Nursery: Initial integration

StimulusProducer: syncAwaitAllSettlements should pump caller io_context

commonLibs/attachmentSupport/stimulusProducer.cpp

@@ -3,10 +3,9 @@
 #include <chrono>
 #include <algorithm>
 #include <boost/asio/io_context.hpp>
-#include <boost/asio/deadline_timer.hpp>
-#include <boost/system/error_code.hpp>
 #include <opts.h>
 #include <componentThread.h>
+#include <adapters/boostAsio/deadlineTimerAReq.h>
 #include <spinscale/spinLock.h>
 #include <user/stimulusProducer.h>
 #include <user/stimulusBuffer.h>
@@ -88,114 +87,136 @@ void StimulusProducer::destroyAttachedStimulusBuffer(
 	}
 }
 
-void StimulusProducer::stop()
+sscl::co::NonViralNonPostingInvoker StimulusProducer::productionCDaemon(
+	std::exception_ptr &, std::function<void()>,
+	sscl::SyncCancelerForAsyncWork &canceler)
 {
-	(void)stimulusProducerCanceler.requestStop();
+	int nextDelayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS;
 
-	// Cancel timer immediately
-	timer.cancel();
-
-	std::cout << __func__ << ": Stopped stimulus producer for device "
-		<< deviceAttachmentSpec->deviceSelector << std::endl;
-}
-
-void StimulusProducer::scheduleNextTimeout(int delayMs)
+	do
 	{
-	if (stimulusProducerCanceler.isCancellationRequestedUnlocked())
-		{ return; }
+		bool shouldProduceFrame = false;
 
-	// Schedule the next timeout using the provided delay
-	timer.expires_from_now(
-		boost::posix_time::milliseconds(delayMs));
-
-	timer.async_wait(
-		std::bind(
-			&StimulusProducer::onTimeout, this, std::placeholders::_1));
-}
-
-void StimulusProducer::onTimeout(const boost::system::error_code& error)
+		if (!canceler.execUncancelableSegmentOrAbort([&]()
 		{
-	// Timer was cancelled, which is expected when stopping
-	if (error == boost::asio::error::operation_aborted) {
-		return;
-	}
-
-	if (error)
-	{
-		std::cerr << "StimulusProducer: Timer error: " << error.message()
-			<< std::endl;
-		return;
-	}
-
-	sscl::SpinLock::Guard guard(stimulusProducerCanceler.s.lock);
-	if (stimulusProducerCanceler.isCancellationRequestedUnlocked())
-		{ return; }
-
 			/**	EXPLANATION:
-	 * We need to ensure that there's only ever one stimframe being produced
-	 * during any CONFIG_STIMBUFF_FRAME_PERIOD_MS period. To guarantee this, we
-	 * use a spinlock.
+			 * We need to ensure that there's only ever one stimframe being
+			 * produced during any CONFIG_STIMBUFF_FRAME_PERIOD_MS period. To
+			 * guarantee this, we use a spinlock.
 			 *
-	 * When a new frame is to be produced, the async producer will first acquire
-	 * the frameAssemblyLimiter spinlock. This way, when the next timeout is
-	 * fired it can check whether its predecessor stimframe has finished being
-	 * produced. If the preceding stimframe is still being produced, then we'll
-	 * sleep for CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS ms before trying again.
+			 * When a new frame is to be produced, the async producer will
+			 * first acquire the frameAssemblyLimiter spinlock. This ensures
+			 * that only one stimframe is produced during any
+			 * CONFIG_STIMBUFF_FRAME_PERIOD_MS interval. When the next 
+			 * timeout fires, it checks if the previous stimframe has 
+			 * finished production. If the previous stimframe is still 
+			 * being produced, we will sleep for 
+			 * CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS ms before retrying.
 			 */
-	int nextWakeupDelayMs;
-	bool deferred = false;
 			if (frameAssemblyRateLimiter.tryAcquire())
 			{
-		nextWakeupDelayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS;
+				nextDelayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS;
 
 				// Check if we're ending a deferral period
 				if (nDeferrals > 0)
 				{
-			auto deferralEndTime = std::chrono::high_resolution_clock::now();
+					auto deferralEndTime =
+						std::chrono::high_resolution_clock::now();
 					auto duration = deferralEndTime - deferralStartTime;
 					auto durationMs = std::chrono::duration_cast<
 						std::chrono::milliseconds>(duration);
 
-			std::cout << __func__ << ": Deferral period ended. "
+					std::cout << "productionCDaemon: Deferral period ended. "
 						<< "Total deferrals: " << nDeferrals
-				<< ", Duration: " << durationMs.count() << "ms" << std::endl;
+						<< ", Duration: " << durationMs.count()
+						<< "ms" << std::endl;
 
 					nDeferrals = 0;
 				}
 
-		/**	EXPLANATION:
-		 * Call the derived class's frame production handler
-		 * Note: The derived class's frame production handler (aka
-		 * its implementation of stimFrameProductionTimesliceInd()) must
-		 * release the lock when frame production completes
-		 */
-		stimFrameProductionTimesliceInd();
+				shouldProduceFrame = true;
 			}
 			else
 			{
-		nextWakeupDelayMs = CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS;
-		deferred = true;
+				nextDelayMs = CONFIG_STIMBUFF_FRAME_RETRY_DELAY_MS;
 
