Async: Drop-in SyncCancelerForAsyncWork without execUncancelableSegment*

We're doing this to prep for the coro port

smocore/deviceManager/deviceReattacher.cpp

@@ -18,8 +18,7 @@ constexpr unsigned int reattachInFlightStaleThresholdMultiplier = 4;
 
 DeviceReattacher::DeviceReattacher(
 	DeviceManager& parent, std::shared_ptr<sscl::ComponentThread> ioThread)
-: parent(parent), ioThread(ioThread), shouldContinue(false),
-timer(ioThread->getIoService())
+: parent(parent), ioThread(ioThread), timer(ioThread->getIoService())
 {
 }
 
@@ -41,16 +40,16 @@ mrntt::MrnttNonViralPostingInvoker DeviceReattacher::reattachKnownListCReq(
 
 void DeviceReattacher::start()
 {
-	shouldContinue = true;
+	deviceReattacherCanceler.startAcceptingWork();
 	scheduleNextTimeout();
 }
 
 void DeviceReattacher::stop()
 {
 	{
-		sscl::SpinLock::Guard lock(shouldContinueLock);
-		shouldContinue = false;
+		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
@@ -65,7 +64,7 @@ void DeviceReattacher::stop()
 
 void DeviceReattacher::scheduleNextTimeout()
 {
-	if (!shouldContinue) {
+	if (deviceReattacherCanceler.isCancellationRequestedUnlocked()) {
 		return;
 	}
 
@@ -88,7 +87,7 @@ void DeviceReattacher::holdReattachCReq()
 		reattachLifetimeExceptionPtr,
 		[this]()
 		{
-			sscl::SpinLock::Guard lock(shouldContinueLock);
+			sscl::SpinLock::Guard guard(deviceReattacherCanceler.s.lock);
 			reattachOpInFlight = false;
 		}));
 }
@@ -107,8 +106,8 @@ void DeviceReattacher::onTimeout(const boost::system::error_code& error)
 		return;
 	}
 
-	sscl::SpinLock::Guard lock(shouldContinueLock);
-	if (!shouldContinue) {
+	sscl::SpinLock::Guard guard(deviceReattacherCanceler.s.lock);
+	if (deviceReattacherCanceler.isCancellationRequestedUnlocked()) {
 		return;
 	}