should be 2).

LSF seems to work this way, so we allow it, but it does seem 
dangerous.

Potential data structure access without lock.
Make some code conform with Linux kernel coding standard.

clear jobid from batch request unless explicitly set on command line 
  (don't use SLURM_JOBID env var). permits submitting new batch job from 
  within an existing job allocation.

srun execute line.

expliclty set on srun execute line, do not re-use it from 
the SLURM_JOBID env var (which prevents submitting a 
series of batch jobs).

(not yet fully implemented).

than SlurmUser or root.

in some xcpu implementations (e.g. SIGKILL not 9).

Warn user attempting to create a job allocation from within an existing job
    allocation.

within a currenly active job.

write fails.

nodes or partitions.

Keep job in completing state until all spawned tasks are terminated.