Automatic sources dropoff on 2020-06-10 18:32:38.095721
The change is generated with prebuilt drop tool.
Change-Id: I24cbf6ba6db262a1ae1445db1427a08fee35b3b4
diff --git a/java/lang/Thread.java b/java/lang/Thread.java
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+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang;
+
+import dalvik.annotation.optimization.FastNative;
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import java.security.AccessController;
+import java.security.AccessControlContext;
+import java.security.PrivilegedAction;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.locks.LockSupport;
+import sun.nio.ch.Interruptible;
+import sun.reflect.CallerSensitive;
+import dalvik.system.RuntimeHooks;
+import dalvik.system.ThreadPrioritySetter;
+import dalvik.system.VMStack;
+import libcore.util.EmptyArray;
+
+
+/**
+ * A <i>thread</i> is a thread of execution in a program. The Java
+ * Virtual Machine allows an application to have multiple threads of
+ * execution running concurrently.
+ * <p>
+ * Every thread has a priority. Threads with higher priority are
+ * executed in preference to threads with lower priority. Each thread
+ * may or may not also be marked as a daemon. When code running in
+ * some thread creates a new <code>Thread</code> object, the new
+ * thread has its priority initially set equal to the priority of the
+ * creating thread, and is a daemon thread if and only if the
+ * creating thread is a daemon.
+ * <p>
+ * When a Java Virtual Machine starts up, there is usually a single
+ * non-daemon thread (which typically calls the method named
+ * <code>main</code> of some designated class). The Java Virtual
+ * Machine continues to execute threads until either of the following
+ * occurs:
+ * <ul>
+ * <li>The <code>exit</code> method of class <code>Runtime</code> has been
+ * called and the security manager has permitted the exit operation
+ * to take place.
+ * <li>All threads that are not daemon threads have died, either by
+ * returning from the call to the <code>run</code> method or by
+ * throwing an exception that propagates beyond the <code>run</code>
+ * method.
+ * </ul>
+ * <p>
+ * There are two ways to create a new thread of execution. One is to
+ * declare a class to be a subclass of <code>Thread</code>. This
+ * subclass should override the <code>run</code> method of class
+ * <code>Thread</code>. An instance of the subclass can then be
+ * allocated and started. For example, a thread that computes primes
+ * larger than a stated value could be written as follows:
+ * <hr><blockquote><pre>
+ * class PrimeThread extends Thread {
+ * long minPrime;
+ * PrimeThread(long minPrime) {
+ * this.minPrime = minPrime;
+ * }
+ *
+ * public void run() {
+ * // compute primes larger than minPrime
+ * . . .
+ * }
+ * }
+ * </pre></blockquote><hr>
+ * <p>
+ * The following code would then create a thread and start it running:
+ * <blockquote><pre>
+ * PrimeThread p = new PrimeThread(143);
+ * p.start();
+ * </pre></blockquote>
+ * <p>
+ * The other way to create a thread is to declare a class that
+ * implements the <code>Runnable</code> interface. That class then
+ * implements the <code>run</code> method. An instance of the class can
+ * then be allocated, passed as an argument when creating
+ * <code>Thread</code>, and started. The same example in this other
+ * style looks like the following:
+ * <hr><blockquote><pre>
+ * class PrimeRun implements Runnable {
+ * long minPrime;
+ * PrimeRun(long minPrime) {
+ * this.minPrime = minPrime;
+ * }
+ *
+ * public void run() {
+ * // compute primes larger than minPrime
+ * . . .
+ * }
+ * }
+ * </pre></blockquote><hr>
+ * <p>
+ * The following code would then create a thread and start it running:
+ * <blockquote><pre>
+ * PrimeRun p = new PrimeRun(143);
+ * new Thread(p).start();
+ * </pre></blockquote>
+ * <p>
+ * Every thread has a name for identification purposes. More than
+ * one thread may have the same name. If a name is not specified when
+ * a thread is created, a new name is generated for it.
+ * <p>
+ * Unless otherwise noted, passing a {@code null} argument to a constructor
+ * or method in this class will cause a {@link NullPointerException} to be
+ * thrown.
+ *
+ * @author unascribed
+ * @see Runnable
+ * @see Runtime#exit(int)
+ * @see #run()
+ * @see #stop()
+ * @since JDK1.0
+ */
+public
+class Thread implements Runnable {
+ // Android-removed: registerNatives() not used on Android.
+ /*
+ /* Make sure registerNatives is the first thing <clinit> does. *
+ private static native void registerNatives();
+ static {
+ registerNatives();
+ }
+ */
+
+ // BEGIN Android-added: Android specific fields lock, nativePeer.
+ /**
+ * The synchronization object responsible for this thread's join/sleep/park operations.
+ */
+ private final Object lock = new Object();
+
+ /**
+ * Reference to the native thread object.
+ *
+ * <p>Is 0 if the native thread has not yet been created/started, or has been destroyed.
+ */
+ private volatile long nativePeer;
+ // END Android-added: Android specific fields lock, nativePeer.
+
+ private volatile String name;
+ private int priority;
+ private Thread threadQ;
+ private long eetop;
+
+ /* Whether or not to single_step this thread. */
+ private boolean single_step;
+
+ /* Whether or not the thread is a daemon thread. */
+ private boolean daemon = false;
+
+ /* JVM state */
+ private boolean stillborn = false;
+
+ /* What will be run. */
+ private Runnable target;
+
+ /* The group of this thread */
+ private ThreadGroup group;
+
+ /* The context ClassLoader for this thread */
+ private ClassLoader contextClassLoader;
+
+ /* The inherited AccessControlContext of this thread */
+ private AccessControlContext inheritedAccessControlContext;
+
+ /* For autonumbering anonymous threads. */
+ private static int threadInitNumber;
+ private static synchronized int nextThreadNum() {
+ return threadInitNumber++;
+ }
+
+ /* ThreadLocal values pertaining to this thread. This map is maintained
+ * by the ThreadLocal class. */
+ ThreadLocal.ThreadLocalMap threadLocals = null;
+
+ /*
+ * InheritableThreadLocal values pertaining to this thread. This map is
+ * maintained by the InheritableThreadLocal class.
+ */
+ ThreadLocal.ThreadLocalMap inheritableThreadLocals = null;
+
+ /*
+ * The requested stack size for this thread, or 0 if the creator did
+ * not specify a stack size. It is up to the VM to do whatever it
+ * likes with this number; some VMs will ignore it.
+ */
+ private long stackSize;
+
+ // BEGIN Android-changed: Keep track of whether this thread was unparked while not alive.
+ /*
+ /*
+ * JVM-private state that persists after native thread termination.
+ *
+ private long nativeParkEventPointer;
+ */
+ /**
+ * Indicates whether this thread was unpark()ed while not alive, in which case start()ing
+ * it should leave it in unparked state. This field is read and written by native code in
+ * the runtime, guarded by thread_list_lock. See http://b/28845097#comment49
+ */
+ private boolean unparkedBeforeStart;
+ // END Android-changed: Keep track of whether this thread was unparked while not alive.
+
+ /*
+ * Thread ID
+ */
+ private long tid;
+
+ /* For generating thread ID */
+ private static long threadSeqNumber;
+
+
+ // Android-added: The concept of "system-daemon" threads. See java.lang.Daemons.
+ /** True if this thread is managed by {@link Daemons}. */
+ private boolean systemDaemon = false;
+
+ /* Java thread status for tools,
+ * initialized to indicate thread 'not yet started'
+ */
+
+ // BEGIN Android-changed: Replace unused threadStatus field with started field.
+ // Upstream this is modified by the native code and read in the start() and getState() methods
+ // but in Android it is unused. The threadStatus is essentially an internal representation of
+ // the Thread.State enum. Android uses two sources for that information, the native thread
+ // state and the started field. The reason two sources are needed is because the native thread
+ // is created when the thread is started and destroyed when the thread is stopped. That means
+ // that the native thread state does not exist before the Thread has started (in State.NEW) or
+ // after it has been stopped (in State.TERMINATED). In that case (i.e. when the nativePeer = 0)
+ // the started field differentiates between the two states, i.e. if started = false then the
+ // thread is in State.NEW and if started = true then the thread is in State.TERMINATED.
+ // private volatile int threadStatus = 0;
+ /**
+ * True if the the Thread has been started, even it has since been stopped.
+ */
+ boolean started = false;
+ // END Android-changed: Replace unused threadStatus field with started field.
+
+
+ private static synchronized long nextThreadID() {
+ return ++threadSeqNumber;
+ }
+
+ /**
+ * The argument supplied to the current call to
+ * java.util.concurrent.locks.LockSupport.park.
+ * Set by (private) java.util.concurrent.locks.LockSupport.setBlocker
+ * Accessed using java.util.concurrent.locks.LockSupport.getBlocker
+ */
+ volatile Object parkBlocker;
+
+ /* The object in which this thread is blocked in an interruptible I/O
+ * operation, if any. The blocker's interrupt method should be invoked
+ * after setting this thread's interrupt status.
+ */
+ private volatile Interruptible blocker;
+ private final Object blockerLock = new Object();
+
+ // Android-changed: Make blockedOn() @hide public, for internal use.
+ // Changed comment to reflect usage on Android
+ /* Set the blocker field; used by java.nio.channels.spi.AbstractInterruptibleChannel
+ */
+ /** @hide */
+ public void blockedOn(Interruptible b) {
+ synchronized (blockerLock) {
+ blocker = b;
+ }
+ }
+
+ /**
+ * The minimum priority that a thread can have.
+ */
+ public final static int MIN_PRIORITY = 1;
+
+ /**
+ * The default priority that is assigned to a thread.
