Threadpublic class Thread extends Object implements Runnable| A thread is a thread of execution in a program. The Java
Virtual Machine allows an application to have multiple threads of
execution running concurrently.
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 Thread 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.
When a Java Virtual Machine starts up, there is usually a single
non-daemon thread (which typically calls the method named
main of some designated class). The Java Virtual
Machine continues to execute threads until either of the following
occurs:
- The
exit method of class Runtime has been
called and the security manager has permitted the exit operation
to take place.
- All threads that are not daemon threads have died, either by
returning from the call to the
run method or by
throwing an exception that propagates beyond the run
method.
There are two ways to create a new thread of execution. One is to
declare a class to be a subclass of Thread. This
subclass should override the run method of class
Thread. 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:
class PrimeThread extends Thread {
long minPrime;
PrimeThread(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
. . .
}
}
The following code would then create a thread and start it running:
PrimeThread p = new PrimeThread(143);
p.start();
The other way to create a thread is to declare a class that
implements the Runnable interface. That class then
implements the run method. An instance of the class can
then be allocated, passed as an argument when creating
Thread, and started. The same example in this other
style looks like the following:
class PrimeRun implements Runnable {
long minPrime;
PrimeRun(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
. . .
}
}
The following code would then create a thread and start it running:
PrimeRun p = new PrimeRun(143);
new Thread(p).start();
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. |
| Fields Summary |
|---|
| private char[] | name | | private int | priority | | private Thread | threadQ | | private long | eetop | | private boolean | single_step | | private boolean | daemon | | private boolean | stillborn | | private Runnable | target | | private ThreadGroup | group | | private ClassLoader | contextClassLoader | | private AccessControlContext | inheritedAccessControlContext | | private static int | threadInitNumber | | ThreadLocal$ThreadLocalMap | threadLocals | | ThreadLocal$ThreadLocalMap | inheritableThreadLocals | | private long | stackSize | | private long | nativeParkEventPointer | | private long | tid | | private static long | threadSeqNumber | | private int | threadStatus | | volatile Object | parkBlockerThe 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 | | private volatile Interruptible | blocker | | private Object | blockerLock | | public static final int | MIN_PRIORITYThe minimum priority that a thread can have. | | public static final int | NORM_PRIORITYThe default priority that is assigned to a thread. | | public static final int | MAX_PRIORITYThe maximum priority that a thread can have. | | private boolean | stopBeforeStart | | private Throwable | throwableFromStop | | private static final StackTraceElement[] | EMPTY_STACK_TRACE | | private static final RuntimePermission | SUBCLASS_IMPLEMENTATION_PERMISSION | | private static final sun.misc.SoftCache | subclassAuditscache of subclass security audit results | | private volatile UncaughtExceptionHandler | uncaughtExceptionHandler | | private static volatile UncaughtExceptionHandler | defaultUncaughtExceptionHandler |
| Constructors Summary |
|---|
public Thread()Allocates a new Thread object. This constructor has
the same effect as Thread(null, null,
gname), where gname is
a newly generated name. Automatically generated names are of the
form "Thread-"+n, where n is an integer.
init(null, null, "Thread-" + nextThreadNum(), 0);
| public Thread(Runnable target)Allocates a new Thread object. This constructor has
the same effect as Thread(null, target,
gname), where gname is
a newly generated name. Automatically generated names are of the
form "Thread-"+n, where n is an integer.
init(null, target, "Thread-" + nextThreadNum(), 0);
| public Thread(ThreadGroup group, Runnable target)Allocates a new Thread object. This constructor has
the same effect as Thread(group, target,
gname), where gname is
a newly generated name. Automatically generated names are of the
form "Thread-"+n, where n is an integer.
init(group, target, "Thread-" + nextThreadNum(), 0);
| public Thread(String name)Allocates a new Thread object. This constructor has
the same effect as Thread(null, null, name).
init(null, null, name, 0);
| public Thread(ThreadGroup group, String name)Allocates a new Thread object. This constructor has
the same effect as Thread(group, null, name)
init(group, null, name, 0);
| public Thread(Runnable target, String name)Allocates a new Thread object. This constructor has
the same effect as Thread(null, target, name).
init(null, target, name, 0);
| public Thread(ThreadGroup group, Runnable target, String name)Allocates a new Thread object so that it has
target as its run object, has the specified
name as its name, and belongs to the thread group
referred to by group.
If group is null and there is a
security manager, the group is determined by the security manager's
getThreadGroup method. If group is
null and there is not a security manager, or the
security manager's getThreadGroup method returns
null, the group is set to be the same ThreadGroup
as the thread that is creating the new thread.
