openfam::fam::fam_max

Atomically replace a value in FAM with the maximum of it and some given value.

Synopsis

void fam_max(Fam_Descriptor *descriptor, uint64_t offset, int32_t value);

void fam_max(Fam_Descriptor *descriptor, uint64_t offset, int64_t value);

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

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

void fam_max(Fam_Descriptor *descriptor, uint64_t offset, float value);

void fam_max(Fam_Descriptor *descriptor, uint64_t offset, double value);

Description

These methods atomically replace a value in FAM with the maximum 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 larger 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 set the maximum value for the first integer element in the array
		myFam->fam_max(descriptor, 0, 100);
	
		// ensure that the max operation is complete
		myFam->fam_quiet();
	
		// The first integer in FAM is now the maximum of its previous value and 100
	 } catch (Fam_Exception &e) {
		printf("fam API failed: %d: %s\n", e.fam_error(), e.fam_error_msg());
	 }

	 // ... Finalization code follows
}