This program illustrates how to use APIs to create and manipulate a user queue.
/*********************************************************************/
/* */
/*Program Name: UQUEUEX */
/* */
/*Program Language: ILE C */
/* */
/*Description: This program illustrates how to use APIs to create */
/* and manipulate a user queue. */
/* */
/* */
/*Header Files Included: <stdio.h> */
/* <signal.h> */
/* <string.h> */
/* <stdlib.h> */
/* <miptrnam.h> */
/* <miqueue.h> */
/* <pointer.h> */
/* <quscrtuq.h> */
/* <qusdltuq.h> */
/* <qusec.h> */
/* */
/*APIs Used: QUSCRTUQ - Create a user queue */
/* QUSDLTUQ - Delete a user queue */
/* */
/*********************************************************************/
/*********************************************************************/
/*********************************************************************/
/* Includes */
/*********************************************************************/
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#include <milib.h> /* from QCLE/h */
#include <miptrnam.h> /* from QCLE/h */
#include <miqueue.h> /* from QCLE/h */
#include <pointer.h>
#include <quscrtuq.h> /* from QSYSINC/h */
#include <qusdltuq.h> /* from QSYSINC/h */
#include <qusec.h> /* from QSYSINC/h */
/*********************************************************************/
/* Structures */
/*********************************************************************/
typedef struct {
Qus_EC_t ec_fields;
char exception_data[100];
} error_code_struct;
/*********************************************************************/
/* */
/* Main */
/* */
/*********************************************************************/
void main()
{
char text_desc[50];
error_code_struct error_code;
_SYSPTR queuelib_sysptr,
user_queue_obj_sysptr;
_RSLV_Template_T rslvsp_template;
_ENQ_Msg_Prefix_T enq_msg_prefix;
_DEQ_Msg_Prefix_T deq_msg_prefix;
char enq_msg[50],
deq_msg[50];
int success=0;
/*******************************************************************/
/* Create a library to create the user queue into. */
/*******************************************************************/
system("CRTLIB LIB(QUEUELIB)");
/*******************************************************************/
/* Initialize the error code parameter. */
/*******************************************************************/
error_code.ec_fields.Bytes_Provided=sizeof(error_code_struct);
/*******************************************************************/
/* Call the QUSCRTUQ API to create a user queue. */
/* */
/* This will create a user queue called EXAMPLEQ in library */
/* QUEUELIB, with the following attributes: */
/* */
/* 1. Extended attribute of "VALID ", which could have */
/* been any valid *NAME. */
/* 2. A queue type of "F", or First-in, first-out. */
/* 3. A key length of 0. If the queue is not keyed, this */
/* value must be 0. */
/* 4. A maximum message size of 10 bytes. This number can */
/* be as large as 64K bytes. */
/* 5. The initial number of messages set to 10. */
/* 6. Additional number of messages set to 10. */
/* 7. Public authority of *USE. */
/* 8. A valid text description. */
/* 9. Replace option of *YES. This means that if a user queue */
/* already exists by the name specified, in the library */
/* specified, that it will be replaced by this */
/* request. */
/* 10. Domain value of *USER. */
/* 11. Pointer value of *NO. Messages in the queue cannot */
/* contain pointer data. */
/*******************************************************************/
memcpy(text_desc, "THIS IS TEXT FOR THE EXAMPLE USER QUEUE ",
50);
QUSCRTUQ("EXAMPLEQ QUEUELIB ", /* Qualified user queue name */
"VALID ", /* Extended attribute */
"F", /* Queue type */
0, /* Key length */
10, /* Maximum message size */
10, /* Initial number of messages */
10, /* Additional number of messages */
"*ALL ", /* Public authority */
text_desc, /* Text Description */
"*YES ", /* Replace existing user queue */
&error_code, /* Error code */
"*USER ", /* Domain of user queue */
"*NO "); /* Allow pointer data */
/*******************************************************************/
/* If an exception occurred, the API would have returned the */
/* exception in the error code parameter. The bytes available */
