z/OS Communications Server: SNA Programmer's LU 6.2 Guide
Previous topic | Next topic | Contents | Contact z/OS | Library | PDF


Using APPCCMD CONTROL=RECEIVE, QUALIFY=ANY|IANY

z/OS Communications Server: SNA Programmer's LU 6.2 Guide
SC27-3669-00

The APPCCMD CONTROL=RECEIVE, QUALIFY=ANY|IANY macroinstructions receive normal information that is available from any conversation that is in continue-any mode. The macroinstruction completes with the first conversation that is in continue-any mode and receives that data.

When data is ready to be received on a continue-any mode conversation, VTAM® copies the data into the data area that is specified on the AREA parameter and completes the macroinstruction. The conversation identifier for the conversation used to complete the macroinstruction is placed in the CONVID field.

The QUALIFY=IANY macroinstruction receives normal information that is immediately available from any conversation that is in continue-any mode. VTAM does not wait for other data before completing this macroinstruction. If there are no conversations in continue-any mode with normal information available, the macroinstruction is completed with an RCPRI, RCSEC combination of X'0000', X'0008', NO_INFORMATION_IMMEDIATELY_AVAILABLE.

When these macroinstructions are issued, VTAM copies data that is available into the supplied data area or control block that is specified by the AREA parameter. VTAM also returns the identification of the conversation that satisfied the macroinstruction in the CONVID parameter.

The APPCCMD CONTROL=RECEIVE, QUALIFY=ANY|IANY macroinstructions allow an application program to monitor several conversations simultaneously with a single macroinstruction.

Typically, an application program uses conversations in continue-any mode to determine which of several conversations has received a transaction to process. However, the application program does not process the transaction while the conversation remains in continue-any mode because the macroinstruction might receive data on another conversation in the middle of a transaction, or the data may become out of order.

To avoid this problem, an application program can change the conversation from continue-any mode when data is received for that conversation. This ensures that the application program can process an entire transaction at one time. The application program specifies a continuation mode of continue specific on the macroinstruction. When data on a continue-any conversation is met by the QUALIFY=ANY|IANY macroinstruction, the conversation's identifier is returned to the application program in RPL6CNVD, and the conversation is put into continue-specific mode. The application program can then issue APPCCMD CONTROL=RECEIVE, QUALIFY=SPEC|ISPEC to finish processing the transaction.

Go to the previous page Go to the next page




Copyright IBM Corporation 1990, 2014