mirror of https://github.com/deavmi/eventy.git
539 lines
13 KiB
D
539 lines
13 KiB
D
module eventy.engine;
|
|
|
|
import eventy.types : EventType;
|
|
import eventy.signal : Signal;
|
|
import eventy.event : Event;
|
|
import eventy.config;
|
|
import eventy.exceptions;
|
|
|
|
import std.container.dlist;
|
|
import core.sync.mutex : Mutex;
|
|
import core.thread : Thread, dur, Duration;
|
|
import std.conv : to;
|
|
|
|
unittest
|
|
{
|
|
import std.stdio;
|
|
|
|
Engine engine = new Engine();
|
|
|
|
/**
|
|
* Let the event engine know what typeIDs are
|
|
* allowed to be queued
|
|
*/
|
|
engine.addEventType(new EventType(1));
|
|
engine.addEventType(new EventType(2));
|
|
|
|
/**
|
|
* Create a new Signal Handler that will handles
|
|
* event types `1` and `2` with the given `handler()`
|
|
* function
|
|
*/
|
|
class SignalHandler1 : Signal
|
|
{
|
|
this()
|
|
{
|
|
super([1, 2]);
|
|
}
|
|
|
|
public override void handler(Event e)
|
|
{
|
|
writeln("Running event", e.getID());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Tell the event engine that I want to register
|
|
* the following handler for its queues `1` and `2`
|
|
*/
|
|
Signal j = new SignalHandler1();
|
|
engine.addSignalHandler(j);
|
|
|
|
Event eTest = new Event(1);
|
|
engine.push(eTest);
|
|
|
|
eTest = new Event(2);
|
|
engine.push(eTest);
|
|
|
|
Thread.sleep(dur!("seconds")(2));
|
|
engine.push(eTest);
|
|
|
|
writeln("done with main thread code");
|
|
|
|
while(engine.hasEventsRunning()) {}
|
|
|
|
/* TODO: Before shutting down, actually test it out (i.e. all events ran) */
|
|
engine.shutdown();
|
|
}
|
|
|
|
unittest
|
|
{
|
|
import std.stdio;
|
|
|
|
EngineSettings customSettings = {holdOffMode: HoldOffMode.YIELD};
|
|
Engine engine = new Engine(customSettings);
|
|
|
|
/**
|
|
* Let the event engine know what typeIDs are
|
|
* allowed to be queued
|
|
*/
|
|
engine.addEventType(new EventType(1));
|
|
engine.addEventType(new EventType(2));
|
|
|
|
/**
|
|
* Create a new Signal Handler that will handles
|
|
* event types `1` and `2` with the given `handler()`
|
|
* function
|
|
*/
|
|
class SignalHandler1 : Signal
|
|
{
|
|
this()
|
|
{
|
|
super([1, 2]);
|
|
}
|
|
|
|
public override void handler(Event e)
|
|
{
|
|
writeln("Running event", e.getID());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Tell the event engine that I want to register
|
|
* the following handler for its queues `1` and `2`
|
|
*/
|
|
Signal j = new SignalHandler1();
|
|
engine.addSignalHandler(j);
|
|
|
|
Event eTest = new Event(1);
|
|
engine.push(eTest);
|
|
|
|
eTest = new Event(2);
|
|
engine.push(eTest);
|
|
|
|
Thread.sleep(dur!("seconds")(2));
|
|
engine.push(eTest);
|
|
|
|
writeln("done with main thread code");
|
|
|
|
while(engine.hasEventsRunning()) {}
|
|
|
|
/* TODO: Before shutting down, actually test it out (i.e. all events ran) */
|
|
engine.shutdown();
|
|
}
|
|
|
|
/**
|
|
* Engine
|
|
*
|
|
* An instance of this represents an engine that
|
|
* can, at any time, handle the delivery of new
|
|
* events, trigger the correct signal handlers
|
|
* for the respective events, remove signal
|
|
* handlers, add signal handlers, among many
|
|
* other things
|
|
*/
|
|
public final class Engine
|
|
{
|
|
/* Registered queues */
|
|
private DList!(EventType) eventTypes;