 				++nDeferrals;
 				// If this is first deferral, capture start stamp and print message
 				if (nDeferrals == 1)
 				{
-			deferralStartTime = std::chrono::high_resolution_clock::now();
-			std::cerr << __func__ << ": Deferral period beginning. "
-				"Configured deferral period: " << nextWakeupDelayMs << "ms"
-				<< std::endl;
+					deferralStartTime =
+						std::chrono::high_resolution_clock::now();
+					std::cerr << "productionCDaemon: Deferral period "
+						"beginning. Configured deferral period: "
+						<< nextDelayMs << "ms" << std::endl;
 				}
 			}
+		}))
+			{ break; }
+
+		if (shouldProduceFrame)
+		{
+			/**	EXPLANATION:
+			 * Call the derived class's frame production handler
+			 * Note: The derived class's frame production handler (aka
+			 * its implementation of stimFrameProductionTimesliceCInd()) must
+			 * release the lock when frame production completes
+			 */
+			co_await stimFrameProductionTimesliceCInd(canceler);
+		}
+		else if (OptionParser::getOptions().verbose)
+		{
+			std::cerr << "productionCDaemon: Deferring frame by "
+				<< nextDelayMs << "ms due to rate limit." << std::endl;
+		}
 
-	scheduleNextTimeout(nextWakeupDelayMs);
+		// Schedule the next timeout using the provided delay
+		const bool expiredNormally = co_await
+			adapters::boostAsio::getDeadlineTimerAReqAwaiter(
+				ioContext,
+				daemonTimer,
+				boost::posix_time::milliseconds(nextDelayMs));
+
+		if (!expiredNormally) {
+			// Timer was cancelled, which is expected when stopping
+			break;
+		}
 
 		// FIXME: We should be able to release the start/stop lock at this point.
 
-	if (deferred && OptionParser::getOptions().verbose)
-	{
-		std::cerr << __func__ << ": Deferring frame by " << nextWakeupDelayMs
-			<< "ms due to rate limit." << std::endl;
+	} while (!canceler.isCancellationRequested());
+
+	co_return;
 }
+
+void StimulusProducer::start()
+{
+	std::cout << __func__ << ": Starting stimulus producer for device "
+		<< deviceAttachmentSpec->deviceSelector << std::endl;
+
+	nDeferrals = 0;
+	taskNursery.openAdmission();
+	taskNursery.launch(
+		[this](sscl::co::NonViralTaskNursery::Slot::Lease &lease)
+		{
+			return productionCDaemon(
+				lease.getExceptionStorage(),
+				lease.getCallerLambda(),
+				lease.getSyncCanceler());
+		});
+}
+
+void StimulusProducer::stop()
+{
+	// Cancel timer immediately
+	daemonTimer.cancel();
+	taskNursery.requestCancelOnAll();
+	taskNursery.closeAdmission();
+	taskNursery.syncAwaitAllSettlements(
+		sscl::ComponentThread::getSelf()->getIoContext());
+
+	std::cout << __func__ << ": Stopped stimulus producer for device "
+		<< deviceAttachmentSpec->deviceSelector << std::endl;
 }
 
 } // namespace stim_buff

commonLibs/livoxProto1/udpCommandDemuxer.cpp

@@ -577,11 +577,11 @@ UdpCommandDemuxer::waitForCommandResponseCReq(
 	 * we will consider the command to have failed.
 	 */
 	boost::asio::io_context &ioContext = componentThread->getIoContext();
-	std::optional<std::shared_ptr<boost::asio::deadline_timer>> raceTimer;
+	boost::asio::deadline_timer raceTimer(ioContext);
 	auto timerAwaiter = adapters::boostAsio::getDeadlineTimerAReqAwaiter(
 		ioContext,
-		boost::posix_time::milliseconds(timeoutMs),
-		raceTimer);
+		raceTimer,
+		boost::posix_time::milliseconds(timeoutMs));
 	auto responseInvoker = waitForCommandResponseCReq(cmdSet, cmdId, deviceIp);
 
 	static constexpr int timerMemberSettlementIndex = 0;
@@ -598,8 +598,8 @@ UdpCommandDemuxer::waitForCommandResponseCReq(
 
 	if (timerWonFirst) {
 		cancelPendingCommandWait(cmdSet, cmdId, deviceIp);
-	} else if (raceTimer) {
-		(*raceTimer)->cancel();
+	} else {
+		raceTimer.cancel();
 	}
 
 	/** Group member adapter coros are fire-and-forget; keep group alive until

include/adapters/boostAsio/deadlineTimerAReq.h

@@ -5,7 +5,6 @@
 #include <atomic>
 #include <coroutine>
 #include <memory>
-#include <optional>
 
 #include <boost/asio/deadline_timer.hpp>
 #include <boost/asio/io_context.hpp>
@@ -15,7 +14,10 @@
 
 namespace adapters::boostAsio {
 
-/** Coroutine awaiter: true if the delay elapsed, false if cancelled/aborted. */
+/** Coroutine awaiter: true if the delay elapsed, false if cancelled/aborted.
+ *
+ * Reuses the caller-supplied deadline_timer; does not allocate a new timer.
+ */
 class DeadlineTimerAReq
 {
 public:
@@ -24,22 +26,17 @@ public:
 		std::atomic<bool> settled{false};
 		bool timerExpiredNormally = false;
 		std::coroutine_handle<> callerSchedHandle;
-		std::shared_ptr<boost::asio::deadline_timer> timer;
 	};
 
