1 /* Copyright (C) 2002, 2003, 2004, 2005 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 <shlib-compat.h>
22 #include <lowlevelcond.h>
23 #include <kernel-features.h>
34 #define FUTEX_WAKE_OP 5
36 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1)
43 /* int pthread_cond_signal (pthread_cond_t *cond) */
44 .globl __pthread_cond_signal
45 .type __pthread_cond_signal, @function
47 __pthread_cond_signal:
54 /* Get internal lock. */
61 cmpxchgl %edx, cond_lock(%edi)
65 2: leal cond_futex(%edi), %ebx
66 movl total_seq+4(%edi), %eax
67 movl total_seq(%edi), %ecx
68 cmpl wakeup_seq+4(%edi), %eax
70 /* Must use leal to preserve the flags. */
71 leal cond_lock(%edi), %edi
75 cmpl wakeup_seq-cond_futex(%ebx), %ecx
78 /* Bump the wakeup number. */
79 3: addl $1, wakeup_seq-cond_futex(%ebx)
80 adcl $0, wakeup_seq-cond_futex+4(%ebx)
83 /* Wake up one thread. */
86 movl $FUTEX_WAKE_OP, %ecx
90 movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %ebp
91 /* FIXME: Until Ingo fixes 4G/4G vDSO, 6 arg syscalls are broken for
98 /* For any kind of error, we try again with WAKE.
99 The general test also covers running on old kernels. */
108 7: movl $FUTEX_WAKE, %ecx
109 movl $SYS_futex, %eax
110 /* %edx should be 1 already from $FUTEX_WAKE_OP syscall.
114 /* Unlock. Note that at this point %edi always points to
120 /* Unlock in loop requires wakeup. */
122 call __lll_mutex_unlock_wake
125 /* Initial locking failed. */
130 leal cond_lock(%edi), %ecx
132 call __lll_mutex_lock_wait
135 .size __pthread_cond_signal, .-__pthread_cond_signal
136 versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,