StimBuff: Use a single StagingBuffer for all StimFrames

We now allocate all the stimFrames for a StimBuffer using a
single StagingBuffer. This gives us all the benefits we're
looking for (pinning, alignment, etc).

include/user/spMcRingBuffer.h

@@ -6,7 +6,9 @@
 #include <stdexcept>
 #include <string>
 #include <new>
+#include <memory>
 #include <user/stimulusFrame.h>
+#include <user/frameAssemblyDesc.h>
 #include <user/sequenceLock.h>
 
 namespace smo {
@@ -24,32 +26,35 @@ class SpMcRingBuffer
 {
 public:
 	/**	EXPLANATION:
-	 * Constructor initializes the ring buffer with the given constraints and
-	 * number of buffers. Allocates slots vector with properly constructed
-	 * StimulusFrame instances.
+	 * Constructor initializes the ring buffer with FrameAssemblyDesc.
+	 * Allocates frames vector with properly constructed StimulusFrame instances,
+	 * each initialized with a SlotDesc from the FrameAssemblyDesc.
 	 */
 	explicit SpMcRingBuffer(
-		size_t nBuffers_,
-		const StagingBuffer::IOEngineConstraints& inputEngineConstraints,
-		const StagingBuffer::IOEngineConstraints& outputEngineConstraints,
-		size_t nSlotsPerStimFrame)
-	: nBuffers(nBuffers_),
-	// Default-construct all frames
-	slots(nBuffers)
+		const std::shared_ptr<FrameAssemblyDesc> &frameAssemblyDesc_)
+	:
+	nBuffers(frameAssemblyDesc_ ? frameAssemblyDesc_->slots.size() : 0),
+	frameAssemblyDesc(frameAssemblyDesc_),
+	slots(nBuffers)  // Default-construct all frames
 	{
+		if (!frameAssemblyDesc)
+		{
+			throw std::invalid_argument(std::string(__func__)
+				+ ": SpMcRingBuffer: frameAssemblyDesc must not be null");
+		}
+
 		if (nBuffers == 0)
 		{
 			throw std::invalid_argument(std::string(__func__)
-				+ ": SpMcRingBuffer: nBuffers must be > 0");
+				+ ": SpMcRingBuffer: frameAssemblyDesc must have at least one "
+				"slot");
 		}
 
 		// Re-invoke constructors w/placement new on default-constructed frames
 		for (size_t i = 0; i < nBuffers; ++i)
 		{
 			slots[i].~StimulusFrame();  // Destroy default-constructed object
-			new (&slots[i]) StimulusFrame(
-				inputEngineConstraints, outputEngineConstraints,
-				nSlotsPerStimFrame);
+			new (&slots[i]) StimulusFrame(frameAssemblyDesc->slots[i]);
 		}
 	}
 
@@ -94,7 +99,9 @@ public:
 	size_t nBuffers;
 
 private:
-	// Frames vector: each frame contains a sequence lock and staging buffer
+	// FrameAssemblyDesc describing the memory layout
+	std::shared_ptr<FrameAssemblyDesc> frameAssemblyDesc;
+	// Frames vector: each frame contains a sequence lock and SlotDesc
 	std::vector<StimulusFrame> slots;
 };