[Chicken-janitors] #1486: Reading and writing to a pipe set up by process can cause scheduler assertion errors

[Chicken Trac]

#1486: Reading and writing to a pipe set up by process can cause scheduler
assertion errors
----------------------------+--------------------------------
 Reporter:  sjamaan         |                 Owner:
     Type:  defect          |                Status:  new
 Priority:  major           |             Milestone:  someday
Component:  core libraries  |               Version:  4.13.0
 Keywords:                  |  Estimated difficulty:  hard
----------------------------+--------------------------------
 As pointed out in [[https://stackoverflow.com/questions/51344859
 /connecting-to-interactive-tools-using-chicken-schemes-process|this
 StackOverflow post]]:

 {{{
 (use posix)
 (let-values (((in out pid) (process "bc")))
   (begin
     (display "2 + 2\n" out)
     (print (read-line in))))
 }}}

 Causes the following crash when evaluated:

 {{{
 thread is registered for I/O on unknown file-descriptor: 4 (expected 3)
 []
 ...more...
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <syntax>
 <eval>
 <eval>
 <eval>
 <eval>
 <eval>  <--
 }}}

 This bug is not easy to trigger.  I happened to get "lucky" and it crashed
 the first time, but after that I tried again several times and it just
 worked.

--
Ticket URL: <https://bugs.call-cc.org/ticket/1486>
CHICKEN Scheme <https://www.call-cc.org/>
CHICKEN Scheme is a compiler for the Scheme programming language.