From: Ulf Betlehem <flu@...>
Date: 2003-03-22T08:26:09+09:00
Subject: [PATCH] non-blocking reads losing data

 This patch fixes a problem that can be reproduced with example.rb:

------------------------------------------ ruby-1.8.0-preview2
--- io.c.orig   2003-03-22 00:09:32.000000000 +0200
+++ io.c        2003-03-22 00:39:32.000000000 +0200
@@ -710,7 +710,7 @@
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
                  case EWOULDBLOCK:
 #endif
-                   if (len - n > 0) {
+                   if (len - n >= 0) {
                        clearerr(f);
                        return len - n;
                    }
------------------------------------------

------------------------------------------ example.rb
#!/usr/bin/env ruby

require 'fcntl'

f = IO.popen("date; sleep 2; date")
f.fcntl(Fcntl::F_SETFL, Fcntl::O_NONBLOCK)
while true
  begin
    s = f.read(1024) or break
    puts s
  rescue Errno::EWOULDBLOCK
    puts("would block")
    sleep(1)
  end
end
------------------------------------------

 Have fun!

-- 
 ulf