[Chicken-janitors] #985: read-line blocks intermittantly on Atom based netbook

[Chicken Trac]

#985: read-line blocks intermittantly on Atom based netbook
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 Reporter:  kiatoa   |       Owner:         
     Type:  defect   |      Status:  new    
 Priority:  minor    |   Milestone:  someday
Component:  unknown  |     Version:  4.8.x  
 Keywords:           |  
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 This problem first shows up in:

 9eef92115fba6034a98cc21ef740fd82ea52387b is the first bad commit
 commit 9eef92115fba6034a98cc21ef740fd82ea52387b
 Author: Peter Bex <address@hidden>
 Date:   Sun Nov 18 21:03:51 2012 +0100

     Fix select() buffer overrun vulnerability by using POSIX poll() on
 systems that support it, leaving only those few systems vulnerable that
 don't (ie, only Windows).

 I used the following code snippet to test. It took as much as 10 runs to
 trigger the bug sometimes:

 =============CODE=============
 (use posix)

 (define (conservative-read port)
   (let loop ((res '()))
     (if (not (eof-object? (peek-char port)))
         (loop (cons (read-char port) res))
         (apply conc (reverse res)))))

 (define (cmd-run-with-stderr->list cmd . params)
    (let-values (((fh fho pid fhe) (if (null? params)
                                       (process* cmd)
                                       (process* cmd params))))
        (let loop ((curr (read-line fh))
                   (result  '()))
          (print "GOT HERE 1, curr=" curr)
          (let ((errstr (conservative-read fhe)))
            (print "GOT HERE 3, errstr=" errstr)
            (if (not (string=? errstr ""))
                (set! result (cons errstr result))))
          (print "GOT HERE 2, result=" result)
          (if (not (eof-object? curr))
              (begin
                (print "GOT HERE 4")
                (loop (read-line fh)
                      (cons curr result)))
              (begin
                (print "GOT HERE 5")
                (close-input-port fh)
                (close-input-port fhe)
                (close-output-port fho)
                (reverse result))))))

 (print "Got: " (cmd-run-with-stderr->list "ls"))

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/985>
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