From: Kero van Gelder <kero@...>
Date: 2003-08-02T18:37:40+09:00
Subject: 1.8.0-previewX  rb_sys_fail() on socket instead of an Exception.

Hi all,

Find some code below to reliably cause a rb_sys_fail() for server.rb,
whenever it is run by ruby 1.8.0-previewX on a Linux system (2.2 kernel RH
6.something, 2.4.21-smp kernel RH 7.3, 2.5 kernel debian unstable). The
client can be ran with 1.6.8, still causes rb_sys_fail().

I get normal exceptions/nil-from-gets for Ruby 1.6.8, or when running on
HP-UX. If I run the server with 1.6.8 and the client with 1.8.0-pX, all is
fine, too.

The code below is simplified from my real codebase at work, where the
rb_sys_fail() means the server crashes, without possibility of recovery.

However, I can not take any more code out of these snippets, or the
behaviour goes to normal/desired: exception or nil-from-gets.

Please find the code below, or here:
  http://httpd.chello.nl/k.vangelder/ruby/broken_socket.zip

Bye,
Kero.

server.rb
---------
require 'socket'

server = TCPServer.new('localhost', 1357)
while socket = server.accept()
  t = Thread.new {
    loop {
      begin
        line = socket.gets
        puts line
      rescue
      end
    }
  }

  i = 0
  loop {
    socket.puts("hello")
    sleep 1
    i += 1
  }
end


client.rb
---------
require 'socket'
require 'duty'

socket = TCPSocket.new('localhost', 1357)
while line = socket.gets()
  puts line

  Heavy::duty()  # client can be killed (^C at command line) ...
  socket.puts("world #{nonexistant}")  # ... or will die here,
                                   #  either causes crash at server.rb
end


duty.c
------
#include <ruby.h>

VALUE rb_duty(VALUE module) {
  int i, j, k;
  for (i=0; i<1000; i++) {
    for (j=0; j<1500; j++) {  /* lower numbers on slower systems... */
      for (k=0; k<2000; k++) {
        int nr = i*j+k;
      }
    }
  }
  return Qnil;
}

void Init_duty() {
  VALUE rb_mHeavy = rb_define_module("Heavy");
  rb_define_module_function(rb_mHeavy, "duty", rb_duty, 0);
}


extconf.rb
----------
require 'mkmf'
create_makefile("duty")