 	DeadlineTimerAReq(
 		boost::asio::io_context &resumeIoContext,
-		const boost::posix_time::milliseconds delay,
-		std::optional<std::shared_ptr<boost::asio::deadline_timer>> &timerOut)
+		boost::asio::deadline_timer &timer,
+		const boost::posix_time::milliseconds delay)
 	:	asyncState(std::make_shared<AsyncState>()),
 	resumeIoContext(resumeIoContext)
 	{
-		asyncState->timer =
-			std::make_shared<boost::asio::deadline_timer>(resumeIoContext);
-		timerOut = asyncState->timer;
-
-		asyncState->timer->expires_from_now(delay);
-		asyncState->timer->async_wait(
+		timer.expires_from_now(delay);
+		timer.async_wait(
 			[this](const boost::system::error_code &error)
 			{
 				onTimer(error);
@@ -92,19 +89,11 @@ private:
 };
 
 inline auto getDeadlineTimerAReqAwaiter(
-	boost::asio::io_context &ioContext,
+	boost::asio::io_context &resumeIoContext,
+	boost::asio::deadline_timer &timer,
 	const boost::posix_time::milliseconds delay)
 {
-	std::optional<std::shared_ptr<boost::asio::deadline_timer>> timerOut;
-	return DeadlineTimerAReq(ioContext, delay, timerOut);
-}
-
-inline auto getDeadlineTimerAReqAwaiter(
-	boost::asio::io_context &ioContext,
-	const boost::posix_time::milliseconds delay,
-	std::optional<std::shared_ptr<boost::asio::deadline_timer>> &timerOut)
-{
-	return DeadlineTimerAReq(ioContext, delay, timerOut);
+	return DeadlineTimerAReq(resumeIoContext, timer, delay);
 }
 
 } // namespace adapters::boostAsio

include/user/stimulusProducer.h

@@ -4,14 +4,14 @@
 #include <vector>
 #include <memory>
 #include <cstdint>
-#include <atomic>
-#include <mutex>
 #include <functional>
 #include <iostream>
 #include <chrono>
 #include <config.h>
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/deadline_timer.hpp>
+#include <spinscale/co/invokers.h>
+#include <spinscale/co/nonViralTaskNursery.h>
 #include <spinscale/spinLock.h>
 #include <spinscale/syncCancelerForAsyncWork.h>
 #include "deviceAttachmentSpec.h"
@@ -39,9 +39,8 @@ public:
 		const std::shared_ptr<device::DeviceAttachmentSpec>
 			&deviceAttachmentSpec,
 		boost::asio::io_context& ioContext_)
-	: deviceAttachmentSpec(deviceAttachmentSpec),
-	ioContext(ioContext_),
-	timer(ioContext), nDeferrals(0)
+	: daemonTimer(ioContext_), nDeferrals(0),
+	deviceAttachmentSpec(deviceAttachmentSpec), ioContext(ioContext_)
 	{}
 
 	virtual ~StimulusProducer() = default;
@@ -52,17 +51,7 @@ public:
 	StimulusProducer(StimulusProducer&&) = default;
 	StimulusProducer& operator=(StimulusProducer&&) = default;
 
-	// Control methods
-	virtual void start()
-	{
-		std::cout << __func__ << ": Starting stimulus producer for device "
-			<< deviceAttachmentSpec->deviceSelector << std::endl;
-
-		stimulusProducerCanceler.startAcceptingWork();
-		nDeferrals = 0;
-		scheduleNextTimeout();
-	}
-
+	virtual void start();
 	virtual void stop();
 
 	void allowNextStimulusFrame()
@@ -96,10 +85,19 @@ protected:
 		return CONFIG_STIMBUFF_FRAME_PERIOD_MS;
 	}
 
-	virtual void stimFrameProductionTimesliceInd() = 0;
+	virtual sscl::co::ViralNonPostingInvoker<void>
+		stimFrameProductionTimesliceCInd(
+			sscl::SyncCancelerForAsyncWork &canceler) = 0;
 
-private:
-	void onTimeout(const boost::system::error_code& error);
+	sscl::co::NonViralNonPostingInvoker productionCDaemon(
+		std::exception_ptr &exceptionPtr,
+		std::function<void()> callback,
+		sscl::SyncCancelerForAsyncWork &canceler);
+
+	sscl::co::NonViralTaskNursery taskNursery;
+	boost::asio::deadline_timer daemonTimer;
+	size_t nDeferrals;
+	std::chrono::high_resolution_clock::time_point deferralStartTime;
 
 public:
 	std::shared_ptr<device::DeviceAttachmentSpec> deviceAttachmentSpec;
@@ -107,14 +105,6 @@ public:
 
 private:
 	boost::asio::io_context& ioContext;
-protected:
-	sscl::SyncCancelerForAsyncWork stimulusProducerCanceler;
-private:
-	boost::asio::deadline_timer timer;
-	size_t nDeferrals;
-	std::chrono::high_resolution_clock::time_point deferralStartTime;
-
-	void scheduleNextTimeout(int delayMs = CONFIG_STIMBUFF_FRAME_PERIOD_MS);
 };
 
