From 1cc927e885e9cbf95ba100ac5b99104c5f742e04 Mon Sep 17 00:00:00 2001
From: Alex Dadgar <alex.dadgar@gmail.com>
Date: Wed, 17 Feb 2016 11:32:17 -0800
Subject: [PATCH] Extract the heartbeat and saveState into their own go
 routines

---
 client/client.go | 69 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 49 insertions(+), 20 deletions(-)

diff --git a/client/client.go b/client/client.go
index bdcde6227aca..19f609809198 100644
--- a/client/client.go
+++ b/client/client.go
@@ -152,16 +152,23 @@ func NewClient(cfg *config.Config) (*Client, error) {
 	// initialized.
 	c.configCopy = c.config.Copy()
 
+	// Start the consul service
+	go c.consulService.SyncWithConsul()
+
 	// Restore the state
 	if err := c.restoreState(); err != nil {
 		return nil, fmt.Errorf("failed to restore state: %v", err)
 	}
 
+	// Register and then start heartbeating to the servers.
+	go c.registerAndHeartbeat()
+
+	// Begin periodic snapshotting of state.
+	go c.periodicSnapshot()
+
 	// Start the client!
 	go c.run()
 
-	// Start the consul service
-	go c.consulService.SyncWithConsul()
 	return c, nil
 }
 
@@ -625,13 +632,12 @@ func (c *Client) retryIntv(base time.Duration) time.Duration {
 	return base + randomStagger(base)
 }
 
-// run is a long lived goroutine used to run the client
-func (c *Client) run() {
+// registerAndHeartbeat is a long lived goroutine used to register the client
+// and then start heartbeatng to the server.
+func (c *Client) registerAndHeartbeat() {
+	// Register the node
 	c.retryRegisterNode()
 
-	// Watch for node changes
-	go c.watchNodeUpdates()
-
 	// Setup the heartbeat timer, for the initial registration
 	// we want to do this quickly. We want to do it extra quickly
 	// in development mode.
@@ -642,14 +648,29 @@ func (c *Client) run() {
 		heartbeat = time.After(randomStagger(initialHeartbeatStagger))
 	}
 
-	// Watch for changes in allocations
-	allocUpdates := make(chan *allocUpdates, 1)
-	go c.watchAllocations(allocUpdates)
+	for {
+		select {
+		case <-heartbeat:
+			if err := c.updateNodeStatus(); err != nil {
+				heartbeat = time.After(c.retryIntv(registerRetryIntv))
+			} else {
+				c.heartbeatLock.Lock()
+				heartbeat = time.After(c.heartbeatTTL)
+				c.heartbeatLock.Unlock()
+			}
 
+		case <-c.shutdownCh:
+			return
+		}
+	}
+}
+
+// periodicSnapshot is a long lived goroutine used to periodically snapshot the
+// state of the client
+func (c *Client) periodicSnapshot() {
 	// Create a snapshot timer
 	snapshot := time.After(stateSnapshotIntv)
 
-	// Periodically update our status and wait for termination
 	for {
 		select {
 		case <-snapshot:
@@ -658,18 +679,26 @@ func (c *Client) run() {
 				c.logger.Printf("[ERR] client: failed to save state: %v", err)
 			}
 
+		case <-c.shutdownCh:
+			return
+		}
+	}
+}
+
+// run is a long lived goroutine used to run the client
+func (c *Client) run() {
+	// Watch for node changes
+	go c.watchNodeUpdates()
+
+	// Watch for changes in allocations
+	allocUpdates := make(chan *allocUpdates, 1)
+	go c.watchAllocations(allocUpdates)
+
+	for {
+		select {
 		case update := <-allocUpdates:
 			c.runAllocs(update)
 
-		case <-heartbeat:
-			if err := c.updateNodeStatus(); err != nil {
-				heartbeat = time.After(c.retryIntv(registerRetryIntv))
-			} else {
-				c.heartbeatLock.Lock()
-				heartbeat = time.After(c.heartbeatTTL)
-				c.heartbeatLock.Unlock()
-			}
-
 		case <-c.shutdownCh:
 			return
 		}