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Select unreliably unblocks when closing sockets on linux #168

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ryanatball opened this Issue Jul 13, 2015 · 0 comments

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ryanatball commented Jul 13, 2015

From Kyle---

This isn’t a very big deal, but something to perhaps clean up in the future. The new headless command server is letting me see much more information on our shutdown and one thing I notice is that we have an interface that is using tcpip_client_interface with nil timeouts for both read and write (it is expected that this interface won’t be constantly transmitting). Anyway, it is failing to shut down cleanly on exit (full message below).

It looks like tcpip_socket_stream expects to get a IOERROR or Errno::ENOTSOCK when the socket is closed while waiting on the select(), but that apparently isn’t happening.

It looks like this may be a common problem that can be refactored around by just doing a blocking read instead of using select:
https://www.ruby-forum.com/topic/4415582

I could refactor the target on the other side to send packets more frequently so we could use a timeout, but that seems a workaround rather than a fix.

2015/07/09 15:02:07.156 INFO: Killing thread for interface BUSMON_INT
2015/07/09 15:02:08.161 WARN: Failed to gracefully kill thread:
Caller Backtrace:
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/interface_thread.rb:124:in stop' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/interfaces.rb:121:instop_thread'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/connections.rb:84:in disconnect' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/connections.rb:44:inblock in stop'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/connections.rb:43:in each' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/connections.rb:43:instop'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/cmd_tlm_server.rb:226:in stop' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/cmd_tlm_server_gui.rb:365:inensure in post_options_parsed_hook'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/cmd_tlm_server_gui.rb:365:in post_options_parsed_hook' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/gui/qt_tool.rb:181:inblock in run'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/top_level.rb:682:in set_working_dir' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/gui/qt_tool.rb:177:inrun'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/cmd_tlm_server_gui.rb:403:in block in run' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/top_level.rb:511:incatch_fatal_exception'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/cmd_tlm_server_gui.rb:376:in run' ./CmdTlmServer:15:inblock in

'
/export/home/j1swtb/cosmos/tool_dispatcher/tools/tool_launch.rb:16:in tool_launch' ./CmdTlmServer:13:in'

Thread Backtrace:
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/core_ext/io.rb:25:in select' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/core_ext/io.rb:25:infast_select'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/tcpip_socket_stream.rb:57:in rescue in read' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/tcpip_socket_stream.rb:51:inread'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/stream_protocol.rb:350:in read_and_handle_timeout' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/stream_protocol.rb:366:inread_minimum_size'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/preidentified_stream_protocol.rb:97:in reduce_to_single_packet' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/stream_protocol.rb:144:inblock in read'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/stream_protocol.rb:139:in loop' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/streams/stream_protocol.rb:139:inread'
/opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/interfaces/stream_interface.rb:56:in read' /opt/ruby-2.1.5/lib/ruby/gems/2.1.0/gems/cosmos-3.5.0/lib/cosmos/tools/cmd_tlm_server/interface_thread.rb:81:inblock in start'

2015/07/09 15:02:08.171 INFO: Disconnected from interface BUSMON_INT

@ryanatball ryanatball added the bug label Jul 17, 2015

jmthomas pushed a commit that referenced this issue Aug 4, 2015

@ryanatball ryanatball closed this in 305d0fe Aug 5, 2015

ryanatball added a commit that referenced this issue Aug 5, 2015

Merge pull request #181 from BallAerospace/fix_select_and_io_performance
closes #168, closes #80 Fix select blocking and implement IO without …

@ryanatball ryanatball modified the milestone: v3.6.0 Aug 7, 2015

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