Asynchronous request

After you issue an asynchronous request for access to a data set, VSAM sets a return code in register 15 to indicate whether the request was accepted. Table 1 describes each return code returned in register 15.

Table 1. Return Code in Register 15 Following an Asynchronous Request
Return Code (RPLRTNCD)	Meaning
0(X'0')	Request was accepted.
4(X'4')	Request was not accepted because the request parameter list indicated by the request (RPL=address) was active for another request.

If the asynchronous request was accepted, issue a CHECK after doing your other processing. This way VSAM can indicate in register 15 whether the request was completed successfully, set a return code in the feedback area, and exit to any appropriate exit routine.

If the request was not accepted, you should either wait until the other request is complete (for example, by issuing a CHECK on the request parameter list) or terminate the other request (using ENDREQ). Then you can reissue the rejected request.