..back

    .HEADING "Interlock memory operations"
    .FORM LINES=55
;++
;
; Copyright (c) 1995-2000 Microsoft Corporation.  All rights reserved.
;
; Module Name:
;
;    intrlock.src
;
; Abstract:
;
;    This module implements the InterlockedIncrement, I...Decrement,
; I...Exchange and I...TestExchange APIs.
;
;    WARNING: This module makes special use of register K1 to inform the
;    GeneralException handler in except.s that an interlocked operation
;    is being performed. Because the exception handler code has detailed
;    knowledge of this code, extreme care must be exercised when modifying
;    this module. For example, the store instruction must be followed
;    immediately by a "j ra" instruction.
;
; Environment:
;
;    Kernel mode or User mode.
;
; Revision History:
;
;--


    .include "ksshx.h"

    LEAF_ENTRY InterlockAPIs
    ALTERNATE_ENTRY _InterlockedExchange
    mov    #USER_KPAGE+h'3c0, r0
    jmp    @r0
    nop

    ALTERNATE_ENTRY _InterlockedTestExchange
    mov    #USER_KPAGE+h'3d0, r0
    jmp    @r0
    nop

    ALTERNATE_ENTRY _InterlockedIncrement
    mov    #USER_KPAGE+h'3e0, r0
    jmp    @r0
    nop

    ALTERNATE_ENTRY _InterlockedDecrement
    mov    #USER_KPAGE+h'3f0, r0
    jmp    @r0
    nop
    .endf

    LEAF_ENTRY _DebugBreak
    trapa    #1
    rts
    nop
    .endf

    .end