Re: Application stalls on thread context switches of Ruby (Rubycocoa-devel 1123) - RubyCocoa

Hi.

The problem seems a bug of ruby 1.8.2.
I'm sorry for my insufficient testing.

I cut the reproduce code into pure Ruby not using RubyCocoa:

  http://limechat.net/rubycocoa/threaded_socket_test.rb

Then I tested it on ruby 1.8.2 and ruby 1.8.6:

  $ /usr/bin/ruby -v threaded_socket_test.rb
  ruby 1.8.2 (2004-12-25) [universal-darwin8.0]
  +++ start writing
  (stalls)

  $ ruby -v threaded_socket_test.rb
  ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.9.1]
  +++ start writing
  *** received
  (snip)
  *** received
  --- end writing
  *** received
  (continues normally)

So I concluded it is a bug of ruby 1.8.2, not of RubyCocoa.

Let's release 0.12.0.

--
Satoshi Nakagawa

On 2007/07/21, at 9:08, Satoshi Nakagawa wrote:

> Hi.
>
> I found a problem, application stalls on thread context switches of Ruby.
> It is reproducible on 0.11.1 and trunk.
>
> How to reproduce the problem:
>
>   1. Start a socket server.
>   2. Connect to the server using Ruby's TCPSocket.
>   3. The server accepts the request.
>   4. Start a thread on the server, sending 256KB per 5 seconds to the client.
>   5. The application stalls. (Rolling rainbow colored cursor forever)
>
> Reproduce code in Xcode project:
>
>   http://limechat.net/rubycocoa/ThreadedSocketTest.zip
>
> In #4, if it sends 64KB per 5 seconds, there are no problem.
>
> This is the code around threaded writing from server to client.
>
>   def write_loop
>     loop do
>       puts '+++ start writing'
>       @sc.write('a' * (1024 * 256))
>       puts '--- end writing'
>       sleep 5
>     end
>   end
>
> The log when it sends 256KB:
>
>   +++ start writing
>   (stalls)
>
> The log when it sends 64KB:
>
>   +++ start writing
>   --- end writing
>   *** received
>   *** received
>   (continues forever)
>
> So I noticed the application stops at:
>
>   @sc.write('a' * (1024 * 256))
>
> It seems to occur on thread context switches of Ruby.
> Then, I added a logging code to RubyCocoa:
>
> Index: framework/src/objc/RBThreadSwitcher.m
> ===================================================================
> --- framework/src/objc/RBThreadSwitcher.m       (revision 1928)
> +++ framework/src/objc/RBThreadSwitcher.m       (working copy)
> @@ -44,6 +44,7 @@
> - (void) sched: (NSTimer*)a_timer
> {
> +  NSLog(@"@@@ timer");
>    CHECK_INTS;
>    if (!rb_thread_critical) rb_thread_schedule();
> }
>
> Then the log is (sends 256KB):
>
>   +++ start writing
>   2007-07-21 08:38:34.247 BridgeTest2[2990] @@@ timer
>   (stalls)
>
> It shows the application stalls after a thread context switch of Ruby.
>
> --
> Satoshi Nakagawa

RubyCocoa

[Rubycocoa-devel 1123] Re: Application stalls on thread context switches of Ruby