 } // namespace stim_buff

smocore/deviceManager/deviceReattacher.cpp

@@ -1,161 +1,88 @@
 #include <config.h>
-#include <chrono>
 #include <iostream>
 #include <functional>
 #include <componentThread.h>
+#include <adapters/boostAsio/deadlineTimerAReq.h>
 #include <deviceManager/deviceReattacher.h>
 #include <deviceManager/deviceManager.h>
-#include <marionette/marionetteThread.h>
 #include <spinscale/co/nonViralCompletion.h>
 
 namespace smo {
 namespace device {
 
-namespace {
-
-constexpr unsigned int reattachInFlightStaleThresholdMultiplier = 4;
-
-} // namespace
-
 DeviceReattacher::DeviceReattacher(
 	DeviceManager& parent, std::shared_ptr<sscl::ComponentThread> ioThread)
-: parent(parent), ioThread(ioThread), timer(ioThread->getIoContext())
+:	parent(parent),
+ioThread(ioThread), daemonTimer(ioThread->getIoContext())
 {
 	/**	EXPLANATION:
-	 * The thread on which DeviceReattacher runs is whichever thread executes
-	 * the io_context that owns deadline_timer. Timer async_wait handlers
-	 * (onTimeout, holdReattachCReq, reattachKnownListCReq) are dispatched on
-	 * that thread. ioThread selects that io_context here; start() only arms
-	 * the timer on it.
+	 * deviceReattacherCDaemon is a dynamic posting non-viral coroutine: start()
+	 * passes ExplicitPostTarget{ioThread->getIoContext()} so the daemon body
+	 * always runs on ioThread. daemonTimer is reused each loop iteration.
 	 */
 }
 
-mrntt::MrnttNonViralNonPostingInvoker DeviceReattacher::reattachKnownListCReq(
+sscl::co::DynamicNonViralPostingInvoker
+DeviceReattacher::deviceReattacherCDaemon(
+	[[maybe_unused]] sscl::co::ExplicitPostTarget postTarget,
 	[[maybe_unused]] std::exception_ptr &exceptionPtr,
-	[[maybe_unused]] std::function<void()> callback)
+	[[maybe_unused]] std::function<void()> callback,
+	sscl::SyncCancelerForAsyncWork &canceler)
 {
-	/**	EXPLANATION:
-	 * Non-posting: invoked from holdReattachCReq on the timer callback thread
-	 * (see ctor). Nested DeviceManager attach APIs still post to MRNTT as
-	 * needed via their own viral posting invokers.
-	 */
+	boost::asio::io_context &timerIoContext =
+		sscl::ComponentThread::getSelf()->getIoContext();
+	const auto periodMs = boost::posix_time::milliseconds(
+		CONFIG_MRNTT_DEVMGR_REATTACHER_PERIOD_MS);
+
+	while (!canceler.isCancellationRequested())
+	{
+		const bool expiredNormally = co_await
+			adapters::boostAsio::getDeadlineTimerAReqAwaiter(
+				timerIoContext, daemonTimer, periodMs);
+
+		if (!expiredNormally) {
+			break;
+		}
+
 		co_await parent.attachAllUnattachedDevicesFromKnownListCReq();
+	}
+
 	co_return;
 }
 
 void DeviceReattacher::start()
 {
-	deviceReattacherCanceler.startAcceptingWork();
-	scheduleNextTimeout();
-}
-
-void DeviceReattacher::stop()
+	taskNursery.openAdmission();
+	taskNursery.launch(
+		[this](sscl::co::NonViralTaskNursery::Slot::Lease &lease)
 		{
+			return deviceReattacherCDaemon(
+				sscl::co::ExplicitPostTarget{ioThread->getIoContext()},
+				lease.getExceptionStorage(),
+				lease.getCallerLambda(),
+				lease.getSyncCanceler());
+		},
+		[](std::exception_ptr &exceptionPtr)
 		{
-		sscl::SpinLock::Guard guard(deviceReattacherCanceler.s.lock);
-		reattachOpInFlight = false;
-		deviceReattacherCanceler.s.rsrc.shouldContinue = false;
-		/**	EXPLANATION:
-		 * Do not call reattachCReqInvoker.reset() here. Forcibly destroying
-		 * the invoker would tear down an in-flight reattach coroutine frame
-		 * mid-operation. During normal program teardown the optional (and
-		 * its invoker) are destroyed with the rest of the binary anyway; leave
-		 * a running reattach time to finish if shutdown races with it.
-		 */
-	}
-
-	timer.cancel();
-}
-
-void DeviceReattacher::scheduleNextTimeout()
-{
-	if (deviceReattacherCanceler.isCancellationRequestedUnlocked()) {
-		return;
-	}
-
-	// Schedule the next timeout using the configured period
-	timer.expires_from_now(
-		boost::posix_time::milliseconds(
-			CONFIG_MRNTT_DEVMGR_REATTACHER_PERIOD_MS));
-
-	timer.async_wait(
-		std::bind(&DeviceReattacher::onTimeout, this, std::placeholders::_1));
-}
-
-void DeviceReattacher::holdReattachCReq()
-{
-	reattachOpInFlight = true;
-	lastReattachReqTimestamp = std::chrono::steady_clock::now();
-
-	reattachCReqInvoker.reset();
-	reattachCReqInvoker.emplace(reattachKnownListCReq(
-		reattachLifetimeExceptionPtr,
-		[this]()
-		{
-			sscl::co::NonViralCompletion nvc(reattachLifetimeExceptionPtr);
+			sscl::co::NonViralCompletion nvc(exceptionPtr);
 			if (nvc.hasException())
 			{
 				try {
 					nvc.checkAndRethrowException();
 				} catch (const std::exception &e) {
-					std::cerr << "DeviceReattacher: " << e.what()
-						<< std::endl;
+					std::cerr << "DeviceReattacher: "
+						<< e.what() << std::endl;
 				}
 			}
+		});
+}
 
