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JDBC driver for MariaDB and MySQL
/*
*
* MariaDB Client for Java
*
* Copyright (c) 2012-2014 Monty Program Ab.
* Copyright (c) 2015-2020 MariaDB Corporation Ab.
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License along
* with this library; if not, write to Monty Program Ab [email protected].
*
* This particular MariaDB Client for Java file is work
* derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
* the following copyright and notice provisions:
*
* Copyright (c) 2009-2011, Marcus Eriksson
*
* 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 the driver nor the names of its contributors may not 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 HOLDER 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, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
*/
package org.mariadb.jdbc.internal.util.scheduler;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicReference;
/**
* Provider for when ever an internal thread pool is needed. This can allow library users to
* override our default pooling behavior with possibly better and faster options.
*/
public class SchedulerServiceProviderHolder {
/** The default provider will construct a new pool on every request. */
public static final SchedulerProvider DEFAULT_PROVIDER =
new SchedulerProvider() {
private DynamicSizedSchedulerInterface dynamicSizedScheduler;
private FixedSizedSchedulerImpl fixedSizedScheduler;
private ScheduledThreadPoolExecutor timeoutScheduler;
private ThreadPoolExecutor threadPoolExecutor;
@Override
public DynamicSizedSchedulerInterface getScheduler(
int minimumThreads, String poolName, int maximumPoolSize) {
if (dynamicSizedScheduler == null) {
synchronized (this) {
if (dynamicSizedScheduler == null) {
dynamicSizedScheduler =
new DynamicSizedSchedulerImpl(minimumThreads, poolName, maximumPoolSize);
}
}
}
return dynamicSizedScheduler;
}
@Override
public ScheduledThreadPoolExecutor getFixedSizeScheduler(
int minimumThreads, String poolName) {
if (fixedSizedScheduler == null) {
synchronized (this) {
if (fixedSizedScheduler == null) {
fixedSizedScheduler = new FixedSizedSchedulerImpl(minimumThreads, poolName);
}
}
}
return fixedSizedScheduler;
}
@Override
public ScheduledThreadPoolExecutor getTimeoutScheduler() {
if (timeoutScheduler == null) {
synchronized (this) {
if (timeoutScheduler == null) {
timeoutScheduler =
new ScheduledThreadPoolExecutor(1, new MariaDbThreadFactory("MariaDb-timeout"));
timeoutScheduler.setRemoveOnCancelPolicy(true);
}
}
}
return timeoutScheduler;
}
@Override
@SuppressWarnings("unchecked")
public ThreadPoolExecutor getBulkScheduler() {
if (threadPoolExecutor == null) {
synchronized (this) {
if (threadPoolExecutor == null) {
threadPoolExecutor =
new ThreadPoolExecutor(
5,
100,
1,
TimeUnit.MINUTES,
new SynchronousQueue(),
new MariaDbThreadFactory("MariaDb-bulk"));
}
}
}
return threadPoolExecutor;
}
public void close() {
synchronized (this) {
if (dynamicSizedScheduler != null) {
dynamicSizedScheduler.shutdownNow();
}
if (fixedSizedScheduler != null) {
fixedSizedScheduler.shutdownNow();
}
if (timeoutScheduler != null) {
timeoutScheduler.shutdownNow();
}
if (threadPoolExecutor != null) {
threadPoolExecutor.shutdownNow();
}
dynamicSizedScheduler = null;
fixedSizedScheduler = null;
timeoutScheduler = null;
threadPoolExecutor = null;
}
}
};
private static AtomicReference currentProvider =
new AtomicReference<>(DEFAULT_PROVIDER);
/**
* Get the currently set {@link SchedulerProvider} from set invocations via {@link
* #setSchedulerProvider(SchedulerProvider)}. If none has been set a default provider will be
* provided (never a {@code null} result).
*
* @return Provider to get scheduler pools from
*/
public static SchedulerProvider getSchedulerProvider() {
return currentProvider.get();
}
/**
* Change the current set scheduler provider. This provider will be provided in future requests to
* {@link #getSchedulerProvider()}.
*
* @param newProvider New provider to use, or {@code null} to use the default provider
*/
public static void setSchedulerProvider(SchedulerProvider newProvider) {
if (newProvider == null) {
newProvider = DEFAULT_PROVIDER;
}
currentProvider.getAndSet(newProvider).close();
}
/** Close currentProvider. */
public static void close() {
currentProvider.get().close();
}
/**
* Get a Dynamic sized scheduler directly with the current set provider.
*
* @param initialThreadCount Number of threads scheduler is allowed to grow to
* @param poolName name of pool to identify threads
* @param maximumPoolSize maximum pool size
* @return Scheduler capable of providing the needed thread count
*/
public static DynamicSizedSchedulerInterface getScheduler(
int initialThreadCount, String poolName, int maximumPoolSize) {
return getSchedulerProvider().getScheduler(initialThreadCount, poolName, maximumPoolSize);
}
/**
* Get a fixed sized scheduler directly with the current set provider.
*
* @param initialThreadCount Number of threads scheduler is allowed to grow to
* @param poolName name of pool to identify threads
* @return Scheduler capable of providing the needed thread count
*/
public static ScheduledExecutorService getFixedSizeScheduler(
int initialThreadCount, String poolName) {
return getSchedulerProvider().getFixedSizeScheduler(initialThreadCount, poolName);
}
/**
* Get a scheduler to handle timeout.
*
* @return Scheduler capable of providing the needed thread count
*/
public static ScheduledExecutorService getTimeoutScheduler() {
return getSchedulerProvider().getTimeoutScheduler();
}
public static ThreadPoolExecutor getBulkScheduler() {
return getSchedulerProvider().getBulkScheduler();
}
/**
* Provider for thread pools which allow scheduling capabilities. It is expected that the thread
* pools entire lifecycle (start to stop) is done through the same provider instance.
*/
public interface SchedulerProvider {
/**
* Request to get a scheduler with a minimum number of AVAILABLE threads.
*
* @param minimumThreads Minimum number of available threads for the returned scheduler
* @param poolName name of pool to identify threads
* @param maximumPoolSize maximum pool size
* @return A new scheduler that is ready to accept tasks
*/
DynamicSizedSchedulerInterface getScheduler(
int minimumThreads, String poolName, int maximumPoolSize);
ScheduledExecutorService getFixedSizeScheduler(int minimumThreads, String poolName);
/**
* Default Timeout scheduler.
*
* This is a one Thread fixed sized scheduler. This specific scheduler is using java 1.7
* RemoveOnCancelPolicy, so the task are removed from queue permitting to avoid memory
* consumption [CONJ-297]
*
* @return A new scheduler that is ready to accept tasks
*/
ScheduledThreadPoolExecutor getTimeoutScheduler();
ThreadPoolExecutor getBulkScheduler();
void close();
}
}