Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jpl-devvax!david
From: david@jpl-devvax.JPL.NASA.GOV (David E. Smyth)
Newsgroups: comp.windows.x
Subject: Re: Maximum number of XOpenDisplay() allowed by a client.
Message-ID: <7152@jpl-devvax.JPL.NASA.GOV>
Date: 23 Feb 90 15:36:11 GMT
References: <3002@soleil.oakhill.UUCP> <9002230051.AA13764@expo.lcs.mit.edu>
Reply-To: david@jpl-devvax.JPL.NASA.GOV (David E. Smyth)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 45

In article <9002230051.AA13764@expo.lcs.mit.edu> converse@EXPO.LCS.MIT.EDU (Donna Converse) writes:
>
>> Is there any limitations on the number
>> of displays a client can open at one time?
>
>What happens when you run this?
>
> [ program deleted ]

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Xlib:  connection to "unix:0.0" refused by server
Xlib:  Maximum number of clients reached

Above on X11R4 on a Sun 3/460 running 4.0.3.  

This can occur because an xalloc failed (the server ran out of memory,
should rarely happen), or if too many file descriptors have been
opened.  For HP machines, this is a #define (_NFILE), for others the
max number of descriptors available to a process (i.e., the number of
descriptors the server can have open) is obtained by from
getdtablesize(2):

NAME
     getdtablesize - get descriptor table size

SYNOPSIS
     nds = getdtablesize()
     int nds;

DESCRIPTION
     Each process has a fixed size  descriptor  table,  which  is
     guaranteed  to  have  at least 20 slots.  The entries in the
     descriptor table are numbered with small  integers  starting
     at  0.   The  call  getdtablesize() returns the size of this
     table.

see mit/server/os/4.2bsd/connection.c