Re: Question about NML

[Will Shackleford <shackle-at-cme.nist.gov>]

The master field is intended to specify the process that will come up first.
On some operating systems one can not have two processes trying to create and initialize the shared memory segments and associated semaphores at the same time without risking a possible mutual exclusion violation. (In Linux, whether it safe to have 2 masters depends on which version of GLIBC,kernel and rcslib you have.)

Generally I recommend people choose only one process to be the master as it is reliable and portable, but there are times when some have complained this is inconvenient.

If a process which is not the master is started first the NML->valid() check will return 0 and the error message "CMS_NO_MASTER_ERROR: An error occured becouse the master was not started." printed.

-- Will




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William Penn Shackleford III			shackle-at-nist.gov
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