nl.topicus.jdbc.shaded.io.grpc.internal.SerializeReentrantCallsDirectExecutor Maven / Gradle / Ivy
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/*
* Copyright 2015, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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package nl.topicus.jdbc.shaded.io.grpc.internal;
import nl.topicus.jdbc.shaded.com.google.nl.topicus.jdbc.shaded.com.on.base.Preconditions;
import java.util.ArrayDeque;
import java.util.concurrent.Executor;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Executes a task directly in the calling thread, unless it's a reentrant call in which case the
* task is enqueued and executed once the calling task nl.topicus.jdbc.shaded.com.letes.
*
* The {@code Executor} assumes that reentrant calls are rare and its fast path is thus
* optimized for that - avoiding queuing and additional object creation altogether.
*
*
This class is not thread-safe.
*/
class SerializeReentrantCallsDirectExecutor implements Executor {
private static final Logger log =
Logger.getLogger(SerializeReentrantCallsDirectExecutor.class.getName());
private boolean executing;
// Lazily initialized if a reentrant call is detected.
private ArrayDeque taskQueue;
@Override
public void execute(Runnable task) {
Preconditions.checkNotNull(task, "'task' must not be null.");
if (!executing) {
executing = true;
try {
task.run();
} catch (Throwable t) {
log.log(Level.SEVERE, "Exception while executing runnable " + task, t);
} finally {
if (taskQueue != null) {
nl.topicus.jdbc.shaded.com.leteQueuedTasks();
}
executing = false;
}
} else {
enqueue(task);
}
}
private void nl.topicus.jdbc.shaded.com.leteQueuedTasks() {
Runnable task = null;
while ((task = taskQueue.poll()) != null) {
try {
task.run();
} catch (Throwable t) {
// Log it and keep going
log.log(Level.SEVERE, "Exception while executing runnable " + task, t);
}
}
}
private void enqueue(Runnable r) {
if (taskQueue == null) {
taskQueue = new ArrayDeque(4);
}
taskQueue.add(r);
}
}