add Async::IO wrapper (see new example)

README.md

@@ -59,6 +59,7 @@ More information in the [API documentation](http://www.rubydoc.info/github/paddo
 
 ### Features
 
+* compatible with [Async](https://github.com/socketry/async) / [Async::IO](https://github.com/socketry/async-io)
 * Ruby-like API
   * method names
     * sending a message via a socket is done with `Socket#<<`

examples/async/.gitignore

@@ -0,0 +1 @@
+/Gemfile.lock

examples/async/Gemfile

@@ -0,0 +1,5 @@
+source 'https://rubygems.org'
+
+gem 'async'
+gem 'cztop', path: '../../'
+gem 'async-io'

examples/async/README.md

@@ -0,0 +1 @@
+Run: `bundle exec ./async.rb`

examples/async/async.rb

@@ -0,0 +1,40 @@
+#! /usr/bin/env ruby
+
+require 'cztop/async'
+
+Async do |task|
+  task.async do |t|
+    socket = CZTop::Socket::REP.new("ipc:///tmp/req_rep_example")
+
+    # Simply echo every message, with every frame String#upcase'd.
+    socket.options.rcvtimeo = 3
+    io = Async::IO.try_convert socket
+
+    msg = io.receive
+    puts "<<< #{msg.to_a.inspect}"
+    io << msg.to_a.map(&:upcase)
+
+    puts "REP done."
+  end
+
+  task.async do
+    socket = CZTop::Socket::REQ.new("ipc:///tmp/req_rep_example")
+    puts ">>> Socket connected."
+
+    io = Async::IO.try_convert socket
+    # sleep 5
+    io << "foobar"
+
+    socket.options.rcvtimeo = 3
+    msg = io.receive
+    puts ">>> #{msg.to_a.inspect}"
+    puts "REQ done."
+  end
+
+  task.async do
+    6.times do
+      sleep 0.5
+      puts "tick"
+    end
+  end
+end

lib/cztop/async.rb

@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+require 'cztop'
+require 'async/io'
+
+module Async
+	module IO
+		class CZTopSocket < Generic
+      CZTop::Socket::Types.constants.each do |name|
+        wraps ::CZTop::Socket.const_get(name)
+      end
+
+
+      def receive
+        wait_readable
+        @io.receive
+      end
+
+
+      def <<(...)
+        wait_writable
+        @io.<<(...)
+      end
+
+
+      def wait_readable(timeout = read_timeout)
+        puts "Async::IO::CZTopSocket#wait_readable: waiting with timeout=#{timeout}"
+        @io_fd ||= ::IO.for_fd @io.fd, autoclose: false
+
+        if timeout
+          timeout_at = now + timeout
+
+          while true
+            @io_fd.wait_readable(timeout)
+            break if @io.readable?
+            raise TimeoutError if now >= timeout_at
+          end
+        else
+          @io_fd.wait_readable until @io.readable?
+        end
+      end
+
+
+      def wait_writable(timeout = write_timeout)
+        puts "Async::IO::CZTopSocket#wait_writable: waiting with timeout=#{timeout}"
+        @io_fd ||= ::IO.for_fd @io.fd, autoclose: false
+
+        if timeout
+          timeout_at = now + timeout
+
+          while true
+            @io_fd.wait_writable(timeout)
+            break if @io.writable?
+            raise TimeoutError if now >= timeout_at
+          end
+        else
+          @io_fd.wait_writable until @io.writable?
+        end
+      end
+
+
+      def read_timeout
+        timeout = @io.options.rcvtimeo
+        timeout = nil if timeout <= 0
+        timeout
+      end
+
+
+      def write_timeout
+        timeout = @io.options.sndtimeo
+        timeout = nil if timeout <= 0
+        timeout
+      end
+
+
+      private
+
+
+      def now
+        Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      end
+		end
+  end
+end