Dynamically calling the WebSphere MQ stub

Instead of link-editing the WebSphere MQ stub program with your object code, we can dynamically call the stub from within your program. We can do this in the batch, IMS™, and CICS environments. This facility is not supported by programs using PL/I in the CICS environment and it is not supported in the RRS environment.

If you call the stub dynamically, the appropriate stub program and its aliases must be available at execution time. To ensure this, include the WebSphere MQ for z/OS data set SCSQLOAD:

For IMS, ensure that the library containing the dynamic stub (built as described in the information about installing the IMS adapter in the WebSphere MQ for z/OS System Setup Guide) is ahead of the data set SCSQLOAD in the STEPLIB concatenation of the region JCL.

Use the names shown in Table 1 when you call the stub dynamically. In PL/I, only declare the call names used in your program.

Call names for dynamic linking
MQI call	Dynamic call name
	Batch (non-RRS)	CICS	IMS
MQBACK	CSQBBACK	not supported	not supported
MQCMIT	CSQBCOMM	not supported	not supported
MQCLOSE	CSQBCLOS	CSQCCLOS	MQCLOSE
MQCONN	CSQBCONN	CSQCCONN	MQCONN
MQCONNX	CSQBCONX	CSQCCONX	MQCONNX
MQDISC	CSQBDISC	CSQCDISC	MQDISC
MQGET	CSQBGET	CSQCGET	MQGET
MQINQ	CSQBINQ	CSQCINQ	MQINQ
MQOPEN	CSQBOPEN	CSQCOPEN	MQOPEN
MQPUT	CSQBPUT	CSQCPUT	MQPUT
MQPUT1	CSQBPUT1	CSQCPUT1	MQPUT1
MQSET	CSQBSET	CSQCSET	MQSET

Figure 1. Dynamic linking using COBOL in the batch environment

⋮
       WORKING-STORAGE SECTION.
⋮
          05 WS-MQOPEN                     PIC X(8) VALUE 'CSQBOPEN'.
⋮
       PROCEDURE DIVISION.
⋮
           CALL WS-MQOPEN WS-HCONN
                          MQOD
                          WS-OPTIONS
                          WS-HOBJ
                          WS-COMPCODE
                          WS-REASON.
⋮

Figure 2. Dynamic linking using COBOL in the CICS environment

⋮
       WORKING-STORAGE SECTION.
⋮
          05 WS-MQOPEN                     PIC X(8) VALUE 'CSQCOPEN'.
⋮
       PROCEDURE DIVISION.
⋮
           CALL WS-MQOPEN WS-HCONN
                          MQOD
                          WS-OPTIONS
                          WS-HOBJ
                          WS-COMPCODE
                          WS-REASON.
⋮

Figure 3. Dynamic linking using COBOL in the IMS environment

⋮
       WORKING-STORAGE SECTION.
⋮
          05 WS-MQOPEN                     PIC X(8) VALUE 'MQOPEN'.
⋮
       PROCEDURE DIVISION.
⋮
           CALL WS-MQOPEN WS-HCONN
                          MQOD
                          WS-OPTIONS
                          WS-HOBJ
                          WS-COMPCODE
                          WS-REASON.
⋮
      * ----------------------------------------------------------- *
      *
      *    If the compile option 'DYNAM' is specified
      *    then you may code the MQ calls as follows
      *
      * ----------------------------------------------------------- *
⋮
           CALL 'MQOPEN'  WS-HCONN
                          MQOD
                          WS-OPTIONS
                          WS-HOBJ
                          WS-COMPCODE
                          WS-REASON.
⋮

Figure 4. Dynamic linking using assembler language in the batch environment

⋮
         LOAD   EP=CSQBOPEN
⋮
         CALL (15),(HCONN,MQOD,OPTIONS,HOBJ,COMPCODE,REASON),VL
⋮
         DELETE EP=CSQBOPEN
⋮

Figure 5. Dynamic linking using assembler language in the CICS environment

⋮
         EXEC CICS LOAD PROGRAM('CSQCOPEN') ENTRY(R15)
⋮
         CALL (15),(HCONN,MQOD,OPTIONS,HOBJ,COMPCODE,REASON),VL
⋮
         EXEC CICS RELEASE PROGRAM('CSQCOPEN')
⋮

Figure 6. Dynamic linking using assembler language in the IMS environment

⋮
         LOAD   EP=MQOPEN
⋮
         CALL (15),(HCONN,MQOD,OPTIONS,HOBJ,COMPCODE,REASON),VL
⋮
         DELETE EP=MQOPEN
⋮

Figure 7. Dynamic linking using C language in the batch environment

⋮
typedef void CALL_ME();
#pragma linkage(CALL_ME, OS)
⋮
main()
{
CALL_ME * csqbopen;
⋮
csqbopen = (CALL_ME *) fetch("CSQBOPEN");
(*csqbopen)(Hconn,&ObjDesc,Options,&Hobj,&CompCode,&Reason);
⋮

Figure 8. Dynamic linking using C language in the CICS environment

⋮
typedef void CALL_ME();
#pragma linkage(CALL_ME, OS)
⋮
main()
{
CALL_ME * csqcopen;
⋮
  EXEC CICS LOAD PROGRAM("CSQCOPEN") ENTRY(csqcopen);
(*csqcopen)(Hconn,&ObjDesc,Options,&Hobj,&CompCode,&Reason);
⋮

Figure 9. Dynamic linking using C language in the IMS environment

⋮
typedef void CALL_ME();
#pragma linkage(CALL_ME, OS)
⋮
main()
{
CALL_ME * mqopen;
⋮
mqopen = (CALL_ME *) fetch("MQOPEN");
(*mqopen)(Hconn,&ObjDesc,Options,&Hobj,&CompCode,&Reason);
⋮

Figure 10. Dynamic linking using PL/I in the batch environment

⋮
      DCL CSQBOPEN ENTRY EXT OPTIONS(ASSEMBLER INTER);
⋮
      FETCH CSQBOPEN;

      CALL CSQBOPEN(HQM,
                    MQOD,
                    OPTIONS,
                    HOBJ,
                    COMPCODE,
                    REASON);

      RELEASE CSQBOPEN;

Figure 11. Dynamic linking using PL/I in the IMS environment

⋮
      DCL MQOPEN   ENTRY EXT OPTIONS(ASSEMBLER INTER);
⋮
      FETCH MQOPEN;

      CALL   MQOPEN(HQM,
                    MQOD,
                    OPTIONS,
                    HOBJ,
                    COMPCODE,
                    REASON);

      RELEASE   MQOPEN;

Parent topic:

Building your application on z/OS

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For batch and IMS	In the STEPLIB concatenation of the JCL
For CICS	In the CICS DFHRPL concatenation

Batch and COBOL	Figure 1
CICS and COBOL	Figure 2
IMS and COBOL	Figure 3
Batch and assembler	Figure 4
CICS and assembler	Figure 5
IMS and assembler	Figure 6
Batch and C	Figure 7
CICS and C	Figure 8
IMS and C	Figure 9
Batch and PL/I	Figure 10
IMS and PL/I	Figure 11