openfam::fam::fam_xor

Atomically replace a value in FAM with the Bitwise XOR of that value and some given value.

Synopsis

void fam_xor(Fam_Descriptor *descriptor, uint64_t offset, uint32_t value);

void fam_xor(Fam_Descriptor *descriptor, uint64_t offset, uint64_t value);

Description

These methods atomically replace a value in FAM with the Bitwise XOR of the value given and the existing value.

Input Arguments

Return Values

None. Throws Fam_Exception on error.

Fam Error Numbers

Notes

These methods atomically replace a value in FAM with the Bitwise XOR of the existing value and the value given in the method, and return before the operation is complete. Note that the offset argument must point to the correct value for the data type. Availability of these methods is dependent on hardware support for the operations.

Successful completion of a subsequent fam_quiet() call ensures the completion of this atomic operation.

Example

#include <string.h>
#include <fam/fam.h>
#include <fam/fam_exception.h>
using namespace std;
using namespace openfam;

int main(void) {
	fam *myFam = new fam();

	// ... Initialization code here

	try {
		// look up the descriptor to a previously allocated data item
		// (an integer array with at least 10 elements)
		Fam_Descriptor *descriptor = myFam->fam_lookup("myItem", "myRegion");
	
		// Atomically replace a value of first integer element in the array
		// with the Bitwise XOR of it and a value of 0x444
		uint32_t value = 0x444;
		myFam->fam_xor(descriptor, 0, value);
	
		// ensure that the OR operation is complete
		myFam->fam_quiet();
	
		// The first integer in FAM is now bitwise XOR with a value of 0x444
	
		// ... subsequent code here
	} catch (Fam_Exception &e) {
		printf("fam API failed: %d: %s\n", e.fam_error(), e.fam_error_msg());
	}
	
	// ... Finalization code follows
}