Categories:
Audio (13)
Biotech (29)
Bytecode (36)
Database (77)
Framework (7)
Game (7)
General (507)
Graphics (53)
I/O (35)
IDE (2)
JAR Tools (101)
JavaBeans (21)
JDBC (121)
JDK (426)
JSP (20)
Logging (108)
Mail (58)
Messaging (8)
Network (84)
PDF (97)
Report (7)
Scripting (84)
Security (32)
Server (121)
Servlet (26)
SOAP (24)
Testing (54)
Web (15)
XML (309)
Collections:
Other Resources:
JDK 17 java.base.jmod - Base Module
JDK 17 java.base.jmod is the JMOD file for JDK 17 Base module.
JDK 17 Base module compiled class files are stored in \fyicenter\jdk-17.0.5\jmods\java.base.jmod.
JDK 17 Base module compiled class files are also linked and stored in the \fyicenter\jdk-17.0.5\lib\modules JImage file.
JDK 17 Base module source code files are stored in \fyicenter\jdk-17.0.5\lib\src.zip\java.base.
You can click and view the content of each source code file in the list below.
✍: FYIcenter
⏎ java/lang/ThreadGroup.java
/* * Copyright (c) 1995, 2021, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.lang; import java.io.PrintStream; import java.util.Arrays; /** * A thread group represents a set of threads. In addition, a thread * group can also include other thread groups. The thread groups form * a tree in which every thread group except the initial thread group * has a parent. * <p> * A thread is allowed to access information about its own thread * group, but not to access information about its thread group's * parent thread group or any other thread groups. * * @since 1.0 */ /* The locking strategy for this code is to try to lock only one level of the * tree wherever possible, but otherwise to lock from the bottom up. * That is, from child thread groups to parents. * This has the advantage of limiting the number of locks that need to be held * and in particular avoids having to grab the lock for the root thread group, * (or a global lock) which would be a source of contention on a * multi-processor system with many thread groups. * This policy often leads to taking a snapshot of the state of a thread group * and working off of that snapshot, rather than holding the thread group locked * while we work on the children. */ public class ThreadGroup implements Thread.UncaughtExceptionHandler { private final ThreadGroup parent; String name; int maxPriority; boolean destroyed; boolean daemon; int nUnstartedThreads = 0; int nthreads; Thread threads[]; int ngroups; ThreadGroup groups[]; /** * Creates an empty Thread group that is not in any Thread group. * This method is used to create the system Thread group. */ private ThreadGroup() { // called from C code this.name = "system"; this.maxPriority = Thread.MAX_PRIORITY; this.parent = null; } /** * Constructs a new thread group. The parent of this new group is * the thread group of the currently running thread. * <p> * The {@code checkAccess} method of the parent thread group is * called with no arguments; this may result in a security exception. * * @param name the name of the new thread group. * @throws SecurityException if the current thread cannot create a * thread in the specified thread group. * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 */ public ThreadGroup(String name) { this(Thread.currentThread().getThreadGroup(), name); } /** * Creates a new thread group. The parent of this new group is the * specified thread group. * <p> * The {@code checkAccess} method of the parent thread group is * called with no arguments; this may result in a security exception. * * @param parent the parent thread group. * @param name the name of the new thread group. * @throws NullPointerException if the thread group argument is * {@code null}. * @throws SecurityException if the current thread cannot create a * thread in the specified thread group. * @see java.lang.SecurityException * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 */ public ThreadGroup(ThreadGroup parent, String name) { this(checkParentAccess(parent), parent, name); } private ThreadGroup(Void unused, ThreadGroup parent, String name) { this.name = name; this.maxPriority = parent.maxPriority; this.daemon = parent.daemon; this.parent = parent; parent.add(this); } /* * @throws NullPointerException if the parent argument is {@code null} * @throws SecurityException if the current thread cannot create a * thread in the specified thread group. */ private static Void checkParentAccess(ThreadGroup parent) { parent.checkAccess(); return null; } /** * Returns the name of this thread group. * * @return the name of this thread group. * @since 1.0 */ public final String getName() { return name; } /** * Returns the parent of this thread group. * <p> * First, if the parent is not {@code null}, the * {@code checkAccess} method of the parent thread group is * called with no arguments; this may result in a security exception. * * @return the parent of this thread group. The top-level thread group * is the only thread group whose parent is {@code null}. * @throws SecurityException if the current thread cannot modify * this thread