-			sscl::SpinLock::Guard guard(deviceReattacherCanceler.s.lock);
-			reattachOpInFlight = false;
-		}));
-}
-
-void DeviceReattacher::onTimeout(const boost::system::error_code& error)
+void DeviceReattacher::stop()
 {
-	// Timer was cancelled, which is expected when stopping
-	if (error == boost::asio::error::operation_aborted) {
-		return;
-	}
-
-	if (error)
-	{
-		std::cerr << "DeviceReattacher: Timer error: " << error.message()
-			<< std::endl;
-		return;
-	}
-
-	sscl::SpinLock::Guard guard(deviceReattacherCanceler.s.lock);
-	if (deviceReattacherCanceler.isCancellationRequestedUnlocked()) {
-		return;
-	}
-
-	const auto staleThreshold = std::chrono::milliseconds(
-		reattachInFlightStaleThresholdMultiplier
-			* CONFIG_MRNTT_DEVMGR_REATTACHER_PERIOD_MS);
-
-	// Attempt to reattach all unattached devices from the known list
-	if (!reattachOpInFlight)
-	{
-		holdReattachCReq();
-	}
-	else
-	{
-		const auto elapsedSinceLastReattachReq =
-			std::chrono::steady_clock::now() - lastReattachReqTimestamp;
-
-		if (elapsedSinceLastReattachReq >= staleThreshold)
-		{
-			std::cerr << "DeviceReattacher: Reattach op still in flight after "
-				<< std::chrono::duration_cast<std::chrono::milliseconds>(
-					elapsedSinceLastReattachReq).count()
-				<< "ms (threshold "
-				<< staleThreshold.count()
-				<< "ms); forcing a new reattach request."
-				<< std::endl;
-			holdReattachCReq();
-		}
-	}
-
-	// Schedule the next timeout
-	scheduleNextTimeout();
+	daemonTimer.cancel();
+	taskNursery.requestCancelOnAll();
+	taskNursery.closeAdmission();
+	taskNursery.syncAwaitAllSettlements(ioThread->getIoContext());
 }
 
 } // namespace device

smocore/include/deviceManager/deviceReattacher.h

@@ -1,14 +1,12 @@
 #ifndef DEVICEREATTACHER_H
 #define DEVICEREATTACHER_H
 
-#include <atomic>
-#include <chrono>
-#include <exception>
 #include <functional>
 #include <memory>
-#include <optional>
 #include <boost/asio/deadline_timer.hpp>
-#include <marionette/marionetteThread.h>
+#include <spinscale/co/dynamicPostingInvoker.h>
+#include <spinscale/co/nonViralTaskNursery.h>
+#include <spinscale/co/postTarget.h>
 #include <spinscale/syncCancelerForAsyncWork.h>
 
 namespace smo {
@@ -32,23 +30,17 @@ public:
 	void stop();
 
 private:
-	void scheduleNextTimeout();
-	void onTimeout(const boost::system::error_code& error);
-	void holdReattachCReq();
-
-	mrntt::MrnttNonViralNonPostingInvoker reattachKnownListCReq(
+	sscl::co::DynamicNonViralPostingInvoker deviceReattacherCDaemon(
+		sscl::co::ExplicitPostTarget postTarget,
 		std::exception_ptr &exceptionPtr,
-		std::function<void()> callback);
+		std::function<void()> callback,
+		sscl::SyncCancelerForAsyncWork &canceler);
 
 	DeviceManager &parent;
-	// io_context thread for timer and non-posting reattach shell (see ctor).
+	// io_context thread for timer (see ctor).
 	std::shared_ptr<sscl::ComponentThread> ioThread;
-	sscl::SyncCancelerForAsyncWork deviceReattacherCanceler;
-	boost::asio::deadline_timer timer;
-	std::exception_ptr reattachLifetimeExceptionPtr;
-	std::optional<mrntt::MrnttNonViralNonPostingInvoker> reattachCReqInvoker;
-	bool reattachOpInFlight = false;
-	std::chrono::steady_clock::time_point lastReattachReqTimestamp{};
+	sscl::co::NonViralTaskNursery taskNursery;
+	boost::asio::deadline_timer daemonTimer;
 };
 
 } // namespace device

smocore/include/marionette/marionette.h

@@ -9,6 +9,7 @@
 #include <memory>
 #include <optional>
 #include <spinscale/component.h>
+#include <spinscale/co/nonViralTaskNursery.h>
 #include <marionette/marionetteThread.h>
 
 namespace sscl {
@@ -29,8 +30,10 @@ public:
 	{}
 	~MarionetteComponent() = default;
 
