From 174d58fd877eb3f060908811b49bd01685fa2fc7 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Mon, 20 Sep 2021 03:03:36 +0200
Subject: [PATCH] Fix the VST thread synchronization on activate/deactivate

---
 plugins/vst/SfizzVstProcessor.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/plugins/vst/SfizzVstProcessor.cpp b/plugins/vst/SfizzVstProcessor.cpp
index cf01f04f5..1e0a71346 100644
--- a/plugins/vst/SfizzVstProcessor.cpp
+++ b/plugins/vst/SfizzVstProcessor.cpp
@@ -740,8 +740,13 @@ void SfizzVstProcessor::doBackgroundWork()
     for (;;) {
         bool isNotified = _semaToWorker.timed_wait(kBackgroundIdleInterval.count());
 
-        if (!_workRunning)
+        if (!_workRunning) {
+            // if the quit signal is sent, the semaphore is also signaled
+            // make sure the count is kept consistent
+            if (!isNotified)
+                _semaToWorker.wait();
             break;
+        }
 
         const char* id = nullptr;
         RTMessagePtr msg;