From 55a917ebe5abfef8e54b3cac2d81a262a51812ff Mon Sep 17 00:00:00 2001
From: hogliux <fabian.renn@gmail.com>
Date: Mon, 23 Oct 2017 12:31:02 +0100
Subject: [PATCH] AU/AUv3:  Ensured that prepareToPlay is called when an AU
 host enables/disables non-realtime mode

---
 .../AU/juce_AU_Wrapper.mm                        | 16 +++++++++++++++-
 .../AU/juce_AUv3_Wrapper.mm                      | 14 +++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/modules/juce_audio_plugin_client/AU/juce_AU_Wrapper.mm b/modules/juce_audio_plugin_client/AU/juce_AU_Wrapper.mm
index 6bd763ffcf..69d7e4b305 100644
--- a/modules/juce_audio_plugin_client/AU/juce_AU_Wrapper.mm
+++ b/modules/juce_audio_plugin_client/AU/juce_AU_Wrapper.mm
@@ -610,10 +610,24 @@ public:
                 }
 
                 case kAudioUnitProperty_OfflineRender:
+                {
+                    auto shouldBeRealtime = (*reinterpret_cast<const UInt32*> (inData) != 0);
+
                     if (juceFilter != nullptr)
-                        juceFilter->setNonRealtime ((*(UInt32*) inData) != 0);
+                    {
+                        auto isCurrentlyRealtime = juceFilter->isNonRealtime();
+
+                        if (isCurrentlyRealtime != shouldBeRealtime)
+                        {
+                            const ScopedLock sl (juceFilter->getCallbackLock());
+
+                            juceFilter->setNonRealtime (shouldBeRealtime);
+                            juceFilter->prepareToPlay (getSampleRate(), (int) GetMaxFramesPerSlice());
+                        }
+                    }
 
                     return noErr;
+                }
 
                 default: break;
             }
diff --git a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
index 5206585030..0d4afcff48 100644
--- a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
+++ b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
@@ -692,7 +692,19 @@ public:
     //==============================================================================
     AUInternalRenderBlock getInternalRenderBlock() override   { return internalRenderBlock;  }
     bool getRenderingOffline() override                       { return getAudioProcessor().isNonRealtime(); }
-    void setRenderingOffline (bool offline) override          { getAudioProcessor().setNonRealtime (offline); }
+    void setRenderingOffline (bool offline) override
+    {
+        auto& processor = getAudioProcessor();
+        auto isCurrentlyNonRealtime = processor.isNonRealtime();
+
+        if (isCurrentlyNonRealtime != offline)
+        {
+            ScopedLock callbackLock (processor.getCallbackLock());
+
+            processor.setNonRealtime (offline);
+            processor.prepareToPlay (processor.getSampleRate(), processor.getBlockSize());
+        }
+    }
 
     //==============================================================================
     NSString* getContextName() const    override              { return juceStringToNS (contextName); }