Package org.lsst.ccs.services

Class AgentStateService

java.lang.Object
org.lsst.ccs.services.AgentStateService
All Implemented Interfaces:
BusMessagePreProcessor, ClusterMembershipListener, ServiceLifecycle, AgentService
public final class AgentStateService extends Object implements AgentService, ServiceLifecycle, BusMessagePreProcessor, ClusterMembershipListener
An AgentService to manage the internal state of an Agent.
Author:
The LSST CCS Team

  • Constructor Details

    • AgentStateService

      public AgentStateService()

  • Method Details

    • getAgentServiceName

      public String getAgentServiceName()
      Description copied from interface: AgentService
      Get the name of this service. This name will be used to add the given service to the lookup tree.
      Specified by:
      getAgentServiceName in interface AgentService
      Returns:
      the AgentService name.

    • startForAgent

      public boolean startForAgent(AgentInfo agentInfo)
      Description copied from interface: AgentService
      This method is invoked after an agent service is created to see if this service is to be started for the tiven Agent.
      Specified by:
      startForAgent in interface AgentService
      Returns:
      true if the service is to be added to the given agent.

    • preStart

      public void preStart()
      Description copied from interface: ServiceLifecycle
      Called from the enclosing Subsystem when org.lsst.ccs.Subsystem#start() has been called.

      The preceding lifecycle step is HasLifecycle.postInit()

      The following lifecycle step is HasLifecycle.start() At the time it is called :

      • the PhaseState is INITIALIZING
      • connection with the messaging layer is effective, the enclosing subsystem has started StatusHeartBeat publication
      Specified by:
      preStart in interface ServiceLifecycle

    • afterInit

      public void afterInit()
      Specified by:
      afterInit in interface ServiceLifecycle

    • preShutdown

      public void preShutdown()
      Specified by:
      preShutdown in interface ServiceLifecycle

    • preBuild

      public void preBuild()
      Specified by:
      preBuild in interface ServiceLifecycle

    • preInit

      public void preInit()
      Specified by:
      preInit in interface ServiceLifecycle

    • registerState

      public final <T extends Enum<T>> void registerState(Class<T> state, String description, Object obj)
      Register a State with the AgentStateService. Only registered states can be set on the Agent state. This registration step is only required for WORKERS.
      Type Parameters:
      T -
      Parameters:
      state - The State Enumeration Class to be registered
      description - The state description
      obj - The object on which the state will be set.

    • getStateLock

      public Object getStateLock()
      Returns the object whose monitor lock guards write-access to the agent state. The state is guaranteed to remain unchanged while this lock is held.
      Returns:
      the inner state lock to perform synchronized operations on states.

    • isInState

      public boolean isInState(Enum state)
      Check if this Agent is in the given state.
      Parameters:
      state - The state to check.
      Returns:
      true if this Agent is in the specified state.

    • isComponentInState

      public boolean isComponentInState(String component, Enum state)
      Check if a component of this Agent is in the given state.
      Parameters:
      component - The name of the component
      state - The state to check.
      Returns:
      true if this Agent's component is in the specified state.

    • isInState

      public boolean isInState(StateBundle state)
      Checks if this Agent is in all of the states contained in the given StateBundle.
      Parameters:
      state - A StateBundle.
      Returns:
      true if the Agent is in the provided StateBundle.

    • getState

      public Enum getState(Class stateClass)
      Returns the state of this Agent for the provided class.
      Parameters:
      stateClass - The class of the Enum for which we would like the Agent's state.
      Returns:
      state for the specified class.

    • getComponentState

      public Enum getComponentState(String component, Class stateClass)
      Returns the state of this Agent's component for the provided class.
      Parameters:
      component - The Agent's component name
      stateClass - The class of the Enum for which we would like the Agent's state.
      Returns:
      The component's state for the specified class.

    • updateAgentState

      public void updateAgentState(Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle When this method is invoked the CCSTimeStamp.currentTime() is assigned to the state transition.
      Parameters:
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(String cause, Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle When this method is invoked the CCSTimeStamp.currentTime() is assigned to the state transition.
      Parameters:
      cause - The reason the state transition happened.
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(org.lsst.ccs.utilities.taitime.CCSTimeStamp stateTransitionTimestamp, Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. The provided CCSTimeStamp is associated to the state transition. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle
      Parameters:
      stateTransitionTimestamp - The CCSTimeStamp corresponding to this state transition
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(String cause, org.lsst.ccs.utilities.taitime.CCSTimeStamp stateTransitionTimestamp, Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. The provided CCSTimeStamp is associated to the state transition. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle
      Parameters:
      cause - The reason the state transition happened.
      stateTransitionTimestamp - The CCSTimeStamp corresponding to this state transition
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(StateBundle stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle When this method is invoked the CCSTimeStamp.currentTime() is assigned to the state transition.
      Parameters:
      stateChanges - The StateBundle with all the changes.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(org.lsst.ccs.utilities.taitime.CCSTimeStamp stateTransitionTimestamp, StateBundle stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. The provided CCSTimeStamp is associated to the state transition. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle
      Parameters:
      stateTransitionTimestamp - The CCSTimeStamp corresponding to this state transition
      stateChanges - The StateBundle with all the changes.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentState

