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Revert "Extend i486 pthread_cond_timedwait to use futex syscall with absolute timeout" 

This reverts commit 1bd57044e9.
This commit is contained in:
Andreas Schwab 2013-01-10 10:43:00 +01:00
parent 557eead076
commit e3f45e2bbe
1 changed files with 66 additions and 315 deletions
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381
nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S
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@ -66,34 +66,6 @@ __pthread_cond_timedwait:
movl $EINVAL, %eax
jae 18f
/* Stack frame:
esp + 32
+--------------------------+
esp + 24 | timeout value |
+--------------------------+
esp + 20 | futex pointer |
+--------------------------+
esp + 16 | pi-requeued flag |
+--------------------------+
esp + 12 | old broadcast_seq value |
+--------------------------+
esp + 4 | old wake_seq value |
+--------------------------+
esp + 0 | old cancellation mode |
+--------------------------+
*/
#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
# ifdef PIC
LOAD_PIC_REG (cx)
cmpl $0, __have_futex_clock_realtime@GOTOFF(%ecx)
# else
cmpl $0, __have_futex_clock_realtime
# endif
je .Lreltmo
#endif
/* Get internal lock. */
movl $1, %edx
xorl %eax, %eax
@ -124,11 +96,7 @@ __pthread_cond_timedwait:
addl $1, cond_futex(%ebx)
addl $(1 << nwaiters_shift), cond_nwaiters(%ebx)
#ifdef __ASSUME_FUTEX_CLOCK_REALTIME
# define FRAME_SIZE 24
#else
# define FRAME_SIZE 32
#endif
#define FRAME_SIZE 32
subl $FRAME_SIZE, %esp
cfi_adjust_cfa_offset(FRAME_SIZE)
cfi_remember_state
@ -137,19 +105,60 @@ __pthread_cond_timedwait:
movl wakeup_seq(%ebx), %edi
movl wakeup_seq+4(%ebx), %edx
movl broadcast_seq(%ebx), %eax
movl %edi, 4(%esp)
movl %edx, 8(%esp)
movl %eax, 12(%esp)
movl %edi, 12(%esp)
movl %edx, 16(%esp)
movl %eax, 20(%esp)
/* Reset the pi-requeued flag. */
movl $0, 16(%esp)
8: movl $0, 24(%esp)
/* Get the current time. */
movl %ebx, %edx
#ifdef __NR_clock_gettime
/* Get the clock number. */
movl cond_nwaiters(%ebx), %ebx
andl $((1 << nwaiters_shift) - 1), %ebx
/* Only clocks 0 and 1 are allowed so far. Both are handled in the
kernel. */
leal 4(%esp), %ecx
movl $__NR_clock_gettime, %eax
ENTER_KERNEL
movl %edx, %ebx
cmpl $0, (%ebp)
/* Compute relative timeout. */
movl (%ebp), %ecx
movl 4(%ebp), %edx
subl 4(%esp), %ecx
subl 8(%esp), %edx
#else
/* Get the current time. */
leal 4(%esp), %ebx
xorl %ecx, %ecx
movl $__NR_gettimeofday, %eax
ENTER_KERNEL
movl %edx, %ebx
/* Compute relative timeout. */
movl 8(%esp), %eax
movl $1000, %edx
mul %edx /* Milli seconds to nano seconds. */
movl (%ebp), %ecx
movl 4(%ebp), %edx
subl 4(%esp), %ecx
subl %eax, %edx
#endif
jns 12f
addl $1000000000, %edx
subl $1, %ecx
12: testl %ecx, %ecx
movl $-ETIMEDOUT, %esi
js 6f
8: movl cond_futex(%ebx), %edi
