[#JRUBY-6418] CLONE - Closing One Stream From IO.popen4 Results in Stream Closed Error When Reading Other Streams - jira.codehaus.org

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Type: Bug
Status: Closed
Priority: Major
Resolution: Fixed
Affects Version/s: JRuby 1.6.6
Fix Version/s: JRuby 1.6.7
Component/s: None
Labels:
None
Environment:
Java 6

Number of attachments :
0

Description

The small snippet below results in an IOError: Stream closed on the stdout_io.each_line line. Removing the stdin.close gets rid of the error.

IO.popen4("ls") do |pid, stdin, stdout, stderr|
  stdin.close
  [
   Thread.new(stdout) {|stdout_io|
     stdout_io.each_line do |l|
       STDOUT.puts l
       STDOUT.flush
     end
     stdout_io.close
   },

   Thread.new(stderr) {|stderr_io|
     stderr_io.each_line do |l|
       STDERR.puts l
       STDERR.flush
     end
   }
  ].each( &:join )
end

RubyIO's close2 method has code to destroy any spawned processes associated with an IO object that gets closed. So, the workaround is to not close any of the IO streams until the process has finished or the program has finished consuming the process output. See:

https://github.com/jruby/jruby/blob/master/src/org/jruby/RubyIO.java#L3810
https://github.com/jruby/jruby/blob/master/src/org/jruby/RubyIO.java#L2002

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Ben Browning added a comment - 02/Feb/12 2:57 PM

Cloned from ~~JRUBY-6291~~ - this issue was present in 1.7 and fixed by the commit https://github.com/jruby/jruby/commit/00d30e159ba2cbbe01c04d4fd2b8bd46d9b2ee6a with test in commit https://github.com/jruby/jruby/commit/70d42fb23b34c021cc18a2980ba65422bd9c4692

I don't know for sure if it's the same underlying issue, but the example code above does exhibit the same problem under 1.6.6

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Ben Browning added a comment - 02/Feb/12 2:57 PM Cloned from JRUBY-6291 - this issue was present in 1.7 and fixed by the commit https://github.com/jruby/jruby/commit/00d30e159ba2cbbe01c04d4fd2b8bd46d9b2ee6a with test in commit https://github.com/jruby/jruby/commit/70d42fb23b34c021cc18a2980ba65422bd9c4692 I don't know for sure if it's the same underlying issue, but the example code above does exhibit the same problem under 1.6.6

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Charles Oliver Nutter added a comment - 13/Feb/12 10:21 AM

Since this change appears to be behaving on master, I'll roll it into 1.6.7. The original logic is obviously wrong anyway.

commit f5b0d4e6e3df5bc6911f7ceaa07be42687dad702
Author: Ben Browning <bbrownin@redhat.com>
Date:   Wed Dec 21 19:59:02 2011 -0500

    Test for JRUBY-6291: Closing One Stream in IO.popen4 Breaks Reading Other Streams

commit 10ff5185ea17158d1a1b62031e86ea49a58456fb
Author: Charles Oliver Nutter <headius@headius.com>
Date:   Tue Dec 20 18:00:38 2011 -0600

    Fix JRUBY-6291: Closing One Stream From IO.popen4 Results in Stream Closed Error When Reading Other Streams
    
    Ben figured this one out. The logic I put in place to ensure the
    child process gets nuked for a popen stream was causing it to be
    nuked prematurely for popen3/4 streams. I added a "popenSpecial"
    boolean to RubyIO, so we know not to do that.

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Charles Oliver Nutter added a comment - 13/Feb/12 10:21 AM Since this change appears to be behaving on master, I'll roll it into 1.6.7. The original logic is obviously wrong anyway. commit f5b0d4e6e3df5bc6911f7ceaa07be42687dad702 Author: Ben Browning <bbrownin@redhat.com> Date: Wed Dec 21 19:59:02 2011 -0500 Test for JRUBY-6291: Closing One Stream in IO.popen4 Breaks Reading Other Streams commit 10ff5185ea17158d1a1b62031e86ea49a58456fb Author: Charles Oliver Nutter <headius@headius.com> Date: Tue Dec 20 18:00:38 2011 -0600 Fix JRUBY-6291: Closing One Stream From IO.popen4 Results in Stream Closed Error When Reading Other Streams Ben figured this one out. The logic I put in place to ensure the child process gets nuked for a popen stream was causing it to be nuked prematurely for popen3/4 streams. I added a "popenSpecial" boolean to RubyIO, so we know not to do that.

CLONE - Closing One Stream From IO.popen4 Results in Stream Closed Error When Reading Other Streams

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