group. * @see java.lang.ThreadGroup#checkAccess() * @see java.lang.SecurityException * @see java.lang.RuntimePermission * @since 1.0 */ public final ThreadGroup getParent() { if (parent != null) parent.checkAccess(); return parent; } /** * Returns the maximum priority of this thread group. Threads that are * part of this group cannot have a higher priority than the maximum * priority. * * @return the maximum priority that a thread in this thread group * can have. * @see #setMaxPriority * @since 1.0 */ public final int getMaxPriority() { return maxPriority; } /** * Tests if this thread group is a daemon thread group. A * daemon thread group is automatically destroyed when its last * thread is stopped or its last thread group is destroyed. * * @return {@code true} if this thread group is a daemon thread group; * {@code false} otherwise. * @since 1.0 * * @deprecated The API and mechanism for destroying a ThreadGroup is inherently * flawed. The ability to explicitly or automatically destroy a * thread group, and the concept of daemon thread group, will be * removed in a future release. */ @Deprecated(since="16", forRemoval=true) public final boolean isDaemon() { return daemon; } /** * Tests if this thread group has been destroyed. * * @return true if this object is destroyed * @since 1.1 * * @deprecated The API and mechanism for destroying a ThreadGroup is inherently * flawed. The ability to explicitly or automatically destroy a * thread group will be removed in a future release. */ @Deprecated(since="16", forRemoval=true) public synchronized boolean isDestroyed() { return destroyed; } /** * Changes the daemon status of this thread group. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * A daemon thread group is automatically destroyed when its last * thread is stopped or its last thread group is destroyed. * * @param daemon if {@code true}, marks this thread group as * a daemon thread group; otherwise, marks this * thread group as normal. * @throws SecurityException if the current thread cannot modify * this thread group. * @see java.lang.SecurityException * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 * * @deprecated The API and mechanism for destroying a ThreadGroup is inherently * flawed. The ability to explicitly or automatically destroy a * thread group, and the concept of daemon thread group, will be * removed in a future release. */ @Deprecated(since="16", forRemoval=true) public final void setDaemon(boolean daemon) { checkAccess(); this.daemon = daemon; } /** * Sets the maximum priority of the group. Threads in the thread * group that already have a higher priority are not affected. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * If the {@code pri} argument is less than * {@link Thread#MIN_PRIORITY} or greater than * {@link Thread#MAX_PRIORITY}, the maximum priority of the group * remains unchanged. * <p> * Otherwise, the priority of this ThreadGroup object is set to the * smaller of the specified {@code pri} and the maximum permitted * priority of the parent of this thread group. (If this thread group * is the system thread group, which has no parent, then its maximum * priority is simply set to {@code pri}.) Then this method is * called recursively, with {@code pri} as its argument, for * every thread group that belongs to this thread group. * * @param pri the new priority of the thread group. * @throws SecurityException if the current thread cannot modify * this thread group. * @see #getMaxPriority * @see java.lang.SecurityException * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 */ public final void setMaxPriority(int pri) { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { checkAccess(); if (pri < Thread.MIN_PRIORITY || pri > Thread.MAX_PRIORITY) { return; } maxPriority = (parent != null) ? Math.min(pri, parent.maxPriority) : pri; ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i++) { groupsSnapshot[i].setMaxPriority(pri); } } /** * Tests if this thread group is either the thread group * argument or one of its ancestor thread groups. * * @param g a thread group. * @return {@code true} if this thread group is the thread group * argument or one of its ancestor thread groups; * {@code false} otherwise. * @since 1.0 */ public final boolean parentOf(ThreadGroup g) { for (; g != null ; g = g.parent) { if (g == this) { return true; } } return false; } /** * Determines if the currently running thread has permission to * modify this thread group. * <p> * If there is a security manager, its {@code checkAccess} method * is called with this thread group as its argument. This may result * in throwing a {@code SecurityException}. * * @throws SecurityException if the current thread is not allowed to * access this thread group. * @see java.lang.SecurityManager#checkAccess(java.lang.ThreadGroup) * @since 1.0 * @deprecated This method is only useful in conjunction with * {@linkplain SecurityManager the Security Manager}, which is * deprecated and subject to removal in a future