movl %edi, 20(%esp)
/* Store relative timeout. */
21: movl %ecx, 4(%esp)
movl %edx, 8(%esp)
movl cond_futex(%ebx), %edi
movl %edi, 28(%esp)
/* Unlock. */
LOCK
@ -164,7 +173,6 @@ __pthread_cond_timedwait:
4: call __pthread_enable_asynccancel
movl %eax, (%esp)
leal (%ebp), %esi
#if FUTEX_PRIVATE_FLAG > 255
xorl %ecx, %ecx
#endif
@ -188,7 +196,9 @@ __pthread_cond_timedwait:
jne 42f
orl $FUTEX_CLOCK_REALTIME, %ecx
42: movl 20(%esp), %edx
/* Requeue-PI uses absolute timeout */
42: leal (%ebp), %esi
movl 28(%esp), %edx
addl $cond_futex, %ebx
.Ladd_cond_futex_pi:
movl $SYS_futex, %eax
@ -199,12 +209,12 @@ __pthread_cond_timedwait:
/* Set the pi-requeued flag only if the kernel has returned 0. The
kernel does not hold the mutex on ETIMEDOUT or any other error. */
cmpl $0, %eax
sete 16(%esp)
sete 24(%esp)
je 41f
/* When a futex syscall with FUTEX_WAIT_REQUEUE_PI returns
successfully, it has already locked the mutex for us and the
pi_flag (16(%esp)) is set to denote that fact. However, if another
pi_flag (24(%esp)) is set to denote that fact. However, if another
thread changed the futex value before we entered the wait, the
syscall may return an EAGAIN and the mutex is not locked. We go
ahead with a success anyway since later we look at the pi_flag to
@ -224,28 +234,22 @@ __pthread_cond_timedwait:
xorl %ecx, %ecx
40: subl $1, %ecx
movl $0, 16(%esp)
#ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
#else
andl %gs:PRIVATE_FUTEX, %ecx
#endif
addl $FUTEX_WAIT_BITSET, %ecx
/* The following only works like this because we only support
two clocks, represented using a single bit. */
testl $1, cond_nwaiters(%ebx)
jne 30f
orl $FUTEX_CLOCK_REALTIME, %ecx
30:
movl 20(%esp), %edx
movl $0xffffffff, %ebp
#if FUTEX_WAIT != 0
addl $FUTEX_WAIT, %ecx
#endif
leal 4(%esp), %esi
movl 28(%esp), %edx
addl $cond_futex, %ebx
.Ladd_cond_futex:
movl $SYS_futex, %eax
ENTER_KERNEL
subl $cond_futex, %ebx
.Lsub_cond_futex:
movl 28+FRAME_SIZE(%esp), %ebp
movl %eax, %esi
41: movl (%esp), %eax
@ -264,7 +268,7 @@ __pthread_cond_timedwait:
jnz 5f
6: movl broadcast_seq(%ebx), %eax
cmpl 12(%esp), %eax
cmpl 20(%esp), %eax
jne 23f
movl woken_seq(%ebx), %eax
@ -273,9 +277,9 @@ __pthread_cond_timedwait:
movl wakeup_seq(%ebx), %edi
movl wakeup_seq+4(%ebx), %edx
cmpl 8(%esp), %edx
cmpl 16(%esp), %edx
jne 7f
cmpl 4(%esp), %edi
cmpl 12(%esp), %edi
je 15f
7: cmpl %ecx, %edx
@ -288,7 +292,7 @@ __pthread_cond_timedwait:
/* We need to go back to futex_wait. If we're using requeue_pi, then
release the mutex we had acquired and go back. */
movl 16(%esp), %edx
movl 24(%esp), %edx
test %edx, %edx
jz 8b
@ -353,13 +357,13 @@ __pthread_cond_timedwait:
11: movl 24+FRAME_SIZE(%esp), %eax
/* With requeue_pi, the mutex lock is held in the kernel. */
movl 16(%esp), %ecx
movl 24(%esp), %ecx
testl %ecx, %ecx