+ */
+ public final static int NORM_PRIORITY = 5;
+
+ /**
+ * The maximum priority that a thread can have.
+ */
+ public final static int MAX_PRIORITY = 10;
+
+ /**
+ * Returns a reference to the currently executing thread object.
+ *
+ * @return the currently executing thread.
+ */
+ @FastNative
+ public static native Thread currentThread();
+
+ /**
+ * A hint to the scheduler that the current thread is willing to yield
+ * its current use of a processor. The scheduler is free to ignore this
+ * hint.
+ *
+ * <p> Yield is a heuristic attempt to improve relative progression
+ * between threads that would otherwise over-utilise a CPU. Its use
+ * should be combined with detailed profiling and benchmarking to
+ * ensure that it actually has the desired effect.
+ *
+ * <p> It is rarely appropriate to use this method. It may be useful
+ * for debugging or testing purposes, where it may help to reproduce
+ * bugs due to race conditions. It may also be useful when designing
+ * concurrency control constructs such as the ones in the
+ * {@link java.util.concurrent.locks} package.
+ */
+ public static native void yield();
+
+ /**
+ * Causes the currently executing thread to sleep (temporarily cease
+ * execution) for the specified number of milliseconds, subject to
+ * the precision and accuracy of system timers and schedulers. The thread
+ * does not lose ownership of any monitors.
+ *
+ * @param millis
+ * the length of time to sleep in milliseconds
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * <i>interrupted status</i> of the current thread is
+ * cleared when this exception is thrown.
+ */
+ // BEGIN Android-changed: Implement sleep() methods using a shared native implementation.
+ public static void sleep(long millis) throws InterruptedException {
+ sleep(millis, 0);
+ }
+
+ @FastNative
+ private static native void sleep(Object lock, long millis, int nanos)
+ throws InterruptedException;
+ // END Android-changed: Implement sleep() methods using a shared native implementation.
+
+ /**
+ * Causes the currently executing thread to sleep (temporarily cease
+ * execution) for the specified number of milliseconds plus the specified
+ * number of nanoseconds, subject to the precision and accuracy of system
+ * timers and schedulers. The thread does not lose ownership of any
+ * monitors.
+ *
+ * @param millis
+ * the length of time to sleep in milliseconds
+ *
+ * @param nanos
+ * {@code 0-999999} additional nanoseconds to sleep
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative, or the value of
+ * {@code nanos} is not in the range {@code 0-999999}
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * <i>interrupted status</i> of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public static void sleep(long millis, int nanos)
+ throws InterruptedException {
+ // BEGIN Android-changed: Improve exception messages.
+ /*
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException(
+ "nanosecond timeout value out of range");
+ }
+ */
+ if (millis < 0) {
+ throw new IllegalArgumentException("millis < 0: " + millis);
+ }
+ if (nanos < 0) {
+ throw new IllegalArgumentException("nanos < 0: " + nanos);
+ }
+ if (nanos > 999999) {
+ throw new IllegalArgumentException("nanos > 999999: " + nanos);
+ }
+ // END Android-changed: Improve exception messages.
+
+ // BEGIN Android-changed: Implement sleep() methods using a shared native implementation.
+ // Attempt nanosecond rather than millisecond accuracy for sleep();
+ // RI code rounds to the nearest millisecond.
+ /*
+ if (nanos >= 500000 || (nanos != 0 && millis == 0)) {
+ millis++;
+ }
+
+ sleep(millis);
+ */
+ // The JLS 3rd edition, section 17.9 says: "...sleep for zero
+ // time...need not have observable effects."
+ if (millis == 0 && nanos == 0) {
+ // ...but we still have to handle being interrupted.
+ if (Thread.interrupted()) {
+ throw new InterruptedException();
+ }
+ return;
+ }
+
+ final int nanosPerMilli = 1000000;
+ long start = System.nanoTime();
+ long duration = (millis * nanosPerMilli) + nanos;
+
+ Object lock = currentThread().lock;
+
+ // The native sleep(...) method actually performs a special type of wait, which may return
+ // early, so loop until sleep duration passes.
+ synchronized (lock) {
+ while (true) {
+ sleep(lock, millis, nanos);
+
+ long now = System.nanoTime();
+ long elapsed = now - start;
+
+ if (elapsed >= duration) {
+ break;
+ }
+
+ duration -= elapsed;
+ start = now;
+ millis = duration / nanosPerMilli;
+ nanos = (int) (duration % nanosPerMilli);
+ }
+ }
+ // END Android-changed: Implement sleep() methods using a shared native implementation.
+ }
+
+ /**
+ * Initializes a Thread with the current AccessControlContext.
+ * @see #init(ThreadGroup,Runnable,String,long,AccessControlContext)
+ */
+ private void init(ThreadGroup g, Runnable target, String name,
+ long stackSize) {
+ init(g, target, name, stackSize, null);
+ }
+
+ /**
+ * Initializes a Thread.
+ *
+ * @param g the Thread group
+ * @param target the object whose run() method gets called
+ * @param name the name of the new Thread
+ * @param stackSize the desired stack size for the new thread, or
+ * zero to indicate that this parameter is to be ignored.
+ * @param acc the AccessControlContext to inherit, or
+ * AccessController.getContext() if null
+ */
+ private void init(ThreadGroup g, Runnable target, String name,
+ long stackSize, AccessControlContext acc) {
+ if (name == null) {
+ throw new NullPointerException("name cannot be null");
+ }
+
+ this.name = name;
+
+ Thread parent = currentThread();
+ // Android-removed: SecurityManager stubbed out on Android
+ // SecurityManager security = System.getSecurityManager();
+ if (g == null) {
+ // Android-changed: SecurityManager stubbed out on Android
+ /*
+ /* Determine if it's an applet or not *
+
+ /* If there is a security manager, ask the security manager
+ what to do. *
+ if (security != null) {
+ g = security.getThreadGroup();
+ }
+
+ /* If the security doesn't have a strong opinion of the matter
+ use the parent thread group. *
+ if (g == null) {
+ */
+ g = parent.getThreadGroup();
+ // }
+ }
+
+ // Android-removed: SecurityManager stubbed out on Android
+ /*
+ /* checkAccess regardless of whether or not threadgroup is
+ explicitly passed in. *
+ g.checkAccess();
+
+ /*
+ * Do we have the required permissions?
+ *
+ if (security != null) {
+ if (isCCLOverridden(getClass())) {
+ security.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
+ }
+ }
+ */
+
+ g.addUnstarted();
+
+ this.group = g;
+ this.daemon = parent.isDaemon();
+ this.priority = parent.getPriority();
+ // Android-changed: Moved into init2(Thread) helper method.
+ /*
+ if (security == null || isCCLOverridden(parent.getClass()))
+ this.contextClassLoader = parent.getContextClassLoader();
+ else
+ this.contextClassLoader = parent.contextClassLoader;
+ this.inheritedAccessControlContext =
+ acc != null ? acc : AccessController.getContext();
+ */
+ this.target = target;
+ // Android-removed: The priority parameter is unchecked on Android.
+ // It is unclear why this is not being done (b/80180276).
+ // setPriority(priority);
+ // Android-changed: Moved into init2(Thread) helper method.
+ // if (parent.inheritableThreadLocals != null)
+ // this.inheritableThreadLocals =
+ // ThreadLocal.createInheritedMap(parent.inheritableThreadLocals);
+ init2(parent);
+
+ /* Stash the specified stack size in case the VM cares */
+ this.stackSize = stackSize;
+
+ /* Set thread ID */
+ tid = nextThreadID();
+ }
+
+ /**
+ * Throws CloneNotSupportedException as a Thread can not be meaningfully
+ * cloned. Construct a new Thread instead.
+ *
+ * @throws CloneNotSupportedException
+ * always
+ */
+ @Override
+ protected Object clone() throws CloneNotSupportedException {
+ throw new CloneNotSupportedException();
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, null, gname)}, where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}<i>n</i>, where <i>n</i> is an integer.
+ */
+ public Thread() {
+ init(null, null, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, target, gname)}, where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}<i>n</i>, where <i>n</i> is an integer.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this classes {@code run} method does
+ * nothing.
+ */
+ public Thread(Runnable target) {
+ init(null, target, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Creates a new Thread that inherits the given AccessControlContext.
+ * This is not a public constructor.
+ */
+ Thread(Runnable target, AccessControlContext acc) {
+ init(null, target, "Thread-" + nextThreadNum(), 0, acc);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (group, target, gname)} ,where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}<i>n</i>, where <i>n</i> is an integer.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ */
+ public Thread(ThreadGroup group, Runnable target) {
+ init(group, target, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, null, name)}.
+ *
+ * @param name
+ * the name of the new thread
+ */
+ public Thread(String name) {
+ init(null, null, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (group, null, name)}.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ */
+ public Thread(ThreadGroup group, String name) {
+ init(group, null, name, 0);
+ }
+
+ // BEGIN Android-added: Private constructor - used by the runtime.
+ /** @hide */
+ Thread(ThreadGroup group, String name, int priority, boolean daemon) {
+ this.group = group;
+ this.group.addUnstarted();
+ // Must be tolerant of threads without a name.
+ if (name == null) {
+ name = "Thread-" + nextThreadNum();
+ }
+
+ // NOTE: Resist the temptation to call setName() here. This constructor is only called
+ // by the runtime to construct peers for threads that have attached via JNI and it's
+ // undesirable to clobber their natively set name.
