Class GuardSupport


  • public class GuardSupport
    extends Base
    A concrete implementation of Guardian/Guardable interactions. GuardSupport is used by a Guardian to manage its responsibilities.
    Since:
    Coherence 3.5
    Author:
    rhl
    • Field Detail

      • GUARDIAN_MAX_CHECK_INTERVAL

        public static final long GUARDIAN_MAX_CHECK_INTERVAL
        The maximum interval at which the Guardian thread should call check() to verify its guardables.
        See Also:
        Constant Field Values
      • GUARDIAN_LATE_THRESHOLD

        protected static final long GUARDIAN_LATE_THRESHOLD
        The threshold past which a guardian considers itself late in checking its guardables.
        See Also:
        Constant Field Values
      • GUARDIAN_EARLY_THRESHOLD

        protected static final long GUARDIAN_EARLY_THRESHOLD
        The threshold before which than which a guardian considers itself early in checking its guardables.
        See Also:
        Constant Field Values
      • GUARDIAN_LOG_INTERVAL

        protected static final long GUARDIAN_LOG_INTERVAL
        The minimum interval at which the Guardian should log thread dumps.
        See Also:
        Constant Field Values
      • m_aGuardContext

        protected GuardSupport.Context[] m_aGuardContext
        Array of GuardContexts for the registered Guardables. May contain nulls.
      • m_cGuardable

        protected int m_cGuardable
        The number of registered Guardables.
      • m_guardian

        protected Guardian m_guardian
        The Guardian that is managing this GuardSupport.
      • m_ldtNextCheck

        protected long m_ldtNextCheck
        The next time at which the Guardables should be checked.
      • m_tlContext

        protected static ThreadLocal m_tlContext
        ThreadLocal containing the GuardContext associated with the current thread.
      • s_atomicLogTime

        protected static AtomicLong s_atomicLogTime
        Atomic counter containing the last log time stamp.
    • Constructor Detail

      • GuardSupport

        public GuardSupport​(Guardian guardian)
        Construct a GuardSupport for the specified Guardian.
        Parameters:
        guardian - the guardian managing this GuardSupport
    • Method Detail

      • getGuardContexts

        protected GuardSupport.Context[] getGuardContexts()
        Return the array of GuardContext objects for the Guardables managed by this GuardSupport.
        Returns:
        the array of managed GuardContext objects
      • setGuardContexts

        protected void setGuardContexts​(GuardSupport.Context[] aGuardContext)
        Set the array of GuardContext objects for the Guardables that are managed by this GuardSupport.
        Parameters:
        aGuardContext - the array of managed GuardContext objects
      • getGuardian

        protected Guardian getGuardian()
        Return the Guardian that manages this GuardSupport.
        Returns:
        the Guardian that manages this GuardSupport
      • getNextCheckTime

        public long getNextCheckTime()
        Return the next time at which the Guardables should be checked.
        Returns:
        the next time at which the Guardables should be checked
      • setNextCheckTime

        protected void setNextCheckTime​(long ldtNextCheck)
        Set the next time at which the Guardables should be checked.
        Parameters:
        ldtNextCheck - the next time at which the Guardables should be checked
      • add

        public Guardian.GuardContext add​(Guardable guardable,
                                         long cMillis,
                                         float flPctRecover)
        Add the specified guardable to the set of Guardables managed by this manager, subject to the specified service parameters. If the specified guardable is already guarded by this manager, adjust the service parameters.
        Parameters:
        guardable - the Guardable object to be managed
        cMillis - the timeout for the specified Guardable
        flPctRecover - the percentage of the timeout after which to attempt recovery of the Guardable; 0 < flPctRecover <= 1.0
        Returns:
        the GuardContext for the specified Guardable
      • remove

        public void remove​(Guardable guardable)
        Remove the specified Guardable from the set of Guardables managed by this manager.
        Parameters:
        guardable - the guardable to remove
      • getGuardableCount

        public int getGuardableCount()
        Return the number of Guardables that are registered with this GuardSupport.
        Returns:
        the number of registered Guardable objects
      • setGuardableCount

        protected void setGuardableCount​(int cGuardable)
        Set the number of Guardables that are registered with this GuardSupport.
        Parameters:
        cGuardable - the number of registered Guardable objects
      • check

        public long check()
        Check the registered Guardable objects for timeout, taking appropriate action and calculate the timestamp when the next check should be performed. The next check time can later be retrieved by the getNextCheckTime() method.
        Returns:
        the number of milliseconds past the time when the guardables should have been checked, or 0 if the check was performed on time
      • release

        public void release()
        Release the Guardables managed by this GuardSupport. Releasing a Guardable causes it to no longer be guarded.
      • instantiateContext

        protected GuardSupport.Context instantiateContext​(Guardable guardable,
                                                          long cMillis,
                                                          float flPctRecover)
        Parameters:
        guardable - the Guardable object to be managed
        cMillis - the timeout for the specified Guardable
        flPctRecover - the percentage of the timeout after which to attempt recovery of the Guardable; 0 < flPctRecover <= 1.0
        Returns:
        a Context for the specified guardable and SLA parameters
      • getThreadContext

        public static Guardian.GuardContext getThreadContext()
        Obtain the GuardContext associated with the current thread.
        Returns:
        the GuardContext or null if it has not been set
      • setThreadContext

        public static void setThreadContext​(Guardian.GuardContext context)
        Associate the specified GuardContext with the current thread.
        Parameters:
        context - the GuardContext to associate with the current thread
      • heartbeat

        public static void heartbeat()
        Issue a heartbeat on the GuardContext associated with the current thread.
      • heartbeat

        public static void heartbeat​(long cMillis)
        Issue a heartbeat of the specified duration on the GuardContext associated with the current thread.
        Parameters:
        cMillis - the number of milliseconds to heartbeat for
      • reset

        public static void reset()
        Issue a reset on the GuardContext associated with the current thread.
      • logStackTraces

        public static void logStackTraces()
        Collect stack traces and synchronization information for all running threads and write them to the error log.
      • getThreadDump

        public static String getThreadDump()
        Get the full thread dump.
        Returns:
        a string containing the thread dump