-	void holdInitializeCReq(std::function<void()> completion);
-	void holdFinalizeCReq(std::function<void()> completion);
+	void holdInitializeCReq(
+		std::function<void(std::exception_ptr &exceptionPtr)> completion);
+	void holdFinalizeCReq(
+		std::function<void(std::exception_ptr &exceptionPtr)> completion);
 
 	MrnttNonViralPostingInvoker initializeCReq(
 		std::exception_ptr &exceptionPtr,
@@ -58,12 +61,7 @@ protected:
 private:
 	std::unique_ptr<boost::asio::signal_set> signals;
 	bool callShutdownSalmanoff = false;
-	std::optional<MrnttNonViralPostingInvoker> initializeCReqInvoker;
-	std::optional<MrnttNonViralPostingInvoker> finalizeCReqInvoker;
-
-public:
-	std::exception_ptr initializeLifetimeExceptionPtr;
-	std::exception_ptr finalizeLifetimeExceptionPtr;
+	sscl::co::NonViralTaskNursery taskNursery;
 };
 
 extern std::shared_ptr<sscl::PuppeteerThread> thread;

smocore/marionette/lifetime.cpp

@@ -30,33 +30,29 @@ void assertMarionetteThread()
 } // namespace
 
 void MarionetteComponent::holdInitializeCReq(
-	std::function<void()> completion)
+	std::function<void(std::exception_ptr &exceptionPtr)> completion)
 {
-	initializeLifetimeExceptionPtr = nullptr;
-	initializeCReqInvoker.emplace(initializeCReq(
-		initializeLifetimeExceptionPtr,
-		[completion = std::move(completion)]()
+	taskNursery.launch(
+		[this](sscl::co::NonViralTaskNursery::Slot::Lease &lease)
 		{
-			sscl::co::NonViralCompletion nvc(
-				mrntt.initializeLifetimeExceptionPtr);
-			nvc.checkAndRethrowException();
-			completion();
-		}));
+			return initializeCReq(
+				lease.getExceptionStorage(),
+				lease.getCallerLambda());
+		},
+		std::move(completion));
 }
 
 void MarionetteComponent::holdFinalizeCReq(
-	std::function<void()> completion)
+	std::function<void(std::exception_ptr &exceptionPtr)> completion)
 {
-	finalizeLifetimeExceptionPtr = nullptr;
-	finalizeCReqInvoker.emplace(finalizeCReq(
-		finalizeLifetimeExceptionPtr,
-		[completion = std::move(completion)]()
+	taskNursery.launch(
+		[this](sscl::co::NonViralTaskNursery::Slot::Lease &lease)
 		{
-			sscl::co::NonViralCompletion nvc(
-				mrntt.finalizeLifetimeExceptionPtr);
-			nvc.checkAndRethrowException();
-			completion();
-		}));
+			return finalizeCReq(
+				lease.getExceptionStorage(),
+				lease.getCallerLambda());
+		},
+		std::move(completion));
 }
 
 MrnttNonViralPostingInvoker MarionetteComponent::initializeCReq(
@@ -107,7 +103,12 @@ void MarionetteComponent::exceptionInd()
 		[]
 		{
 			mrntt.holdFinalizeCReq(
-				[]() { marionetteFinalizeReqCb(true); });
+				[](std::exception_ptr &exceptionPtr)
+				{
+					sscl::co::NonViralCompletion nvc(exceptionPtr);
+					nvc.checkAndRethrowException();
+					marionetteFinalizeReqCb(true);
+				});
 		});
 }
 

smocore/marionette/main.cpp

@@ -5,6 +5,7 @@
 #include <spinscale/component.h>
 #include <spinscale/componentThread.h>
 #include <marionette/marionette.h>
+#include <spinscale/co/nonViralCompletion.h>
 #include <spinscale/runtime.h>
 #include <componentThread.h>
 #include <mindManager/mindManager.h>
@@ -33,7 +34,12 @@ void marionetteInitializeReqCb(bool success)
 		<< '\n';
 
 	mrntt.holdFinalizeCReq(
-		[]() { marionetteFinalizeReqCb(true); });
+		[](std::exception_ptr &exceptionPtr)
+		{
+			sscl::co::NonViralCompletion nvc(exceptionPtr);
+			nvc.checkAndRethrowException();
+			marionetteFinalizeReqCb(true);
+		});
 }
 
 void marionetteFinalizeReqCb(bool success)
@@ -82,7 +88,12 @@ void MarionetteComponent::postJoltHook()
 					break;
 			}
 			mrntt.holdFinalizeCReq(
-				[]() { marionetteFinalizeReqCb(true); });
+				[](std::exception_ptr &exceptionPtr)
+				{
+					sscl::co::NonViralCompletion nvc(exceptionPtr);
+					nvc.checkAndRethrowException();
+					marionetteFinalizeReqCb(true);
+				});
 		});
 }
 
@@ -128,14 +139,24 @@ void MarionetteComponent::preLoopHook()
 	smo::initializeSalmanoff();
 	callShutdownSalmanoff = true;
 
