DevReattacher: Spinlock-protect stop() call

Replace the current delay timeout mechanism with a spinlock.
Both mechanisms try to eliminate the possibility of an in-flight
async op accessing state that has been destroyed by stop().

But the spinlock is less arbitrary.

smocore/deviceManager/deviceReattacher.cpp

@@ -3,7 +3,6 @@
 #include <functional>
 #include <componentThread.h>
 #include <callback.h>
-#include <asynchronousBridge.h>
 #include <deviceManager/deviceReattacher.h>
 #include <deviceManager/deviceManager.h>
 
@@ -28,37 +27,23 @@ timer(ioThread->getIoService())
 
 void DeviceReattacher::start()
 {
-	shouldContinue.store(true);
+	shouldContinue = true;
 	scheduleNextTimeout();
 }
 
 void DeviceReattacher::stop()
 {
-	shouldContinue.store(false);
+	{
+		SpinLock::Guard lock(shouldContinueLock);
+		shouldContinue = false;
+	}
+
 	timer.cancel();
-
-	// Set up a timeout bridge using the provided ioThread's io_service
-	auto& ioService = ioThread->getIoService();
-	boost::asio::deadline_timer timeoutTimer(ioService);
-	AsynchronousBridge bridge(ioService);
-
-	// Set up the timeout for ~10ms
-	timeoutTimer.expires_from_now(boost::posix_time::milliseconds(20));
-	timeoutTimer.async_wait(
-		[&bridge](const boost::system::error_code& error)
-		{
-			(void)error;
-
-			// Always signal complete, whether timeout expired or was cancelled
-			bridge.setAsyncOperationComplete();
-		});
-
-	bridge.waitForAsyncOperationCompleteOrIoServiceStopped();
 }
 
 void DeviceReattacher::scheduleNextTimeout()
 {
-	if (!shouldContinue.load()) {
+	if (!shouldContinue) {
 		return;
 	}
 
@@ -85,7 +70,8 @@ void DeviceReattacher::onTimeout(const boost::system::error_code& error)
 		return;
 	}
 
-	if (!shouldContinue.load()) {
+	SpinLock::Guard lock(shouldContinueLock);
+	if (!shouldContinue) {
 		return;
 	}
 

smocore/include/deviceManager/deviceReattacher.h

@@ -5,6 +5,7 @@
 #include <atomic>
 #include <memory>
 #include <boost/asio/deadline_timer.hpp>
+#include <spinLock.h>
 
 namespace smo {
 
@@ -35,7 +36,8 @@ private:
 
     DeviceManager &parent;
     std::shared_ptr<ComponentThread> ioThread;
-    std::atomic<bool> shouldContinue;
+    SpinLock shouldContinueLock;
+    bool shouldContinue;
     boost::asio::deadline_timer timer;
 };