From: Daniel Berger <djberg96@...>
Date: 2009-08-01T11:54:23+09:00
Subject: JRuby, ffi, bad file descriptor

Hi,

JRuby 1.3.1
OS X 10.4.9

The following code is a port of a tempfile library I wrote. Ruby 1.8.6 
and 1.9.x work alright, but with JRuby I'm getting a bad file descriptor 
error.

Any ideas? Here's the code:

require 'ffi'

class FileTemp < File
    extend FFI::Library

    attach_function 'fileno',  [:pointer], :int
    attach_function 'fclose',  [:pointer], :int
    attach_function 'mkstemp', [:string],  :int
    attach_function 'tmpfile', [],         :pointer
    attach_function 'tmpnam',  [:string],  :string
    attach_function 'umask',   [:int],     :int

    TMPDIR = ENV['TEMP'] || ENV['TMP'] || '/tmp'

    def initialize(delete = true, template = 'rb_file_temp_XXXXXX')
       @fptr = nil

       if delete
          @fptr = tmpfile()
          fd = fileno(@fptr)
       else
          begin
             omask = umask(077)
             fd = mkstemp(template)
             raise SystemCallError, 'mkstemp()' if fd < 0
          ensure
             umask(omask)
          end
       end

       super(fd, 'wb+')
    end

    def close
       super
       fclose(@fptr) if @fptr
    end

    def self.temp_name
       TMPDIR + tmpnam(nil) << '.tmp'
    end
end

if $0 == __FILE__
    fh = FileTemp.new
    fh.print 'hello'
    fh.close
end

Result:

temp.rb:42:in `initialize': Bad file descriptor - Bad file descriptor 
(Errno::EBADF)
         from temp.rb:56:in `new'
         from temp.rb:56

Regards,

Dan