+	taskNursery.openAdmission();
+
 	holdInitializeCReq(
-		[] { marionetteInitializeReqCb(true); });
+		[](std::exception_ptr &exceptionPtr)
+		{
+			sscl::co::NonViralCompletion nvc(exceptionPtr);
+			nvc.checkAndRethrowException();
+			marionetteInitializeReqCb(true);
+		});
 
 	std::cout << "PuppeteerThread::main: Entering event loop" << "\n";
 }
 
 void MarionetteComponent::postLoopHook()
 {
+	taskNursery.requestCancelOnAll();
+	taskNursery.closeAdmission();
+
 	std::cout << "PuppeteerThread::main: Exited event loop" << "\n";
 }
 

stimBuffApis/livoxGen1/livoxGen1.cpp

@@ -355,8 +355,11 @@ attachByCreatingProducer(
 	 * may not yet be ready for another command.
 	 */
 	// Initialize timer with LivoxGen1 metadata io_context
+	boost::asio::deadline_timer commandDelayTimer(
+		componentThread->getIoContext());
 	const bool delayOk = co_await adapters::boostAsio::getDeadlineTimerAReqAwaiter(
 		componentThread->getIoContext(),
+		commandDelayTimer,
 		boost::posix_time::milliseconds(LIVOX_GEN1_DEVICE_COMMAND_DELAY_MS));
 
 	if (!delayOk)
@@ -542,8 +545,11 @@ livoxGen1_detachDeviceCReq(
 
     // Helper method to delay and then call destroyDeviceReq
     // Initialize timer with LivoxGen1 metadata io_context
+	boost::asio::deadline_timer commandDelayTimer(
+		requestComponentThread->getIoContext());
 	co_await adapters::boostAsio::getDeadlineTimerAReqAwaiter(
 		requestComponentThread->getIoContext(),
+		commandDelayTimer,
 		boost::posix_time::milliseconds(LIVOX_GEN1_DEVICE_COMMAND_DELAY_MS));
 
 	// No other buffers - stop and remove StimProducer

stimBuffApis/livoxGen1/pcloudStimulusProducer.cpp

@@ -428,11 +428,6 @@ PcloudStimulusProducer::getOrCreateAttachedStimulusBuffer(
 	}
 }
 
-void PcloudStimulusProducer::stimFrameProductionTimesliceInd()
-{
-	holdProduceFrameCReq();
-}
-
 struct AllowNextStimulusFrameGuard
 {
 	PcloudStimulusProducer& producer;
@@ -445,22 +440,14 @@ struct AllowNextStimulusFrameGuard
 		{ producer.allowNextStimulusFrame(); }
 };
 
-void PcloudStimulusProducer::holdProduceFrameCReq()
-{
 /**	EXPLANATION:
-	 * We shouldn't acquire stimulusProducerCanceler.s.lock here because
-	 * this function is called from
-	 * StimulusProducer::stimFrameProductionTimesliceInd(), which is already
-	 * holding the lock.
+ * productionCDaemon co_awaits this viral timeslice and passes its
+ * nursery-slot canceler. Cooperative shutdown uses that canceler between
+ * co_await steps; do not use execUncancelableSegmentOrAbort here.
  */
-	activeProduceFrameInvoker.emplace(produceFrameCReq(
-		produceFrameExceptionPtr,
-		[this]() { activeProduceFrameInvoker.reset(); }));
-}
-
-sscl::co::NonViralNonPostingInvoker PcloudStimulusProducer::produceFrameCReq(
-	[[maybe_unused]] std::exception_ptr& exceptionPtr,
-	[[maybe_unused]] std::function<void()> completion)
+sscl::co::ViralNonPostingInvoker<void>
+PcloudStimulusProducer::stimFrameProductionTimesliceCInd(
+	sscl::SyncCancelerForAsyncWork &canceler)
 {
 	AllowNextStimulusFrameGuard allowNextGuard(*this);
 	StimulusFrame& stimulusFrame = tempStimulusFrame;
@@ -473,14 +460,11 @@ sscl::co::NonViralNonPostingInvoker PcloudStimulusProducer::produceFrameCReq(
 
 	// produceFrameReq1_doAssemble_posted
 	/**	EXPLANATION:
-	 * stimFrameProductionTimesliceInd() is entered with
-	 * stimulusProducerCanceler.s.lock held; do not re-acquire here.
-	 *
-     * This function is called from
-     * StimulusProducer::stimFrameProductionTimesliceInd(), whose caller is
-	 * already holding the lock.
+	 * productionCDaemon co_awaits this timeslice outside its uncancelable
+	 * rate-limiter segment; use isCancellationRequested() here, not
+	 * execUncancelableSegmentOrAbort.
      */
-	if (stimulusProducerCanceler.isCancellationRequestedUnlocked())
+	if (canceler.isCancellationRequested())
 		{ co_return; }
 
 	cpsBoundary::AssembleFrameResult assembleResult = co_await
@@ -491,8 +475,8 @@ sscl::co::NonViralNonPostingInvoker PcloudStimulusProducer::produceFrameCReq(
 	std::optional<AmbienceProductionDesc> lightAmbienceProductionDescDesc;
 	std::optional<AmbienceProductionDesc> darkAmbienceProductionDescDesc;
 	{
-		sscl::SpinLock::Guard guard(stimulusProducerCanceler.s.lock);
-		if (stimulusProducerCanceler.isCancellationRequestedUnlocked())
+		sscl::SpinLock::Guard guard(canceler.s.lock);
+		if (canceler.isCancellationRequestedUnlocked())
 			{ co_return; }
 
 		if (!assembleResult.success)
@@ -612,8 +596,8 @@ sscl::co::NonViralNonPostingInvoker PcloudStimulusProducer::produceFrameCReq(
 	}
 