/* field will be set to zero if no exception occurred and greater */
/* than zero if an exception did occur. */
/*******************************************************************/
if (error_code.ec_fields.Bytes_Available > 0)
{
printf("ATTEMPT TO CREATE A USER QUEUE FAILED WITH EXCEPTION:%.7s",
error_code.ec_fields.Exception_Id);
exit(1);
}
/*******************************************************************/
/* Send information to the queue. */
/* */
/* We will need to use MI instructions to accomplish this. */
/* There are three steps that must be done: */
/* */
/* 1. Resolve a system pointer to the library containing the user */
/* queue object. */
/* 2. Using the system pointer to the library, resolve a system */
/* pointer to user queue object in the library. */
/* 3. Enqueue the entry using the system pointer for the user */
/* queue. */
/* */
/*******************************************************************/
/*******************************************************************/
/* First we must resolve to library QUEUELIB. */
/*******************************************************************/
memset(rslvsp_template.Obj.Name,' ',30);
memcpy(rslvsp_template.Obj.Name,"QUEUELIB",8);
rslvsp_template.Obj.Type_Subtype = _Library; /* found in milib.h */
rslvsp_template.Auth = _AUTH_NONE; /* found in milib.h */
_RSLVSP6(&queuelib_sysptr, /* system pointer to be set */
&rslvsp_template, /* resolve template */
&rslvsp_template.Auth); /* authority to set in sysptr */
/*******************************************************************/
/* We can now resolve to the user queue object. We will pass the */
/* system pointer to library QUEUELIB to RSLVSP so the resolve */
/* will only search library QUEUELIB for the user queue object. */
/* This is necessary so that we ensure that we are using the */
/* correct object. */
/*******************************************************************/
memset(rslvsp_template.Obj.Name,' ',30);
memcpy(rslvsp_template.Obj.Name, "EXAMPLEQ", 8);
rslvsp_template.Obj.Type_Subtype = _Usrq; /* found in milib.h */
rslvsp_template.Auth = _AUTH_ALL; /* found in milib.h */
_RSLVSP8(&user_queue_obj_sysptr, /* system pointer to be set */
&rslvsp_template, /* resolve template */
&queuelib_sysptr, /* sysptr to library */
&rslvsp_template.Auth); /* authority to set in sysptr */
/*******************************************************************/
/* Enqueue the entry. */
/*******************************************************************/
enq_msg_prefix.Msg_Len = 10;
enq_msg_prefix.Msg[0] = '\0'; /* Only used for keyed queues*/
memcpy(enq_msg, "EXAMPLE ", 10);
_ENQ(&user_queue_obj_sysptr, /* system pointer to user queue */
&enq_msg_prefix, /* message prefix */
(_SPCPTR)enq_msg); /* message text */
/*******************************************************************/
/* Dequeue the entry. */
/*******************************************************************/
success = _DEQI(&deq_msg_prefix, /* message prefix */
(_SPCPTR)deq_msg, /* message text */
&user_queue_obj_sysptr); /* sys ptr to user queue */
if(success)
{
printf("Queue entry information: %.10s\n", deq_msg);
}
else
{
printf("Entry not dequeued\n");
}
/*******************************************************************/
/* Delete the user queue. */
/*******************************************************************/
QUSDLTUQ("EXAMPLEQ QUEUELIB ", /* Qualified user queue name */
&error_code); /* Error code */
/*******************************************************************/
/* If an exception occurred, the API would have returned the */
/* exception in the error code parameter. The bytes available */
/* field will be set to zero if no exception occurred and greater */
/* than zero if an exception did occur. */
/*******************************************************************/
if (error_code.ec_fields.Bytes_Available > 0)
{
printf("ATTEMPT TO DELETE A USER QUEUE FAILED WITH EXCEPTION:%.7s",
error_code.ec_fields.Exception_Id);
exit(1);
}
/*******************************************************************/
/* Delete the library created for this example. */
/*******************************************************************/
system("DLTLIB LIB(QUEUELIB)");
}