If there is a security manager, its checkAccess
method is called with the ThreadGroup as its argument.
In addition, its checkPermission
method is called with the
RuntimePermission("enableContextClassLoaderOverride")
permission when invoked directly or indirectly by the constructor
of a subclass which overrides the getContextClassLoader
or setContextClassLoader methods.
This may result in a SecurityException.
If the target argument is not null, the
run method of the target is called when
this thread is started. If the target argument is
null, this thread's run method is called
when this thread is started.
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 setPriority may be used to
change the priority to a new value.
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 setDaemon may be used
to change whether or not a thread is a daemon.
init(group, target, name, 0);
| public Thread(ThreadGroup group, Runnable target, String name, long stackSize)Allocates a new Thread object so that it has
target as its run object, has the specified
name as its name, belongs to the thread group referred to
by group, and has the specified stack size.
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. The effect of the
stackSize parameter, if any, is highly platform dependent.
On some platforms, specifying a higher value for the
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 stackSize parameter
and the maximum recursion depth and concurrency level are
platform-dependent. On some platforms, the value of the
stackSize parameter may have no effect whatsoever.
The virtual machine is free to treat the 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).
Specifying a value of zero for the stackSize parameter will
cause this constructor to behave exactly like the
Thread(ThreadGroup, Runnable, String) constructor.
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.
Implementation note: Java platform implementers are encouraged to
document their implementation's behavior with respect to the
stackSize parameter.
init(group, target, name, stackSize);
|
| Methods Summary |
|---|
| public static int | activeCount()Returns the number of active threads in the current thread's thread
group.
return currentThread().getThreadGroup().activeCount();
| | private static boolean | auditSubclass(java.lang.Class subcl)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.
Boolean result = (Boolean) AccessController.doPrivileged(
new PrivilegedAction() {
public Object 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();
| | void | blockedOn(sun.nio.ch.Interruptible b)
/* Set the blocker field; invoked via sun.misc.SharedSecrets from java.nio code
*/
synchronized (blockerLock) {
blocker = b;
}
| | public final void | checkAccess()Determines if the currently running thread has permission to
modify this thread.
If there is a security manager, its checkAccess method
is called with this thread as its argument. This may result in
throwing a SecurityException.
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkAccess(this);
}
| | public native int | countStackFrames()Counts the number of stack frames in this thread. The thread must
be suspended.
| | public static native java.lang.Thread | currentThread()Returns a reference to the currently executing thread object.
| | public void | destroy()Throws {@link NoSuchMethodError}.
throw new NoSuchMethodError();
| | private void | dispatchUncaughtException(java.lang.Throwable e)Dispatch an uncaught exception to the handler. This method is
intended to be called only by the JVM.
getUncaughtExceptionHandler().uncaughtException(this, e);
| | public static void | dumpStack()Prints a stack trace of the current thread to the standard error stream.
This method is used only for debugging.
new Exception("Stack trace").printStackTrace();
| | private static native java.lang.StackTraceElement[][] | dumpThreads(java.lang.Thread[] threads)
| | public static int | enumerate(java.lang.Thread[] tarray)Copies into the specified array every active thread in
the current thread's thread group and its subgroups. This method simply
calls the enumerate method of the current thread's thread
group with the array argument.
First, if there is a security manager, that enumerate
method calls the security
manager's checkAccess method
with the thread group as its argument. This may result
in throwing a SecurityException.
return currentThread().getThreadGroup().enumerate(tarray);
| | private void | exit()This method is called by the system to give a Thread
a chance to clean up before it actually exits.
if (group != null) {
group.remove(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;
| | public static java.util.Map | getAllStackTraces()Returns a map of stack traces for all live threads.
The map keys are threads and each map value is an array of
StackTraceElement that represents the stack dump
of the corresponding Thread.
The returned stack traces are in the format specified for
the {@link #getStackTrace getStackTrace} method.
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.
If there is a security manager, then the security manager's
checkPermission method is called with a
RuntimePermission("getStackTrace") permission as well as
RuntimePermission("modifyThreadGroup") permission
to see if it is ok to get the stack trace of all threads.
// 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
Thread[] threads = getThreads();
StackTraceElement[][] traces = dumpThreads(threads);
Map<Thread, StackTraceElement[]> m
= new HashMap<Thread, StackTraceElement[]>(threads.length);
for (int i = 0; i < threads.length; i++) {
if (threads[i].isAlive()) {
StackTraceElement[] stackTrace = traces[i];
if (stackTrace == null) {
stackTrace = EMPTY_STACK_TRACE;
}
m.put(threads[i], stackTrace);
}
}
return m;
| | public java.lang.ClassLoader | getContextClassLoader()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 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.
