, LLL_PRIVATE);
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}
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/* This thread is the first here. Do the initialization.
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Register a cleanup handler so that in case the thread gets
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interrupted the initialization can be restarted. */
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pthread_cleanup_push (clear_once_control, once_control);
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init_routine ();
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pthread_cleanup_pop (0);
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/* Say that the initialisation is done. */
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*once_control = __fork_generation | 2;
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/* Wake up all other threads. */
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lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
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return 0;
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}
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weak_alias (__pthread_once, pthread_once)
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hidden_def (__pthread_once)
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