release. * Consequently, this method is also deprecated and subject to * removal. There is no replacement for the Security Manager or this * method. */ @Deprecated(since="17", forRemoval=true) public final void checkAccess() { @SuppressWarnings("removal") SecurityManager security = System.getSecurityManager(); if (security != null) { security.checkAccess(this); } } /** * Returns an estimate of the number of active threads in this thread * group and its subgroups. Recursively iterates over all subgroups in * this 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 this thread * group and in any other thread group that has this thread * group as an ancestor * * @since 1.0 */ public int activeCount() { int result; // Snapshot sub-group data so we don't hold this lock // while our children are computing. int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { if (destroyed) { return 0; } result = nthreads; ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i++) { result += groupsSnapshot[i].activeCount(); } return result; } /** * Copies into the specified array every active thread in this * thread group and its subgroups. * * <p> An invocation of this method behaves in exactly the same * way as the invocation * * <blockquote> * {@linkplain #enumerate(Thread[], boolean) enumerate}{@code (list, true)} * </blockquote> * * @param list * an array into which to put the list of threads * * @return the number of threads put into the array * * @throws SecurityException * if {@linkplain #checkAccess checkAccess} determines that * the current thread cannot access this thread group * * @since 1.0 */ public int enumerate(Thread list[]) { checkAccess(); return enumerate(list, 0, true); } /** * Copies into the specified array every active thread in this * thread group. If {@code recurse} is {@code true}, * this method recursively enumerates all subgroups of this * thread group and references to every active thread in these * subgroups are also included. If the array is too short to * hold all the threads, the extra threads are silently ignored. * * <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 this thread group, the caller should verify that the returned * int value is strictly less than the length of {@code list}. * * <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 list * an array into which to put the list of threads * * @param recurse * if {@code true}, recursively enumerate all subgroups of this * thread group * * @return the number of threads put into the array * * @throws SecurityException * if {@linkplain #checkAccess checkAccess} determines that * the current thread cannot access this thread group * * @since 1.0 */ public int enumerate(Thread list[], boolean recurse) { checkAccess(); return enumerate(list, 0, recurse); } private int enumerate(Thread list[], int n, boolean recurse) { int ngroupsSnapshot = 0; ThreadGroup[] groupsSnapshot = null; synchronized (this) { if (destroyed) { return n; } int nt = nthreads; if (nt > list.length - n) { nt = list.length - n; } for (int i = 0; i < nt; i++) { if (threads[i].isAlive()) { list[n++] = threads[i]; } } if (recurse) { ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } } if (recurse) { for (int i = 0 ; i < ngroupsSnapshot ; i++) { n = groupsSnapshot[i].enumerate(list, n, true); } } return n; } /** * Returns an estimate of the number of active groups in this * thread group and its subgroups. Recursively iterates over * all subgroups in this thread group. * * <p> The value returned is only an estimate because the number of * thread groups may change dynamically while this method traverses * internal data structures. This method is intended primarily for * debugging and monitoring purposes. * * @return the number of active thread groups with this thread group as * an ancestor * * @since 1.0 */ public int activeGroupCount() { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { if (destroyed) { return 0; } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } int n = ngroupsSnapshot; for (int i = 0 ; i < ngroupsSnapshot ; i++) { n += groupsSnapshot[i].activeGroupCount(); } return n; } /** * Copies into the specified array references to every active * subgroup in this thread group and its subgroups. * * <p> An invocation of this method behaves in exactly the same * way as the invocation * * <blockquote> * {@linkplain #enumerate(ThreadGroup[], boolean) enumerate}{@code (list, true)} * </blockquote> * * @param list * an array into which to put the list of thread groups * * @return the number of thread groups put into the array * * @throws SecurityException * if {@linkplain #checkAccess checkAccess} determines that * the current thread cannot access this thread group * * @since 1.0 */ public int enumerate(ThreadGroup list[]) { checkAccess(); return enumerate(list, 0, true); } /** * Copies into the specified array references to every active * subgroup in this thread group. If {@code recurse} is * {@code true}, this method recursively enumerates all subgroups of this * thread group and references to every active thread group in these * subgroups are also included. * * <p> An application might use the * {@linkplain #activeGroupCount activeGroupCount} method to * get an estimate of how big the array should be, however <i>if the * array is too short to hold all the thread groups, the extra thread * groups are silently ignored.