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The module for FunctionalJ Core.
// ============================================================================
// Copyright (c) 2017-2021 Nawapunth Manusitthipol (NawaMan - http://nawaman.net).
// ----------------------------------------------------------------------------
// MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// ============================================================================
package functionalj.promise;
import static functionalj.function.Func.carelessly;
import java.util.concurrent.atomic.AtomicReference;
import functionalj.environments.AsyncRunner;
import functionalj.function.Func0;
import functionalj.ref.ComputeBody;
import functionalj.ref.Ref;
import functionalj.result.Result;
import functionalj.supportive.Default;
import lombok.val;
// This class create a defer action with a task.
// Since there are a specific steps for this, we have this one in one place.
// Any customization from Configure or Builder will have to go through this to create DeferAction in the same way.
// This way the customization can be done in a limited way.
public class DeferActionCreator {
@Default
public static final DeferActionCreator instance = new DeferActionCreator();
public static final Ref current
= Ref.of(DeferActionCreator.class)
.orTypeDefaultOrGet(DeferActionCreator::new);
public DeferAction create(
Func0 supplier,
Runnable onStart,
boolean interruptOnCancel,
AsyncRunner runner) {
val promiseRef = new AtomicReference>();
val runTask = new RunTask(interruptOnCancel, supplier, onStart, runner, promiseRef::get);
val action = new DeferAction(runTask, null);
val promise = action.getPromise();
promiseRef.set(promise);
return action;
}
private static class RunTask implements Runnable {
private final boolean interruptOnCancel;
private final Func0 supplier;
private final Runnable onStart;
private final AsyncRunner runner;
private final Func0> promiseRef;
private final AtomicReference threadRef = new AtomicReference();
public RunTask(boolean interruptOnCancel,
Func0 supplier,
Runnable onStart,
AsyncRunner runner,
Func0> promiseRef) {
this.interruptOnCancel = interruptOnCancel;
this.supplier = supplier;
this.onStart = onStart;
this.runner = runner;
this.promiseRef = promiseRef;
}
@Override
public void run() {
AsyncRunner
.run(runner, new Body())
.onComplete(result->{
val promise = promiseRef.get();
val action = new PendingAction(promise);
if (result.isValue())
action.complete(null);
else if (result.isCancelled())
action.abort(result.exception());
else action.fail (result.exception());
});
}
class Body implements ComputeBody {
public void prepared() {
val promise = promiseRef.get();
if (!promise.isNotDone())
return;
setupInterruptOnCancel(promise);
carelessly(onStart);
}
@Override
public Void compute() throws RuntimeException {
val promise = promiseRef.get();
val action = new PendingAction(promise);
val result = Result.of(this::runSupplier);
action.completeWith(result);
return null;
}
private D runSupplier() {
try {
return supplier.get();
} finally {
doInterruptOnCancel();
}
}
private void setupInterruptOnCancel(Promise promise) {
if (!interruptOnCancel)
return;
threadRef.set(Thread.currentThread());
promise.eavesdrop(r -> {
r.ifCancelled(() -> {
val thread = threadRef.get();
val isCurrentThread = (thread != null) && !thread.equals(Thread.currentThread());
if (isCurrentThread) {
thread.interrupt();
}
});
});
}
}
private void doInterruptOnCancel() {
if (!interruptOnCancel)
return;
threadRef.set(null);
// This is to reset the status in case the task was done
// but threadRed is yet to be set to null.
Thread.currentThread().isInterrupted();
}
}
}