--- /dev/null
+package net.mograsim.logic.core.timeline;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.function.BooleanSupplier;
+import java.util.function.Consumer;
+import java.util.function.LongSupplier;
+
+/**
+ * Orders Events by the time they are due to be executed. Can execute Events individually.
+ *
+ * @author Fabian Stemmler
+ *
+ */
+public class Timeline
+{
+ private PriorityQueue<InnerEvent> events;
+ private LongSupplier time;
+ private long lastTimeUpdated = 0;
+ private long eventCounter = 0;
+
+ private final List<Consumer<TimelineEvent>> eventAddedListener;
+
+ public final LongSupplier stepByStepExec = () -> lastTimeUpdated;
+ public final LongSupplier realTimeExec = () -> System.currentTimeMillis();
+
+ /**
+ * Constructs a Timeline object. Per default the time function is set to step by step execution.
+ *
+ * @param initCapacity The initial capacity of the event queue.
+ */
+ public Timeline(int initCapacity)
+ {
+ events = new PriorityQueue<>(initCapacity);
+ eventAddedListener = new ArrayList<>();
+ time = stepByStepExec;
+ }
+
+ /**
+ * @param timestamp exclusive
+ * @return <code>true</code> if the first event in queue is later than the given timestamp
+ */
+ public BooleanSupplier laterThan(long timestamp)
+ {
+ return () -> timeCmp(events.peek().getTiming(), timestamp) > 0;
+ }
+
+ /**
+ * @return <code>true</code> if there is at least one event enqueued. <code>false</code> otherwise
+ */
+ public boolean hasNext()
+ {
+ return !events.isEmpty();
+ }
+
+ /**
+ * Executes all events at the next timestamp, at which there are any
+ */
+ public void executeNext()
+ {
+ InnerEvent first = events.peek();
+ if (first != null)
+ executeUntil(laterThan(first.getTiming()), -1);
+ }
+
+ /**
+ * Executes all events enqueued in the {@link Timeline}. Use very carefully! Events may generate new events, causing an infinite loop.
+ */
+ public void executeAll()
+ {
+ while (hasNext())
+ executeNext();
+ }
+
+ /**
+ * Executes all events until a given condition is met. The simulation process can be constrained by a real world timestamp.
+ *
+ * @param condition the condition until which the events are be processed
+ * @param stopMillis the System.currentTimeMillis() when simulation definitely needs to stop. A value of -1 means no timeout.
+ * @return State of the event execution
+ * @formatter:off
+ * <code>NOTHING_DONE</code> if the {@link Timeline} was already empty
+ * <code>EXEC_OUT_OF_TIME</code> if the given maximum time was reached
+ * <code>EXEC_UNTIL_CONDITION</code> if the condition was met
+ * <code>EXEC_UNTIL_EMPTY</code> if events were executed until the {@link Timeline} was empty
+ * @formatter:on
+ */
+ public ExecutionResult executeUntil(BooleanSupplier condition, long stopMillis)
+ {
+ if (events.isEmpty())
+ {
+ lastTimeUpdated = getSimulationTime();
+ return ExecutionResult.NOTHING_DONE;
+ }
+ int checkStop = 0;
+ while (hasNext() && !condition.getAsBoolean())
+ {
+ InnerEvent event;
+ synchronized (events)
+ {
+ event = events.remove();
+ }
+ lastTimeUpdated = event.getTiming();
+ event.run();
+ // Don't check after every run
+ checkStop = (checkStop + 1) % 10;
+ if (checkStop == 0 && System.currentTimeMillis() >= stopMillis)
+ return ExecutionResult.EXEC_OUT_OF_TIME;
+ }
+ lastTimeUpdated = getSimulationTime();
+ return hasNext() ? ExecutionResult.EXEC_UNTIL_EMPTY : ExecutionResult.EXEC_UNTIL_CONDITION;
+ }
+
+ /**
+ * Sets the function, which defines the current simulation time at any time.
