BPX4QGT (msgget) example

The following code creates a private message queue. For the callable service, see msgget (BPX1QGT, BPX4QGT) — Create or find a message queue. For the data structure, see BPXYMSG — Map interprocess communication message queues. AMODE 31 callers use BPX1QGT (msgget) example.

                                              
         MVI   S_TYPE,IPC_CREAT+IPC_EXCL     Error if exists            
         MVI   S_MODE1,0             Not used                           
         MVI   S_MODE2,S_IRUSR       All read and write permissions     
         MVI   S_MODE3,S_IWUSR+S_IRGRP+S_IWGRP+S_IROTH+S_IWOTH          
         SPACE ,                                                        
         CALL  BPX4QGT,              Create a message queue            +
               (=A(IPC_PRIVATE),     Input: Key                        +
               S_MODE,               Input: Creation flags BPXYMODE/IPC+
               RETVAL,               Return value: -1 or msg ID  +532200
               RETCODE,              Return code                       +
               RSNCODE),             Reason code                       +
               MF=(E,PLIST)          ---------------------------------- 
         SPACE ,                                                        
         ICM   R15,B'1111',RETVAL    Test return value                  
         BNP   PSEUDO                Branch on msgget failure           
         ST    R15,MSG_ID            Store MSG_ID associated with key