+ this.name = name;
+
+ this.priority = priority;
+ this.daemon = daemon;
+ init2(currentThread());
+ tid = nextThreadID();
+ }
+
+ // Android-added: Helper method for previous constructor and init(...) method.
+ private void init2(Thread parent) {
+ this.contextClassLoader = parent.getContextClassLoader();
+ this.inheritedAccessControlContext = AccessController.getContext();
+ if (parent.inheritableThreadLocals != null) {
+ this.inheritableThreadLocals = ThreadLocal.createInheritedMap(
+ parent.inheritableThreadLocals);
+ }
+ }
+ // END Android-added: Private constructor - used by the runtime.
+
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, target, name)}.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ */
+ public Thread(Runnable target, String name) {
+ init(null, target, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object so that it has {@code target}
+ * as its run object, has the specified {@code name} as its name,
+ * and belongs to the thread group referred to by {@code group}.
+ *
+ * <p>If there is a security manager, its
+ * {@link SecurityManager#checkAccess(ThreadGroup) checkAccess}
+ * method is invoked with the ThreadGroup as its argument.
+ *
+ * <p>In addition, its {@code checkPermission} method is invoked with
+ * the {@code RuntimePermission("enableContextClassLoaderOverride")}
+ * permission when invoked directly or indirectly by the constructor
+ * of a subclass which overrides the {@code getContextClassLoader}
+ * or {@code setContextClassLoader} methods.
+ *
+ * <p>The priority of the newly created thread is set equal to the
+ * priority of the thread creating it, that is, the currently running
+ * thread. The method {@linkplain #setPriority setPriority} may be
+ * used to change the priority to a new value.
+ *
+ * <p>The newly created thread is initially marked as being a daemon
+ * thread if and only if the thread creating it is currently marked
+ * as a daemon thread. The method {@linkplain #setDaemon setDaemon}
+ * may be used to change whether or not a thread is a daemon.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group or cannot override the context class loader methods.
+ */
+ public Thread(ThreadGroup group, Runnable target, String name) {
+ init(group, target, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object so that it has {@code target}
+ * as its run object, has the specified {@code name} as its name,
+ * and belongs to the thread group referred to by {@code group}, and has
+ * the specified <i>stack size</i>.
+ *
+ * <p>This constructor is identical to {@link
+ * #Thread(ThreadGroup,Runnable,String)} with the exception of the fact
+ * that it allows the thread stack size to be specified. The stack size
+ * is the approximate number of bytes of address space that the virtual
+ * machine is to allocate for this thread's stack. <b>The effect of the
+ * {@code stackSize} parameter, if any, is highly platform dependent.</b>
+ *
+ * <p>On some platforms, specifying a higher value for the
+ * {@code stackSize} parameter may allow a thread to achieve greater
+ * recursion depth before throwing a {@link StackOverflowError}.
+ * Similarly, specifying a lower value may allow a greater number of
+ * threads to exist concurrently without throwing an {@link
+ * OutOfMemoryError} (or other internal error). The details of
+ * the relationship between the value of the <tt>stackSize</tt> parameter
+ * and the maximum recursion depth and concurrency level are
+ * platform-dependent. <b>On some platforms, the value of the
+ * {@code stackSize} parameter may have no effect whatsoever.</b>
+ *
+ * <p>The virtual machine is free to treat the {@code stackSize}
+ * parameter as a suggestion. If the specified value is unreasonably low
+ * for the platform, the virtual machine may instead use some
+ * platform-specific minimum value; if the specified value is unreasonably
+ * high, the virtual machine may instead use some platform-specific
+ * maximum. Likewise, the virtual machine is free to round the specified
+ * value up or down as it sees fit (or to ignore it completely).
+ *
+ * <p>Specifying a value of zero for the {@code stackSize} parameter will
+ * cause this constructor to behave exactly like the
+ * {@code Thread(ThreadGroup, Runnable, String)} constructor.
+ *
+ * <p><i>Due to the platform-dependent nature of the behavior of this
+ * constructor, extreme care should be exercised in its use.
+ * The thread stack size necessary to perform a given computation will
+ * likely vary from one JRE implementation to another. In light of this
+ * variation, careful tuning of the stack size parameter may be required,
+ * and the tuning may need to be repeated for each JRE implementation on
+ * which an application is to run.</i>
+ *
+ * <p>Implementation note: Java platform implementers are encouraged to
+ * document their implementation's behavior with respect to the
+ * {@code stackSize} parameter.
+ *
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @param stackSize
+ * the desired stack size for the new thread, or zero to indicate
+ * that this parameter is to be ignored.
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ *
+ * @since 1.4
+ */
+ public Thread(ThreadGroup group, Runnable target, String name,
+ long stackSize) {
+ init(group, target, name, stackSize);
+ }
+
+ /**
+ * Causes this thread to begin execution; the Java Virtual Machine
+ * calls the <code>run</code> method of this thread.
+ * <p>
+ * The result is that two threads are running concurrently: the
+ * current thread (which returns from the call to the
+ * <code>start</code> method) and the other thread (which executes its
+ * <code>run</code> method).
+ * <p>
+ * It is never legal to start a thread more than once.
+ * In particular, a thread may not be restarted once it has completed
+ * execution.
+ *
+ * @exception IllegalThreadStateException if the thread was already
+ * started.
+ * @see #run()
+ * @see #stop()
+ */
+ public synchronized void start() {
+ /**
+ * This method is not invoked for the main method thread or "system"
+ * group threads created/set up by the VM. Any new functionality added
+ * to this method in the future may have to also be added to the VM.
+ *
+ * A zero status value corresponds to state "NEW".
+ */
+ // Android-changed: Replace unused threadStatus field with started field.
+ // The threadStatus field is unused on Android.
+ if (started)
+ throw new IllegalThreadStateException();
+
+ /* Notify the group that this thread is about to be started
+ * so that it can be added to the group's list of threads
+ * and the group's unstarted count can be decremented. */
+ group.add(this);
+
+ // Android-changed: Use field instead of local variable.
+ // It is necessary to remember the state of this across calls to this method so that it
+ // can throw an IllegalThreadStateException if this method is called on an already
+ // started thread.
+ started = false;
+ try {
+ // Android-changed: Use Android specific nativeCreate() method to create/start thread.
+ // start0();
+ nativeCreate(this, stackSize, daemon);
+ started = true;
+ } finally {
+ try {
+ if (!started) {
+ group.threadStartFailed(this);
+ }
+ } catch (Throwable ignore) {
+ /* do nothing. If start0 threw a Throwable then
+ it will be passed up the call stack */
+ }
+ }
+ }
+
+ // Android-changed: Use Android specific nativeCreate() method to create/start thread.
+ // The upstream native method start0() only takes a reference to this object and so must obtain
+ // the stack size and daemon status directly from the field whereas Android supplies the values
+ // explicitly on the method call.
+ // private native void start0();
+ private native static void nativeCreate(Thread t, long stackSize, boolean daemon);
+
+ /**
+ * If this thread was constructed using a separate
+ * <code>Runnable</code> run object, then that
+ * <code>Runnable</code> object's <code>run</code> method is called;
+ * otherwise, this method does nothing and returns.
+ * <p>
+ * Subclasses of <code>Thread</code> should override this method.
+ *
+ * @see #start()
+ * @see #stop()
+ * @see #Thread(ThreadGroup, Runnable, String)
+ */
+ @Override
+ public void run() {
+ if (target != null) {
+ target.run();
+ }
+ }
+
+ /**
+ * This method is called by the system to give a Thread
+ * a chance to clean up before it actually exits.
+ */
+ private void exit() {
+ if (group != null) {
+ group.threadTerminated(this);
+ group = null;
+ }
+ /* Aggressively null out all reference fields: see bug 4006245 */
+ target = null;
+ /* Speed the release of some of these resources */
+ threadLocals = null;
+ inheritableThreadLocals = null;
+ inheritedAccessControlContext = null;
+ blocker = null;
+ uncaughtExceptionHandler = null;
+ }
+
+ // Android-changed: Throws UnsupportedOperationException.
+ /**
+ * Throws {@code UnsupportedOperationException}.
+ *
+ * @deprecated This method was originally designed to force a thread to stop
+ * and throw a {@code ThreadDeath} as an exception. It was inherently unsafe.
+ * Stopping a thread with
+ * Thread.stop causes it to unlock all of the monitors that it
+ * has locked (as a natural consequence of the unchecked
+ * <code>ThreadDeath</code> exception propagating up the stack). If
+ * any of the objects previously protected by these monitors were in
+ * an inconsistent state, the damaged objects become visible to
+ * other threads, potentially resulting in arbitrary behavior. Many
+ * uses of <code>stop</code> should be replaced by code that simply
+ * modifies some variable to indicate that the target thread should
+ * stop running. The target thread should check this variable
+ * regularly, and return from its run method in an orderly fashion
+ * if the variable indicates that it is to stop running. If the
+ * target thread waits for long periods (on a condition variable,
+ * for example), the <code>interrupt</code> method should be used to
+ * interrupt the wait.
+ * For more information, see
+ * <a href="{@docRoot}/../technotes/guides/concurrency/threadPrimitiveDeprecation.html">Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?</a>.
+ */
+ @Deprecated
+ public final void stop() {
+ /*
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ checkAccess();
+ if (this != Thread.currentThread()) {
+ security.checkPermission(SecurityConstants.STOP_THREAD_PERMISSION);
+ }
+ }
+ // A zero status value corresponds to "NEW", it can't change to
+ // not-NEW because we hold the lock.
+ if (threadStatus != 0) {
+ resume(); // Wake up thread if it was suspended; no-op otherwise
+ }
+
+ // The VM can handle all thread states
+ stop0(new ThreadDeath());
+ */
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * Throws {@code UnsupportedOperationException}.