|
|
private Mutex eventTypesLock;
|
|
|
|
/* Registered signal handlers */
|
|
private DList!(Signal) handlers;
|
|
private Mutex handlerLock;
|
|
|
|
/* Engine configuration */
|
|
private EngineSettings settings;
|
|
|
|
/* Whether engine is running or not */
|
|
private bool running;
|
|
|
|
/* Dispatched threads */
|
|
private DList!(DispatchWrapper) threadStore;
|
|
private Mutex threadStoreLock;
|
|
|
|
/**
|
|
* Instantiates a new Eventy engine with the provided
|
|
* configuration
|
|
*
|
|
* Params:
|
|
* settings = The EngineSettings to use
|
|
*/
|
|
this(EngineSettings settings)
|
|
{
|
|
eventTypesLock = new Mutex();
|
|
handlerLock = new Mutex();
|
|
threadStoreLock = new Mutex();
|
|
|
|
this.settings = settings;
|
|
}
|
|
|
|
/**
|
|
* Instantiates a new Eventy engine with the default
|
|
* settings
|
|
*/
|
|
this()
|
|
{
|
|
EngineSettings defaultSettings;
|
|
|
|
/* Yield if a lock fails (prevent potential thread starvation) */
|
|
defaultSettings.agressiveTryLock = false;
|
|
|
|
// FIXME: Investigate ways to lower load average
|
|
// /* Make the event engine loop sleep (1) and for 50ms (2) (TODO: Adjust this) */
|
|
// defaultSettings.holdOffMode = HoldOffMode.SLEEP;
|
|
// defaultSettings.sleepTime = dur!("msecs")(50);
|
|
|
|
/* Use yeilding for most responsiveness */
|
|
defaultSettings.holdOffMode = HoldOffMode.YIELD;
|
|
|
|
/* Do not gracefully shutdown */
|
|
defaultSettings.gracefulShutdown = false;
|
|
|
|
this(defaultSettings);
|
|
}
|
|
|
|
/**
|
|
* Returns the current configuration paremeters being
|
|
* used by the engine
|
|
*
|
|
* Returns: The EngineSettings struct
|
|
*/
|
|
public EngineSettings getConfig()
|
|
{
|
|
return settings;
|
|
}
|
|
|
|
/**
|
|
* Updates the current configuration of the engine
|
|
*
|
|
* Params:
|
|
* newSettings = The new EngineSettings struct to use
|
|
*/
|
|
public void setConfig(EngineSettings newSettings)
|
|
{
|
|
this.settings = newSettings;
|
|
}
|
|
|
|
/**
|
|
* Attaches a new signal handler to the engine
|
|
*
|
|
* Params:
|
|
* e = the signal handler to add
|
|
*/
|
|
public void addSignalHandler(Signal e)
|
|
{
|
|
/* Lock the signal-set */
|
|
handlerLock.lock();
|
|
|
|
/* Add the new handler */
|
|
handlers ~= e;
|
|
|
|
/* Unlock the signal-set */
|
|
handlerLock.unlock();
|
|
}
|
|
|
|
/**
|
|
* Shuts down the event engine
|
|
*/
|
|
public void shutdown()
|
|
{
|
|
/* TODO: Insert a lock here, that dispatch should adhere too as well */
|
|
|
|
/* FIXME: We should prevent adding of queues during shutdown */
|
|
/* FIXME: We should prevent pushing of events during shutdown */
|
|
|
|
/* Wait for any pendings events (if configured) */
|
|
if(settings.gracefulShutdown)
|
|
{
|
|
while(hasEventsRunning()) {}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Creates a new thread per signal and dispatches the event to them
|
|
*
|
|
* Params:
|
|
* signalSet = The signal handlers to use for dispatching
|
|
* e = the Event to be dispatched to each handler
|
|
*/
|
|
private void dispatch(Signal[] signalSet, Event e)
|
|
{
|
|
foreach (Signal signal; signalSet)
|
|
{
|
|
/* Create a new Thread */
|
|
DispatchWrapper handlerThread = new DispatchWrapper(signal, e);
|
|
|
|
/**
|
|
* TODO
|
|
*
|
|
* When we call `shutdown()` there may very well be a case of
