1 files changed, 65 insertions, 0 deletions
diff --git a/externals/gridflow/extra/server_2.rb b/externals/gridflow/extra/server_2.rb
new file mode 100644
index 00000000..4807d502
--- /dev/null
+++ b/externals/gridflow/extra/server_2.rb
@@ -0,0 +1,65 @@
+# a server program to connect 2 or more clients together.
+# by Mathieu Bouchard
+
+require "fcntl"
+require "socket"
+
+class IO
+  def nonblock=flag
+    bit = Fcntl::O_NONBLOCK
+    fcntl(Fcntl::F_SETFL, (fcntl(Fcntl::F_GETFL) & ~bit) |
+      if flag then bit else 0 end)
+  end
+  # does not work with any ruby version, due to a bug. see below.
+  def read_at_most n
+    s=""
+    k=1<<(Math.log(n)/Math.log(2)).to_i
+    while k>0
+      unless k+s.length>n
+        puts "trying #{k}"
+        (s << read(k)) rescue Errno::EWOULDBLOCK
+      end
+      k>>=1
+    end
+    s
+  end
+  # this one works but is slow.
+  def bugfree_read_at_most n
+    s=""
+    (s << (read 1) while s.length<n) rescue Errno::EWOULDBLOCK
+    s 
+  end
+end
+
+serv = TCPServer.new 4242
+socks = [serv]
+
+loop {
+  puts "waiting for connection (port 4242)"
+  begin
+    loop {
+      puts "waiting"
+      ready,blah,crap = IO.select socks, [], socks, 1
+      (ready||[]).each {|s|
+	if s==serv then
+          sock = serv.accept
+          sock.nonblock=true
+          socks << sock
+          puts "incoming connection (total: #{socks.length-1})"
+	else
+          other = socks.find_all{|x|not TCPServer===x} - [s]
+          stuff = s.bugfree_read_at_most 1024
+          p stuff
+          (s.close; socks.delete s) if not stuff or stuff.length==0
+          other.each {|x|
+            p x
+            x.write stuff
+          }
+        end
+      }
+    }
+  rescue Errno::EPIPE # Broken Pipe
+    puts "connection closed (by client)"
+    # it's ok, go back to waiting.
+  end
+}