improve comment explaining the use of alloca()

1 files changed, 8 insertions, 2 deletions

diff --git a/libs/ardour/vst_plugin.cc b/libs/ardour/vst_plugin.cc
index 09a6f59e7c..5c9c94bdac 100644
--- a/libs/ardour/vst_plugin.cc
+++ b/libs/ardour/vst_plugin.cc
@@ -535,8 +535,14 @@ VSTPlugin::connect_and_run (BufferSet& bufs,
 	BufferSet& silent_bufs  = _session.get_silent_buffers(bufs_count);
 	BufferSet& scratch_bufs = _session.get_scratch_buffers(bufs_count);
 
-	// VC++ doesn't support this C99 extension. Use alloca instead of dynamic
-	// array (rather than std::vector which allocs on the heap)
+	/* VC++ doesn't support the C99 extension that allows 
+
+	   typeName foo[variableDefiningSize];
+	   
+	   Use alloca instead of dynamic array (rather than std::vector which
+	   allocs on the heap) because this is realtime code.
+	*/
+	   
 	float** ins = (float**)alloca(_plugin->numInputs*sizeof(float*));
 	float** outs = (float**)alloca(_plugin->numInputs*sizeof(float*));