+ *
+ * @param obj ignored
+ *
+ * @deprecated This method was originally designed to force a thread to stop
+ * and throw a given {@code Throwable} as an exception. It was
+ * inherently unsafe (see {@link #stop()} for details), and furthermore
+ * could be used to generate exceptions that the target thread was
+ * not prepared to handle.
+ * For more information, see
+ * <a href="{@docRoot}/../technotes/guides/concurrency/threadPrimitiveDeprecation.html">Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?</a>.
+ */
+ @Deprecated
+ public final synchronized void stop(Throwable obj) {
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * Interrupts this thread.
+ *
+ * <p> Unless the current thread is interrupting itself, which is
+ * always permitted, the {@link #checkAccess() checkAccess} method
+ * of this thread is invoked, which may cause a {@link
+ * SecurityException} to be thrown.
+ *
+ * <p> If this thread is blocked in an invocation of the {@link
+ * Object#wait() wait()}, {@link Object#wait(long) wait(long)}, or {@link
+ * Object#wait(long, int) wait(long, int)} methods of the {@link Object}
+ * class, or of the {@link #join()}, {@link #join(long)}, {@link
+ * #join(long, int)}, {@link #sleep(long)}, or {@link #sleep(long, int)},
+ * methods of this class, then its interrupt status will be cleared and it
+ * will receive an {@link InterruptedException}.
+ *
+ * <p> If this thread is blocked in an I/O operation upon an {@link
+ * java.nio.channels.InterruptibleChannel InterruptibleChannel}
+ * then the channel will be closed, the thread's interrupt
+ * status will be set, and the thread will receive a {@link
+ * java.nio.channels.ClosedByInterruptException}.
+ *
+ * <p> If this thread is blocked in a {@link java.nio.channels.Selector}
+ * then the thread's interrupt status will be set and it will return
+ * immediately from the selection operation, possibly with a non-zero
+ * value, just as if the selector's {@link
+ * java.nio.channels.Selector#wakeup wakeup} method were invoked.
+ *
+ * <p> If none of the previous conditions hold then this thread's interrupt
+ * status will be set. </p>
+ *
+ * <p> Interrupting a thread that is not alive need not have any effect.
+ *
+ * @throws SecurityException
+ * if the current thread cannot modify this thread
+ *
+ * @revised 6.0
+ * @spec JSR-51
+ */
+ public void interrupt() {
+ if (this != Thread.currentThread())
+ checkAccess();
+
+ synchronized (blockerLock) {
+ Interruptible b = blocker;
+ if (b != null) {
+ interrupt0(); // Just to set the interrupt flag
+ b.interrupt(this);
+ return;
+ }
+ }
+ interrupt0();
+ }
+
+ /**
+ * Tests whether the current thread has been interrupted. The
+ * <i>interrupted status</i> of the thread is cleared by this method. In
+ * other words, if this method were to be called twice in succession, the
+ * second call would return false (unless the current thread were
+ * interrupted again, after the first call had cleared its interrupted
+ * status and before the second call had examined it).
+ *
+ * <p>A thread interruption ignored because a thread was not alive
+ * at the time of the interrupt will be reflected by this method
+ * returning false.
+ *
+ * @return <code>true</code> if the current thread has been interrupted;
+ * <code>false</code> otherwise.
+ * @see #isInterrupted()
+ * @revised 6.0
+ */
+ // Android-changed: Use native interrupted()/isInterrupted() methods.
+ // Upstream has one native method for both these methods that takes a boolean parameter that
+ // determines whether the interrupted status of the thread should be cleared after reading
+ // it. While that approach does allow code reuse it is less efficient/more complex than having
+ // a native implementation of each method because:
+ // * The pure Java interrupted() method requires two native calls, one to get the current
+ // thread and one to get its interrupted status.
+ // * Updating the interrupted flag is more complex than simply reading it. Knowing that only
+ // the current thread can clear the interrupted status makes the code simpler as it does not
+ // need to be concerned about multiple threads trying to clear the status simultaneously.
+ // public static boolean interrupted() {
+ // return currentThread().isInterrupted(true);
+ // }
+ @FastNative
+ public static native boolean interrupted();
+
+ /**
+ * Tests whether this thread has been interrupted. The <i>interrupted
+ * status</i> of the thread is unaffected by this method.
+ *
+ * <p>A thread interruption ignored because a thread was not alive
+ * at the time of the interrupt will be reflected by this method
+ * returning false.
+ *
+ * @return <code>true</code> if this thread has been interrupted;
+ * <code>false</code> otherwise.
+ * @see #interrupted()
+ * @revised 6.0
+ */
+ // Android-changed: Use native interrupted()/isInterrupted() methods.
+ // public boolean isInterrupted() {
+ // return isInterrupted(false);
+ // }
+ @FastNative
+ public native boolean isInterrupted();
+
+ // Android-removed: Use native interrupted()/isInterrupted() methods.
+ /*
+ /**
+ * Tests if some Thread has been interrupted. The interrupted state
+ * is reset or not based on the value of ClearInterrupted that is
+ * passed.
+ *
+ private native boolean isInterrupted(boolean ClearInterrupted);
+ */
+
+ // BEGIN Android-changed: Throw UnsupportedOperationException instead of NoSuchMethodError.
+ /**
+ * Throws {@link UnsupportedOperationException}.
+ *
+ * @deprecated This method was originally designed to destroy this
+ * thread without any cleanup. Any monitors it held would have
+ * remained locked. However, the method was never implemented.
+ * If if were to be implemented, it would be deadlock-prone in
+ * much the manner of {@link #suspend}. If the target thread held
+ * a lock protecting a critical system resource when it was
+ * destroyed, no thread could ever access this resource again.
+ * If another thread ever attempted to lock this resource, deadlock
+ * would result. Such deadlocks typically manifest themselves as
+ * "frozen" processes. For more information, see
+ * <a href="{@docRoot}/../technotes/guides/concurrency/threadPrimitiveDeprecation.html">
+ * Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?</a>.
+ * @throws UnsupportedOperationException always
+ */
+ @Deprecated
+ public void destroy() {
+ throw new UnsupportedOperationException();
+ }
+ // END Android-changed: Throw UnsupportedOperationException instead of NoSuchMethodError.
+
+ /**
+ * Tests if this thread is alive. A thread is alive if it has
+ * been started and has not yet died.
+ *
+ * @return <code>true</code> if this thread is alive;
+ * <code>false</code> otherwise.
+ */
+ // Android-changed: Provide pure Java implementation of isAlive().
+ public final boolean isAlive() {
+ return nativePeer != 0;
+ }
+
+ // Android-changed: Updated JavaDoc as it always throws an UnsupportedOperationException.
+ /**
+ * Throws {@link UnsupportedOperationException}.
+ *
+ * @deprecated This method was designed to suspend the Thread but it was
+ * inherently deadlock-prone. If the target thread holds a lock on the
+ * monitor protecting a critical system resource when it is suspended, no
+ * thread can access this resource until the target thread is resumed. If
+ * the thread that would resume the target thread attempts to lock this
+ * monitor prior to calling <code>resume</code>, deadlock results. Such
+ * deadlocks typically manifest themselves as "frozen" processes.
+ * For more information, see
+ * <a href="{@docRoot}/../technotes/guides/concurrency/threadPrimitiveDeprecation.html">Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?</a>.
+ * @throws UnsupportedOperationException always
+ */
+ @Deprecated
+ public final void suspend() {
+ // Android-changed: Unsupported on Android.
+ // checkAccess();
+ // suspend0();
+
+ throw new UnsupportedOperationException();
+ }
+
+ // Android-changed: Updated JavaDoc as it always throws an UnsupportedOperationException.
+ /**
+ * Throws {@link UnsupportedOperationException}.
+ *
+ * @deprecated This method exists solely for use with {@link #suspend},
+ * which has been deprecated because it is deadlock-prone.
+ * For more information, see
+ * <a href="{@docRoot}/../technotes/guides/concurrency/threadPrimitiveDeprecation.html">Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?</a>.
+ * @throws UnsupportedOperationException always
+ */
+ @Deprecated
+ public final void resume() {
+ // Android-changed: Unsupported on Android.
+ // checkAccess();
+ // resume0();
+ throw new UnsupportedOperationException();
+ }
+
+ /**
+ * Changes the priority of this thread.
+ * <p>
+ * First the <code>checkAccess</code> method of this thread is called
+ * with no arguments. This may result in throwing a
+ * <code>SecurityException</code>.
+ * <p>
+ * Otherwise, the priority of this thread is set to the smaller of
+ * the specified <code>newPriority</code> and the maximum permitted
+ * priority of the thread's thread group.
+ *
+ * @param newPriority priority to set this thread to
+ * @exception IllegalArgumentException If the priority is not in the
+ * range <code>MIN_PRIORITY</code> to
+ * <code>MAX_PRIORITY</code>.
+ * @exception SecurityException if the current thread cannot modify
+ * this thread.
+ * @see #getPriority
+ * @see #checkAccess()
+ * @see #getThreadGroup()
+ * @see #MAX_PRIORITY
+ * @see #MIN_PRIORITY
+ * @see ThreadGroup#getMaxPriority()
+ */
+ public final void setPriority(int newPriority) {
+ ThreadGroup g;
+ checkAccess();
+ if (newPriority > MAX_PRIORITY || newPriority < MIN_PRIORITY) {
+ // Android-changed: Improve exception message when the new priority is out of bounds.