</i> If it is critical to obtain every * active subgroup in this thread group, the caller should verify that * the returned int value is strictly less than the length of * {@code list}. * * <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 list * an array into which to put the list of thread groups * * @param recurse * if {@code true}, recursively enumerate all subgroups * * @return the number of thread groups put into the array * * @throws SecurityException * if {@linkplain #checkAccess checkAccess} determines that * the current thread cannot access this thread group * * @since 1.0 */ public int enumerate(ThreadGroup list[], boolean recurse) { checkAccess(); return enumerate(list, 0, recurse); } private int enumerate(ThreadGroup list[], int n, boolean recurse) { int ngroupsSnapshot = 0; ThreadGroup[] groupsSnapshot = null; synchronized (this) { if (destroyed) { return n; } int ng = ngroups; if (ng > list.length - n) { ng = list.length - n; } if (ng > 0) { System.arraycopy(groups, 0, list, n, ng); n += ng; } if (recurse) { ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } } if (recurse) { for (int i = 0 ; i < ngroupsSnapshot ; i++) { n = groupsSnapshot[i].enumerate(list, n, true); } } return n; } /** * Stops all threads in this thread group. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * This method then calls the {@code stop} method on all the * threads in this thread group and in all of its subgroups. * * @throws SecurityException if the current thread is not allowed * to access this thread group or any of the threads in * the thread group. * @see java.lang.SecurityException * @see java.lang.Thread#stop() * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 * @deprecated This method is inherently unsafe. See * {@link Thread#stop} for details. */ @Deprecated(since="1.2", forRemoval=true) public final void stop() { if (stopOrSuspend(false)) Thread.currentThread().stop(); } /** * Interrupts all threads in this thread group. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * This method then calls the {@code interrupt} method on all the * threads in this thread group and in all of its subgroups. * * @throws SecurityException if the current thread is not allowed * to access this thread group or any of the threads in * the thread group. * @see java.lang.Thread#interrupt() * @see java.lang.SecurityException * @see java.lang.ThreadGroup#checkAccess() * @since 1.2 */ public final void interrupt() { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { checkAccess(); for (int i = 0 ; i < nthreads ; i++) { threads[i].interrupt(); } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i++) { groupsSnapshot[i].interrupt(); } } /** * Suspends all threads in this thread group. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * This method then calls the {@code suspend} method on all the * threads in this thread group and in all of its subgroups. * * @throws SecurityException if the current thread is not allowed * to access this thread group or any of the threads in * the thread group. * @see java.lang.Thread#suspend() * @see java.lang.SecurityException * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 * @deprecated This method is inherently deadlock-prone. See * {@link Thread#suspend} for details. */ @Deprecated(since="1.2", forRemoval=true) @SuppressWarnings("removal") public final void suspend() { if (stopOrSuspend(true)) Thread.currentThread().suspend(); } /** * Helper method: recursively stops or suspends (as directed by the * boolean argument) all of the threads in this thread group and its * subgroups, except the current thread. This method returns true * if (and only if) the current thread is found to be in this thread * group or one of its subgroups. */ @SuppressWarnings({"deprecation", "removal"}) private boolean stopOrSuspend(boolean suspend) { boolean suicide = false; Thread us = Thread.currentThread(); int ngroupsSnapshot; ThreadGroup[] groupsSnapshot = null; synchronized (this) { checkAccess(); for (int i = 0 ; i < nthreads ; i++) { if (threads[i]==us) suicide = true; else if (suspend) threads[i].suspend(); else threads[i].stop(); } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } } for (int i = 0 ; i < ngroupsSnapshot ; i++) suicide = groupsSnapshot[i].stopOrSuspend(suspend) || suicide; return suicide; } /** * Resumes all threads in this thread group. