71 lines
2.3 KiB
C
71 lines
2.3 KiB
C
/* Copyright (C) 2010-2017 Free Software Foundation, Inc.
|
|
Contributed by ARM Ltd.
|
|
|
|
This file is part of the GNU Offloading and Multi Processing 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* Provide target-specific access to the futex system call. */
|
|
|
|
/* The include file hierachy above us (wait.h) has pushed visibility
|
|
hidden, this will be applied to prototypes with headers we include
|
|
with the effect that we cannot link against an external function
|
|
(syscall). The solution here is to push default visibility, include
|
|
our required headers then reinstante the original visibility. */
|
|
|
|
#pragma GCC visibility push(default)
|
|
|
|
#define _GNU_SOURCE
|
|
#include <unistd.h>
|
|
#include <sys/syscall.h>
|
|
|
|
#pragma GCC visibility pop
|
|
|
|
static inline void
|
|
futex_wait (int *addr, int val)
|
|
{
|
|
int err = syscall (SYS_futex, addr, gomp_futex_wait, val, NULL);
|
|
if (__builtin_expect (err < 0 && errno == ENOSYS, 0))
|
|
{
|
|
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
|
|
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
|
|
syscall (SYS_futex, addr, gomp_futex_wait, val, NULL);
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
futex_wake (int *addr, int count)
|
|
{
|
|
int err = syscall (SYS_futex, addr, gomp_futex_wake, count);
|
|
if (__builtin_expect (err < 0 && errno == ENOSYS, 0))
|
|
{
|
|
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
|
|
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
|
|
syscall (SYS_futex, addr, gomp_futex_wake, count);
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
cpu_relax (void)
|
|
{
|
|
__asm volatile ("" : : : "memory");
|
|
}
|