 	{
-		sscl::SpinLock::Guard guard(stimulusProducerCanceler.s.lock);
-		if (stimulusProducerCanceler.isCancellationRequestedUnlocked())
+		sscl::SpinLock::Guard guard(canceler.s.lock);
+		if (canceler.isCancellationRequestedUnlocked())
 			{ co_return; }
 
 		if (!compactCollateSuccess) {

stimBuffApis/livoxGen1/pcloudStimulusProducer.h

@@ -82,13 +82,9 @@ public:
 		const std::shared_ptr<StimulusBuffer>& buffer) override;
 
 protected:
-	void stimFrameProductionTimesliceInd() override;
-
-	void holdProduceFrameCReq();
-
-	sscl::co::NonViralNonPostingInvoker produceFrameCReq(
-		std::exception_ptr& exceptionPtr,
-		std::function<void()> completion);
+	sscl::co::ViralNonPostingInvoker<void>
+		stimFrameProductionTimesliceCInd(
+			sscl::SyncCancelerForAsyncWork &canceler) override;
 
 public:
 	size_t nDgramsPerStagingBufferFrame;
@@ -112,9 +108,6 @@ public:
 		lightAmbienceStimulusBuffer;
 	std::atomic<std::shared_ptr<PcloudDarkAmbienceStimulusBuffer>>
 		darkAmbienceStimulusBuffer;
-
-	std::optional<sscl::co::NonViralNonPostingInvoker> activeProduceFrameInvoker;
-	std::exception_ptr produceFrameExceptionPtr;
 };
 
 } // namespace stim_buff

tests/libspinscale/nonViralTaskNursery_tests.cpp

@@ -139,7 +139,9 @@ TEST_F(NonViralTaskNurseryTest, SetOnSettledHookRejectsAfterFillSlot)
 				lease.getCallerLambda());
 		});
 
-	EXPECT_THROW(lease.setOnSettledHook([]() {}), std::runtime_error);
+	EXPECT_THROW(
+		lease.setOnSettledHook([](std::exception_ptr &) {}),
+		std::runtime_error);
 	lease.commit();
 }
 
@@ -322,6 +324,26 @@ TEST_F(NonViralTaskNurseryTest, LaunchSugar)
 	EXPECT_TRUE(nursery.allSettled());
 }
 
+TEST_F(NonViralTaskNurseryTest, LaunchWithOnSettledHook)
+{
+	std::atomic<bool> hookRan{false};
+
+	nursery.launch(
+		[](sscl::co::NonViralTaskNursery::Slot::Lease &lease)
+		{
+			return immediateCompleteCReq(
+				lease.getExceptionStorage(),
+				lease.getCallerLambda());
+		},
+		[&hookRan](std::exception_ptr &)
+		{
+			hookRan.store(true, std::memory_order_release);
+		});
+
+	EXPECT_TRUE(hookRan.load(std::memory_order_acquire));
+	EXPECT_TRUE(nursery.allSettled());
+}
+
 TEST_F(NonViralTaskNurseryTest, HandleStability)
 {
 	auto handle = nursery.launch(
@@ -520,7 +542,7 @@ TEST_F(NonViralTaskNurseryTest, OnSettledHookRunsAtRetirement)
 
 	auto lease = nursery.getNewSlotLease();
 	lease.setOnSettledHook(
-		[&hookRan]()
+		[&hookRan](std::exception_ptr &)
 		{
 			hookRan.store(true, std::memory_order_release);
 		});
@@ -536,13 +558,14 @@ TEST_F(NonViralTaskNurseryTest, OnSettledHookRunsAtRetirement)
 	EXPECT_TRUE(hookRan.load(std::memory_order_acquire));
 }
 
-TEST_F(NonViralTaskNurseryTest, OnSettledHookExceptionStillRetiresSlot)
+TEST_F(NonViralTaskNurseryTest, OnSettledHookSeesRetiredSlot)
 {
 	auto lease = nursery.getNewSlotLease();
 	lease.setOnSettledHook(
-		[]()
+		[this](std::exception_ptr &)
 		{
-			throw std::runtime_error("onSettled hook failure");
+			EXPECT_TRUE(nursery.allSettled());
+			EXPECT_EQ(nursery.unsettledCount(), 0U);
 		});
 	lease.fillSlot(
 		[&lease]()
@@ -552,9 +575,6 @@ TEST_F(NonViralTaskNurseryTest, OnSettledHookExceptionStillRetiresSlot)
 				lease.getCallerLambda());
 		});
 	lease.commit();
-
-	EXPECT_TRUE(nursery.allSettled());
-	EXPECT_EQ(nursery.unsettledCount(), 0U);
 }
 
 TEST_F(NonViralTaskNurseryTest, DuplicateRetireThrows)

tests/smocore/qutex_tests.cpp

@@ -25,6 +25,7 @@ public:
     }
 
     void awaken(bool forceAwaken = false) override {
+        (void)forceAwaken;
         awakened = true;
     }
 };