Package net.sf.eBus.client

Class EClient.RQThread

  • All Implemented Interfaces:
    java.lang.Runnable
    Enclosing class:
    EClient
    public static final class EClient.RQThread
extends java.lang.Thread
    A Dispatcher run queue thread watches a given run queue for EClient instances ready to run, attempting to acquire the next ready client. When the thread successfully acquires a client, this thread has the client execute its pending tasks until either 1) the client has no more tasks or 2) the client exhausts its run quantum. Each run queue has a configurable run quantum (default is EConfigure.DEFAULT_QUANTUM). When a client exhausts this quantum and still has tasks to run, the client is placed at the end of the run queue and its quantum is replenished.

    A client instance is referenced by only one dispatcher thread at time. This means a client is effectively single-threaded at any given instance while it may be accessed by multiple, different dispatcher threads over time.

    Note: this only applies to eBus threads. Non-eBus threads may still access the client object at the same time.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  EClient.RQThread.RQThreadState
      A run queue thread is either idle (waiting for an available eBus object) or busy (running an eBus object).

      • Nested classes/interfaces inherited from class java.lang.Thread

        java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String NO_EOBJECT
      Set eBus object name to "(idle)" when run queue thread is idle.

      • Fields inherited from class java.lang.Thread

        MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void alarmCondition​(AlarmCondition alarmState)
      Sets maximum quantum overrun alarm condition.
      RQThreadInfo currentInfo()
      Returns this run queue thread's current information.
      EClient.RQStats currentStats()
      Returns this run queue thread's current stats.
      long maximumQuantum()
      Returns configured maximum quantum for this run queue thread.
      void run()
      A client executor thread continues processing ready eBus clients until the JVM exits.
      EClient spinSleepPoll()
      Spins a fixed number of times calling ConcurrentLinkedQueue.poll() to extract the next available client from the run queue.
      EClient spinYieldPoll()
      Spins a fixed number of times calling ConcurrentLinkedQueue.poll() to extract the next available client from the run queue.

      • Methods inherited from class java.lang.Thread

        activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, suspend, toString, yield

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • NO_EOBJECT

        public static final java.lang.String NO_EOBJECT
        Set eBus object name to "(idle)" when run queue thread is idle.
        See Also:
        Constant Field Values

    • Method Detail

      • run

        public void run()
        A client executor thread continues processing ready eBus clients until the JVM exits. On each iteration, this thread acquires the next available client. Then iterates over the client's task list and executing each task. This continues until the client has no more tasks or has used up its runtime quantum. The client is put back on the run queue (if the quantum is expired, the value is reset to the configured maximum) and this thread goes back to the loop's top and acquires the next available client.

        Because an eBus client is posted to only one, unique run queue and each Dispatcher thread works with only one run queue, once a dispatcher thread acquires an eBus client, it is guaranteed that no other dispatcher thread has access to the client. Therefore, from an eBus perspective, eBus client access is single-threaded.

        (Non-eBus threads may still access a client simultaneously as a dispatcher thread. This is an application design decision.)

        Specified by:
        run in interface java.lang.Runnable
        Overrides:
        run in class java.lang.Thread

      • currentStats

        public EClient.RQStats currentStats()
        Returns this run queue thread's current stats. May return null.
        Returns:
        current run queue stats.

      • currentInfo

        public RQThreadInfo currentInfo()
        Returns this run queue thread's current information.
        Returns:
        run queue thread information.

      • maximumQuantum

        public long maximumQuantum()
        Returns configured maximum quantum for this run queue thread.
        Returns:
        run queue thread maximum quantum.

      • alarmCondition

        public void alarmCondition​(AlarmCondition alarmState)
        Sets maximum quantum overrun alarm condition.
        Parameters:
        alarmState - thread overrun alarm condition.

      • spinSleepPoll

        public EClient spinSleepPoll()
        Spins a fixed number of times calling ConcurrentLinkedQueue.poll() to extract the next available client from the run queue. When the spin limit is reached, then parks for a fixed number of nanoseconds.
        Returns:
        next available client. Does not return null.

      • spinYieldPoll

        public EClient spinYieldPoll()
        Spins a fixed number of times calling ConcurrentLinkedQueue.poll() to extract the next available client from the run queue. When the spin limit is reached, then this Dispatcher thread yields.
        Returns:
        next available client. Does not return null.