diff options
Diffstat (limited to 'nptl')
| -rw-r--r-- | nptl/ChangeLog | 6 | ||||
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S | 381 |
2 files changed, 321 insertions, 66 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog index 517dfeffb1..d2a1e477e4 100644 --- a/nptl/ChangeLog +++ b/nptl/ChangeLog @@ -1,3 +1,9 @@ +2013-04-11 Andreas Schwab <schwab@suse.de> + + * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S + (__pthread_cond_timedwait): If possible use FUTEX_WAIT_BITSET to + directly use absolute timeout. + 2013-04-07 Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/sem_post.c: Include atomic.h. diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S index 02f8013a41..a6d6bc460a 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S +++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S @@ -66,6 +66,34 @@ __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 @@ -96,7 +124,11 @@ __pthread_cond_timedwait: addl $1, cond_futex(%ebx) addl $(1 << nwaiters_shift), cond_nwaiters(%ebx) -#define FRAME_SIZE 32 +#ifdef __ASSUME_FUTEX_CLOCK_REALTIME +# define FRAME_SIZE 24 +#else +# define FRAME_SIZE 32 +#endif subl $FRAME_SIZE, %esp cfi_adjust_cfa_offset(FRAME_SIZE) cfi_remember_state @@ -105,60 +137,19 @@ __pthread_cond_timedwait: movl wakeup_seq(%ebx), %edi movl wakeup_seq+4(%ebx), %edx movl broadcast_seq(%ebx), %eax - movl %edi, 12(%esp) - movl %edx, 16(%esp) - movl %eax, 20(%esp) + movl %edi, 4(%esp) + movl %edx, 8(%esp) + movl %eax, 12(%esp) /* Reset the pi-requeued flag. */ -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 - - /* 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 + movl $0, 16(%esp) - /* 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 + cmpl $0, (%ebp) movl $-ETIMEDOUT, %esi js 6f - /* Store relative timeout. */ -21: movl %ecx, 4(%esp) - movl %edx, 8(%esp) - - movl cond_futex(%ebx), %edi - movl %edi, 28(%esp) +8: movl cond_futex(%ebx), %edi + movl %edi, 20(%esp) /* Unlock. */ LOCK @@ -173,6 +164,7 @@ __pthread_cond_timedwait: 4: call __pthread_enable_asynccancel movl %eax, (%esp) + leal (%ebp), %esi #if FUTEX_PRIVATE_FLAG > 255 xorl %ecx, %ecx #endif @@ -196,9 +188,7 @@ __pthread_cond_timedwait: jne 42f orl $FUTEX_CLOCK_REALTIME, %ecx - /* Requeue-PI uses absolute timeout */ -42: leal (%ebp), %esi - movl 28(%esp), %edx +42: movl 20(%esp), %edx addl $cond_futex, %ebx .Ladd_cond_futex_pi: movl $SYS_futex, %eax @@ -209,12 +199,12 @@ __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 24(%esp) + sete 16(%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 (24(%esp)) is set to denote that fact. However, if another + pi_flag (16(%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 @@ -234,22 +224,28 @@ __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 -#if FUTEX_WAIT != 0 - addl $FUTEX_WAIT, %ecx -#endif - leal 4(%esp), %esi - movl 28(%esp), %edx + 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 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 @@ -268,7 +264,7 @@ __pthread_cond_timedwait: jnz 5f 6: movl broadcast_seq(%ebx), %eax - cmpl 20(%esp), %eax + cmpl 12(%esp), %eax jne 23f movl woken_seq(%ebx), %eax @@ -277,9 +273,9 @@ __pthread_cond_timedwait: movl wakeup_seq(%ebx), %edi movl wakeup_seq+4(%ebx), %edx - cmpl 16(%esp), %edx + cmpl 8(%esp), %edx jne 7f - cmpl 12(%esp), %edi + cmpl 4(%esp), %edi je 15f 7: cmpl %ecx, %edx @@ -292,7 +288,7 @@ __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 24(%esp), %edx + movl 16(%esp), %edx test %edx, %edx jz 8b @@ -357,13 +353,13 @@ __pthread_cond_timedwait: 11: movl 24+FRAME_SIZE(%esp), %eax /* With requeue_pi, the mutex lock is held in the kernel. */ - movl 24(%esp), %ecx + movl 16(%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 @@ -509,6 +505,245 @@ __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, @@ -552,7 +787,7 @@ __condvar_tw_cleanup: call __lll_lock_wait 1: movl broadcast_seq(%ebx), %eax - cmpl 20(%esp), %eax + cmpl 12(%esp), %eax jne 3f /* We increment the wakeup_seq counter only if it is lower than @@ -706,6 +941,20 @@ __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 |