CoapClient

- Added a `Condition` variable for the `requestsLock` mutex
- Added `transmitRequest(CoapRequest request)` which will take in the `CoapRequest`, yank the `CoapPacket` from it, encode it, send it over the underlying transport and then start the request's timer
- Added some code for a future "watcher" routine

CoapRequest

- Added a `StopWatch` timer which does not auto start
- Added `startTime()` which starts the timer
- Added `getAndReset()` which gets the elapsed time and resets it

source/doap/client/client.d

@@ -5,7 +5,9 @@ import doap.client.messaging : CoapMessagingLayer;
 import doap.protocol;
 import doap.client.request : CoapRequestBuilder, CoapRequest, CoapRequestFuture;
 import core.sync.mutex : Mutex;
+import core.sync.condition : Condition;
 import std.container.slist : SList;
+import core.thread : dur, Duration, Thread;
 
 /** 
  * A CoAP client
@@ -43,6 +45,11 @@ public class CoapClient
      */
     private Mutex requestsLock;
 
+    /** 
+     * Condition variable for watcher signalling
+     */
+    private Condition watcherSignal;
+
     /** 
      * Creates a new CoAP client to the
      * provided endpoint address
@@ -56,6 +63,7 @@ public class CoapClient
         this.messaging = new CoapMessagingLayer(this);
 
         this.requestsLock = new Mutex();
+        this.watcherSignal = new Condition(this.requestsLock);
 
         init();
     }
@@ -92,6 +100,8 @@ public class CoapClient
         // Set status to running
         this.running = true;
 
+
+
         // Start the messaging layer
         this.messaging.start();
     }
@@ -156,8 +166,8 @@ public class CoapClient
         // Store the request
         storeRequest(request);
 
-        // Send
-        this.socket.send(requestPacket.getBytes());
+        // Transmit the request
+        transmitRequest(request);
 
         return future;
     }
@@ -205,6 +215,54 @@ public class CoapClient
 
         return foundRequest;
     }
+
+    /** 
+     * Transmits the given request's associated
+     * packet to the underlying transport
+     *
+     * Params:
+     *   request = the `CoapRequest` to put into
+     * flight
+     */
+    private void transmitRequest(CoapRequest request)
+    {
+        // Encode the request packet and send it
+        this.socket.send(request.getRequestPacket().getBytes());
+
+        // Now start ticking the timer
+        request.startTime();
+    }
+
+    // private Duration sweepInterval;
+    private Duration retransmitTimeout;
+
+    private void watch()
+    {
+        while(true)
+        {
+            // TODO: Sleep on a 
+
+            /**
+             * Acquire the requests lock so we
+             * can sleep on the condition
+             * (temporarily unlock mutex)
+             */
+            // requestsLock.lock();
+            // watcherSignal.wait();
+
+            requestsLock.lock();
+            foreach(CoapRequest curReq; outgoingRequests)
+            {
+                if(curReq.getAndReset() >= retransmitTimeout)
+                {
+                    // TODO: Retransmit
+                }
+            }
+            requestsLock.unlock();
+
+            Thread.sleep(retransmitTimeout);
+        }
+    }
 }
 
 /**

source/doap/client/request.d

@@ -3,6 +3,8 @@ module doap.client.request;
 import doap.client.client : CoapClient;
 import doap.protocol;
 import doap.exceptions;
+import core.time : Duration;
+import std.datetime.stopwatch : StopWatch, AutoStart;
 
 /**
  * Represents a request that has been made. This is
@@ -32,6 +34,11 @@ package class CoapRequest
      */
     package CoapRequestFuture future;
 
+    /**
+     * Stopwatch for counting elapsed time
+     */
+    private StopWatch timer;
+
     /** 
      * Constructs a new request
      *
@@ -44,6 +51,7 @@ package class CoapRequest
     {
         this.requestPacket = requestPacket;
         this.future = future;
+        this.timer = StopWatch(AutoStart.no);
     }
 
     public CoapPacket getRequestPacket()
@@ -55,6 +63,28 @@ package class CoapRequest
     {
         return this.requestPacket.getToken();
     }
+
+    /** 
+     * Starts the timer
+     */
+    package void startTime()
+    {
+        timer.start();
+    }
+
+    /** 
+     * Gets the current elapsed time and
+     * then resets it
+     *
+     * Returns: the elapsed time
+     */
+    package Duration getAndReset()
+    {
+        // Get the value and restart timer
+        Duration elapsed = timer.peek();
+        timer.reset();
+        return elapsed;
+    }
 }
 
 /**