Package org.bitcoinj.utils

Class Threading

java.lang.Object
org.bitcoinj.utils.Threading
public class Threading extends 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.

  • Field Details

    • USER_THREAD

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

  • Constructor Details

    • Threading

      public Threading()

  • Method Details

    • 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 ReentrantLock lock(Class clazz)

    • lock

      public static ReentrantLock lock(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()