CC-Tweaked/src/main/java/dan200/computercraft/api/peripheral/IWorkMonitor.java

78 lines
2.7 KiB
Java

/*
* This file is part of the public ComputerCraft API - http://www.computercraft.info
* Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
* For help using the API, and posting your mods, visit the forums at computercraft.info.
*/
package dan200.computercraft.api.peripheral;
import javax.annotation.Nonnull;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
/**
* Monitors "work" associated with a computer, keeping track of how much a computer has done, and ensuring every
* computer receives a fair share of any processing time.
*
* This is primarily intended for work done by peripherals on the main thread (such as on a tile entity's tick), but
* could be used for other purposes (such as complex computations done on another thread).
*
* Before running a task, one should call {@link #canWork()} to determine if the computer is currently allowed to
* execute work. If that returns true, you should execute the task and use {@link #trackWork(long, TimeUnit)} to inform
* the monitor how long that task took.
*
* Alternatively, use {@link #runWork(Runnable)} to run and keep track of work.
*
* @see IComputerAccess#getMainThreadMonitor()
*/
public interface IWorkMonitor
{
/**
* If the owning computer is currently allowed to execute work.
*
* @return If we can execute work right now.
*/
boolean canWork();
/**
* If the owning computer is currently allowed to execute work, and has ample time to do so.
*
* This is effectively a more restrictive form of {@link #canWork()}. One should use that in order to determine if
* you may do an initial piece of work, and shouldWork to determine if any additional task may be performed.
*
* @return If we should execute work right now.
*/
boolean shouldWork();
/**
* Inform the monitor how long some piece of work took to execute.
*
* @param time The time some task took to run
* @param unit The unit that {@code time} was measured in.
*/
void trackWork( long time, @Nonnull TimeUnit unit );
/**
* Run a task if possible, and inform the monitor of how long it took.
*
* @param runnable The task to run.
* @return If the task was actually run (namely, {@link #canWork()} returned {@code true}).
*/
default boolean runWork( @Nonnull Runnable runnable )
{
Objects.requireNonNull( runnable, "runnable should not be null" );
if( !canWork() ) return false;
long start = System.nanoTime();
try
{
runnable.run();
}
finally
{
trackWork( System.nanoTime() - start, TimeUnit.NANOSECONDS );
}
return true;
}
}