1 /* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 #include <lowlevelrwlock.h>
22 #include <pthread-errnos.h>
38 .globl __pthread_rwlock_rdlock
39 .type __pthread_rwlock_rdlock,@function
41 __pthread_rwlock_rdlock:
55 cmpxchgl %edx, MUTEX(%ebx)
59 2: movl WRITER(%ebx), %eax
62 cmpl $0, WRITERS_QUEUED(%ebx)
67 3: addl $1, READERS_QUEUED(%ebx)
70 movl READERS_WAKEUP(%ebx), %edx
81 #if __ASSUME_PRIVATE_FUTEX
82 movzbl PSHARED(%ebx), %ecx
83 xorl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %ecx
85 movzbl PSHARED(%ebx), %ecx
89 xorl %gs:PRIVATE_FUTEX, %ecx
91 addl $READERS_WAKEUP, %ebx
95 subl $READERS_WAKEUP, %ebx
102 cmpxchgl %edx, (%ebx)
104 cmpxchgl %edx, MUTEX(%ebx)
108 13: subl $1, READERS_QUEUED(%ebx)
112 addl $1, NR_READERS(%ebx)
132 leal MUTEX(%ebx), %ecx
134 call __lll_mutex_lock_wait
137 14: cmpl %gs:TID, %eax
139 /* Deadlock detected. */
147 leal MUTEX(%ebx), %eax
149 call __lll_mutex_unlock_wake
153 8: subl $1, NR_READERS(%ebx)
158 4: subl $1, READERS_QUEUED(%ebx)
166 leal MUTEX(%ebx), %eax
168 call __lll_mutex_unlock_wake
175 leal MUTEX(%ebx), %ecx
177 call __lll_mutex_lock_wait
179 .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock
181 .globl pthread_rwlock_rdlock
182 pthread_rwlock_rdlock = __pthread_rwlock_rdlock
184 .globl __pthread_rwlock_rdlock_internal
185 __pthread_rwlock_rdlock_internal = __pthread_rwlock_rdlock