/* * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * Written by Doug Lea with assistance from members of JCP JSR-166 * Expert Group and released to the public domain, as explained at * http://creativecommons.org/publicdomain/zero/1.0/ */
package java.util.concurrent.locks;
/** * A synchronizer that may be exclusively owned by a thread. This * class provides a basis for creating locks and related synchronizers * that may entail a notion of ownership. The * <tt>AbstractOwnableSynchronizer</tt> class itself does not manage or * use this information. However, subclasses and tools may use * appropriately maintained values to help control and monitor access * and provide diagnostics. * 一个线程,可能独占一个同步锁。AbstractOwnableSynchronizer用于表示锁与持有者之间的关系; AbstractOwnableSynchronizer不管理这种关系;主要是其子类,用于控制或监视锁的状态,提供 帮助。 * @since 1.6 * @author Doug Lea */ public abstract class AbstractOwnableSynchronizer implements java.io.Serializable {
/** Use serial ID even though all fields transient. */ private static final long serialVersionUID = 3737899427754241961L;
/** * Empty constructor for use by subclasses. */ protected AbstractOwnableSynchronizer() { }
/** * The current owner of exclusive mode synchronization. */ //独占模式,锁的持有者 private transient Thread exclusiveOwnerThread;
/** * Sets the thread that currently owns exclusive access. A * <tt>null</tt> argument indicates that no thread owns access. * This method does not otherwise impose any synchronization or * <tt>volatile</tt> field accesses. */ //设置锁持有者 protected final void setExclusiveOwnerThread(Thread t) { exclusiveOwnerThread = t; }
/** * Returns the thread last set by * <tt>setExclusiveOwnerThread</tt>, or <tt>null</tt> if never * set. This method does not otherwise impose any synchronization * or <tt>volatile</tt> field accesses. * @return the owner thread */ //获取锁的持有线程 protected final Thread getExclusiveOwnerThread() { return exclusiveOwnerThread; } }