+ throw new IllegalArgumentException("Priority out of range: " + newPriority);
+ }
+ if((g = getThreadGroup()) != null) {
+ if (newPriority > g.getMaxPriority()) {
+ newPriority = g.getMaxPriority();
+ }
+ // Android-changed: Avoid native call if Thread is not yet started.
+ // setPriority0(priority = newPriority);
+ synchronized(this) {
+ this.priority = newPriority;
+ if (isAlive()) {
+ // BEGIN Android-added: Customize behavior of Thread.setPriority().
+ // http://b/139521784
+ // setPriority0(newPriority);
+ ThreadPrioritySetter threadPrioritySetter =
+ RuntimeHooks.getThreadPrioritySetter();
+ int nativeTid = this.getNativeTid();
+ if (threadPrioritySetter != null && nativeTid != 0) {
+ threadPrioritySetter.setPriority(nativeTid, newPriority);
+ } else {
+ setPriority0(newPriority);
+ }
+ // END Android-added: Customize behavior of Thread.setPriority().
+ }
+ }
+ }
+ }
+
+ /**
+ * Returns this thread's priority.
+ *
+ * @return this thread's priority.
+ * @see #setPriority
+ */
+ public final int getPriority() {
+ return priority;
+ }
+
+ /**
+ * Changes the name of this thread to be equal to the argument
+ * <code>name</code>.
+ * <p>
+ * First the <code>checkAccess</code> method of this thread is called
+ * with no arguments. This may result in throwing a
+ * <code>SecurityException</code>.
+ *
+ * @param name the new name for this thread.
+ * @exception SecurityException if the current thread cannot modify this
+ * thread.
+ * @see #getName
+ * @see #checkAccess()
+ */
+ public final synchronized void setName(String name) {
+ checkAccess();
+ if (name == null) {
+ throw new NullPointerException("name cannot be null");
+ }
+
+ this.name = name;
+ // Android-changed: Use isAlive() not threadStatus to check whether Thread has started.
+ // The threadStatus field is not used in Android.
+ // if (threadStatus != 0) {
+ if (isAlive()) {
+ setNativeName(name);
+ }
+ }
+
+ /**
+ * Returns this thread's name.
+ *
+ * @return this thread's name.
+ * @see #setName(String)
+ */
+ public final String getName() {
+ return name;
+ }
+
+ /**
+ * Returns the thread group to which this thread belongs.
+ * This method returns null if this thread has died
+ * (been stopped).
+ *
+ * @return this thread's thread group.
+ */
+ public final ThreadGroup getThreadGroup() {
+ // BEGIN Android-added: Work around exit() not being called.
+ // Android runtime does not call exit() when a Thread exits so the group field is not
+ // set to null so it needs to pretend as if it did. If we are not going to call exit()
+ // then this should probably just check isAlive() here rather than getState() as the
+ // latter requires a native call.
+ if (getState() == Thread.State.TERMINATED) {
+ return null;
+ }
+ // END Android-added: Work around exit() not being called.
+ return group;
+ }
+
+ /**
+ * Returns an estimate of the number of active threads in the current
+ * thread's {@linkplain java.lang.ThreadGroup thread group} and its
+ * subgroups. Recursively iterates over all subgroups in the current
+ * thread's thread group.
+ *
+ * <p> The value returned is only an estimate because the number of
+ * threads may change dynamically while this method traverses internal
+ * data structures, and might be affected by the presence of certain
+ * system threads. This method is intended primarily for debugging
+ * and monitoring purposes.
+ *
+ * @return an estimate of the number of active threads in the current
+ * thread's thread group and in any other thread group that
+ * has the current thread's thread group as an ancestor
+ */
+ public static int activeCount() {
+ return currentThread().getThreadGroup().activeCount();
+ }
+
+ /**
+ * Copies into the specified array every active thread in the current
+ * thread's thread group and its subgroups. This method simply
+ * invokes the {@link java.lang.ThreadGroup#enumerate(Thread[])}
+ * method of the current thread's thread group.
+ *
+ * <p> An application might use the {@linkplain #activeCount activeCount}
+ * method to get an estimate of how big the array should be, however
+ * <i>if the array is too short to hold all the threads, the extra threads
+ * are silently ignored.</i> If it is critical to obtain every active
+ * thread in the current thread's thread group and its subgroups, the
+ * invoker should verify that the returned int value is strictly less
+ * than the length of {@code tarray}.
+ *
+ * <p> Due to the inherent race condition in this method, it is recommended
+ * that the method only be used for debugging and monitoring purposes.
+ *
+ * @param tarray
+ * an array into which to put the list of threads
+ *
+ * @return the number of threads put into the array
+ *
+ * @throws SecurityException
+ * if {@link java.lang.ThreadGroup#checkAccess} determines that
+ * the current thread cannot access its thread group
+ */
+ public static int enumerate(Thread tarray[]) {
+ return currentThread().getThreadGroup().enumerate(tarray);
+ }
+
+ /**
+ * Counts the number of stack frames in this thread. The thread must
+ * be suspended.
+ *
+ * @return the number of stack frames in this thread.
+ * @exception IllegalThreadStateException if this thread is not
+ * suspended.
+ * @deprecated The definition of this call depends on {@link #suspend},
+ * which is deprecated. Further, the results of this call
+ * were never well-defined.
+ */
+ @Deprecated
+ // Android-changed: Provide non-native implementation of countStackFrames().
+ // public native int countStackFrames();
+ public int countStackFrames() {
+ return getStackTrace().length;
+ }
+
+ /**
+ * Waits at most {@code millis} milliseconds for this thread to
+ * die. A timeout of {@code 0} means to wait forever.
+ *
+ * <p> This implementation uses a loop of {@code this.wait} calls
+ * conditioned on {@code this.isAlive}. As a thread terminates the
+ * {@code this.notifyAll} method is invoked. It is recommended that
+ * applications not use {@code wait}, {@code notify}, or
+ * {@code notifyAll} on {@code Thread} instances.
+ *
+ * @param millis
+ * the time to wait in milliseconds
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * <i>interrupted status</i> of the current thread is
+ * cleared when this exception is thrown.
+ */
+ // BEGIN Android-changed: Synchronize on separate lock object not this Thread.
+ // public final synchronized void join(long millis)
+ public final void join(long millis)
+ throws InterruptedException {
+ synchronized(lock) {
+ long base = System.currentTimeMillis();
+ long now = 0;
+
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (millis == 0) {
+ while (isAlive()) {
+ lock.wait(0);
+ }
+ } else {
+ while (isAlive()) {
+ long delay = millis - now;
+ if (delay <= 0) {
+ break;
+ }
+ lock.wait(delay);
+ now = System.currentTimeMillis() - base;
+ }
+ }
+ }
+ }
+ // END Android-changed: Synchronize on separate lock object not this Thread.
+
+ /**
+ * Waits at most {@code millis} milliseconds plus
+ * {@code nanos} nanoseconds for this thread to die.
+ *
+ * <p> This implementation uses a loop of {@code this.wait} calls
+ * conditioned on {@code this.isAlive}. As a thread terminates the
+ * {@code this.notifyAll} method is invoked. It is recommended that
+ * applications not use {@code wait}, {@code notify}, or
+ * {@code notifyAll} on {@code Thread} instances.
+ *
+ * @param millis
+ * the time to wait in milliseconds
+ *
+ * @param nanos
+ * {@code 0-999999} additional nanoseconds to wait
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative, or the value
+ * of {@code nanos} is not in the range {@code 0-999999}
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * <i>interrupted status</i> of the current thread is
+ * cleared when this exception is thrown.
+ */
+ // BEGIN Android-changed: Synchronize on separate lock object not this Thread.
+ // public final synchronized void join(long millis, int nanos)
+ public final void join(long millis, int nanos)
+ throws InterruptedException {
+
+ synchronized(lock) {
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException(
+ "nanosecond timeout value out of range");
+ }
+
+ if (nanos >= 500000 || (nanos != 0 && millis == 0)) {
+ millis++;
+ }
+
+ join(millis);
+ }
+ }
+ // END Android-changed: Synchronize on separate lock object not this Thread.
+
+ /**
+ * Waits for this thread to die.
+ *
+ * <p> An invocation of this method behaves in exactly the same
+ * way as the invocation
+ *
+ * <blockquote>
+ * {@linkplain #join(long) join}{@code (0)}
+ * </blockquote>
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * <i>interrupted status</i> of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public final void join() throws InterruptedException {
+ join(0);
+ }
+
+ /**
+ * Prints a stack trace of the current thread to the standard error stream.
+ * This method is used only for debugging.
+ *
+ * @see Throwable#printStackTrace()
+ */
+ public static void dumpStack() {
+ new Exception("Stack trace").printStackTrace();
+ }
+
+ /**
+ * Marks this thread as either a {@linkplain #isDaemon daemon} thread
+ * or a user thread. The Java Virtual Machine exits when the only
+ * threads running are all daemon threads.
+ *
+ * <p> This method must be invoked before the thread is started.
+ *
+ * @param on
+ * if {@code true}, marks this thread as a daemon thread
+ *
+ * @throws IllegalThreadStateException
+ * if this thread is {@linkplain #isAlive alive}
+ *
+ * @throws SecurityException
+ * if {@link #checkAccess} determines that the current
+ * thread cannot modify this thread
+ */
+ public final void setDaemon(boolean on) {
+ checkAccess();
+ if (isAlive()) {
+ throw new IllegalThreadStateException();
+ }
+ daemon = on;
+ }
+
+ /**
+ * Tests if this thread is a daemon thread.
+ *
+ * @return <code>true</code> if this thread is a daemon thread;
+ * <code>false</code> otherwise.
