From 6019207bd431ca879b96d4a18d43ec39fcd8bc71 Mon Sep 17 00:00:00 2001
From: vsonnier <vsonnier@users.noreply.github.com>
Date: Sun, 15 Oct 2017 08:51:01 +0200
Subject: [PATCH] VisualProcessor : protect against null input queue

---
 src/process/VisualProcessor.h | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/process/VisualProcessor.h b/src/process/VisualProcessor.h
index e5afd6e..bdc5c2e 100644
--- a/src/process/VisualProcessor.h
+++ b/src/process/VisualProcessor.h
@@ -29,8 +29,12 @@ public:
     
     bool isInputEmpty() {
         std::lock_guard < std::mutex > busy_lock(busy_update);
+		
+		if (input) {
+			return input->empty();
+		}
 
-        return input->empty();
+		return true;
     }
     
     bool isOutputEmpty() {
@@ -84,7 +88,12 @@ public:
     //this is purposefully (almost) non-blocking call.
     void flushQueues() {
        
-        input->flush();
+		//capture a local copy atomically, so we don't need to protect input.
+		VisualInputQueueTypePtr localInput = input;
+
+		if (localInput) {
+			localInput->flush();
+		}
 
 		//scoped-lock: create a local copy of outputs, and work with it.
 		std::vector<VisualOutputQueueTypePtr> local_outputs;