Issue #11121 has been reported by Pep Turr Mauri.

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Bug #11121: openssl ext does not handle EWOULDBLOCK
https://bugs.ruby-lang.org/issues/11121

* Author: Pep Turr Mauri
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: ruby 1.9.3p551 (2014-11-13) [i386-mingw32]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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On Windows, non-blocking IO on sockets seems to return EWOULDBLOCK instead of EAGAIN. The openssl ruby library only handles EAGAIN, which results in EWOULDBLOCK being raised to the caller.

This was noticed while using httpclient to send a POST request to an https server via an http proxy on a Windows system:

~~~
A non-blocking socket operation could not be completed immediately. (Errno::EWOULDBLOCK)
  C:/Ruby193/lib/ruby/1.9.1/openssl/buffering.rb:53:in `sysread'
  C:/Ruby193/lib/ruby/1.9.1/openssl/buffering.rb:53:in `sysread'
  C:/Ruby193/lib/ruby/1.9.1/openssl/buffering.rb:53:in `fill_rbuff'
  C:/Ruby193/lib/ruby/1.9.1/openssl/buffering.rb:200:in `gets'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:356:in `gets'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:876:in `block in parse_header'
  C:/Ruby193/lib/ruby/1.9.1/timeout.rb:55:in `timeout'
  C:/Ruby193/lib/ruby/1.9.1/timeout.rb:100:in `timeout'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:872:in `parse_header'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:833:in `connect_ssl_proxy'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:753:in `block in connect'
  C:/Ruby193/lib/ruby/1.9.1/timeout.rb:55:in `timeout'
  C:/Ruby193/lib/ruby/1.9.1/timeout.rb:100:in `timeout'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:746:in `connect'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:612:in `query'
  C:/Ruby193/lib/ruby/gems/1.9.1/gems/httpclient-2.6.0.1/lib/httpclient/session.rb:164:in `query'
  ...
~~~

We could only reproduce it in this environment so far (old version, invoking this particular call, over a proxy) but I believe the same problem can appear at any time with current versions.

An example from current trunk (ext/openssl/lib/openssl/buffering.rb):

~~~
  def fill_rbuff
    begin
      @rbuffer << self.sysread(BLOCK_SIZE)
    rescue Errno::EAGAIN
      retry
    rescue EOFError
      @eof = true
    end
  end
~~~

there are multiple references in that file, e.g.
 https://github.com/ruby/ruby/blob/trunk/ext/openssl/lib/openssl/buffering.rb#L62
 https://github.com/ruby/ruby/blob/trunk/ext/openssl/lib/openssl/buffering.rb#L327




-- 
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