First, if there is a security manager, and the caller's class
loader is not null and the caller's class loader is not the same as or
an ancestor of the context class loader for the thread whose
context class loader is being requested, then the security manager's
checkPermission
method is called with a
RuntimePermission("getClassLoader") permission
to see if it's ok to get the context ClassLoader..
if (contextClassLoader == null)
return null;
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
ClassLoader ccl = ClassLoader.getCallerClassLoader();
if (ccl != null && ccl != contextClassLoader &&
!contextClassLoader.isAncestor(ccl)) {
sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
}
}
return contextClassLoader;
| | public static java.lang.Thread$UncaughtExceptionHandler | getDefaultUncaughtExceptionHandler()Returns the default handler invoked when a thread abruptly terminates
due to an uncaught exception. If the returned value is null,
there is no default.
return defaultUncaughtExceptionHandler;
| | public long | getId()Returns the identifier of this Thread. The thread ID is a positive
long 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 tid;
| | public final java.lang.String | getName()Returns this thread's name.
return String.valueOf(name);
| | public final int | getPriority()Returns this thread's priority.
return priority;
| | public java.lang.StackTraceElement[] | getStackTrace()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 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.
If there is a security manager, and this thread is not
the current thread, then the security manager's
checkPermission method is called with a
RuntimePermission("getStackTrace") permission
to see if it's ok to get the stack trace.
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.
if (this != Thread.currentThread()) {
// check for getStackTrace permission
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkPermission(
SecurityConstants.GET_STACK_TRACE_PERMISSION);
}
if (!isAlive()) {
return EMPTY_STACK_TRACE;
}
return dumpThreads(new Thread[] {this})[0];
} else {
// Don't need JVM help for current thread
return (new Exception()).getStackTrace();
}
| | public java.lang.Thread$State | getState()Returns the state of this thread.
This method is designed for use in monitoring of the system state,
not for synchronization control.
// get current thread state
return sun.misc.VM.toThreadState(threadStatus);
| | public final java.lang.ThreadGroup | getThreadGroup()Returns the thread group to which this thread belongs.
This method returns null if this thread has died
(been stopped).
return group;
| | private static native java.lang.Thread[] | getThreads()
| | public java.lang.Thread$UncaughtExceptionHandler | getUncaughtExceptionHandler()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
ThreadGroup object is returned, unless this thread
has terminated, in which case null is returned.
return uncaughtExceptionHandler != null ?
uncaughtExceptionHandler : group;
| | public static native boolean | holdsLock(java.lang.Object obj)Returns true if and only if the current thread holds the
monitor lock on the specified object.
This method is designed to allow a program to assert that
the current thread already holds a specified lock:
assert Thread.holdsLock(obj);
| | private void | init(java.lang.ThreadGroup g, java.lang.Runnable target, java.lang.String name, long stackSize)Initializes a Thread.
Thread parent = currentThread();
SecurityManager security = System.getSecurityManager();
if (g == null) {
/* 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();
}
}
/* 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();
this.name = name.toCharArray();
if (security == null || isCCLOverridden(parent.getClass()))
this.contextClassLoader = parent.getContextClassLoader();
else
this.contextClassLoader = parent.contextClassLoader;
this.inheritedAccessControlContext = AccessController.getContext();
this.target = target;
setPriority(priority);
if (parent.inheritableThreadLocals != null)
this.inheritableThreadLocals =
ThreadLocal.createInheritedMap(parent.inheritableThreadLocals);
/* Stash the specified stack size in case the VM cares */
this.stackSize = stackSize;
/* Set thread ID */
tid = nextThreadID();
| | public void | interrupt()Interrupts this thread.
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.
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}.
If this thread is blocked in an I/O operation upon an {@link
java.nio.channels.InterruptibleChannel interruptible
channel} 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}.
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.
If none of the previous conditions hold then this thread's interrupt
status will be set.
Interrupting a thread that is not alive need not have any effect.
if (this != Thread.currentThread())
checkAccess();
synchronized (blockerLock) {
Interruptible b = blocker;
if (b != null) {
interrupt0(); // Just to set the interrupt flag
b.interrupt();
return;
}
}
interrupt0();
| | private native void | interrupt0()
| | public static boolean | interrupted()Tests whether the current thread has been interrupted. The
interrupted status 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).
