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45 lines
1.4 KiB
C
45 lines
1.4 KiB
C
/** @file
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InterlockedCompareExchange64 function
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Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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/**
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Performs an atomic compare exchange operation on a 64-bit unsigned integer.
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Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
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by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
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CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
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The compare exchange operation must be performed using MP safe mechanisms.
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@param Value A pointer to the 64-bit value for the compare exchange
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operation.
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@param CompareValue A 64-bit value used in a compare operation.
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@param ExchangeValue A 64-bit value used in an exchange operation.
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@return The original *Value before exchange.
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**/
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UINT64
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EFIAPI
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InternalSyncCompareExchange64 (
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IN volatile UINT64 *Value,
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IN UINT64 CompareValue,
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IN UINT64 ExchangeValue
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)
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{
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_asm {
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mov esi, Value
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mov eax, dword ptr [CompareValue + 0]
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mov edx, dword ptr [CompareValue + 4]
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mov ebx, dword ptr [ExchangeValue + 0]
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mov ecx, dword ptr [ExchangeValue + 4]
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lock cmpxchg8b qword ptr [esi]
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}
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}
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