From: "m_josenhans (Michael Josenhans)" Date: 2013-05-24T06:18:49+09:00 Subject: [ruby-core:55147] [ruby-trunk - Bug #8442][Open] sendmesg (blocking) of class BasicSocket is repeatably sent by the ruby kernel Issue #8442 has been reported by m_josenhans (Michael Josenhans). ---------------------------------------- Bug #8442: sendmesg (blocking) of class BasicSocket is repeatably sent by the ruby kernel https://bugs.ruby-lang.org/issues/8442 Author: m_josenhans (Michael Josenhans) Status: Open Priority: Normal Assignee: Category: core Target version: next minor ruby -v: ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-linux] Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN =begin (1) The error occurs with the method "sendmesg" (blocking) of class BasicSocket on Ruby 2.0.0-p0 (rvm), but does not occur on Ruby 1.9.3-p392 (rvm). (2) The error does not occur with the method "send" (non-blocking) of class BasicSocket on Ruby 1.9.3-p392 (rvm) and Ruby 2.0.0-p0 (rvm). The bug can be reproduced with the code attached. * For (1) use the code as attached. The send message occurs at line 50 & 51. * For (2) comment out line 50 & 51 and uncomment line 52 & 53. How to reproduce the error: run: * (({ruby halfsync_halfasync.rb})) on second terminal (unix): * (({telnet localhost 10001})) on Windows use telnet client e.g. putty and make sure to configure putty as passive ("Connection->Telnet->Telnet negotiation mode: Passive") What the code does: It implements the halfsync_halfasync design-pattern (see references in the code). * An (({EchoAcceptor})) is registered with the reactor to accept connection setup. * A thread pool is started waiting for tasks to be retrieved from a shared queue * Upon connection-setup of the telnet the (({EchoAcceptor})) is called and registers an (({EchoServerHandler})) with the Reactor to handle data received via the connection from the telnet client. * Upon reception of data via the telent connection, the (({EchoServerHandler})) assembles data until a newline (\n or \r\n) is received. When that is received, the whole line is put into the shared queue. * The first thread from the thread pool waiting grabs the received data and the socket from the shared queue and in line 50/51 adds the thread-ID, the number of messages handled by that thread and sends it as a reply to the sender using the received socket. What to expect as output: * Upon entering e.g. text "!1234" and pressing return On Ruby 1.9.3-p392 on Linux: * See the as response the thread ID, the number of messages within the thread and the text. On Ruby 2.0.0-p0 on Linux: * See same as with Ruby 1.9.3-p392 , but when pressing very fast return after entering no text, the message of thread-id and number of messages sent will be repeatedly received by the server. * As the number of messages is not increased with each sending, it will be repeatedly sent by the ruby kernel (c-code) On Ruby 2.0.0-p0 on Windows: * Nothing is is sent back to the the telnet server, despite the fact that the message had been received at the servers of the thread pool. * Everything works file, if instead of blocking send (line 50/51) the non-blocking send (line 52/53) is used. However correct implementation of the halfsync-halfasync pattern, requires reasonably the usage of blocking "send" in thread pool. I have to apologize that the program to reproduce the error is slightly large and complicated, but I believe that there is value, when ruby is able to run well known design patterns correctly. Note: The code does not run with ruby 1.8.7 and Jruby and Rubinius. =end -- http://bugs.ruby-lang.org/