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Extend x86-64 __lll_robust_timedlock_wait to use futex syscall with absolute timeout.

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This commit is contained in:
Ulrich Drepper 2009-07-19 00:00:17 -07:00
parent 3d77b2687f
commit e2dca2fea3
2 changed files with 80 additions and 2 deletions
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4
nptl/ChangeLog
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@ -1,5 +1,9 @@
2009-07-18 Ulrich Drepper <drepper@redhat.com>
* sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S
(__lll_robust_timedlock_wait): If possible use FUTEX_WAIT_BITSET to
directly use absolute timeout.
* tst-sem5.c (do_test): Add test for premature timeout.
* Makefile: Linu tst-sem5 with librt.

78
nptl/sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S
View File

@ -1,4 +1,4 @@
/* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
/* Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2009
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
@ -32,6 +32,8 @@
#ifdef __ASSUME_PRIVATE_FUTEX
# define LOAD_FUTEX_WAIT(reg) \
xorl $(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg
# define LOAD_FUTEX_WAIT_ABS(reg) \
xorl $(FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME), reg
#else
# if FUTEX_WAIT == 0
# define LOAD_FUTEX_WAIT(reg) \
@ -43,6 +45,10 @@
andl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAIT, reg
# endif
# define LOAD_FUTEX_WAIT_ABS(reg) \
xorl $FUTEX_PRIVATE_FLAG, reg ; \
andl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME, reg
#endif
/* For the calculation see asm/vsyscall.h. */
@ -110,6 +116,73 @@ __lll_robust_lock_wait:
.align 16
__lll_robust_timedlock_wait:
cfi_startproc
# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
# ifdef PIC
cmpl $0, __have_futex_clock_realtime(%rip)
# else
cmpl $0, __have_futex_clock_realtime
# endif
je .Lreltmo
# endif
pushq %r9
cfi_adjust_cfa_offset(8)
cfi_rel_offset(%r9, 0)
movq %rdx, %r10
movl $0xffffffff, %r9d
LOAD_FUTEX_WAIT_ABS (%esi)
1: testl $FUTEX_OWNER_DIED, %eax
jnz 3f
movl %eax, %edx
orl $FUTEX_WAITERS, %edx
cmpl %eax, %edx
je 5f
LOCK
cmpxchgl %edx, (%rdi)
movq $0, %rcx /* Must use mov to avoid changing cc. */
jnz 6f
5: movl $SYS_futex, %eax
syscall
movl %eax, %ecx
movl (%rdi), %eax
6: testl %eax, %eax
jne 2f
movl %fs:TID, %edx
orl $FUTEX_WAITERS, %edx
LOCK
cmpxchgl %edx, (%rdi)
jnz 2f
3: popq %r9
cfi_adjust_cfa_offset(-8)
cfi_restore(%r9)
retq
cfi_adjust_cfa_offset(8)
cfi_rel_offset(%r9, 0)
/* Check whether the time expired. */
2: cmpl $-ETIMEDOUT, %ecx
je 4f
cmpl $-EINVAL, %ecx
jne 1b
4: movl %ecx, %eax
negl %eax
jmp 3b
cfi_adjust_cfa_offset(-8)
cfi_restore(%r9)
# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
.Lreltmo:
/* Check for a valid timeout value. */
cmpq $1000000000, 8(%rdx)
jae 3f
@ -223,10 +296,11 @@ __lll_robust_timedlock_wait:
cfi_offset(%r12, -32)
cfi_offset(%r13, -40)
/* Check whether the time expired. */
7: cmpq $-ETIMEDOUT, %rcx
7: cmpl $-ETIMEDOUT, %ecx
jne 1b
8: movl $ETIMEDOUT, %eax
jmp 6b
#endif
cfi_endproc
.size __lll_robust_timedlock_wait,.-__lll_robust_timedlock_wait