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 <lowlevellock.h>
22 #include <lowlevelrwlock.h>
23 #include <pthread-errnos.h>
24 #include <kernel-features.h>
29 .globl __pthread_rwlock_rdlock
30 .type __pthread_rwlock_rdlock,@function
32 __pthread_rwlock_rdlock:
46 cmpxchgl %edx, MUTEX(%ebx)
50 2: movl WRITER(%ebx), %eax
53 cmpl $0, WRITERS_QUEUED(%ebx)
58 3: addl $1, READERS_QUEUED(%ebx)
61 movl READERS_WAKEUP(%ebx), %edx
72 #ifdef __ASSUME_PRIVATE_FUTEX
73 movzbl PSHARED(%ebx), %ecx
74 xorl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %ecx
76 movzbl PSHARED(%ebx), %ecx
80 xorl %gs:PRIVATE_FUTEX, %ecx
82 addl $READERS_WAKEUP, %ebx
86 subl $READERS_WAKEUP, %ebx
95 cmpxchgl %edx, MUTEX(%ebx)
99 13: subl $1, READERS_QUEUED(%ebx)
103 addl $1, NR_READERS(%ebx)
123 leal MUTEX(%ebx), %edx
125 movzbl PSHARED(%ebx), %ecx
129 14: cmpl %gs:TID, %eax
131 /* Deadlock detected. */
139 leal MUTEX(%ebx), %eax
141 movzbl PSHARED(%ebx), %ecx
142 call __lll_unlock_wake
146 8: subl $1, NR_READERS(%ebx)
151 4: subl $1, READERS_QUEUED(%ebx)
159 leal MUTEX(%ebx), %eax
161 movzbl PSHARED(%ebx), %ecx
162 call __lll_unlock_wake
169 leal MUTEX(%ebx), %edx
171 movzbl PSHARED(%ebx), %ecx
174 .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock
176 .globl pthread_rwlock_rdlock
177 pthread_rwlock_rdlock = __pthread_rwlock_rdlock
179 .globl __pthread_rwlock_rdlock_internal
180 __pthread_rwlock_rdlock_internal = __pthread_rwlock_rdlock