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 currentThread().isInterrupted(true);
| | public final native boolean | isAlive()Tests if this thread is alive. A thread is alive if it has
been started and has not yet died.
| | private static boolean | isCCLOverridden(java.lang.Class cl)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.
if (cl == Thread.class)
return false;
Boolean result = null;
synchronized (subclassAudits) {
result = (Boolean) subclassAudits.get(cl);
if (result == null) {
/*
* Note: only new Boolean instances (i.e., not Boolean.TRUE or
* Boolean.FALSE) must be used as cache values, otherwise cache
* entry will pin associated class.
*/
result = new Boolean(auditSubclass(cl));
subclassAudits.put(cl, result);
}
}
return result.booleanValue();
| | public final boolean | isDaemon()Tests if this thread is a daemon thread.
return daemon;
| | public boolean | isInterrupted()Tests whether this thread has been interrupted. The interrupted
status of the thread is unaffected by this method.
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 isInterrupted(false);
| | private native boolean | isInterrupted(boolean ClearInterrupted)Tests if some Thread has been interrupted. The interrupted state
is reset or not based on the value of ClearInterrupted that is
passed.
| | public final synchronized void | join(long millis)Waits at most millis milliseconds for this thread to
die. A timeout of 0 means to wait forever.
long base = System.currentTimeMillis();
long now = 0;
if (millis < 0) {
throw new IllegalArgumentException("timeout value is negative");
}
if (millis == 0) {
while (isAlive()) {
wait(0);
}
} else {
while (isAlive()) {
long delay = millis - now;
if (delay <= 0) {
break;
}
wait(delay);
now = System.currentTimeMillis() - base;
}
}
| | public final synchronized void | join(long millis, int nanos)Waits at most millis milliseconds plus
nanos nanoseconds for this thread to die.
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);
| | public final void | join()Waits for this thread to die.
join(0);
| | private static synchronized long | nextThreadID()
return ++threadSeqNumber;
| | private static synchronized int | nextThreadNum()
return threadInitNumber++;
| | private static native void | registerNatives()
| | public final void | resume()Resumes a suspended thread.
First, the checkAccess method of this thread is called
with no arguments. This may result in throwing a
SecurityException (in the current thread).
If the thread is alive but suspended, it is resumed and is
permitted to make progress in its execution.
checkAccess();
resume0();
| | private native void | resume0()
| | public void | run()If this thread was constructed using a separate
Runnable run object, then that
Runnable object's run method is called;
otherwise, this method does nothing and returns.
Subclasses of Thread should override this method.
if (target != null) {
target.run();
}
| | public void | setContextClassLoader(java.lang.ClassLoader cl)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
to code running in the thread when loading classes and resources.
First, if there is a security manager, its checkPermission
method is called with a
RuntimePermission("setContextClassLoader") permission
to see if it's ok to set the context ClassLoader..
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("setContextClassLoader"));
}
contextClassLoader = cl;
| | public final void | setDaemon(boolean on)Marks this thread as either a daemon thread or a user thread. The
Java Virtual Machine exits when the only threads running are all
daemon threads.
This method must be called before the thread is started.
This method first calls the checkAccess method
of this thread
with no arguments. This may result in throwing a
SecurityException (in the current thread).
checkAccess();
if (isAlive()) {
throw new IllegalThreadStateException();
}
daemon = on;
| | public static void | setDefaultUncaughtExceptionHandler(java.lang.Thread$UncaughtExceptionHandler eh)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.
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
uncaughtException method, then the default handler's
uncaughtException method will be invoked.
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.
Note that the default uncaught exception handler should not usually
defer to the thread's ThreadGroup object, as that could cause
infinite recursion.
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(
new RuntimePermission("setDefaultUncaughtExceptionHandler")
);
}
defaultUncaughtExceptionHandler = eh;
| | public final void | setName(java.lang.String name)Changes the name of this thread to be equal to the argument
name.
First the checkAccess method of this thread is called
with no arguments. This may result in throwing a
SecurityException.
checkAccess();
this.name = name.toCharArray();
| | public final void | setPriority(int newPriority)Changes the priority of this thread.
First the checkAccess method of this thread is called
with no arguments. This may result in throwing a
SecurityException.
Otherwise, the priority of this thread is set to the smaller of
the specified newPriority and the maximum permitted
priority of the thread's thread group.
ThreadGroup g;
checkAccess();
if (newPriority > MAX_PRIORITY || newPriority < MIN_PRIORITY) {
throw new IllegalArgumentException();
}
if((g = getThreadGroup()) != null) {
if (newPriority > g.getMaxPriority()) {
newPriority = g.getMaxPriority();
}
setPriority0(priority = newPriority);
}
| | private native void | setPriority0(int newPriority)
| | public void | setUncaughtExceptionHandler(java.lang.Thread$UncaughtExceptionHandler eh)Set the handler invoked when this thread abruptly terminates
due to an uncaught exception.