|
|
* where the threadStoreLock unlocks after the clean up
|
|
* loop, but storeThread hangs here during that time,
|
|
* then proceeds to start the thread, we should therefore,
|
|
* either block on running changed (solution 1, not as granular)
|
|
*
|
|
* Solution 2: Block on dispatch being called <- use this method rather
|
|
* But still needs a running check, it must not go ahead if running is now
|
|
* false
|
|
*/
|
|
|
|
/* Store the thread */
|
|
storeThread(handlerThread);
|
|
|
|
/* Start the thread */
|
|
handlerThread.start();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Adds a thread to the thread store
|
|
*
|
|
* Params:
|
|
* t = the thread to add
|
|
*/
|
|
private void storeThread(DispatchWrapper t)
|
|
{
|
|
/**
|
|
* TODO: This can only be implemented if we use
|
|
* wrapper threads that exit, and we can signal
|
|
* removal from thread store then
|
|
*/
|
|
|
|
/* Lock the thread store from editing */
|
|
threadStoreLock.lock();
|
|
|
|
/* Add the thread */
|
|
threadStore ~= t;
|
|
|
|
/* Unlock the thread store for editing */
|
|
threadStoreLock.unlock();
|
|
}
|
|
|
|
/**
|
|
* Removes a thread from the thread store
|
|
*
|
|
* Params:
|
|
* t = the thread to remove
|
|
*/
|
|
private void removeThread(DispatchWrapper t)
|
|
{
|
|
/* Lock the thread store from editing */
|
|
threadStoreLock.lock();
|
|
|
|
/* Remove the thread */
|
|
threadStore.linearRemoveElement(t);
|
|
|
|
/* Unlock the thread store for editing */
|
|
threadStoreLock.unlock();
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not there are still events
|
|
* running at the time of calling
|
|
*
|
|
* Returns: <code>true</code> if there are events
|
|
* still running, <code>false</code> otherwise
|
|
*/
|
|
public bool hasEventsRunning()
|
|
{
|
|
/* Whether there are events running or not */
|
|
bool has = false;
|
|
|
|
/* Lock the thread store */
|
|
threadStoreLock.lock();
|
|
|
|
has = !threadStore.empty();
|
|
|
|
/* Unlock the thread store */
|
|
threadStoreLock.unlock();
|
|
|
|
return has;
|
|
}
|
|
|
|
/**
|
|
* DispatchWrapper
|
|
*
|
|
* Effectively a thread but with the Signal,
|
|
* Event included with clean-up routines
|
|
*/
|
|
private class DispatchWrapper : Thread
|
|
{
|
|
private Signal signal;
|
|
private Event e;
|
|
|
|
this(Signal signal, Event e)
|
|
{
|
|
super(&run);
|
|
this.signal = signal;
|
|
this.e = e;
|
|
}
|
|
|
|
private void run()
|
|
{
|
|
/* Run the signal handler */
|
|
signal.handler(e);
|
|
|
|
/* Remove myself from the thread store */
|
|
removeThread(this);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns all the signal handlers responsible
|
|
* for handling the type of Event provided
|
|
*
|
|
* Params:
|
|
* e = the Event type to match to
|
|
* Returns: A Signal[] containing each handler
|
|
* registered to handle type <code>e</code>
|
|
*/
|
|
public Signal[] getSignalsForEvent(Event e)
|
|
{
|
|
/* Matched handlers */
|
|
Signal[] matchedHandlers;
|
|
|
|
/* Lock the signal-set */
|
|
handlerLock.lock();
|
|
|
|
/* Find all handlers matching */
|
|
foreach (Signal signal; handlers)
|
|
{
|
|
if (signal.handles(e.getID()))
|
|
{
|
|
matchedHandlers ~= signal;
|
|
}
|
|
}
|
|
|
|
/* Unlock the signal-set */
|
|
handlerLock.unlock();
|
|
|
|
return matchedHandlers;
|
|
}
|
|
|
|
/**