+ *
+ * @param time The return value of calling this function is the current simulation time.
+ */
+ public void setTimeFunction(LongSupplier time)
+ {
+ this.time = time;
+ }
+
+ /**
+ * Calculates the current simulation time.
+ *
+ * @return The simulation time as defined by the time function.
+ */
+ public long getSimulationTime()
+ {
+ return time.getAsLong();
+ }
+
+ /**
+ * Retrieves the timestamp of the next event.
+ *
+ * @return The timestamp of the next enqueued event, if the {@link Timeline} is not empty, -1 otherwise.
+ */
+ public long nextEventTime()
+ {
+ if (!hasNext())
+ return -1;
+ return events.peek().getTiming();
+ }
+
+ /**
+ * Clears the {@link Timeline} of enqueued events.
+ */
+ public void reset()
+ {
+ synchronized (events)
+ {
+ events.clear();
+ }
+ lastTimeUpdated = 0;
+ }
+
+ /**
+ * Adds a listener, that is called when a {@link TimelineEvent} is added.
+ */
+ public void addEventAddedListener(Consumer<TimelineEvent> listener)
+ {
+ eventAddedListener.add(listener);
+ }
+
+ /**
+ * Removes the listener, if possible. It will no longer be called when a {@link TimelineEvent} is added.
+ */
+ public void removeEventAddedListener(Consumer<TimelineEvent> listener)
+ {
+ eventAddedListener.remove(listener);
+ }
+
+ /**
+ * Adds an Event to the {@link Timeline}
+ *
+ * @param function The {@link TimelineEventHandler} that will be executed, when the {@link InnerEvent} occurs on the timeline.
+ * @param relativeTiming The amount of MI ticks in which the {@link InnerEvent} is called, starting from the current time.
+ */
+ public void addEvent(TimelineEventHandler function, int relativeTiming)
+ {
+ long timing = getSimulationTime() + relativeTiming;
+ TimelineEvent event = new TimelineEvent(timing);
+ synchronized (events)
+ {
+ events.add(new InnerEvent(function, event, eventCounter++));
+ }
+ eventAddedListener.forEach(l -> l.accept(event));
+ }
+
+ private class InnerEvent implements Runnable, Comparable<InnerEvent>
+ {
+ private final TimelineEventHandler function;
+ private final TimelineEvent event;
+ private final long id;
+
+ /**
+ * Creates an {@link InnerEvent}
+ *
+ * @param function {@link TimelineEventHandler} to be executed when the {@link InnerEvent} occurs
+ * @param timing Point in the MI simulation {@link Timeline}, at which the {@link InnerEvent} is executed;
+ */
+ InnerEvent(TimelineEventHandler function, TimelineEvent event, long id)
+ {
+ this.function = function;
+ this.event = event;
+ this.id = id;
+ }
+
+ public long getTiming()
+ {
+ return event.getTiming();
+ }
+
+ @Override
+ public void run()
+ {
+ function.handle(event);
+ }
+
+ @Override
+ public String toString()
+ {
+ return event.toString();
+ }
+
+ @Override
+ public int compareTo(InnerEvent o)
+ {
+ int c1;
+ return (c1 = timeCmp(getTiming(), o.getTiming())) == 0 ? timeCmp(id, o.id) : c1;
+ }
+ }
+
+ public static int timeCmp(long a, long b)
+ {
+ return Long.signum(a - b);
+ }
+
+ @Override
+ public String toString()
+ {
+ String eventsString;
+ synchronized (events)
+ {
+ eventsString = events.toString();
+ }
+ return String.format("Simulation time: %s, Last update: %d, Events: %s", getSimulationTime(), lastTimeUpdated, eventsString);
+ }
+
+ public enum ExecutionResult
+ {
+ NOTHING_DONE, EXEC_UNTIL_EMPTY, EXEC_UNTIL_CONDITION, EXEC_OUT_OF_TIME
+ }
+}
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projects / Mograsim.git / blobdiff