StimBuff: make start/stop virtual;

We can now have the derived StimBuff class implement its own
start()/stop() preamble and epilogue.

stimBuffApis/livoxGen1/pcloudStimulusBuffer.cpp

@@ -32,6 +32,22 @@ ioUringAssemblyEngine(*this)
 {
 }
 
+void PcloudStimulusBuffer::start()
+{
+	// Call ioUringAssemblyEngine setup() as the final step
+	// ioUringAssemblyEngine.setup();
+	// Call base class start() as the final step
+	StimulusBuffer::start();
+}
+
+void PcloudStimulusBuffer::stop()
+{
+	// Call base class stop() as the first step
+	StimulusBuffer::stop();
+	// Call ioUringAssemblyEngine stop() as the final step
+	// ioUringAssemblyEngine.finalize();
+}
+
 void PcloudStimulusBuffer::stimFrameProductionTimesliceInd()
 {
 	// Release the spinlock for now