Package org.bitcoinj.utils

Class Threading

  • public class Threading
extends java.lang.Object
    Various threading related utilities. Provides a wrapper around explicit lock creation that lets you control whether bitcoinj performs cycle detection or not. Cycle detection is useful to detect bugs but comes with a small cost. Also provides a worker thread that is designed for event listeners to be dispatched on.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  Threading.UserThread  

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static com.google.common.util.concurrent.CycleDetectingLockFactory factory  
      static java.util.concurrent.Executor SAME_THREAD
      A dummy executor that just invokes the runnable immediately.
      static java.util.concurrent.ExecutorService THREAD_POOL
      A caching thread pool that creates daemon threads, which won't keep the JVM alive waiting for more work.
      static java.lang.Thread.UncaughtExceptionHandler uncaughtExceptionHandler
      An exception handler that will be invoked for any exceptions that occur in the user thread, and any unhandled exceptions that are caught whilst the framework is processing network traffic or doing other background tasks.
      static java.util.concurrent.Executor USER_THREAD
      An executor with one thread that is intended for running event listeners on.

    • Constructor Summary

      Constructors 
      Constructor Description
      Threading()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static com.google.common.util.concurrent.CycleDetectingLockFactory.Policy getPolicy()  
      static void ignoreLockCycles()  
      static java.util.concurrent.locks.ReentrantLock lock​(java.lang.Class clazz)  
      static java.util.concurrent.locks.ReentrantLock lock​(java.lang.String name)  
      static void setPolicy​(com.google.common.util.concurrent.CycleDetectingLockFactory.Policy policy)  
      static void throwOnLockCycles()  
      static void waitForUserCode()
      Put a dummy task into the queue and wait for it to be run.
      static void warnOnLockCycles()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • USER_THREAD

        public static java.util.concurrent.Executor USER_THREAD
        An executor with one thread that is intended for running event listeners on. This ensures all event listener code runs without any locks being held. It's intended for the API user to run things on. Callbacks registered by bitcoinj internally shouldn't normally run here, although currently there are a few exceptions.

      • SAME_THREAD

        public static final java.util.concurrent.Executor SAME_THREAD
        A dummy executor that just invokes the runnable immediately. Use this over more complex executors (e.g. those extending ExecutorService), which are overkill for our needs.

      • uncaughtExceptionHandler

        @Nullable
public static volatile java.lang.Thread.UncaughtExceptionHandler uncaughtExceptionHandler
        An exception handler that will be invoked for any exceptions that occur in the user thread, and any unhandled exceptions that are caught whilst the framework is processing network traffic or doing other background tasks. The purpose of this is to allow you to report back unanticipated crashes from your users to a central collection center for analysis and debugging. You should configure this before any bitcoinj library code is run, setting it after you started network traffic and other forms of processing may result in the change not taking effect.

      • factory

        public static com.google.common.util.concurrent.CycleDetectingLockFactory factory

      • THREAD_POOL

        public static java.util.concurrent.ExecutorService THREAD_POOL
        A caching thread pool that creates daemon threads, which won't keep the JVM alive waiting for more work.

    • Constructor Detail

      • Threading

        public Threading()

    • Method Detail

      • waitForUserCode

        public static void waitForUserCode()
        Put a dummy task into the queue and wait for it to be run. Because it's single threaded, this means all tasks submitted before this point are now completed. Usually you won't want to use this method - it's a convenience primarily used in unit testing. If you want to wait for an event to be called the right thing to do is usually to create a CompletableFuture and then call CompletableFuture.complete(Object) on it. For example: 
        
 CompletableFuture f = CompletableFuture.supplyAsync(() -> event, USER_THREAD)
        You can then either block on that future, compose it, add listeners to it and so on.

      • lock

        public static java.util.concurrent.locks.ReentrantLock lock​(java.lang.Class clazz)

      • lock

        public static java.util.concurrent.locks.ReentrantLock lock​(java.lang.String name)

      • warnOnLockCycles

        public static void warnOnLockCycles()

      • throwOnLockCycles

        public static void throwOnLockCycles()

      • ignoreLockCycles

        public static void ignoreLockCycles()

      • setPolicy

        public static void setPolicy​(com.google.common.util.concurrent.CycleDetectingLockFactory.Policy policy)

      • getPolicy

        public static com.google.common.util.concurrent.CycleDetectingLockFactory.Policy getPolicy()