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#include <sys/linux-syscalls.h>
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
/*
* int __futex_wait(volatile void *ftx, int val, const struct timespec *timeout)
*/
.text
.globl __futex_wait
.type __futex_wait, @function
.align 4
__futex_wait:
pushl %ebx
pushl %esi
mov 12(%esp), %ebx /* ftx */
movl $FUTEX_WAIT, %ecx
mov 16(%esp), %edx /* val */
mov 20(%esp), %esi /* timeout */
movl $__NR_futex, %eax
int $0x80
popl %esi
popl %ebx
ret
/* int __futex_wake(volatile void *ftx, int count) */
.text
.globl __futex_wake
.type __futex_wake, @function
.align 4
__futex_wake:
pushl %ebx
mov 8(%esp), %ebx /* ftx */
movl $FUTEX_WAKE, %ecx
mov 12(%esp), %edx /* count */
movl $__NR_futex, %eax
int $0x80
popl %ebx
ret
/* int __atomic_cmpxchg(int old, int new, volatile int* addr) */
.text
.globl __atomic_cmpxchg
.type __atomic_cmpxchg, @function
.align 4
__atomic_cmpxchg:
mov 4(%esp), %eax /* old */
mov 8(%esp), %ecx /* new */
mov 12(%esp), %edx /* addr */
lock cmpxchg %ecx, (%edx)
jnz 1f
xor %eax, %eax
jmp 2f
1:
movl $1, %eax
2:
ret /* 0 == success, 1 == failure */
/* int __atomic_swap(int new, volatile int* addr) */
.text
.globl __atomic_swap
.type __atomic_swap, @function
.align 4
__atomic_swap:
mov 4(%esp), %ecx /* new */
mov 8(%esp), %edx /* addr */
lock xchg %ecx, (%edx)
mov %ecx, %eax
ret
/*
* int __atomic_dec(volatile int* addr)
*
* My x86 asm is really rusty.. this is probably suboptimal
*/
.text
.globl __atomic_dec
.type __atomic_dec, @function
.align 4
__atomic_dec:
pushl %ebx
pushl %esi
movl 12(%esp), %ebx /* addr */
1:
movl (%ebx), %esi /* old = *addr */
movl %esi, %edx
subl $1, %edx /* new = old - 1 */
pushl %ebx
pushl %edx
pushl %esi
call __atomic_cmpxchg
addl $12, %esp
test %eax, %eax
jnz 1b
movl %esi, %eax /* return old */
popl %esi
popl %ebx
ret
.text
/* int __atomic_inc(volatile int* addr) */
.globl __atomic_inc
.type __atomic_inc, @function
.align 4
__atomic_inc:
pushl %ebx
pushl %esi
movl 12(%esp), %ebx /* addr */
1:
movl (%ebx), %esi /* old = *addr */
movl %esi, %edx
addl $1, %edx /* new = old + 1 */
pushl %ebx
pushl %edx
pushl %esi
call __atomic_cmpxchg
addl $12, %esp
test %eax, %eax
jnz 1b
movl %esi, %eax /* return old */
popl %esi
popl %ebx
ret
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