StimBuff: Add opportunity for early lock release

commonLibs/attachmentSupport/stimulusBuffer.cpp

@@ -6,7 +6,6 @@
 #include <boost/asio/deadline_timer.hpp>
 #include <boost/system/error_code.hpp>
 #include <spinLock.h>
-#include <asynchronousBridge.h>
 #include <user/stimulusBuffer.h>
 
 namespace smo {
@@ -14,37 +13,21 @@ namespace stim_buff {
 
 void StimulusBuffer::stop()
 {
-	shouldContinue.store(false);
+	{
+		SpinLock::Guard lock(shouldContinueLock);
+		shouldContinue = false;
+	}
 
-	// Set up a timeout bridge using the io_service
+	// Cancel timer immediately
-	boost::asio::deadline_timer delayTimer(ioService);
+	timer.cancel();
-	AsynchronousBridge bridge(ioService);
-
-	// Set up the delay to let in-flight operation finish
-	delayTimer.expires_from_now(
-		boost::posix_time::milliseconds(getStopDelayMs()));
-
-	delayTimer.async_wait(
-		[&bridge](const boost::system::error_code& error)
-		{
-			(void)error;
-
-			// Always signal complete, whether timeout expired or was cancelled
-			bridge.setAsyncOperationComplete();
-		});
-
-	bridge.waitForAsyncOperationCompleteOrIoServiceStopped();
 
 	std::cout << __func__ << ": Stopped stimulus buffer for device "
 		<< deviceAttachmentSpec->deviceSelector << std::endl;
-
-	// After delay, cancel timer and perform cleanup
-	timer.cancel();
 }
 
 void StimulusBuffer::scheduleNextTimeout(int delayMs)
 {
-	if (!shouldContinue.load())
+	if (!shouldContinue)
 		{ return; }
 
 	// Schedule the next timeout using the provided delay
@@ -70,7 +53,8 @@ void StimulusBuffer::onTimeout(const boost::system::error_code& error)
 		return;
 	}
 
-	if (!shouldContinue.load())
+	SpinLock::Guard lock(shouldContinueLock);
+	if (!shouldContinue)
 		{ return; }
 
 	/**	EXPLANATION:
@@ -85,6 +69,7 @@ void StimulusBuffer::onTimeout(const boost::system::error_code& error)
 	 * sleep for CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS ms before trying again.
 	 */
 	int nextWakeupDelayMs;
+	bool deferred = false;
 	if (frameAssemblyRateLimiter.tryAcquire())
 	{
 		nextWakeupDelayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS;
@@ -97,13 +82,21 @@ void StimulusBuffer::onTimeout(const boost::system::error_code& error)
 		 */
 		stimFrameProductionTimesliceInd();
 	}
-	else {
+	else
-std::cout << __func__ << ": Deferring frame production due to rate limit." << std::endl;
+	{
-			nextWakeupDelayMs = CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS;
+		nextWakeupDelayMs = CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS;
+		deferred = true;
 	}
 
 	// Schedule next timeout with the pre-determined duration
 	scheduleNextTimeout(nextWakeupDelayMs);
+
+	// We should be able to release the start/stop lock before printing here.
+	if (deferred)
+	{
+		std::cout << __func__ << ": Deferring frame by " << nextWakeupDelayMs
+			<< "ms due to rate limit." << std::endl;
+	}
 }
 
 } // namespace stim_buff

include/user/stimulusBuffer.h

@@ -13,7 +13,6 @@
 #include <boost/asio/io_service.hpp>
 #include <boost/asio/deadline_timer.hpp>
 #include <spinLock.h>
-#include <asynchronousBridge.h>
 #include <user/spMcRingBuffer.h>
 #include "stimulusFrame.h"
 #include "deviceAttachmentSpec.h"
@@ -74,7 +73,7 @@ public:
 		std::cout << __func__ << ": Starting stimulus buffer for device "
 			<< deviceAttachmentSpec->deviceSelector << std::endl;
 
-		shouldContinue.store(true);
+		shouldContinue = true;
 		scheduleNextTimeout();
 	}
 
@@ -105,7 +104,8 @@ protected:
 
 private:
 	boost::asio::io_service& ioService;
-	std::atomic<bool> shouldContinue;
+	SpinLock shouldContinueLock;
+	bool shouldContinue;
 	boost::asio::deadline_timer timer;
 
 	void scheduleNextTimeout(int delayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS);