Re: [HACKERS] postmaster.pid - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] postmaster.pid
Date
Msg-id 199912030806.DAA07950@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] postmaster.pid  (Tatsuo Ishii <t-ishii@sra.co.jp>)
Responses Re: [HACKERS] postmaster.pid
List pgsql-hackers
> > > I have committed changes to postmaster.c. Now it creates a file called
> > > "postmaster.pid" under $PGDATA, which holds postmaster's process
> > > id. If the file has already existed, postmaster won't start. So we
> > > cannot start more than on postmaster with same $PGDATA any more. I
> > > believe it's a good thing. The file will be deleted upon postmaster
> > > shutting down.
> > 
> > I assume you do a kill(0) on the pid if the file exists on startup to
> > check to see if the pid is still valid?
> 
> A little bit different.
> 
> 1) if the port is already in use, postmaster exits (same as before)

OK

> 2) if it fails to create pid file, call
> ExitPostmaster(1). ExitPostmaster calls proc_exit() and proc_exit
> calls exit().

So you don't start if the pid file is there, or do you delete it if the
port is free?

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
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