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/* Copyright (C) 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <lowlevellock.h>
#include <lowlevelbarrier.h>
#include "lowlevel-atomic.h"
.text
.globl pthread_barrier_wait
.type pthread_barrier_wait,@function
.align 5
pthread_barrier_wait:
mov.l r9, @-r15
mov.l r8, @-r15
sts.l pr, @-r15
mov r4, r8
/* Get the mutex. */
mov #0, r3
mov #1, r4
CMPXCHG (r3, @(MUTEX,r8), r4, r2)
bf 1f
/* One less waiter. If this was the last one needed wake
everybody. */
2:
mov.l @(LEFT,r8), r0
add #-1, r0
mov.l r0, @(LEFT,r8)
tst r0, r0
bt 3f
/* There are more threads to come. */
mov.l @(CURR_EVENT,r8), r6
/* Release the mutex. */
DEC (@(MUTEX,r8), r2)
tst r2, r2
bf 6f
7:
/* Wait for the remaining threads. The call will return immediately
if the CURR_EVENT memory has meanwhile been changed. */
mov r8, r4
#if CURR_EVENT != 0
add #CURR_EVENT, r4
#endif
#if FUTEX_WAIT == 0
mov.l @(PRIVATE,r8), r5
#else
mov #FUTEX_WAIT, r5
mov.l @(PRIVATE,r8), r0
or r0, r5
#endif
mov #0, r7
8:
mov #SYS_futex, r3
extu.b r3, r3
trapa #0x14
SYSCALL_INST_PAD
/* Don't return on spurious wakeups. The syscall does not change
any register except r0 so there is no need to reload any of
them. */
mov.l @(CURR_EVENT,r8), r0
cmp/eq r0, r6
bt 8b
/* Increment LEFT. If this brings the count back to the
initial count unlock the object. */
mov #1, r3
mov.l @(INIT_COUNT,r8), r4
XADD (r3, @(LEFT,r8), r2, r5)
add #-1, r4
cmp/eq r2, r4
bf 10f
/* Release the mutex. We cannot release the lock before
waking the waiting threads since otherwise a new thread might
arrive and gets waken up, too. */
DEC (@(MUTEX,r8), r2)
tst r2, r2
bf 9f
10:
mov #0, r0 /* != PTHREAD_BARRIER_SERIAL_THREAD */
lds.l @r15+, pr
mov.l @r15+, r8
rts
mov.l @r15+, r9
3:
/* The necessary number of threads arrived. */
mov.l @(CURR_EVENT,r8), r1
add #1, r1
mov.l r1, @(CURR_EVENT,r8)
/* Wake up all waiters. The count is a signed number in the kernel
so 0x7fffffff is the highest value. */
mov.l .Lall, r6
mov r8, r4
#if CURR_EVENT != 0
add #CURR_EVENT, r4
#endif
mov #0, r7
mov #FUTEX_WAKE, r5
mov.l @(PRIVATE,r8), r0
or r0, r5
mov #SYS_futex, r3
extu.b r3, r3
trapa #0x14
SYSCALL_INST_PAD
/* Increment LEFT. If this brings the count back to the
initial count unlock the object. */
mov #1, r3
mov.l @(INIT_COUNT,r8), r4
XADD (r3, @(LEFT,r8), r2, r5)
add #-1, r4
cmp/eq r2, r4
bf 5f
/* Release the mutex. */
DEC (@(MUTEX,r8), r2)
tst r2, r2
bf 4f
5:
mov #-1, r0 /* == PTHREAD_BARRIER_SERIAL_THREAD */
lds.l @r15+, pr
mov.l @r15+, r8
rts
mov.l @r15+, r9
1:
mov.l @(PRIVATE,r8), r6
mov #LLL_SHARED, r0
extu.b r0, r0
xor r0, r6
mov r2, r4
mov r8, r5
mov.l .Lwait0, r1
bsrf r1
add #MUTEX, r5
.Lwait0b:
bra 2b
nop
4:
mov.l @(PRIVATE,r8), r5
mov #LLL_SHARED, r0
extu.b r0, r0
xor r0, r5
mov r8, r4
mov.l .Lwake0, r1
bsrf r1
add #MUTEX, r4
.Lwake0b:
bra 5b
nop
6:
mov r6, r9
mov.l @(PRIVATE,r8), r5
mov #LLL_SHARED, r0
extu.b r0, r0
xor r0, r5
mov r8, r4
mov.l .Lwake1, r1
bsrf r1
add #MUTEX, r4
.Lwake1b:
bra 7b
mov r9, r6
9:
mov r6, r9
mov.l @(PRIVATE,r8), r5
mov #LLL_SHARED, r0
extu.b r0, r0
xor r0, r5
mov r8, r4
mov.l .Lwake2, r1
bsrf r1
add #MUTEX, r4
.Lwake2b:
bra 10b
mov r9, r6
.align 2
.Lall:
.long 0x7fffffff
.Lwait0:
.long __lll_lock_wait-.Lwait0b
.Lwake0:
.long __lll_unlock_wake-.Lwake0b
.Lwake1:
.long __lll_unlock_wake-.Lwake1b
.Lwake2:
.long __lll_unlock_wake-.Lwake2b
.size pthread_barrier_wait,.-pthread_barrier_wait
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