jnz 27f
call __pthread_mutex_cond_lock
26: addl $FRAME_SIZE, %esp
cfi_adjust_cfa_offset(-FRAME_SIZE)
cfi_adjust_cfa_offset(-FRAME_SIZE);
/* We return the result of the mutex_lock operation if it failed. */
testl %eax, %eax
@ -505,245 +509,6 @@ __pthread_cond_timedwait:
#endif
call __lll_unlock_wake
jmp 11b
cfi_adjust_cfa_offset(-FRAME_SIZE)
#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
.Lreltmo:
/* Get internal lock. */
movl $1, %edx
xorl %eax, %eax
LOCK
# if cond_lock == 0
cmpxchgl %edx, (%ebx)
# else
cmpxchgl %edx, cond_lock(%ebx)
# endif
jnz 101f
/* Store the reference to the mutex. If there is already a
different value in there this is a bad user bug. */
102: cmpl $-1, dep_mutex(%ebx)
movl 24(%esp), %eax
je 117f
movl %eax, dep_mutex(%ebx)
/* Unlock the mutex. */
117: xorl %edx, %edx
call __pthread_mutex_unlock_usercnt
testl %eax, %eax
jne 16b
addl $1, total_seq(%ebx)
adcl $0, total_seq+4(%ebx)
addl $1, cond_futex(%ebx)
addl $(1 << nwaiters_shift), cond_nwaiters(%ebx)
subl $FRAME_SIZE, %esp
cfi_adjust_cfa_offset(FRAME_SIZE)
/* Get and store current wakeup_seq value. */
movl wakeup_seq(%ebx), %edi
movl wakeup_seq+4(%ebx), %edx
movl broadcast_seq(%ebx), %eax
movl %edi, 4(%esp)
movl %edx, 8(%esp)
movl %eax, 12(%esp)
/* Reset the pi-requeued flag. */
movl $0, 16(%esp)
/* Get the current time. */
108: movl %ebx, %edx
# ifdef __NR_clock_gettime
/* Get the clock number. */
movl cond_nwaiters(%ebx), %ebx
andl $((1 << nwaiters_shift) - 1), %ebx
/* Only clocks 0 and 1 are allowed so far. Both are handled in the
kernel. */
leal 24(%esp), %ecx
movl $__NR_clock_gettime, %eax
ENTER_KERNEL
movl %edx, %ebx
/* Compute relative timeout. */
movl (%ebp), %ecx
movl 4(%ebp), %edx
subl 24(%esp), %ecx
subl 28(%esp), %edx
# else
/* Get the current time. */
leal 24(%esp), %ebx
xorl %ecx, %ecx
movl $__NR_gettimeofday, %eax
ENTER_KERNEL
movl %edx, %ebx
/* Compute relative timeout. */
movl 28(%esp), %eax
movl $1000, %edx
mul %edx /* Milli seconds to nano seconds. */
movl (%ebp), %ecx
movl 4(%ebp), %edx
subl 24(%esp), %ecx
subl %eax, %edx
# endif
jns 112f
addl $1000000000, %edx
subl $1, %ecx
112: testl %ecx, %ecx
movl $-ETIMEDOUT, %esi
js 106f
/* Store relative timeout. */
121: movl %ecx, 24(%esp)
movl %edx, 28(%esp)
movl cond_futex(%ebx), %edi
movl %edi, 20(%esp)
/* Unlock. */
LOCK
# if cond_lock == 0
subl $1, (%ebx)
# else
subl $1, cond_lock(%ebx)
# endif
jne 103f
.LcleanupSTART2:
104: call __pthread_enable_asynccancel
movl %eax, (%esp)
leal 24(%esp), %esi
# if FUTEX_PRIVATE_FLAG > 255
xorl %ecx, %ecx
# endif
cmpl $-1, dep_mutex(%ebx)
sete %cl
subl $1, %ecx
# ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
# else
andl %gs:PRIVATE_FUTEX, %ecx
# endif
# if FUTEX_WAIT != 0
addl $FUTEX_WAIT, %ecx
# endif
movl 20(%esp), %edx
addl $cond_futex, %ebx
