chech max followers when followers change, removes timeout

src/lavinmq/replication/server.cr

@@ -19,7 +19,7 @@ module LavinMQ
     # The follower sends back/acknowledges how many bytes it has received
     class Server
       Log = ::Log.for("replication")
-      getter wait_for_followers = Channel(Nil).new
+      getter followers_changed = Channel(Nil).new
       @lock = Mutex.new(:unchecked)
       @followers = Array(Follower).new
       @password : String
@@ -102,10 +102,7 @@ module LavinMQ
 
       def wait_for_max_lag
         until @followers.size >= Config.instance.min_followers
-          select
-          when @wait_for_followers.receive
-          when timeout(1.seconds)
-          end
+          break unless @followers_changed.receive?
         end
         @followers.each_with_index do |f, i|
           break if i > Config.instance.min_followers
@@ -223,7 +220,7 @@ module LavinMQ
 
         def read_acks(socket = @socket) : Nil
           spawn action_loop, name: "Follower#action_loop"
-          @server.wait_for_followers.try_send nil
+          @server.followers_changed.try_send nil
           loop do
             len = socket.read_bytes(Int64, IO::ByteFormat::LittleEndian)
             @acked_bytes += len
@@ -416,6 +413,7 @@ module LavinMQ
           Log.info { "Disconnected" }
           @actions.close
           @ack.close
+          @server.followers_changed.try_send nil
           @lz4.close
           @socket.close
         rescue IO::Error