/* * Copyright (c) 1995-1998 John Birrell . * All rights reserved. * copyright Douglas Santry 1996 * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the above copyright is retained * in the source form. * * THIS SOFTWARE IS PROVIDED BY Douglas Santry AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL Douglas Santry OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $Id$ * */ #if defined(LIBC_RCS) && !defined(lint) .text .asciz "$Id$" #endif /* LIBC_RCS and not lint */ #include "DEFS.h" /* * Atomicly lock a location with an identifier provided the location * is not currently locked. * * long _atomic_lock(long *, long); * eax will contain the return value. */ ENTRY(_atomic_lock) movl 4(%esp), %ecx movl 8(%esp), %eax xchg %eax, (%ecx) ret /* * Unlock a location. * * long _atomic_unlock(long *); */ ENTRY(_atomic_unlock) movl 4(%esp), %ecx movl $0, %eax xchg %eax, (%ecx) ret