What causes OpenSSL::SSL::SSLErrorWaitReadable "read would block"? - ruby

Question

What does the OpenSSL::SSL::SSLErrorWaitReadable "read would block" mean?
I am getting the error OpenSSL::SSL::SSLErrorWaitReadable with the message read would block. I think this is because of timeouts, but I can't find any documentation on the subject.
Can anyone help me figure out what is causing this? Also what I can do to prevent the issue?
The code that is producing this error every now and then:
data = {hello: "world"}
path = "https://example.com/api"
uri = URI.parse(path)
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == "https")
http.verify_mode = OpenSSL::SSL::VERIFY_PEER
request = Net::HTTP::Post.new(uri.request_uri)
request.body = Oj.dump(data)
request["Content-Type"] = "application/json"
begin
response = http.request(request) #this line produces the error.
rescue
return nil
end
I am using ruby version 2.1.5p273 and openssl version 1.0.1i on osx 10.10.3.
Versions are found using the command ruby -v -ropenssl -rfiddle -e 'puts Fiddle::Function.new(Fiddle.dlopen(nil)["SSLeay_version"], [Fiddle::TYPE_INT], Fiddle::TYPE_VOIDP).call(0)'
Thanks to #bayendor

Answer 1

Couldn't reproduce in my local machine. It works. Here is my version, so could you confirm with your system? Or if your machine is Mac and you installed ruby with system openssl and readline, it may cause because it's old. Try to install new openssl and readline and build ruby, then execute the script again.
% brew install openssl readline
% RUBY_CONFIGURE_OPTS="--enable-shared --with-readline-dir=$(brew --prefix readline) --with-openssl-dir=$(brew --prefix openssl)" rbenv install 2.0.0-p598
OS: MaxOSX 10.10.2
ruby: 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin12.0]
oj (2.12.9)
% ruby test.rb
OK
% cat test.rb
require 'uri'
require 'net/http'
require 'openssl'
require 'oj'
data = {hello: "world"}
path = "https://example.com/api"
uri = URI.parse(path)
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == "https")
http.verify_mode = OpenSSL::SSL::VERIFY_PEER
request = Net::HTTP::Post.new(uri.request_uri)
request.body = Oj.dump(data)
request["Content-Type"] = "application/json"
begin
response = http.request(request) #this line produces the error.
puts('OK')
rescue
return nil
end