/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
/* Copyright (C) 2014 OSCAR lab, Stony Brook University
This file is part of Graphene Library OS.
Graphene Library OS 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 of the
License, or (at your option) any later version.
Graphene Library OS 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.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/*
* db_spinlock.c
*
* This file contains APIs that provide operations of (futex based) mutexes.
* Based on "Mutexes and Condition Variables using Futexes"
* (http://locklessinc.com/articles/mutex_cv_futex)
*/
#include "pal_defs.h"
#include "pal_linux_defs.h"
#include "pal.h"
#include "pal_internal.h"
#include "pal_linux.h"
#include "pal_error.h"
#include "pal_debug.h"
#include "api.h"
#include
#include
int _DkSpinLock (struct spinlock * lock)
{
struct atomic_int * m = &lock->value;
while (1) {
int c = atomic_read(m);
if (!c && atomic_cmpxchg(m, 0, 1) == 0)
break;
cpu_relax();
}
return 0;
}
int _DkSpinUnlock (struct spinlock * lock)
{
struct atomic_int * m = &lock->value;
atomic_set(m, 0);
return 0;
}