+ * @see #setDaemon(boolean)
+ */
+ public final boolean isDaemon() {
+ return daemon;
+ }
+
+ /**
+ * Determines if the currently running thread has permission to
+ * modify this thread.
+ * <p>
+ * If there is a security manager, its <code>checkAccess</code> method
+ * is called with this thread as its argument. This may result in
+ * throwing a <code>SecurityException</code>.
+ *
+ * @exception SecurityException if the current thread is not allowed to
+ * access this thread.
+ * @see SecurityManager#checkAccess(Thread)
+ */
+ public final void checkAccess() {
+ // Android-removed: SecurityManager stubbed out on Android
+ // SecurityManager security = System.getSecurityManager();
+ // if (security != null) {
+ // security.checkAccess(this);
+ // }
+ }
+
+ /**
+ * Returns a string representation of this thread, including the
+ * thread's name, priority, and thread group.
+ *
+ * @return a string representation of this thread.
+ */
+ public String toString() {
+ ThreadGroup group = getThreadGroup();
+ if (group != null) {
+ return "Thread[" + getName() + "," + getPriority() + "," +
+ group.getName() + "]";
+ } else {
+ return "Thread[" + getName() + "," + getPriority() + "," +
+ "" + "]";
+ }
+ }
+
+ /**
+ * Returns the context ClassLoader for this Thread. The context
+ * ClassLoader is provided by the creator of the thread for use
+ * by code running in this thread when loading classes and resources.
+ * If not {@linkplain #setContextClassLoader set}, the default is the
+ * ClassLoader context of the parent Thread. The context ClassLoader of the
+ * primordial thread is typically set to the class loader used to load the
+ * application.
+ *
+ * <p>If a security manager is present, and the invoker's class loader is not
+ * {@code null} and is not the same as or an ancestor of the context class
+ * loader, then this method invokes the security manager's {@link
+ * SecurityManager#checkPermission(java.security.Permission) checkPermission}
+ * method with a {@link RuntimePermission RuntimePermission}{@code
+ * ("getClassLoader")} permission to verify that retrieval of the context
+ * class loader is permitted.
+ *
+ * @return the context ClassLoader for this Thread, or {@code null}
+ * indicating the system class loader (or, failing that, the
+ * bootstrap class loader)
+ *
+ * @throws SecurityException
+ * if the current thread cannot get the context ClassLoader
+ *
+ * @since 1.2
+ */
+ @CallerSensitive
+ public ClassLoader getContextClassLoader() {
+ // Android-removed: SecurityManager stubbed out on Android
+ /*
+ if (contextClassLoader == null)
+ return null;
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ ClassLoader.checkClassLoaderPermission(contextClassLoader,
+ Reflection.getCallerClass());
+ }
+ */
+ return contextClassLoader;
+ }
+
+ /**
+ * Sets the context ClassLoader for this Thread. The context
+ * ClassLoader can be set when a thread is created, and allows
+ * the creator of the thread to provide the appropriate class loader,
+ * through {@code getContextClassLoader}, to code running in the thread
+ * when loading classes and resources.
+ *
+ * <p>If a security manager is present, its {@link
+ * SecurityManager#checkPermission(java.security.Permission) checkPermission}
+ * method is invoked with a {@link RuntimePermission RuntimePermission}{@code
+ * ("setContextClassLoader")} permission to see if setting the context
+ * ClassLoader is permitted.
+ *
+ * @param cl
+ * the context ClassLoader for this Thread, or null indicating the
+ * system class loader (or, failing that, the bootstrap class loader)
+ *
+ * @throws SecurityException
+ * if the current thread cannot set the context ClassLoader
+ *
+ * @since 1.2
+ */
+ public void setContextClassLoader(ClassLoader cl) {
+ // Android-removed: SecurityManager stubbed out on Android
+ // SecurityManager sm = System.getSecurityManager();
+ // if (sm != null) {
+ // sm.checkPermission(new RuntimePermission("setContextClassLoader"));
+ // }
+ contextClassLoader = cl;
+ }
+
+ /**
+ * Returns <tt>true</tt> if and only if the current thread holds the
+ * monitor lock on the specified object.
+ *
+ * <p>This method is designed to allow a program to assert that
+ * the current thread already holds a specified lock:
+ * <pre>
+ * assert Thread.holdsLock(obj);
+ * </pre>
+ *
+ * @param obj the object on which to test lock ownership
+ * @throws NullPointerException if obj is <tt>null</tt>
+ * @return <tt>true</tt> if the current thread holds the monitor lock on
+ * the specified object.
+ * @since 1.4
+ */
+ public static native boolean holdsLock(Object obj);
+
+ private static final StackTraceElement[] EMPTY_STACK_TRACE
+ = new StackTraceElement[0];
+
+ /**
+ * Returns an array of stack trace elements representing the stack dump
+ * of this thread. This method will return a zero-length array if
+ * this thread has not started, has started but has not yet been
+ * scheduled to run by the system, or has terminated.
+ * If the returned array is of non-zero length then the first element of
+ * the array represents the top of the stack, which is the most recent
+ * method invocation in the sequence. The last element of the array
+ * represents the bottom of the stack, which is the least recent method
+ * invocation in the sequence.
+ *
+ * <p>If there is a security manager, and this thread is not
+ * the current thread, then the security manager's
+ * <tt>checkPermission</tt> method is called with a
+ * <tt>RuntimePermission("getStackTrace")</tt> permission
+ * to see if it's ok to get the stack trace.
+ *
+ * <p>Some virtual machines may, under some circumstances, omit one
+ * or more stack frames from the stack trace. In the extreme case,
+ * a virtual machine that has no stack trace information concerning
+ * this thread is permitted to return a zero-length array from this
+ * method.
+ *
+ * @return an array of <tt>StackTraceElement</tt>,
+ * each represents one stack frame.
+ *
+ * @throws SecurityException
+ * if a security manager exists and its
+ * <tt>checkPermission</tt> method doesn't allow
+ * getting the stack trace of thread.
+ * @see SecurityManager#checkPermission
+ * @see RuntimePermission
+ * @see Throwable#getStackTrace
+ *
+ * @since 1.5
+ */
+ public StackTraceElement[] getStackTrace() {
+ // Android-changed: Use native VMStack to get stack trace.
+ StackTraceElement ste[] = VMStack.getThreadStackTrace(this);
+ return ste != null ? ste : EmptyArray.STACK_TRACE_ELEMENT;
+ }
+
+ /**
+ * Returns a map of stack traces for all live threads.
+ * The map keys are threads and each map value is an array of
+ * <tt>StackTraceElement</tt> that represents the stack dump
+ * of the corresponding <tt>Thread</tt>.
+ * The returned stack traces are in the format specified for
+ * the {@link #getStackTrace getStackTrace} method.
+ *
+ * <p>The threads may be executing while this method is called.
+ * The stack trace of each thread only represents a snapshot and
+ * each stack trace may be obtained at different time. A zero-length
+ * array will be returned in the map value if the virtual machine has
+ * no stack trace information about a thread.
+ *
+ * <p>If there is a security manager, then the security manager's
+ * <tt>checkPermission</tt> method is called with a
+ * <tt>RuntimePermission("getStackTrace")</tt> permission as well as
+ * <tt>RuntimePermission("modifyThreadGroup")</tt> permission
+ * to see if it is ok to get the stack trace of all threads.
+ *
+ * @return a <tt>Map</tt> from <tt>Thread</tt> to an array of
+ * <tt>StackTraceElement</tt> that represents the stack trace of
+ * the corresponding thread.
+ *
+ * @throws SecurityException
+ * if a security manager exists and its
+ * <tt>checkPermission</tt> method doesn't allow
+ * getting the stack trace of thread.
+ * @see #getStackTrace
+ * @see SecurityManager#checkPermission
+ * @see RuntimePermission
+ * @see Throwable#getStackTrace
+ *
+ * @since 1.5
+ */
+ public static Map<Thread, StackTraceElement[]> getAllStackTraces() {
+ // Android-removed: SecurityManager stubbed out on Android
+ /*
+ // check for getStackTrace permission
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkPermission(
+ SecurityConstants.GET_STACK_TRACE_PERMISSION);
+ security.checkPermission(
+ SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
+ }
+ */
+
+ // Get a snapshot of the list of all threads
+ // BEGIN Android-changed: Use ThreadGroup and getStackTrace() instead of native methods.
+ // Allocate a bit more space than needed, in case new ones are just being created.
+ /*
+ Thread[] threads = getThreads();
+ StackTraceElement[][] traces = dumpThreads(threads);
+ Map<Thread, StackTraceElement[]> m = new HashMap<>(threads.length);
+ for (int i = 0; i < threads.length; i++) {
+ StackTraceElement[] stackTrace = traces[i];
+ if (stackTrace != null) {
+ m.put(threads[i], stackTrace);
+ }
+ // else terminated so we don't put it in the map
+ }
+ */
+ int count = ThreadGroup.systemThreadGroup.activeCount();
+ Thread[] threads = new Thread[count + count / 2];
+
+ // Enumerate the threads.
+ count = ThreadGroup.systemThreadGroup.enumerate(threads);
+
+ // Collect the stacktraces
+ Map<Thread, StackTraceElement[]> m = new HashMap<Thread, StackTraceElement[]>();
+ for (int i = 0; i < count; i++) {
+ StackTraceElement[] stackTrace = threads[i].getStackTrace();
+ m.put(threads[i], stackTrace);
+ }
+ // END Android-changed: Use ThreadGroup and getStackTrace() instead of native methods.
