From: nobu.nokada@...
Date: 2004-02-26T15:44:46+09:00
Subject: Re: thread gurus please help...

Hi,

At Thu, 26 Feb 2004 13:54:48 +0900,
Ara.T.Howard wrote in [ruby-talk:93721]:
> what is a 'bean jam ball'? sounds like something good...

'Bean jam' is sweet paste made boiling red beans and sugar.  It
looks black in common, but there is white one and others.  And
Japanese are in the habit of eating rice balls with bean jam in
each equinox.

> i tried replacing with sysread but am now failing with
> 
>   sysread for buffered IO (IOError)

See [ruby-talk:93722] about sysread.

Anyway, I feel non-blocking IO should never block in this case,
simpler code which can reproduce your issue.

  require 'io/nonblock'

  unless rio = IO.popen("-")
    loop do
      p Time.now
      sleep 1
    end
  end

  Thread.new do
    until rio.eof?
      #Thread.critical = true             # blocks w/o this
      text = rio.nonblock{ rio.read }
      #Thread.critical = false            # blocks w/o this
      print text
    end
  end.join


Index: io.c
===================================================================
RCS file: /cvs/ruby/src/ruby/io.c,v
retrieving revision 1.261
diff -u -2 -p -d -r1.261 io.c
--- io.c	25 Feb 2004 12:17:39 -0000	1.261
+++ io.c	26 Feb 2004 06:38:59 -0000
@@ -889,4 +889,10 @@ rb_io_to_io(io)
 }
 
+#ifndef O_NONBLOCK
+# ifdef O_NDELAY
+# define O_NONBLOCK O_NDELAY
+# endif
+#endif
+
 /* reading functions */
 long
@@ -903,4 +909,8 @@ rb_io_fread(ptr, len, f)
 	long i = READ_DATA_PENDING_COUNT(f);
 	if (i <= 0) {
+#if defined(HAVE_FCNTL) && defined(F_GETFL) && defined(O_NONBLOCK)
+	    i = fcntl(fileno(f), F_GETFL);
+	    if (i == -1 || (i & O_NONBLOCK)) break;
+#endif
 	    rb_thread_wait_fd(fileno(f));
 	    i = READ_DATA_PENDING_COUNT(f);
@@ -5508,10 +5518,6 @@ Init_IO()
     rb_file_const("CREAT", INT2FIX(O_CREAT));
     rb_file_const("EXCL", INT2FIX(O_EXCL));
-#if defined(O_NDELAY) || defined(O_NONBLOCK)
-#   ifdef O_NONBLOCK
+#ifdef O_NONBLOCK
     rb_file_const("NONBLOCK", INT2FIX(O_NONBLOCK));
-#   else
-    rb_file_const("NONBLOCK", INT2FIX(O_NDELAY));
-#   endif
 #endif
     rb_file_const("TRUNC", INT2FIX(O_TRUNC));


-- 
Nobu Nakada