["plantuml", "08_processAppSingleInst", "svg"]

------------
@startuml


  autonumber "<font color=red><b>[00]"

  participant "OSGi container" as osgi
  participant "AbstractModule<ODL app>" as module
  participant "ODL ServiceProvider\nextends ClusterSingletonService" as provider
  participant "ODL app Body" as body
  participant "ClusterSingletonServiceProvider" as cssProvider
  participant "ClusterSingletonServiceGroup" as cssGroup
  participant "EntityOwnershipService" as eos

  == Initialization ==

  activate osgi
    osgi -> module : <<init>>
    activate module
      module -> provider : initializeProvider()
      activate provider
        provider -> cssProvider : registerClusterSingletonService()
        activate cssProvider
  alt "New Group"
          cssProvider -> cssGroup : <<init>>
          activate cssProvider
            activate cssGroup
              cssProvider <-- cssGroup
            deactivate cssGroup
          deactivate cssProvider
          cssProvider -> cssGroup : initializationClusterSingletonGroup()
          activate cssProvider
            activate cssGroup
              cssGroup -> eos : registerCandidate
              activate eos
                cssGroup <-- eos
              deactivate eos
              cssProvider <-- cssGroup
            deactivate cssGroup
          deactivate cssProvider
  else "Group is exist"
          cssProvider -> cssGroup : registerService
          activate cssProvider
            activate cssGroup
              cssProvider <-- cssGroup
            deactivate cssGroup
          deactivate cssProvider
  end
        provider <-- cssProvider
        deactivate cssProvider
        module <-- provider
      deactivate provider
      osgi <-- module
    deactivate module
  deactivate osgi

  alt "Get MainCandidate Role Master"
    eos -> eos : <<getRole(MainCandidate)>>
    note over eos
      hasOwner=false call election
      hasOwner=true return Slave for every new registration
    end note
    activate eos
      cssProvider <- eos : ownershipChanged(MainEntity, isOwner=true)
      activate cssProvider
        cssProvider -> cssGroup : ownerchipChanged(MainEntity, isOwner=true)
        activate cssGroup
          cssGroup -> eos : registerCandidate(CloseGuardEntity)
          activate eos
            cssGroup <-- eos
          deactivate eos
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos
    eos -> eos : newElection
    note over eos
      initialization phase does not have close guard
      candidate registration so it starts with election
    end note
    activate eos
      cssProvider <- eos : ownershipChanged(CloseGuardEntity, isOwner=true)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(CloseGuardEntity, isOwner=true)
        activate cssGroup
          cssGroup -> provider : instantiateServiceInstance()
          activate provider
            provider -> body : <<init>>
            activate body
              ...
              provider <-- body
            deactivate body
            cssGroup <-- provider
          deactivate provider
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos

  else "Get MainCandidate Role Slave"
    eos -> eos : getRole
    activate eos
      cssProvider <- eos : ownershipChanged(MainEntity, isOwner=false)
      activate cssProvider
        cssProvider -> cssGroup
        activate cssGroup
          note over cssGroup : "NOOP"
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos
  end

  == Repetition ==

  alt "Get MainCandidate Role Master"
    eos -> eos : <<newElection>>
    activate eos
      cssProvider <- eos : ownershipChanged(MainEntity, isOwner=true)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(MainEntity, isOwner=true)
        activate cssGroup
          cssGroup -> eos : registerCandidate(CloseGuardEntity)
          activate eos
            cssGroup <-- eos
          deactivate eos
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos
    eos -> eos : getRole
    note over eos
      hasOwner=true so EOS returns Slave and we have to
      wait for unregistration old Leader of CloseGuard Candidate
    end note
    activate eos
      cssProvider <-eos : ownershipChanged(CloseGuardEntity, isOwner=false)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(CloseGuardEntity, isOwner=false)
        activate cssGroup
          note over cssGroup : "NOOP"
            cssProvider <-cssGroup
        deactivate cssGroup
      cssProvider --> eos
      deactivate cssProvider
    deactivate eos

  else "Get MainCandidate Role Slave"
    eos -> eos : <<newElection>>
    activate eos
      cssProvider <- eos : ownershipChanged(MainEntity, isOwner=false)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(MainEntity, isOwner=false)
        activate cssGroup
          cssGroup -> provider : closeServiceInstance()
          activate provider
            provider -\ body : <<close>>
            activate body
              ...
              note over body : "close could be async. operation"
              provider \-- body
            deactivate body
            cssGroup <-- provider
          deactivate provider
          cssGroup -> eos : unregisterCandidate(CloseGuardEntity)
          activate eos
            cssGroup <-- eos
          deactivate eos
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos

  else "Get CloseGuardCandidate Role Master"
    eos -> eos : <<newElection>>
    activate eos
      cssProvider <- eos : ownershipChanged(CloseGuardEntity, isOwner=true)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(CloseGuardEntity, isOwner=true)
        activate cssGroup
          cssGroup -> provider : instantiateServiceInstance()
          activate provider
            provider -> body : <<init>>
            activate body
              ...
              provider <-- body
            deactivate body
            cssGroup <-- provider
          deactivate provider
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos

  end

  == Termination ==

  activate osgi
    osgi -> module : <<close>>
    activate module
      module -> provider : close()
      activate provider
        provider -> cssGroup : closeRegistration()
        activate cssGroup
          cssGroup -> eos : unregisterCandidate(MainEntity)
          activate eos
            cssGroup <-- eos
          deactivate eos
          provider <-- cssGroup
        deactivate cssGroup
        module <-- provider
      deactivate provider
      osgi <-- module
    deactivate module
  deactivate osgi

  alt "Get MainCandidate Leader Role Slave"
    activate eos
      cssProvider <- eos : ownersipChanged(MainEntity, wasOwner=true)
      activate cssProvider
        cssProvider -> cssGroup : ownershipChanged(MainEntity, wasOwner=true)
        activate cssGroup
          cssGroup -> provider : closeServiceInstance()
          activate provider
            provider -\ body : <<close>>
          deactivate provider
        deactivate cssGroup
      deactivate cssProvider
    deactivate eos
    activate body
      note over body : "close could be async. operation"
      ...
      provider \-- body
    deactivate body
    activate provider
      provider -> cssGroup : unregisterCandidate(CloseGuardEntity)
      activate cssGroup
        cssGroup -> eos : unregisterCandidate(CloseGuardEntity)
        activate eos
          cssGroup <-- eos
        deactivate eos
        provider <-- cssGroup
      deactivate cssGroup
    deactivate provider

  else "Get MainCandidate NotLeader Role Slave"
    activate eos
      cssProvider <- eos : ownershipChange(MainEntity, wasOwner=false)
      activate cssProvider
        cssProvider -> cssGroup
        activate cssGroup
          note over cssGroup : "NOOP"
          cssProvider <-- cssGroup
        deactivate cssGroup
        cssProvider --> eos
      deactivate cssProvider
    deactivate eos

  end


@enduml
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