winamp/Src/replicant/nu/win-x86/LockFreeLIFO.asm

51 lines
989 B
NASM

.686
.model FLAT
PUBLIC _lifo_push
_TEXT SEGMENT
lifo = 4 ; size = 4
entry = 8 ; size = 4
_lifo_push PROC
mov ecx, DWORD PTR 4[esp] ; ecx holds lifo
mov edx, DWORD PTR 8[esp] ; edx holds the new entry
again:
mov eax, DWORD PTR [ecx] ; eax holds the old head
mov DWORD PTR[edx], eax ; new node's 'next' is set to the old head
lock cmpxchg DWORD PTR [ecx], edx
jnz again
ret 0
_lifo_push ENDP
PUBLIC _lifo_pop
_TEXT SEGMENT
lifo = 4 ; size = 4
_lifo_pop PROC
push esi
push ebx
mov esi, DWORD PTR 12[esp] ; esi holds lifo
again:
; if re-ordered loads become an issue, we could use cmpxchg8b to read in (after zeroing ebx/ecx) or maybe use movq
mov edx, DWORD PTR [esi+4] ; counter
; or we could put an LFENCE here
mov eax, DWORD PTR [esi] ; pointer
test eax, eax
jz bail
mov ecx, edx ; counter
mov ebx, DWORD PTR [eax] ; pointer->next
inc ecx
lock cmpxchg8b QWORD PTR [esi]
jnz again
bail:
pop ebx
pop esi
ret 0
_lifo_pop ENDP
_TEXT ENDS
END