      public void updateAgentState(String cause, org.lsst.ccs.utilities.taitime.CCSTimeStamp stateTransitionTimestamp, StateBundle stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. The provided CCSTimeStamp is associated to the state transition. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle
      Parameters:
      cause - The reason the state transition happened.
      stateTransitionTimestamp - The CCSTimeStamp corresponding to this state transition
      stateChanges - The StateBundle with all the changes.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentComponentState

      public void updateAgentComponentState(Object component, Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. When this method is invoked the CCSTimeStamp.currentTime() is assigned to the state transition. This method can be invoked at any stage of HasLifecycle
      Parameters:
      component - The name of the component to be updated
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateAgentComponentState

      public void updateAgentComponentState(org.lsst.ccs.utilities.taitime.CCSTimeStamp stateTransitionTimestamp, Object component, Enum... stateChanges)
      Updates the state of this Agent and publishes StateChangeNotification message only if the Agent is connected to the buses. The provided CCSTimeStamp is associated to the state transition. Note that this method should be used to modify subsystem-defined states only. Internal Agent states (AlertState, CommandState, OperationalState, PhaseState) are managed by the Agent. This method will produce a StatusStateChangeNotification to be published on the buses only if there are state changes. This method can be invoked at any stage of HasLifecycle
      Parameters:
      stateTransitionTimestamp - The CCSTimeStamp corresponding to this state transition
      component - The name of the component to be updated
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the list of arguments contains internal Agent states.

    • updateInternalState

      public final void updateInternalState(AgentState... stateChanges)
      Updates the internal state of this Agent and publishes StateChangeNotification message.
      Parameters:
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the update would bring this Agent into a prohibited state

    • updateInternalState

      public final void updateInternalState(String cause, AgentState... stateChanges)
      Updates the internal state of this Agent and publishes StateChangeNotification message.
      Parameters:
      cause - The reason the state transition happened.
      stateChanges - The list of the states that have changed.
      Throws:
      IllegalArgumentException - if the update would bring this Agent into a prohibited state

    • waitFor

      @Deprecated public final boolean waitFor(Predicate<StateBundle> target, long timeout, TimeUnit unit) throws InterruptedException
      Deprecated.
      Block until this Agent is in state that satisfies the specified predicate. The condition is not guaranteed to remain true when the thread resumes. The predicate provided to this method should not depend on anything other than its argument, and should not have side effects.
      Parameters:
      target - Condition to be satisfied for this method to return.
      timeout - Timeout value.
      unit - Timeout unit.
      Returns:
      True if the condition was satisfied; false if the method timed out.
      Throws:
      InterruptedException - if the thread is interrupted while waiting.

    • waitForStatePredicate

      public final void waitForStatePredicate(Predicate<StateBundle> target, long timeout, TimeUnit unit) throws InterruptedException, TimeoutException
      Throws:
      InterruptedException
      TimeoutException

    • addStateChangeListener

      public void addStateChangeListener(StateChangeListener stateChangeListener, Class... states)

    • removeStateChangeListener

      public void removeStateChangeListener(StateChangeListener stateChangeListener)

    • getState

      public StateBundle getState()
      Returns a clone of the current Agent state. The returned object is a snapshot of the current state. It is not modified by subsequent changes to the agent state.
      Returns:
      A clone of the current Agent state.

    • preProcessMessage

      public BusMessage preProcessMessage(BusMessage msg)
      Description copied from interface: BusMessagePreProcessor
      Pre-process the incoming BusMessage and return the message to be forwarded to the bus message listeners. The returned message can either be a modified version of the original message or a brand new message. The Class of the returned message can be different than the incoming message. If null is returned the message will not be sent to the BusMessage listeners, but it will still be passed to other BusMessagePreProcessors This method can be invoked by separate threads, but it's invoked by one thread at a time; there is no concurrent invocation of the method.
      Specified by:
      preProcessMessage in interface BusMessagePreProcessor
      Parameters:
      msg - The incoming BusMessage
      Returns:
      The modified BusMessage to be forwarded to the BusMessageListeners

    • getStateBundleForAgent

      public StateBundle getStateBundleForAgent(String agentName)

    • getBus

      public Bus getBus()
      Description copied from interface: BusMessagePreProcessor
      The Bus this BusMessagePreProcessor applies to.
      Specified by:
      getBus in interface BusMessagePreProcessor
      Returns:
      The Bus.

    • membersJoined

      public void membersJoined(List<String> joined, boolean isMerge)
      Specified by:
      membersJoined in interface ClusterMembershipListener

    • membersLeft

      public void membersLeft(List<String> left)
      Specified by:
      membersLeft in interface ClusterMembershipListener