System Introspection for System Analysis on Mobile Devices

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that has been received from a client. All properties to be send to connectedclients are stored in the propertiesToSend list. For creating new messagesthe base class offers several functionality. New value pairs can be added to thepropertiesToSend list by using the addProperty() method. By calling thesendMessage() message the base class iterates over the propertiesToSendlist and adds each value pair to a message. When the message is successfullycreated the base class sends the message to each client which is part of theconnectedClients list. After sending the message the propertiesToSendlist gets cleared.Figure 6.4: Base class and interface <strong>for</strong> a component thread -The ComponentThread class is abstract and implementsthe ComponentThreadInterface. The baseclass handles all needed communication via a referenceto the Communicator. LaserDataThread is a concreteclass extending the ComponentThread class. Themethods prepare(), processNewProperties() andprocessing() are used by the concrete implementation.A concrete implementation has to extend the ComponentThread base classand must implement the methods defined by the interface. An example of animplementation is shown on Figure 6.4. The prepare() method is called oncethe component thread is initialized. It can be used to initialize parameters onthe concrete class (e.g. configuring the laser range finder). The processing()method is called on every cycle of the component thread. To collect data thismethod can access the ComponentHolder and read data of components of therobot. Collected data can be added as new value to the propertiesToSendmap by calling addProperty(). At the end of the processing() methodthe base class automatically calls the sendMessage(). At the end of theprocessing method a delay is placed which allows to define a frequency <strong>for</strong> theprocess of collecting data. This delay can be changed in the XML configurationfile. The method processNewProperties() is called whenever a new message39
is received containing the TAG of the component thread. Passed to this methodis the receivedProperties map containing all extracted value pairs of themessage. The list can be used <strong>for</strong> further processing of client commands insidethe component thread (e.g. setting a navigation goal <strong>for</strong> the robot).Each component thread holds an attribute showing its current state (see chapter5.2). When a component thread is created it is first put into the SLEEPstate due to no connected clients. Inactive component threads are not activelyreading data and can only be activated by the ComponentDispatcher.When a new client connects and the component thread is activated by theComponentDispatcher the state is changed to RUNNING. While active collecteddata is <strong>for</strong>warded to clients in the connectedClients list. Wheneverthe component thread receives an error from the component holder or an erroroccurs inside the defined methods, the state of the component thread changesto ERROR and the component thread gets deactivated. Component threads inerror state are not collecting data and cannot be activated. In the currentimplementation component threads in ERROR state can only be activated byrestarting the probe.LogDispatcherThe LogDispatcher class controls the creation of logging cycles. It uses theConstants class with enumerations <strong>for</strong> commands to handle clients requests.The LogDispatcher holds a reference to the globalClients list and theloggingList containing clients currently running logging cycles. To sendmessages a reference to the Communicator is stored and <strong>for</strong> receiving messagesthe LogDispatcher observes the Communicator. The list of availablelogging components is parsed from the ServerConfig. On request by a clientthe LogDispatcher offers a list of available logging components. When aclient requests a new logging cycle, the LogDispatcher parses the incomingmessage and extracts all requested components to be logged. Once parsed theLogDispatcher creates a new LogThread, passes all requested logging componentsto this thread and executes it. When the client requests to stop thelogging cycle the LogDispatcher checks the loggingList <strong>for</strong> a correspondingLogThread and interrupts it. In case of a notify from the list of all clients concerninga clients disconnect the loggingList gets parsed and logging cycles<strong>for</strong> the client get interrupted.40
Page 1: Bringing System <s
Page 5 and 6: AbstractSystem <st
Page 7 and 8: output, so each component is offeri
Page 9 and 10: of the system and the decisions mad
Page 11 and 12: created a telelaboratory where two
Page 13 and 14: Like the telelaboratory there is a
Page 15 and 16: with a very high frequency which ma
Page 17 and 18: Due to improving technology the use
Page 19 and 20: Figure 4.1: ToBI platfor</s
Page 21 and 22: Figure 4.3: The architecture behind
Page 23 and 24: Figure 4.5: Typical instant messagi
Page 25 and 26: 5 System DesignThe
Page 27 and 28: Figure 5.2: Message exchange betwee
Page 29 and 30: Figure 5.4: Beacon running between
Page 31 and 32: Figure 5.5: Reading and processing
Page 33 and 34: data and only forw
Page 35 and 36: For example a developer can select
Page 37 and 38: Figure 5.13: Principle of tabbed na
Page 39 and 40: 6.1 The Communication InterfaceThe
Page 41 and 42: 6.2 The Probe - Implementation of t
Page 43: stop all active processes of the co
Page 47 and 48: The selected sensors give a good im
Page 49 and 50: 1 2 4 6 8 Listing 6.2: Example of t
Page 51 and 52: TabConfig - The Status ViewThe TabC
Page 53 and 54: Each view adds a listener to the co
Page 55 and 56: LoginController which also observes
Page 57 and 58: tends the JPanel class. The templat
Page 59 and 60: 7 EvaluationIn the previous chapter
Page 61 and 62: Name Description CharactersSingleli
Page 63 and 64: Figure 7.1: Latency of receiving da
Page 65 and 66: For this thesis only a rough estima
Page 67 and 68: Laptop CPU load without Probe CPU l
Page 69 and 70: 8 ConclusionsIn the context of this
Page 71 and 72: 9 OutlookGiven this new tool its no
Page 74: BibliographyBurrell, A. and A. Soda
Page 77 and 78: 6.10 Main classes of the Java clien
Page 79 and 80: AppendixUse CasesUse Case 1: Connec
Page 81 and 82: Use Case 4: Disconnect from compone
Page 83 and 84: Use Case 9: Sending beacon to keep
Page 85 and 86: Figure 9.4: Latency of receiving da

System Introspection for System Analysis on Mobile Devices

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