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * <p> * This method then calls the {@code resume} method on all the * threads in this thread group and in all of its sub groups. * * @throws SecurityException if the current thread is not allowed to * access this thread group or any of the threads in the * thread group. * @see java.lang.SecurityException * @see java.lang.Thread#resume() * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 * @deprecated This method is used solely in conjunction with * {@code Thread.suspend} and {@code ThreadGroup.suspend}, * both of which have been deprecated, as they are inherently * deadlock-prone. See {@link Thread#suspend} for details. */ @Deprecated(since="1.2", forRemoval=true) @SuppressWarnings("removal") public final void resume() { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { checkAccess(); for (int i = 0 ; i < nthreads ; i++) { threads[i].resume(); } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i++) { groupsSnapshot[i].resume(); } } /** * Destroys this thread group and all of its subgroups. This thread * group must be empty, indicating that all threads that had been in * this thread group have since stopped. * <p> * First, the {@code checkAccess} method of this thread group is * called with no arguments; this may result in a security exception. * * @throws IllegalThreadStateException if the thread group is not * empty or if the thread group has already been destroyed. * @throws SecurityException if the current thread cannot modify this * thread group. * @see java.lang.ThreadGroup#checkAccess() * @since 1.0 * * @deprecated The API and mechanism for destroying a ThreadGroup is inherently * flawed. The ability to explicitly or automatically destroy a * thread group will be removed in a future release. */ @Deprecated(since="16", forRemoval=true) public final void destroy() { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { checkAccess(); if (destroyed || (nthreads > 0)) { throw new IllegalThreadStateException(); } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } if (parent != null) { destroyed = true; ngroups = 0; groups = null; nthreads = 0; threads = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i += 1) { groupsSnapshot[i].destroy(); } if (parent != null) { parent.remove(this); } } /** * Adds the specified Thread group to this group. * @param g the specified Thread group to be added * @throws IllegalThreadStateException If the Thread group has been destroyed. */ private final void add(ThreadGroup g){ synchronized (this) { if (destroyed) { throw new IllegalThreadStateException(); } if (groups == null) { groups = new ThreadGroup[4]; } else if (ngroups == groups.length) { groups = Arrays.copyOf(groups, ngroups * 2); } groups[ngroups] = g; // This is done last so it doesn't matter in case the // thread is killed ngroups++; } } /** * Removes the specified Thread group from this group. * @param g the Thread group to be removed * @return if this Thread has already been destroyed. */ private void remove(ThreadGroup g) { synchronized (this) { if (destroyed) { return; } for (int i = 0 ; i < ngroups ; i++) { if (groups[i] == g) { ngroups -= 1; System.arraycopy(groups, i + 1, groups, i, ngroups - i); // Zap dangling reference to the dead group so that // the garbage collector will collect it. groups[ngroups] = null; break; } } if (nthreads == 0) { notifyAll(); } if (daemon && (nthreads == 0) && (nUnstartedThreads == 0) && (ngroups == 0)) { destroy(); } } } /** * Increments the count of unstarted threads in the thread group. * Unstarted threads are not added to the thread group so that they * can be collected if they are never started, but they must be * counted so that daemon thread groups with unstarted threads in * them are not destroyed. */ void addUnstarted() { synchronized(this) { if (destroyed) { throw new IllegalThreadStateException(); } nUnstartedThreads++; } } /** * Adds the specified thread to this thread group. * * <p> Note: This method is called from both library code * and the Virtual Machine. It is called from VM to add * certain system threads to the system thread group. * * @param t * the Thread to be added * * @throws IllegalThreadStateException * if the Thread group has been destroyed */ void add(Thread t) { synchronized (this) { if (destroyed) { throw new IllegalThreadStateException(); } if (threads == null) { threads = new Thread[4]; } else if (nthreads == threads.length) { threads = Arrays.copyOf(threads, nthreads * 2); } threads[nthreads] = t; // This is done last so it doesn't matter in case the // thread is killed nthreads++; // The thread is now a fully fledged member of the group, even // though it may, or may not, have been started yet. It will prevent // the group from being destroyed so the unstarted Threads count is // decremented. nUnstartedThreads--; } } /** * Notifies the group that the thread {@code t} has failed * an attempt to start. * * <p> The state of this thread group is rolled back as if the * attempt to start the thread has never occurred. The thread is again * considered an unstarted member of the thread group, and a subsequent * attempt to start the thread is permitted. * * @param t * the Thread whose start method was invoked */ void threadStartFailed(Thread