+ return m;
+ }
+
+
+ private static final RuntimePermission SUBCLASS_IMPLEMENTATION_PERMISSION =
+ new RuntimePermission("enableContextClassLoaderOverride");
+
+ /** cache of subclass security audit results */
+ /* Replace with ConcurrentReferenceHashMap when/if it appears in a future
+ * release */
+ private static class Caches {
+ /** cache of subclass security audit results */
+ static final ConcurrentMap<WeakClassKey,Boolean> subclassAudits =
+ new ConcurrentHashMap<>();
+
+ /** queue for WeakReferences to audited subclasses */
+ static final ReferenceQueue<Class<?>> subclassAuditsQueue =
+ new ReferenceQueue<>();
+ }
+
+ /**
+ * Verifies that this (possibly subclass) instance can be constructed
+ * without violating security constraints: the subclass must not override
+ * security-sensitive non-final methods, or else the
+ * "enableContextClassLoaderOverride" RuntimePermission is checked.
+ */
+ private static boolean isCCLOverridden(Class<?> cl) {
+ if (cl == Thread.class)
+ return false;
+
+ processQueue(Caches.subclassAuditsQueue, Caches.subclassAudits);
+ WeakClassKey key = new WeakClassKey(cl, Caches.subclassAuditsQueue);
+ Boolean result = Caches.subclassAudits.get(key);
+ if (result == null) {
+ result = Boolean.valueOf(auditSubclass(cl));
+ Caches.subclassAudits.putIfAbsent(key, result);
+ }
+
+ return result.booleanValue();
+ }
+
+ /**
+ * Performs reflective checks on given subclass to verify that it doesn't
+ * override security-sensitive non-final methods. Returns true if the
+ * subclass overrides any of the methods, false otherwise.
+ */
+ private static boolean auditSubclass(final Class<?> subcl) {
+ Boolean result = AccessController.doPrivileged(
+ new PrivilegedAction<Boolean>() {
+ public Boolean run() {
+ for (Class<?> cl = subcl;
+ cl != Thread.class;
+ cl = cl.getSuperclass())
+ {
+ try {
+ cl.getDeclaredMethod("getContextClassLoader", new Class<?>[0]);
+ return Boolean.TRUE;
+ } catch (NoSuchMethodException ex) {
+ }
+ try {
+ Class<?>[] params = {ClassLoader.class};
+ cl.getDeclaredMethod("setContextClassLoader", params);
+ return Boolean.TRUE;
+ } catch (NoSuchMethodException ex) {
+ }
+ }
+ return Boolean.FALSE;
+ }
+ }
+ );
+ return result.booleanValue();
+ }
+
+ // Android-removed: Native methods that are unused on Android.
+ // private native static StackTraceElement[][] dumpThreads(Thread[] threads);
+ // private native static Thread[] getThreads();
+
+ /**
+ * Returns the identifier of this Thread. The thread ID is a positive
+ * <tt>long</tt> number generated when this thread was created.
+ * The thread ID is unique and remains unchanged during its lifetime.
+ * When a thread is terminated, this thread ID may be reused.
+ *
+ * @return this thread's ID.
+ * @since 1.5
+ */
+ public long getId() {
+ return tid;
+ }
+
+ /**
+ * A thread state. A thread can be in one of the following states:
+ * <ul>
+ * <li>{@link #NEW}<br>
+ * A thread that has not yet started is in this state.
+ * </li>
+ * <li>{@link #RUNNABLE}<br>
+ * A thread executing in the Java virtual machine is in this state.
+ * </li>
+ * <li>{@link #BLOCKED}<br>
+ * A thread that is blocked waiting for a monitor lock
+ * is in this state.
+ * </li>
+ * <li>{@link #WAITING}<br>
+ * A thread that is waiting indefinitely for another thread to
+ * perform a particular action is in this state.
+ * </li>
+ * <li>{@link #TIMED_WAITING}<br>
+ * A thread that is waiting for another thread to perform an action
+ * for up to a specified waiting time is in this state.
+ * </li>
+ * <li>{@link #TERMINATED}<br>
+ * A thread that has exited is in this state.
+ * </li>
+ * </ul>
+ *
+ * <p>
+ * A thread can be in only one state at a given point in time.
+ * These states are virtual machine states which do not reflect
+ * any operating system thread states.
+ *
+ * @since 1.5
+ * @see #getState
+ */
+ public enum State {
+ /**
+ * Thread state for a thread which has not yet started.
+ */
+ NEW,
+
+ /**
+ * Thread state for a runnable thread. A thread in the runnable
+ * state is executing in the Java virtual machine but it may
+ * be waiting for other resources from the operating system
+ * such as processor.
+ */
+ RUNNABLE,
+
+ /**
+ * Thread state for a thread blocked waiting for a monitor lock.
+ * A thread in the blocked state is waiting for a monitor lock
+ * to enter a synchronized block/method or
+ * reenter a synchronized block/method after calling
+ * {@link Object#wait() Object.wait}.
+ */
+ BLOCKED,
+
+ /**
+ * Thread state for a waiting thread.
+ * A thread is in the waiting state due to calling one of the
+ * following methods:
+ * <ul>
+ * <li>{@link Object#wait() Object.wait} with no timeout</li>
+ * <li>{@link #join() Thread.join} with no timeout</li>
+ * <li>{@link LockSupport#park() LockSupport.park}</li>
+ * </ul>
+ *
+ * <p>A thread in the waiting state is waiting for another thread to
+ * perform a particular action.
+ *
+ * For example, a thread that has called <tt>Object.wait()</tt>
+ * on an object is waiting for another thread to call
+ * <tt>Object.notify()</tt> or <tt>Object.notifyAll()</tt> on
+ * that object. A thread that has called <tt>Thread.join()</tt>
+ * is waiting for a specified thread to terminate.
+ */
+ WAITING,
+
+ /**
+ * Thread state for a waiting thread with a specified waiting time.
+ * A thread is in the timed waiting state due to calling one of
+ * the following methods with a specified positive waiting time:
+ * <ul>
+ * <li>{@link #sleep Thread.sleep}</li>
+ * <li>{@link Object#wait(long) Object.wait} with timeout</li>
+ * <li>{@link #join(long) Thread.join} with timeout</li>
+ * <li>{@link LockSupport#parkNanos LockSupport.parkNanos}</li>
+ * <li>{@link LockSupport#parkUntil LockSupport.parkUntil}</li>
+ * </ul>
+ */
+ TIMED_WAITING,
+
+ /**
+ * Thread state for a terminated thread.
+ * The thread has completed execution.
+ */
+ TERMINATED;
+ }
+
+ /**
+ * Returns the state of this thread.
+ * This method is designed for use in monitoring of the system state,
+ * not for synchronization control.
+ *
+ * @return this thread's state.
+ * @since 1.5
+ */
+ public State getState() {
+ // get current thread state
+ // Android-changed: Replace unused threadStatus field with started field.
+ // Use Android specific nativeGetStatus() method. See comment on started field for more
+ // information.
+ // return sun.misc.VM.toThreadState(threadStatus);
+ return State.values()[nativeGetStatus(started)];
+ }
+
+ // Added in JSR-166
+
+ /**
+ * Interface for handlers invoked when a <tt>Thread</tt> abruptly
+ * terminates due to an uncaught exception.
+ * <p>When a thread is about to terminate due to an uncaught exception
+ * the Java Virtual Machine will query the thread for its
+ * <tt>UncaughtExceptionHandler</tt> using
+ * {@link #getUncaughtExceptionHandler} and will invoke the handler's
+ * <tt>uncaughtException</tt> method, passing the thread and the
+ * exception as arguments.
+ * If a thread has not had its <tt>UncaughtExceptionHandler</tt>
+ * explicitly set, then its <tt>ThreadGroup</tt> object acts as its
+ * <tt>UncaughtExceptionHandler</tt>. If the <tt>ThreadGroup</tt> object
+ * has no
+ * special requirements for dealing with the exception, it can forward
+ * the invocation to the {@linkplain #getDefaultUncaughtExceptionHandler
+ * default uncaught exception handler}.
+ *
+ * @see #setDefaultUncaughtExceptionHandler
+ * @see #setUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ @FunctionalInterface
+ public interface UncaughtExceptionHandler {
+ /**
+ * Method invoked when the given thread terminates due to the
+ * given uncaught exception.
+ * <p>Any exception thrown by this method will be ignored by the
+ * Java Virtual Machine.
+ * @param t the thread
+ * @param e the exception
+ */
+ void uncaughtException(Thread t, Throwable e);
+ }
+
+ // null unless explicitly set
+ private volatile UncaughtExceptionHandler uncaughtExceptionHandler;
+
+ // null unless explicitly set
+ private static volatile UncaughtExceptionHandler defaultUncaughtExceptionHandler;
+
+ /**
+ * Set the default handler invoked when a thread abruptly terminates
+ * due to an uncaught exception, and no other handler has been defined
+ * for that thread.
+ *
+ * <p>Uncaught exception handling is controlled first by the thread, then
+ * by the thread's {@link ThreadGroup} object and finally by the default
+ * uncaught exception handler. If the thread does not have an explicit
+ * uncaught exception handler set, and the thread's thread group
+ * (including parent thread groups) does not specialize its
+ * <tt>uncaughtException</tt> method, then the default handler's
+ * <tt>uncaughtException</tt> method will be invoked.
+ * <p>By setting the default uncaught exception handler, an application
+ * can change the way in which uncaught exceptions are handled (such as
+ * logging to a specific device, or file) for those threads that would
+ * already accept whatever "default" behavior the system
+ * provided.
