_interlockedbittestandset, _interlockedbittestandset64

Microsoft Specific

Generate the lock bts instruction, which examines bit b of the address a and returns its current value before setting it to 1.

unsigned char _interlockedbittestandset(
   long *a,
   long b
);
unsigned char _interlockedbittestandset64(
   __int64 *a,
   __int64 b
);

Parameters

• [in] a
  A pointer to the memory to examine.

• [in] b
  The bit position to test.

Return Value

The bit at the position specified before it is set.

Requirements

Header file <intrin.h>

Remarks

As a result of the lock bts instruction, the bit is set to 1. The operation is atomic.

These functions behave as read-write memory barriers. For more information, see _ReadWriteBarrier.

This routine is only available as an intrinsic.

See Also

Reference

Compiler Intrinsics

Conflicts with the x86 Compiler

Change History