livoxGen1: Add correctness checks to attachDeviceReq

stimBuffApis/livoxGen1/livoxGen1.cpp

@@ -67,8 +67,8 @@ getStimulusProducer(
 	{
 		// Compare device selectors to find matching buffer
 		if (livoxProto1::comms::deviceIdentifiersEqual(
-			stimProducer->deviceAttachmentSpec->deviceSelector,
-			spec->deviceSelector)
+				stimProducer->deviceAttachmentSpec->deviceSelector,
+				spec->deviceSelector)
 			&& isProducerForStimFeature(stimProducer, spec->qualeIfaceApi))
 		{
 			return stimProducer;
@@ -258,6 +258,13 @@ public:
 			return;
 		}
 
+		if (1 || smoHooksPtr->OptionParser_getOptions().verbose)
+		{
+			std::cout << __func__ << ": Got return mode (" << (int)mode
+				<< ") for device: " << context->spec->deviceSelector
+				<< std::endl;
+		}
+
 		/* Check if PcloudStimulusProducer already exists
 		 * (race condition or double-add)
 		 */
@@ -280,17 +287,43 @@ public:
 
 		context->stimProducer = pcloudDataProducer;
 		context->deviceTmp->nAttachedStimulusProducers++;
+		if (context->deviceTmp->nAttachedStimulusProducers > 2)
+		{
+			throw std::runtime_error(
+				std::string(__func__) + ": Each LivoxGen1 device can only have "
+					"at most two StimulusProducers attached to it. Found "
+					+ std::to_string(
+						context->deviceTmp->nAttachedStimulusProducers) + ".");
+		}
+
 		attachedStimulusProducers.push_back(pcloudDataProducer);
+		if (false
+			/*attachedStimulusProducers.size() >= 2*nDevicesKnownToGen1Lib */)
+		{
+			/**	TODO:
+			 * It would be nice to add an nDevicesKnownToGen1Lib counter, and
+			 * then add a check here to ensure that
+			 * attachedStimulusProducers.size() is always less than or equal to
+			 * 2*nDevicesKnownToGen1Lib.
+			 *
+			 * (2 stim producers per device).
+			 */
+#if 0
+			throw std::runtime_error(
+				std::string(__func__) + ": Number of StimulusProducers attached "
+				"to LivoxGen1 devices known to the library ("
+				+ std::to_string(attachedStimulusProducers.size())
+				+ ") is greater than "
+				"expected. Lib knows about "
+				+ std::to_string(nDevicesKnownToGen1Lib) + " devices, "
+				"so there should be at most "
+				+ std::to_string(2*nDevicesKnownToGen1Lib)
+				+ " StimulusProducers attached to devices.");
+#endif
+		}
 
 		pcloudDataProducer->start();
 
-		if (1 || smoHooksPtr->OptionParser_getOptions().verbose)
-		{
-			std::cout << __func__ << ": Got return mode (" << (int)mode
-				<< ") for device: " << context->spec->deviceSelector
-				<< std::endl;
-		}
-
 		// Ensure StimBuffer is attached
 		attachDeviceReq4_doCreateStimBuff_maybeDirectlyCalled(context);
 	}
@@ -651,12 +684,10 @@ extern "C" void livoxGen1_attachDeviceReq(
 	auto request = std::make_shared<AttachDeviceReq>(desc, cb);
 
 	// Case 1: Check if StimBuffer already exists
-	auto stimProducerBase = getStimulusProducer(desc);
-	if (stimProducerBase)
+	auto stimProducer = std::dynamic_pointer_cast<PcloudStimulusProducer>(
+		getStimulusProducer(desc));
+	if (stimProducer)
 	{
-		auto stimProducer = std::static_pointer_cast<PcloudStimulusProducer>(
-			stimProducerBase);
-
 		auto existingBuffer = stimProducer->getAttachedStimulusBuffer(desc);
 		if (existingBuffer)
 		{