|
|
* Checks if there is a signal handler that handles
|
|
* the given event id
|
|
*
|
|
* Params:
|
|
* id = the event ID to check
|
|
* Returns: <code>true</code> if a signal handler does
|
|
* exist, <code>false</code> otherwise
|
|
*/
|
|
public bool isSignalExists(ulong id)
|
|
{
|
|
return getSignalsForEvent(new Event(id)).length != 0;
|
|
}
|
|
|
|
/**
|
|
* Pushes the given Event into the engine
|
|
* for eventual dispatch
|
|
*
|
|
* Params:
|
|
* e = the event to push
|
|
*/
|
|
public void push(Event e)
|
|
{
|
|
//TODO: New code goes below here
|
|
/**
|
|
* What we want to do here is to effectively
|
|
* wake up a checker thread and also (before that)
|
|
* perhaps we say what queue was modified
|
|
*
|
|
* THEN the checker thread goes to said queue and
|
|
* executes said event (dispatches it) and then sleep
|
|
* again till it is interrupted. We need Pids and kill etc for this
|
|
*
|
|
* Idea (2)
|
|
*
|
|
* If we cannot do a checker thread then we can spwan a thread here
|
|
* but then we get no control for priorities etc, although actually we could
|
|
* maybe? It depends, we don't want multiple dispathers at same time then
|
|
* (A checker thread would ensure we don't get this)
|
|
*/
|
|
|
|
/* Obtain all signal handlers for the given event */
|
|
Signal[] handlersMatched = getSignalsForEvent(e);
|
|
|
|
/* If we get signal handlers then dispatch them */
|
|
if(handlersMatched.length)
|
|
{
|
|
dispatch(handlersMatched, e);
|
|
}
|
|
/* If there are no matching events */
|
|
else
|
|
{
|
|
//TODO: Add default handler support
|
|
//TODO: Add error throwing in case where not true
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Registers a new EventType with the engine
|
|
* and then adds it.
|
|
*
|
|
* Throws EventyException if the id of the given
|
|
* EventType is is already in use by another
|
|
*
|
|
* Params:
|
|
* id = the id of the new event type to add
|
|
* Throws: EventyException
|
|
*/
|
|
public void addEventType(EventType evType)
|
|
{
|
|
/* Lock the event types list */
|
|
eventTypesLock.lock();
|
|
|
|
/* If no such queue exists then add it (recursive mutex used) */
|
|
if (!findEventType(evType.getID()))
|
|
{
|
|
/* Add the event types list */
|
|
eventTypes ~= evType;
|
|
}
|
|
else
|
|
{
|
|
throw new EventyException("Failure to add EventType with id '"~to!(string)(evType.getID())~"\' as it is already in use");
|
|
}
|
|
|
|
/* Unlock the event types list */
|
|
eventTypesLock.unlock();
|
|
}
|
|
|
|
/**
|
|
* Given an if, this will return the EventType
|
|
* associated with said id
|
|
*
|
|
* Params:
|
|
* id = the id of the EventType
|
|
* Returns: The EventType if found, otherwise
|
|
* <code>null</code>
|
|
*/
|
|
public EventType findEventType(ulong id)
|
|
{
|
|
/* Lock the EventType list */
|
|
eventTypesLock.lock();
|
|
|
|
/* Find the matching EventType */
|
|
EventType matchedEventType;
|
|
foreach (EventType eventType; eventTypes)
|
|
{
|
|
if (eventType.getID() == id)
|
|
{
|
|
matchedEventType = eventType;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Unlock the EventType list */
|
|
eventTypesLock.unlock();
|
|
|
|
return matchedEventType;
|
|
}
|
|
|
|
/* TODO: Add coumentation */
|
|
private ulong[] getTypes()
|
|
{
|
|
/* TODO: Implement me */
|
|
return null;
|
|
}
|
|
} |