Source code of Windows XP (NT5)
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/*++
Copyright (c) 2000 Microsoft Corporation
Module Name:
intbits.c
Abstract:
This module contains routines to do interlocked bit manipulation
Author:
Neill Clift (NeillC) 12-May-2000
Environment:
User and kernel mode.
Revision History:
Rob Earhart (earhart) October 13, 2000
Moved from Ex to Rtl
--*/
#include "ntrtlp.h"
#pragma hdrstop
#undef RtlInterlockedSetBits
NTKERNELAPI
ULONG
FASTCALL
RtlInterlockedSetBits (
IN OUT PULONG Flags,
IN ULONG Flag
)
/*++
Routine Description:
This function atomically sets the specified flags in the target
Arguments:
Flags - Pointer to variable containing current mask.
Flag - Flags to set in target
Return Value:
ULONG - Old value of mask before modification
--*/
{
ULONG NewFlags, OldFlags;
OldFlags = *Flags;
NewFlags = OldFlags | Flag;
while (NewFlags != OldFlags) {
NewFlags = InterlockedCompareExchange ((PLONG) Flags, (LONG) NewFlags, (LONG) OldFlags);
if (NewFlags == OldFlags) {
break;
}
OldFlags = NewFlags;
NewFlags |= Flag;
}
return OldFlags;
}
#undef RtlInterlockedClearBits
NTKERNELAPI
ULONG
FASTCALL
RtlInterlockedClearBits (
IN OUT PULONG Flags,
IN ULONG Flag
)
/*++
Routine Description:
This function atomically clears the specified flags in the target
Arguments:
Flags - Pointer to variable containing current mask.
Flag - Flags to clear in target
Return Value:
ULONG - Old value of mask before modification
--*/
{
ULONG NewFlags, OldFlags;
OldFlags = *Flags;
NewFlags = OldFlags & ~Flag;
while (NewFlags != OldFlags) {
NewFlags = InterlockedCompareExchange ((PLONG) Flags, (LONG) NewFlags, (LONG) OldFlags);
if (NewFlags == OldFlags) {
break;
}
OldFlags = NewFlags;
NewFlags &= ~Flag;
}
return OldFlags;
}
#undef RtlInterlockedSetClearBits
NTKERNELAPI
ULONG
FASTCALL
RtlInterlockedSetClearBits (
IN OUT PULONG Flags,
IN ULONG sFlag,
IN ULONG cFlag
)
/*++
Routine Description:
This function atomically sets and clears the specified flags in the target
Arguments:
Flags - Pointer to variable containing current mask.
sFlag - Flags to set in target
CFlag - Flags to clear in target
Return Value:
ULONG - Old value of mask before modification
--*/
{
ULONG NewFlags, OldFlags;
OldFlags = *Flags;
NewFlags = (OldFlags | sFlag) & ~cFlag;
while (NewFlags != OldFlags) {
NewFlags = InterlockedCompareExchange ((PLONG) Flags, (LONG) NewFlags, (LONG) OldFlags);
if (NewFlags == OldFlags) {
break;
}
OldFlags = NewFlags;
NewFlags = (NewFlags | sFlag) & ~cFlag;
}
return OldFlags;
}