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SystemCleaner
public final class SystemCleaner
extends Object
Java.lang.ref.Cleaner encourages each library to create a Cleaner, with an associated thread, to process Cleaner Runnables for that library's registered cleaning actions. This approach isolates cleaning actions from different libraries from each other; a slow cleaning action in one library will only minimally affect cleaning actions in another. However, this comes at the cost of introducing one Cleaner thread per library that uses Cleaners. This could introduce dozens of additional threads per process, which is often not an acceptable cost, especially on memory-limited devices. SystemCleaner instead provides access to a shared Cleaner, shared across the entire process. It is greatly preferred when all cleaning actions registered by a client are known to complete quickly, without explicit I/O, interprocess communication, or network access. Registering a non-terminating or excessively slow cleaning action with the shared cleaner may cause the process to perform very badly, hang, or be killed.
Summary
Public methods |
static Cleaner | cleaner() Return a single Cleaner that's shared across the entire process. |
Inherited methods |
From class java.lang.Object Object | clone() Creates and returns a copy of this object. | boolean | equals(Object obj) Indicates whether some other object is "equal to" this one. | void | finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | final Class<?> | getClass() Returns the runtime class of this Object . | int | hashCode() Returns a hash code value for the object. | final void | notify() Wakes up a single thread that is waiting on this object's monitor. | final void | notifyAll() Wakes up all threads that are waiting on this object's monitor. | String | toString() Returns a string representation of the object. | final void | wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. | final void | wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. | final void | wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted. | |
Public methods
cleaner
public static Cleaner cleaner ()
Return a single Cleaner that's shared across the entire process. Thread-safe. Unlike normal Cleaners, uncaught exceptions during cleaning will throw an uncaught exception from the daemon running the cleaning action. This will normally cause the process to crash, and thus cause the problem to be reported.
Returns |
Cleaner | This value cannot be null . |
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Last updated 2025-02-10 UTC.
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