usr/src/lib/libc/i386/sys/_lwp_mutex_unlock.s

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27         .file   "_lwp_mutex_unlock.s"
  28
  29 #include "SYS.h"
  30 #include <../assym.h>
  31
  32         ENTRY(_lwp_mutex_unlock)
  33         movl    4(%esp), %eax
  34         addl    $MUTEX_LOCK_WORD, %eax
  35         xorl    %ecx, %ecx
  36         xchgl   (%eax), %ecx    / clear lock and get old lock into %ecx
  37         andl    $WAITER_MASK, %ecx / was anyone waiting on it?
  38         je      1f
  39         movl    0(%esp), %ecx   / prepare to call lwp_mutex_wakeup()
  40         movl    4(%esp), %edx
  41         movl    $0, 4(%esp)
  42         movl    %edx, 0(%esp)
  43         pushl   %ecx
  44         SYSTRAP_RVAL1(lwp_mutex_wakeup) / lwp_mutex_wakeup(mp, 0)
  45         popl    %ecx            / reconstruct the stack frame
  46         movl    0(%esp), %edx
  47         movl    %edx, 4(%esp)
  48         movl    %ecx, 0(%esp)
  49         SYSLWPERR
  50         RET
  51 1:
  52         RETC
  53         SET_SIZE(_lwp_mutex_unlock)