Jobs continue to run but the events will be queued(the first time a job sends data it will 'lock' its read buffer, `alloc_cb` always return buf->len == 0.. If `os_call_shell` runs for long enough then it's possible that the OS buffer for the job will be full, which will cause the job process to :

- block if it uses blocking writes
- receive EAGAIN if it's writing with O_NONBLOCK

It would normalize once `os_call_shell` returns