+ *
+ * <p>Note that the default uncaught exception handler should not usually
+ * defer to the thread's <tt>ThreadGroup</tt> object, as that could cause
+ * infinite recursion.
+ *
+ * @param eh the object to use as the default uncaught exception handler.
+ * If <tt>null</tt> then there is no default handler.
+ *
+ * @throws SecurityException if a security manager is present and it
+ * denies <tt>{@link RuntimePermission}
+ * ("setDefaultUncaughtExceptionHandler")</tt>
+ *
+ * @see #setUncaughtExceptionHandler
+ * @see #getUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ public static void setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler eh) {
+ // Android-removed: SecurityManager stubbed out on Android
+ /*
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(
+ new RuntimePermission("setDefaultUncaughtExceptionHandler")
+ );
+ }
+ */
+
+ defaultUncaughtExceptionHandler = eh;
+ }
+
+ /**
+ * Returns the default handler invoked when a thread abruptly terminates
+ * due to an uncaught exception. If the returned value is <tt>null</tt>,
+ * there is no default.
+ * @since 1.5
+ * @see #setDefaultUncaughtExceptionHandler
+ * @return the default uncaught exception handler for all threads
+ */
+ public static UncaughtExceptionHandler getDefaultUncaughtExceptionHandler(){
+ return defaultUncaughtExceptionHandler;
+ }
+
+ // BEGIN Android-added: The concept of an uncaughtExceptionPreHandler for use by platform.
+ // See http://b/29624607 for background information.
+ // null unless explicitly set
+ private static volatile UncaughtExceptionHandler uncaughtExceptionPreHandler;
+
+ /**
+ * Sets an {@link UncaughtExceptionHandler} that will be called before any
+ * returned by {@link #getUncaughtExceptionHandler()}. To allow the standard
+ * handlers to run, this handler should never terminate this process. Any
+ * throwables thrown by the handler will be ignored by
+ * {@link #dispatchUncaughtException(Throwable)}.
+ *
+ * @hide used when configuring the runtime for exception logging; see
+ * {@link dalvik.system.RuntimeHooks} b/29624607
+ */
+ public static void setUncaughtExceptionPreHandler(UncaughtExceptionHandler eh) {
+ uncaughtExceptionPreHandler = eh;
+ }
+
+ /** @hide */
+ public static UncaughtExceptionHandler getUncaughtExceptionPreHandler() {
+ return uncaughtExceptionPreHandler;
+ }
+ // END Android-added: The concept of an uncaughtExceptionPreHandler for use by platform.
+
+ /**
+ * Returns the handler invoked when this thread abruptly terminates
+ * due to an uncaught exception. If this thread has not had an
+ * uncaught exception handler explicitly set then this thread's
+ * <tt>ThreadGroup</tt> object is returned, unless this thread
+ * has terminated, in which case <tt>null</tt> is returned.
+ * @since 1.5
+ * @return the uncaught exception handler for this thread
+ */
+ public UncaughtExceptionHandler getUncaughtExceptionHandler() {
+ return uncaughtExceptionHandler != null ?
+ uncaughtExceptionHandler : group;
+ }
+
+ /**
+ * Set the handler invoked when this thread abruptly terminates
+ * due to an uncaught exception.
+ * <p>A thread can take full control of how it responds to uncaught
+ * exceptions by having its uncaught exception handler explicitly set.
+ * If no such handler is set then the thread's <tt>ThreadGroup</tt>
+ * object acts as its handler.
+ * @param eh the object to use as this thread's uncaught exception
+ * handler. If <tt>null</tt> then this thread has no explicit handler.
+ * @throws SecurityException if the current thread is not allowed to
+ * modify this thread.
+ * @see #setDefaultUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ public void setUncaughtExceptionHandler(UncaughtExceptionHandler eh) {
+ checkAccess();
+ uncaughtExceptionHandler = eh;
+ }
+
+ /**
+ * Dispatch an uncaught exception to the handler. This method is
+ * intended to be called only by the runtime and by tests.
+ *
+ * @hide
+ */
+ // Android-changed: Make dispatchUncaughtException() public, for use by tests.
+ public final void dispatchUncaughtException(Throwable e) {
+ // BEGIN Android-added: uncaughtExceptionPreHandler for use by platform.
+ Thread.UncaughtExceptionHandler initialUeh =
+ Thread.getUncaughtExceptionPreHandler();
+ if (initialUeh != null) {
+ try {
+ initialUeh.uncaughtException(this, e);
+ } catch (RuntimeException | Error ignored) {
+ // Throwables thrown by the initial handler are ignored
+ }
+ }
+ // END Android-added: uncaughtExceptionPreHandler for use by platform.
+ getUncaughtExceptionHandler().uncaughtException(this, e);
+ }
+
+ // BEGIN Android-added: The concept of "system-daemon" threads. See java.lang.Daemons.
+ /**
+ * Marks this thread as either a special runtime-managed ("system daemon")
+ * thread or a normal (i.e. app code created) daemon thread.)
+ *
+ * <p>System daemon threads get special handling when starting up in some
+ * cases.
+ *
+ * <p>This method must be invoked before the thread is started.
+ *
+ * <p>This method must only be invoked on Thread instances that have already
+ * had {@code setDaemon(true)} called on them.
+ *
+ * <p>Package-private since only {@link java.lang.Daemons} needs to call
+ * this.
+ *
+ * @param on if {@code true}, marks this thread as a system daemon thread
+ *
+ * @throws IllegalThreadStateException
+ * if this thread is {@linkplain #isAlive alive} or not a
+ * {@linkplain #isDaemon daemon}
+ *
+ * @throws SecurityException
+ * if {@link #checkAccess} determines that the current
+ * thread cannot modify this thread
+ *
+ * @hide For use by Daemons.java only.
+ */
+ final void setSystemDaemon(boolean on) {
+ checkAccess();
+ if (isAlive() || !isDaemon()) {
+ throw new IllegalThreadStateException();
+ }
+ systemDaemon = on;
+ }
+ // END Android-added: The concept of "system-daemon" threads. See java.lang.Daemons.
+
+ /**
+ * Removes from the specified map any keys that have been enqueued
+ * on the specified reference queue.
+ */
+ static void processQueue(ReferenceQueue<Class<?>> queue,
+ ConcurrentMap<? extends
+ WeakReference<Class<?>>, ?> map)
+ {
+ Reference<? extends Class<?>> ref;
+ while((ref = queue.poll()) != null) {
+ map.remove(ref);
+ }
+ }
+
+ /**
+ * Weak key for Class objects.
+ **/
+ static class WeakClassKey extends WeakReference<Class<?>> {
+ /**
+ * saved value of the referent's identity hash code, to maintain
+ * a consistent hash code after the referent has been cleared
+ */
+ private final int hash;
+
+ /**
+ * Create a new WeakClassKey to the given object, registered
+ * with a queue.
+ */
+ WeakClassKey(Class<?> cl, ReferenceQueue<Class<?>> refQueue) {
+ super(cl, refQueue);
+ hash = System.identityHashCode(cl);
+ }
+
+ /**
+ * Returns the identity hash code of the original referent.
+ */
+ @Override
+ public int hashCode() {
+ return hash;
+ }
+
+ /**
+ * Returns true if the given object is this identical
+ * WeakClassKey instance, or, if this object's referent has not
+ * been cleared, if the given object is another WeakClassKey
+ * instance with the identical non-null referent as this one.
+ */
+ @Override
+ public boolean equals(Object obj) {
+ if (obj == this)
+ return true;
+
+ if (obj instanceof WeakClassKey) {
+ Object referent = get();
+ return (referent != null) &&
+ (referent == ((WeakClassKey) obj).get());
+ } else {
+ return false;
+ }
+ }
+ }
+
+
+ // The following three initially uninitialized fields are exclusively
+ // managed by class java.util.concurrent.ThreadLocalRandom. These
+ // fields are used to build the high-performance PRNGs in the
+ // concurrent code, and we can not risk accidental false sharing.
+ // Hence, the fields are isolated with @Contended.
+
+ // BEGIN Android-changed: @sun.misc.Contended is not supported on Android.
+ /** The current seed for a ThreadLocalRandom */
+ // @sun.misc.Contended("tlr")
+ long threadLocalRandomSeed;
+
+ /** Probe hash value; nonzero if threadLocalRandomSeed initialized */
+ // @sun.misc.Contended("tlr")
+ int threadLocalRandomProbe;
+
+ /** Secondary seed isolated from public ThreadLocalRandom sequence */
+ // @sun.misc.Contended("tlr")
+ int threadLocalRandomSecondarySeed;
+ // END Android-changed: @sun.misc.Contended is not supported on Android.
+
+ /* Some private helper methods */
+ private native void setPriority0(int newPriority);
+
+ // BEGIN Android-removed: Native methods that are unused on Android.
+ /*
+ private native void stop0(Object o);
+ private native void suspend0();
+ private native void resume0();
+ */
+ // END Android-removed: Native methods that are unused on Android.
+
+ @FastNative
+ private native void interrupt0();
+ private native void setNativeName(String name);
+
+ // Android-added: Android specific nativeGetStatus() method.
+ private native int nativeGetStatus(boolean hasBeenStarted);
+
+ // BEGIN Android-added: Customize behavior of Thread.setPriority(). http://b/139521784
+ /**
+ * Returns the thread ID of the underlying native thread -- which is different from
+ * the {@link #getId() managed thread ID} -- or 0 if the native thread is not
+ * started or has stopped.
+ */
+ @FastNative
+ private native int getNativeTid();
+ // END Android-added: Customize behavior of Thread.setPriority(). http://b/139521784
+}
