X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;ds=sidebyside;f=include%2Fthreadengine.h;h=a8b66ad98de5afb33c73f8695bb5a18e2b9a570e;hb=8e735c8f3ab15db211259d5d8436884ab33fea44;hp=7d27b867ac8b911c34131bd0d066e132eb57c4e6;hpb=9dbd7d10ac81c6445c58f4abb4f0eff240a8f9d2;p=user%2Fhenk%2Fcode%2Finspircd.git

diff --git a/include/threadengine.h b/include/threadengine.h
index 7d27b867a..a8b66ad98 100644
--- a/include/threadengine.h
+++ b/include/threadengine.h
@@ -21,33 +21,194 @@
 #include "base.h"
 
 class InspIRCd;
+class Thread;
 
-class CoreExport Thread : public Extensible
-{
- public:
-	Thread() { };
-	virtual ~Thread() { };
-	virtual void Run() = 0;
-};
-
+/** The ThreadEngine class has the responsibility of initialising
+ * Thread derived classes. It does this by creating operating system
+ * level threads which are then associated with the class transparently.
+ * This allows Thread classes to be derived without needing to know how
+ * the OS implements threads. You should ensure that any sections of code
+ * that use threads are threadsafe and do not interact with any other
+ * parts of the code which are NOT known threadsafe! If you really MUST
+ * access non-threadsafe code from a Thread, use the Mutex class to wrap
+ * access to the code carefully.
+ */
 class CoreExport ThreadEngine : public Extensible
 {
  protected:
 
+	 /** Creator instance
+	  */
 	 InspIRCd* ServerInstance;
+
+	 /** New Thread being created.
+	  */
 	 Thread* NewThread;
 
+	 /** Enable or disable system-wide mutex for threading.
+	  * Remember that if you toggle the mutex you MUST UNSET
+	  * IT LATER otherwise the program will DEADLOCK!
+	  * It is recommended that you AVOID USE OF THIS METHOD
+	  * and use your own Mutex class, this function is mainly
+	  * reserved for use by the core and by the Thread engine
+	  * itself.
+	  * @param enable True to lock the mutex.
+	  */
+	 virtual bool Mutex(bool enable) = 0;
  public:
 
+	/** Constructor.
+	 * @param Instance Creator object
+	 */
 	ThreadEngine(InspIRCd* Instance);
 
+	/** Destructor
+	 */
 	virtual ~ThreadEngine();
 
-	virtual bool Mutex(bool enable) = 0;
+	/** Lock the system wide mutex. See the documentation for
+	 * ThreadEngine::Mutex().
+	 */
+	void Lock() { this->Mutex(true); }
 
+	/** Unlock the system wide mutex. See the documentation for
+	 * ThreadEngine::Mutex()
+	 */
+	void Unlock() { this->Mutex(false); }
+
+	/** Run the newly created thread.
+	 */
 	virtual void Run() = 0;
 
+	/** Create a new thread. This takes an already allocated
+	 * Thread* pointer and initializes it to use this threading
+	 * engine. On failure, this function may throw a CoreException.
+	 * @param thread_to_init Pointer to a newly allocated Thread
+	 * derived object.
+	 */
 	virtual void Create(Thread* thread_to_init) = 0;
+
+	/** This is called by the default destructor of the Thread
+	 * class to ensure that the thread engine which created the thread
+	 * is responsible for destroying it.
+	 * @param thread Existing and active thread to delete.
+	 */
+	virtual void FreeThread(Thread* thread) = 0;
+
+	/** Returns the thread engine's name for display purposes
+	 * @return The thread engine name
+	 */
+	virtual const std::string GetName()
+	{
+		return "<pure-virtual>";
+	}
+};
+
+/** The Mutex class represents a mutex, which can be used to keep threads
+ * properly synchronised. Use mutexes sparingly, as they are a good source
+ * of thread deadlocks etc, and should be avoided except where absolutely
+ * neccessary. Note that the internal behaviour of the mutex varies from OS
+ * to OS depending on the thread engine, for example in windows a Mutex
+ * in InspIRCd uses critical sections, as they are faster and simpler to
+ * manage.
+ */
+class CoreExport Mutex : public Extensible
+{
+ protected:
+
+	/** Creator object
+	 */
+	InspIRCd* ServerInstance;
+
+	/** Enable or disable the Mutex. This method has somewhat confusing
+	 * wording (e.g. the function name and parameters) so it is protected
+	 * in preference of the Lock() and Unlock() methods which are user-
+	 * accessible.
+	 *
+	 * @param enable True to enable the mutex (enter it) and false to
+	 * disable the mutex (leave it).
+	 */
+	virtual void Enable(bool enable) = 0;
+ public:
+
+	/** Constructor.
+	 * @param Instance Creator object
+	 */
+	Mutex(InspIRCd* Instance);
+
+	/** Enter/enable the mutex lock.
+	 */
+	void Lock() { Enable(true); }
+
+	/** Leave/disable the mutex lock.
+	 */
+	void Unlock() { Enable(false); }
+
+	/** Destructor
+	 */
+	~Mutex() { }
+};
+
+/** Derive from this class to implement your own threaded sections of
+ * code. Be sure to keep your code thread-safe and not prone to deadlocks
+ * and race conditions if you MUST use threading!
+ */
+class CoreExport Thread : public Extensible
+{
+ private:
+	/** Set to true when the thread is to exit
+	 */
+	bool ExitFlag;
+ public:
+
+	/** Creator thread engine
+	 */
+	ThreadEngine* Creator;
+
+	/** Set Creator to NULL at this point
+	 */
+	Thread() : ExitFlag(false), Creator(NULL)
+	{
+	}
+
+	/** If this thread has a Creator set, call it to
+	 * free the thread
+	 */
+	virtual ~Thread()
+	{
+		if (Creator)
+			Creator->FreeThread(this);
+	}
+
+	/** Override this method to put your actual
+	 * threaded code here.
+	 */
+	virtual void Run() = 0;
+
+	/** Signal the thread to exit gracefully.
+	 */
+	void SetExitFlag()
+	{
+		ExitFlag = true;
+	}
+
+	/** Cancel an exit state.
+	 */
+	void ClearExitFlag()
+	{
+		ExitFlag = false;
+	}
+
+	/** Get thread's current exit status.
+	 * (are we being asked to exit?)
+	 */
+	bool GetExitFlag()
+	{
+		return ExitFlag;
+	}
 };
 
+
+
 #endif
+