t) { synchronized(this) { remove(t); nUnstartedThreads++; } } /** * Notifies the group that the thread {@code t} has terminated. * * <p> Destroy the group if all of the following conditions are * true: this is a daemon thread group; there are no more alive * or unstarted threads in the group; there are no subgroups in * this thread group. * * @param t * the Thread that has terminated */ void threadTerminated(Thread t) { synchronized (this) { remove(t); if (nthreads == 0) { notifyAll(); } if (daemon && (nthreads == 0) && (nUnstartedThreads == 0) && (ngroups == 0)) { destroy(); } } } /** * Removes the specified Thread from this group. Invoking this method * on a thread group that has been destroyed has no effect. * * @param t * the Thread to be removed */ private void remove(Thread t) { synchronized (this) { if (destroyed) { return; } for (int i = 0 ; i < nthreads ; i++) { if (threads[i] == t) { System.arraycopy(threads, i + 1, threads, i, --nthreads - i); // Zap dangling reference to the dead thread so that // the garbage collector will collect it. threads[nthreads] = null; break; } } } } /** * Prints information about this thread group to the standard * output. This method is useful only for debugging. * * @since 1.0 */ public void list() { list(System.out, 0); } void list(PrintStream out, int indent) { int ngroupsSnapshot; ThreadGroup[] groupsSnapshot; synchronized (this) { for (int j = 0 ; j < indent ; j++) { out.print(" "); } out.println(this); indent += 4; for (int i = 0 ; i < nthreads ; i++) { for (int j = 0 ; j < indent ; j++) { out.print(" "); } out.println(threads[i]); } ngroupsSnapshot = ngroups; if (groups != null) { groupsSnapshot = Arrays.copyOf(groups, ngroupsSnapshot); } else { groupsSnapshot = null; } } for (int i = 0 ; i < ngroupsSnapshot ; i++) { groupsSnapshot[i].list(out, indent); } } /** * Called by the Java Virtual Machine when a thread in this * thread group stops because of an uncaught exception, and the thread * does not have a specific {@link Thread.UncaughtExceptionHandler} * installed. * <p> * The {@code uncaughtException} method of * {@code ThreadGroup} does the following: * <ul> * <li>If this thread group has a parent thread group, the * {@code uncaughtException} method of that parent is called * with the same two arguments. * <li>Otherwise, this method checks to see if there is a * {@linkplain Thread#getDefaultUncaughtExceptionHandler default * uncaught exception handler} installed, and if so, its * {@code uncaughtException} method is called with the same * two arguments. * <li>Otherwise, this method determines if the {@code Throwable} * argument is an instance of {@link ThreadDeath}. If so, nothing * special is done. Otherwise, a message containing the * thread's name, as returned from the thread's {@link * Thread#getName getName} method, and a stack backtrace, * using the {@code Throwable}'s {@link * Throwable#printStackTrace printStackTrace} method, is * printed to the {@linkplain System#err standard error stream}. * </ul> * <p> * Applications can override this method in subclasses of * {@code ThreadGroup} to provide alternative handling of * uncaught exceptions. * * @param t the thread that is about to exit. * @param e the uncaught exception. * @since 1.0 */ public void uncaughtException(Thread t, Throwable e) { if (parent != null) { parent.uncaughtException(t, e); } else { Thread.UncaughtExceptionHandler ueh = Thread.getDefaultUncaughtExceptionHandler(); if (ueh != null) { ueh.uncaughtException(t, e); } else if (!(e instanceof ThreadDeath)) { System.err.print("Exception in thread \"" + t.getName() + "\" "); e.printStackTrace(System.err); } } } /** * Used by VM to control lowmem implicit suspension. * * @param b boolean to allow or disallow suspension * @return true on success * @since 1.1 * @deprecated The definition of this call depends on {@link #suspend}, * which is deprecated. Further, the behavior of this call * was never specified. */ @Deprecated(since="1.2", forRemoval=true) public boolean allowThreadSuspension(boolean b) { return true; } /** * Returns a string representation of this Thread group. * * @return a string representation of this thread group. * @since 1.0 */ public String toString() { return getClass().getName() + "[name=" + getName() + ",maxpri=" + maxPriority + "]"; } }
⏎ java/lang/ThreadGroup.java
Or download all of them as a single archive file:
File name: java.base-17.0.5-src.zip File size: 8883851 bytes Release date: 2022-09-13 Download
2023-09-26, 94293👍, 1💬
Popular Posts:
How to display types defined in an XML Schema file with the xs\QueryXS.java provided in the Apache X...
What Is junit-3.8.1.jar? junit-3.8.1.jar is the version 3.8.1 of JUnit JAR library file. JUnit is a ...
What Is wstx-asl-3.2.8.jar? wstx-asl-3.2.8.jar is JAR file for the ASL component of Woodstox 3.2.8. ...
iText is an ideal library for developers looking to enhance web- and other applications with dynamic...
Apache Avalon began in 1999 as the Java Apache Server Framework and in late 2002 separated from the ...