From c2aafe7e511d3e9449d5068eed7fa999e8aed590 Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Wed, 2 Aug 2017 20:55:51 -0700
Subject: [PATCH] server: add a method to query if the server has started

This commit adds a new utility method to the server struct itself. This
method will allow callers to query the state of the server in order to
decide if the server has been started or not. This can be useful
elsewhere in the project as we start to decouple the lifetime of
certain sub-systems from others.
---
 server.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/server.go b/server.go
index aa57c8b6..fdb19e89 100644
--- a/server.go
+++ b/server.go
@@ -302,11 +302,16 @@ func newServer(listenAddrs []string, chanDB *channeldb.DB, cc *chainControl,
 	return s, nil
 }
 
+// Started returns true if the server has been started, and false otherwise.
+func (s *server) Started() bool {
+	return atomic.LoadInt32(&s.started) != 0
+}
+
 // Start starts the main daemon server, all requested listeners, and any helper
 // goroutines.
 func (s *server) Start() error {
 	// Already running?
-	if atomic.AddInt32(&s.started, 1) != 1 {
+	if !atomic.CompareAndSwapInt32(&s.started, 0, 1) {
 		return nil
 	}
 
@@ -353,7 +358,7 @@ func (s *server) Start() error {
 // all successfully exited. Additionally, any/all listeners are closed.
 func (s *server) Stop() error {
 	// Bail if we're already shutting down.
-	if atomic.AddInt32(&s.shutdown, 1) != 1 {
+	if !atomic.CompareAndSwapInt32(&s.shutdown, 0, 1) {
 		return nil
 	}