openfam::fam::fam_fetch_or
Atomically replaces a value in FAM with the Bitwise OR of that value and some given value, and returns the old value.
Synopsis
uint32_t fam_fetch_or(Fam_Descriptor *descriptor, uint64_t offset, uint32_t value);
uint64_t fam_fetch_or(Fam_Descriptor *descriptor, uint64_t offset, uint64_t value);
Description
These methods atomically replaces a value in FAM with the Bitwise OR of the value given and the existing value. The old value is returned.
Input Arguments
Name | Description |
---|---|
descriptor | Descriptor associated with the data item. |
offset | Offset within the data item in FAM where value is located. |
value | Value to be combined with the existing value at the given location. |
Return Values
The old value from FAM. Throws Fam_Exception
on
error.
Fam Error Numbers
Error | Description |
---|---|
FAM_ERR_INVALID | API called with incorrect parameters. |
FAM_ERR_NOPERM | Caller does not have access rights. |
FAM_ERR_LIBFABRIC | Libfabric error occurred. |
FAM_ERR_NOTFOUND | Item not found in the region. |
FAM_ERR_RPC | Communication error from grpc layer. |
FAM_ERR_RPC_CLIENT_NOTFOUND | RPC service not available. |
FAM_ERR_METADATA | Metadata service error. |
FAM_ERR_MEMORY | Memory service error. |
FAM_ERR_RESOURCE | Resource not available. |
FAM_ERR_TIMEOUT | Number of libfabric retry count reached. |
Notes
These methods atomically replace a value in FAM with the Bitwise OR of that value and the value given in the method. The old value is returned. 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.
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 Fam_Descriptor *descriptor = myFam->fam_lookup("myItem", "myRegion"); // Atomically replace the first element of the array with // the Bitwise OR of it and a value of 0x444 uint32_t oldValue = myFam->fam_fetch_or(descriptor, 0, 0x0444); // The first integer in FAM is now bitwise OR 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 }