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 ThreadGroup
object acts as its handler.
checkAccess();
uncaughtExceptionHandler = eh;
| | public static native void | sleep(long millis)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.
| | public static void | sleep(long millis, int nanos)Causes the currently executing thread to sleep (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.
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++;
}
sleep(millis);
| | public synchronized void | start()Causes this thread to begin execution; the Java Virtual Machine
calls the run method of this thread.
The result is that two threads are running concurrently: the
current thread (which returns from the call to the
start method) and the other thread (which executes its
run method).
It is never legal to start a thread more than once.
In particular, a thread may not be restarted once it has completed
execution.
/**
* 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".
*/
if (threadStatus != 0)
throw new IllegalThreadStateException();
group.add(this);
start0();
if (stopBeforeStart) {
stop0(throwableFromStop);
}
| | private native void | start0()
| | public final void | stop()Forces the thread to stop executing.
If there is a security manager installed, its checkAccess
method is called with this
as its argument. This may result in a
SecurityException being raised (in the current thread).
If this thread is different from the current thread (that is, the current
thread is trying to stop a thread other than itself), the
security manager's checkPermission method (with a
RuntimePermission("stopThread") argument) is called in
addition.
Again, this may result in throwing a
SecurityException (in the current thread).
The thread represented by this thread is forced to stop whatever
it is doing abnormally and to throw a newly created
ThreadDeath object as an exception.
It is permitted to stop a thread that has not yet been started.
If the thread is eventually started, it immediately terminates.
An application should not normally try to catch
ThreadDeath unless it must do some extraordinary
cleanup operation (note that the throwing of
ThreadDeath causes finally clauses of
try statements to be executed before the thread
officially dies). If a catch clause catches a
ThreadDeath object, it is important to rethrow the
object so that the thread actually dies.
The top-level error handler that reacts to otherwise uncaught
exceptions does not print out a message or otherwise notify the
application if the uncaught exception is an instance of
ThreadDeath.
// If the thread is already dead, return.
// A zero status value corresponds to "NEW".
if ((threadStatus != 0) && !isAlive()) {
return;
}
stop1(new ThreadDeath());
| | public final synchronized void | stop(java.lang.Throwable obj)Forces the thread to stop executing.
If there is a security manager installed, the checkAccess
method of this thread is called, which may result in a
SecurityException being raised (in the current thread).
If this thread is different from the current thread (that is, the current
thread is trying to stop a thread other than itself) or
obj is not an instance of ThreadDeath, the
security manager's checkPermission method (with the
RuntimePermission("stopThread") argument) is called in
addition.
Again, this may result in throwing a
SecurityException (in the current thread).
If the argument obj is null, a
NullPointerException is thrown (in the current thread).
The thread represented by this thread is forced to stop
whatever it is doing abnormally and to throw the
Throwable object obj as an exception. This
is an unusual action to take; normally, the stop method
that takes no arguments should be used.
It is permitted to stop a thread that has not yet been started.
If the thread is eventually started, it immediately terminates.
stop1(obj);
| | private native void | stop0(java.lang.Object o)
| | private final synchronized void | stop1(java.lang.Throwable th)Common impl for stop() and stop(Throwable).
SecurityManager security = System.getSecurityManager();
if (security != null) {
checkAccess();
if ((this != Thread.currentThread()) ||
(!(th instanceof ThreadDeath))) {
security.checkPermission(SecurityConstants.STOP_THREAD_PERMISSION);
}
}
// A zero status value corresponds to "NEW"
if (threadStatus != 0) {
resume(); // Wake up thread if it was suspended; no-op otherwise
stop0(th);
} else {
// Must do the null arg check that the VM would do with stop0
if (th == null) {
throw new NullPointerException();
}
// Remember this stop attempt for if/when start is used
stopBeforeStart = true;
throwableFromStop = th;
}
| | public final void | suspend()Suspends this thread.
First, the checkAccess method of this thread is called
with no arguments. This may result in throwing a
SecurityException (in the current thread).
If the thread is alive, it is suspended and makes no further
progress unless and until it is resumed.
checkAccess();
suspend0();
| | private native void | suspend0()
| | public java.lang.String | toString()Returns a string representation of this thread, including the
thread's name, priority, and thread group.
ThreadGroup group = getThreadGroup();
if (group != null) {
return "Thread[" + getName() + "," + getPriority() + "," +
group.getName() + "]";
} else {
return "Thread[" + getName() + "," + getPriority() + "," +
"" + "]";
}
| | public static native void | yield()Causes the currently executing thread object to temporarily pause
and allow other threads to execute.
|
|
