The QIBM_CHILD_JOB_SNDINQMSG environment variable is the variable that controls whether the batch immediate (BCI) job, where the Java™ virtual machine runs, waits before starting the Java virtual machine.
If you set the environment variable to 1 when the Run Java (RUNJVA) command runs, a message is sent to the user's message queue. The message is sent before the Java virtual machine starts in the BCI job. The message looks like this:
Spawned (child) process 023173/JOB/QJVACMDSRV is stopped (G C)
To view this message, enter SYSREQ and select option 4.
The BCI job waits until you enter a reply to this message. A reply of (G) starts the Java virtual machine.
You can set breakpoints in a *SRVPGM or *PGM, which the BCI job calls, before replying to the message.