reset/terminate problems; preventing multiple XWin instances

cygwinx2eran@tromer.org cygwinx2eran@tromer.org
Wed Mar 3 21:54:00 GMT 2004


Hi,

On 29-02-2004 14:11, Takuma Murakami wrote:

 >> As for preventing multiple instances of XWin
 > This feature is already implemented in my local tree (not
 > port based but mutex based detection).

I see that it's in 4.3.0-50 and working well, but I don't see how the 
current implementation addresses the common task I mentioned:
   "open an xterm; run XWin first if needed"
If I use a batchfile that always runs XWin and then xterm, from the 2nd 
invocation onwards it will produce the error popup reporting a "Fatal 
error" and directing me a to log file... Not quite what's needed here.[1]

Perhaps there should be a switch that says "if the display already 
exists, exit silently".

But that doesn't solve the case where I want to run additional programs 
(say, twm and xeyes) whenever a new display is created -- again a common 
scenario, I believe. One way to solve this is to add an option for 
checking the presence of an XWin instance on the given display number 
and exiting immediately with a corresponding errorcode; a batchfile can 
then check for the existance of an XWin instance, and if negative spawn 
XWin and related stuff. But this could lead to a race condition if two 
batchfiles do the check simultaneously. An alternative is to add an 
option for XWin to run some executable iff its startup succeeded.

Yes, I realize this is getting somewhat convoluted, but I think it's an 
important and common use case. I'm trying to move a certain large group 
of people to Cygwin/X, and the issue of "transparently" invoking 
Cygwin/X is one of the two major issues holding things back (the other 
one is multiwindow mode performance).

Regards,
   Eran


[1] For extra helpfulness, perhaps you could specify the nature of the 
fatal error at a prominent location inside the dialog box and not just 
inside the log file?



More information about the Cygwin-xfree mailing list