From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libgomp/config/linux/sem.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 libgomp/config/linux/sem.c (limited to 'libgomp/config/linux/sem.c') diff --git a/libgomp/config/linux/sem.c b/libgomp/config/linux/sem.c new file mode 100644 index 000000000..ea981024c --- /dev/null +++ b/libgomp/config/linux/sem.c @@ -0,0 +1,61 @@ +/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc. + Contributed by Richard Henderson . + + This file is part of the GNU OpenMP Library (libgomp). + + Libgomp is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + Libgomp 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 General Public License for + more details. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + . */ + +/* This is a Linux specific implementation of a semaphore synchronization + mechanism for libgomp. This type is private to the library. This + implementation uses atomic instructions and the futex syscall. */ + +#include "wait.h" + + +void +gomp_sem_wait_slow (gomp_sem_t *sem) +{ + while (1) + { + int val = __sync_val_compare_and_swap (sem, 0, -1); + if (val > 0) + { + if (__sync_bool_compare_and_swap (sem, val, val - 1)) + return; + } + do_wait (sem, -1); + } +} + +void +gomp_sem_post_slow (gomp_sem_t *sem) +{ + int old, tmp = *sem, wake; + + do + { + old = tmp; + wake = old > 0 ? old + 1 : 1; + tmp = __sync_val_compare_and_swap (sem, old, wake); + } + while (old != tmp); + + futex_wake (sem, wake); +} -- cgit v1.2.3