Qutexes: Implement them and supporting classes

Implements: LockSet, SerializedAsynchronousContinuation,
	LockerAndInvoker, LockerAndInvokerBase, Qutex.

Very big leap in functionality here. See qutexes.md for
an explanation of what we've done.

include/lockerAndInvokerBase.h

@@ -0,0 +1,82 @@
+#ifndef LOCKER_AND_INVOKER_BASE_H
+#define LOCKER_AND_INVOKER_BASE_H
+
+#include <functional>
+#include <list>
+#include <memory>
+
+namespace smo {
+
+// Forward declaration
+class Qutex;
+
+/**
+ * @brief LockerAndInvokerBase - Base class for lockvoking mechanism
+ *
+ * This base class contains the common functionality needed by Qutex,
+ * including the serialized continuation reference and comparison operators.
+ */
+class LockerAndInvokerBase
+{
+public:
+	/**
+	 * @brief Constructor
+	 * @param serializedContinuationVaddr Raw pointer to the serialized continuation
+	 */
+	explicit LockerAndInvokerBase(const void* serializedContinuationVaddr)
+	: serializedContinuationVaddr(serializedContinuationVaddr)
+	{}
+
+	/**
+	 * @brief Typedef for list of LockerAndInvokerBase shared pointers
+	 */
+	typedef std::list<std::shared_ptr<LockerAndInvokerBase>> List;
+
+	/**
+	 * @brief Get the iterator for this lockvoker in the specified Qutex's queue
+	 * @param qutex The Qutex to get the iterator for
+	 * @return Iterator pointing to this lockvoker in the Qutex's queue
+	 */
+	virtual List::iterator getLockvokerIteratorForQutex(Qutex& qutex) = 0;
+
+	/**
+	 * @brief Awaken this lockvoker by posting it to its io_service
+	 * @param forceAwaken If true, post even if already awake
+	 */
+	virtual void awaken(bool forceAwaken = false) = 0;
+
+	/**
+	 * @brief Equality operator
+	 * 
+	 * Compare by the address of the continuation objects. Why?
+	 * Because there's no guarantee that the lockvoker object that was
+	 * passed in by the io_service invocation is the same object as that
+	 * which is in the qutexQs. Especially because we make_shared() a
+	 * copy when registerInQutexQueues()ing.
+	 *
+	 * Generally when we "wake" a lockvoker by enqueuing it, boost's
+	 * io_service::post will copy the lockvoker object.
+	 */
+	bool operator==(const LockerAndInvokerBase &other) const
+	{
+		return serializedContinuationVaddr == other.serializedContinuationVaddr;
+	}
+
+	/**
+	 * @brief Inequality operator
+	 */
+	bool operator!=(const LockerAndInvokerBase &other) const
+	{
+		return serializedContinuationVaddr != other.serializedContinuationVaddr;
+	}
+
+protected:
+	/* Never let this monstrosity be seen beyond this class's scope.
+	 * Remember what I've taught you, quasi-modo?
+	 */
+	const void* serializedContinuationVaddr;
+};
+
+} // namespace smo
+
+#endif // LOCKER_AND_INVOKER_BASE_H