[Chicken-janitors] #766: posix: can't collect exit status and close all process ports at the same time

[Chicken Trac]

#766: posix: can't collect exit status and close all process ports at the same
time
---------------------+------------------------------------------------------
 Reporter:  syn      |       Owner:       
     Type:  defect   |      Status:  new  
 Priority:  major    |   Milestone:  4.8.0
Component:  unknown  |     Version:  4.7.x
 Keywords:           |  
---------------------+------------------------------------------------------
 It is currently impossible to call {{{process-wait}}} on a PID to collect
 the exit status of child process and close all associated input and output
 ports afterwards. This is due to {{{close-[input|output]-port}}}
 implicitly calling {{{process-wait}}} on process pipe ports. This leads to
 errors like

 {{{
 Error: (process-wait) waiting for child process failed - No child
 processes: 10872
 }}}

 because the process has already been purged by the OS at that point.   For
 the time being this can be worked around by calling {{{file-close}}} on
 the ports' file descriptors.

 A possible solution might be to
 [http://www.scsh.net/docu/html/man-Z-H-4.html#node_sec_3.4.1 encapsulate
 processes in process objects similar to Scsh] (or [http://docs.racket-
 lang.org/reference/subprocess.html subprocess values as Racket calls
 them]) and change {{{process-wait}}} to retain the process' exit status
 once it has been collected, allowing for it to be called multiple times.
 This would of course break backwards compatibility and thus should be
 handled as a Change Request. See also: [https://github.com/sellout
 /external-program/wiki/API Common Lisp external-program library]. Comments
 welcome.

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/766>
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