Another approach is to write a wrapper script (in Perl) to run each job. That wrapper script attempts to claim a semaphore that has a maximum count of 3. The attempt will block if there are 3 (or more) jobs running. After claiming the semaphore the job is run, then (important) it releases the semaphore, which should allow a waiting job to run.

See perlipc.

In reply to Re: Implement Queue mechanism in Perl by cdarke
in thread Implement Queue mechanism in Perl by doubledecker

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