.Ladd_cond_futex2:
movl $SYS_futex, %eax
ENTER_KERNEL
subl $cond_futex, %ebx
.Lsub_cond_futex2:
movl %eax, %esi
141: movl (%esp), %eax
call __pthread_disable_asynccancel
.LcleanupEND2:
/* Lock. */
movl $1, %edx
xorl %eax, %eax
LOCK
# if cond_lock == 0
cmpxchgl %edx, (%ebx)
# else
cmpxchgl %edx, cond_lock(%ebx)
# endif
jnz 105f
106: movl broadcast_seq(%ebx), %eax
cmpl 12(%esp), %eax
jne 23b
movl woken_seq(%ebx), %eax
movl woken_seq+4(%ebx), %ecx
movl wakeup_seq(%ebx), %edi
movl wakeup_seq+4(%ebx), %edx
cmpl 8(%esp), %edx
jne 107f
cmpl 4(%esp), %edi
je 115f
107: cmpl %ecx, %edx
jne 9b
cmp %eax, %edi
jne 9b
115: cmpl $-ETIMEDOUT, %esi
je 28b
jmp 8b
cfi_adjust_cfa_offset(-FRAME_SIZE)
/* Initial locking failed. */
101:
# if cond_lock == 0
movl %ebx, %edx
# else
leal cond_lock(%ebx), %edx
# endif
# if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
# endif
cmpl $-1, dep_mutex(%ebx)
setne %cl
subl $1, %ecx
andl $(LLL_SHARED-LLL_PRIVATE), %ecx
# if LLL_PRIVATE != 0
addl $LLL_PRIVATE, %ecx
# endif
call __lll_lock_wait
jmp 102b
cfi_adjust_cfa_offset(FRAME_SIZE)
/* Unlock in loop requires wakeup. */
103:
# if cond_lock == 0
movl %ebx, %eax
# else
leal cond_lock(%ebx), %eax
# endif
# if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
# endif
cmpl $-1, dep_mutex(%ebx)
setne %cl
subl $1, %ecx
andl $(LLL_SHARED-LLL_PRIVATE), %ecx
# if LLL_PRIVATE != 0
addl $LLL_PRIVATE, %ecx
# endif
call __lll_unlock_wake
jmp 104b
/* Locking in loop failed. */
105:
# if cond_lock == 0
movl %ebx, %edx
# else
leal cond_lock(%ebx), %edx
# endif
# if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
# endif
cmpl $-1, dep_mutex(%ebx)
setne %cl
subl $1, %ecx
andl $(LLL_SHARED-LLL_PRIVATE), %ecx
# if LLL_PRIVATE != 0
addl $LLL_PRIVATE, %ecx
# endif
call __lll_lock_wait
jmp 106b
cfi_adjust_cfa_offset(-FRAME_SIZE)
#endif
.size __pthread_cond_timedwait, .-__pthread_cond_timedwait
versioned_symbol (libpthread, __pthread_cond_timedwait, pthread_cond_timedwait,
@ -787,7 +552,7 @@ __condvar_tw_cleanup:
call __lll_lock_wait
1: movl broadcast_seq(%ebx), %eax
cmpl 12(%esp), %eax
cmpl 20(%esp), %eax
jne 3f
/* We increment the wakeup_seq counter only if it is lower than
@ -941,20 +706,6 @@ __condvar_tw_cleanup:
.long .LcleanupEND-.Lsub_cond_futex
.long __condvar_tw_cleanup-.LSTARTCODE
.uleb128 0
#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
.long .LcleanupSTART2-.LSTARTCODE
.long .Ladd_cond_futex2-.LcleanupSTART2
.long __condvar_tw_cleanup-.LSTARTCODE
.uleb128 0
.long .Ladd_cond_futex2-.LSTARTCODE
.long .Lsub_cond_futex2-.Ladd_cond_futex2
.long __condvar_tw_cleanup2-.LSTARTCODE
.uleb128 0
.long .Lsub_cond_futex2-.LSTARTCODE
.long .LcleanupEND2-.Lsub_cond_futex2
.long __condvar_tw_cleanup-.LSTARTCODE
.uleb128 0
#endif
.long .LcallUR-.LSTARTCODE
.long .LENDCODE-.LcallUR
.long 0