Advanced Queuing - Oracle

AQ and Memory Usage
/* Allocate an instance of SCOTT.MESSAGE, and get its null indicator: */
checkerr(errhp, OCIObjectNew(envhp, errhp, svchp, OCI_TYPECODE_OBJECT,
mesgtdo, (dvoid *)0, OCI_DURATION_SESSION,
TRUE, (dvoid **)&mesg));
checkerr(errhp, OCIObjectGetInd(envhp, errhp, (dvoid *)mesg,
(dvoid **)&mesgind));
/* Allocate a descriptor for dequeue options and set wait time, navigation: */
checkerr(errhp, OCIDescriptorAlloc(envhp, (dvoid **)&deqopt,
OCI_DTYPE_AQDEQ_OPTIONS, 0, (dvoid **)0));
checkerr(errhp, OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS,
(dvoid *)&wait, 0, OCI_ATTR_WAIT, errhp));
checkerr(errhp, OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS,
(dvoid *)&navigation, 0,
OCI_ATTR_NAVIGATION, errhp));
/* Dequeue the message and commit: */
checkerr(errhp, OCIAQDeq(svchp, errhp, (CONST text *)"msgqueue",
deqopt, 0, mesgtdo, (dvoid **)&mesg,
(dvoid **)&mesgind, 0, 0));
checkerr(errhp, OCITransCommit(svchp, errhp, (ub4) 0));
/* Copy the message payload text into the user buffer: */
if (mesgind->null_data)
*buflen = 0;
else
memcpy((dvoid *)buf, (dvoid *)OCIStringPtr(envhp, mesg->data),
(size_t)(*buflen = OCIStringSize(envhp, mesg->data)));
/* Free the dequeue options descriptor: */
checkerr(errhp, OCIDescriptorFree((dvoid *)deqopt, OCI_DTYPE_AQDEQ_OPTIONS));
/* Free the memory for the objects: */
Checkerr(errhp, OCIObjectFree(envhp, errhp, (dvoid *)mesg,
OCI_OBJECTFREE_FORCE));
} /* end deqmesg */
void main()
{
OCIServer *srvhp;
OCISession *usrhp;
dvoid *tmp;
text buf[80]; /* payload text */
A-74 Oracle9i Application Developer’s Guide - Advanced Queuing