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:
35 cfi_adjust_cfa_offset(4)
37 cfi_adjust_cfa_offset(4)
51 cmpxchgl %edx, MUTEX(%ebx)
55 2: movl WRITER(%ebx), %eax
58 cmpl $0, WRITERS_QUEUED(%ebx)
63 3: addl $1, READERS_QUEUED(%ebx)
66 movl READERS_WAKEUP(%ebx), %edx
77 #ifdef __ASSUME_PRIVATE_FUTEX
78 movzbl PSHARED(%ebx), %ecx
79 xorl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %ecx
81 movzbl PSHARED(%ebx), %ecx
85 xorl %gs:PRIVATE_FUTEX, %ecx
87 addl $READERS_WAKEUP, %ebx
91 subl $READERS_WAKEUP, %ebx
100 cmpxchgl %edx, MUTEX(%ebx)
104 13: subl $1, READERS_QUEUED(%ebx)
108 addl $1, NR_READERS(%ebx)
121 cfi_adjust_cfa_offset(-4)
124 cfi_adjust_cfa_offset(-4)
128 cfi_adjust_cfa_offset(8)
130 cfi_offset(%ebx, -12)
135 leal MUTEX(%ebx), %edx
137 movzbl PSHARED(%ebx), %ecx
141 14: cmpl %gs:TID, %eax
143 /* Deadlock detected. */
151 leal MUTEX(%ebx), %eax
153 movzbl PSHARED(%ebx), %ecx
154 call __lll_unlock_wake
158 8: subl $1, NR_READERS(%ebx)
163 4: subl $1, READERS_QUEUED(%ebx)
171 leal MUTEX(%ebx), %eax
173 movzbl PSHARED(%ebx), %ecx
174 call __lll_unlock_wake
181 leal MUTEX(%ebx), %edx
183 movzbl PSHARED(%ebx), %ecx
187 .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock
189 .globl pthread_rwlock_rdlock
190 pthread_rwlock_rdlock = __pthread_rwlock_rdlock
192 .globl __pthread_rwlock_rdlock_internal
193 __pthread_rwlock_rdlock_internal = __pthread_rwlock_rdlock