InterlockedDecrementAcquire function

Decrements (decreases by one) the value of the specified 32-bit variable as an atomic operation. The operation is performed with acquire memory ordering semantics.

Syntax

LONG __cdecl InterlockedDecrementAcquire(
  _Inout_ LONG volatile *Addend
);

Parameters

  • Addend [in, out]
    A pointer to the variable to be decremented.

Return value

The function returns the resulting decremented value.

Remarks

The variable pointed to by the Addend parameter must be aligned on a 32-bit boundary; otherwise, this function will behave unpredictably on multiprocessor x86 systems and any non-x86 systems. See _aligned_malloc.

The interlocked functions provide a simple mechanism for synchronizing access to a variable that is shared by multiple threads. This function is atomic with respect to calls to other interlocked functions.

This function is implemented using a compiler intrinsic where possible. For more information, see the WinBase.h header file and _InterlockedDecrement_acq.

Note  This function is supported on Windows RT-based systems.

 

For processors that do not support acquire memory ordering semantics, this function is defined as a call to the InterlockedDecrement function. For more information, see WinBase.h.

Requirements

Minimum supported client

Windows Vista [desktop apps | UWP apps]

Minimum supported server

Windows Server 2003 [desktop apps | UWP apps]

Header

WinBase.h (include Windows.h)

See also

Interlocked Variable Access

InterlockedDecrement

InterlockedDecrementRelease

InterlockedDecrementNoFence

InterlockedDecrement16

InterlockedDecrement16Acquire

InterlockedDecrement16Release

InterlockedDecrement16NoFence

InterlockedDecrement64

InterlockedDecrementAcquire64

InterlockedDecrementRelease64

InterlockedDecrementNoFence64

Synchronization Functions