\contentsline {chapter}{List of Figures}{vi}
\contentsline {chapter}{Abstract}{viii}
\contentsline {chapter}{Acknowledgments}{x}
\contentsline {chapter}{\numberline {1}Introduction}{1}
\contentsline {section}{\numberline {1.1}Thesis Structure}{2}
\contentsline {chapter}{\numberline {2}Garbage Collection}{4}
\contentsline {section}{\numberline {2.1}Principle}{4}
\contentsline {subsection}{\numberline {2.1.1}Motivation for Garbage Collection}{4}
\contentsline {subsection}{\numberline {2.1.2}Definitions}{5}
\contentsline {subsection}{\numberline {2.1.3}The Two Phase Abstraction}{6}
\contentsline {subsection}{\numberline {2.1.4}Collector Completeness}{6}
\contentsline {section}{\numberline {2.2}Garbage Collection Techniques}{7}
\contentsline {subsection}{\numberline {2.2.1}Reference Counting}{7}
\contentsline {subsubsection}{The Problem with Reference Counting}{9}
\contentsline {subsection}{\numberline {2.2.2}Tracing Algorithms}{10}
\contentsline {subsubsection}{The Problem with Tracing}{11}
\contentsline {subsection}{\numberline {2.2.3}Copy Collection}{12}
\contentsline {subsection}{\numberline {2.2.4}Smalltalk Garbage Collection}{13}
\contentsline {subsubsection}{Scavenger}{14}
\contentsline {subsubsection}{Incremental Garbage Collector}{14}
\contentsline {subsubsection}{Compacting Garbage Collector}{15}
\contentsline {subsubsection}{Global Garbage Collector}{15}
\contentsline {subsection}{\numberline {2.2.5}Java Garbage Collection}{15}
\contentsline {subsubsection}{The {\tt finalize} Method}{15}
\contentsline {subsubsection}{Running the Collection Mechanism}{16}
\contentsline {subsubsection}{Conclusion}{16}
\contentsline {chapter}{\numberline {3}Distributed Systems}{17}
\contentsline {section}{\numberline {3.1}Remote Procedure Calls}{17}
\contentsline {section}{\numberline {3.2}The OMG's Distributed Computing Solution}{19}
\contentsline {subsection}{\numberline {3.2.1}Object Management Architecture}{19}
\contentsline {subsubsection}{Object Model}{19}
\contentsline {subsubsection}{Reference Model}{19}
\contentsline {subsection}{\numberline {3.2.2}OMG Interface Definition Language}{21}
\contentsline {subsubsection}{Modules}{21}
\contentsline {subsubsection}{Interfaces}{21}
\contentsline {subsubsection}{Constructed Types}{22}
\contentsline {subsubsection}{Template Types}{23}
\contentsline {subsubsection}{Array Type}{24}
\contentsline {subsection}{\numberline {3.2.3}Limitations of OMG IDL}{24}
\contentsline {subsubsection}{Method overloading}{25}
\contentsline {subsubsection}{Behavioural Specification}{25}
\contentsline {subsubsection}{Exceptions}{27}
\contentsline {subsubsection}{Quality of Service}{28}
\contentsline {subsubsection}{Object Definition}{30}
\contentsline {subsubsection}{Static Non-Blocking Requests}{31}
\contentsline {subsection}{\numberline {3.2.4}Evaluation of OMG IDL}{32}
\contentsline {subsection}{\numberline {3.2.5}Common Object Request Broker Architecture}{33}
\contentsline {subsubsection}{Object Request Broker}{33}
\contentsline {subsubsection}{Language Mappings}{34}
\contentsline {subsubsection}{Interface Repository}{34}
\contentsline {subsubsection}{Stubs And Skeletons}{34}
\contentsline {subsubsection}{Dynamic Invocation Interface}{35}
\contentsline {subsubsection}{Object Adapter}{35}
\contentsline {section}{\numberline {3.3}Microsoft's Distributed Component Object Model}{35}
\contentsline {subsection}{\numberline {3.3.1}Component Object Model}{36}
\contentsline {subsection}{\numberline {3.3.2}Globally Unique Indentifiers}{36}
\contentsline {subsection}{\numberline {3.3.3}Microsoft's Interface Definition Language}{36}
\contentsline {section}{\numberline {3.4}Java's Remote Method Invocation}{37}
\contentsline {chapter}{\numberline {4}Distributed Garbage Collection}{39}
\contentsline {section}{\numberline {4.1}Reference Counting}{39}
\contentsline {section}{\numberline {4.2}Reference Listing}{41}
\contentsline {section}{\numberline {4.3}Distributed Tracing}{42}
\contentsline {section}{\numberline {4.4}DCOM Garbage Collection}{42}
\contentsline {section}{\numberline {4.5}The Soul Object Support System}{43}
\contentsline {section}{\numberline {4.6}Java's Remote Method Invocation}{44}
\contentsline {section}{\numberline {4.7}Garbage Collection in CORBA}{44}
\contentsline {chapter}{\numberline {5}Collecting Garbage in a CORBA Environment}{46}
\contentsline {section}{\numberline {5.1}The Research Problem}{46}
\contentsline {section}{\numberline {5.2}Objectives}{48}
\contentsline {section}{\numberline {5.3}Technical Design}{48}
\contentsline {subsection}{\numberline {5.3.1}Overview}{48}
\contentsline {subsection}{\numberline {5.3.2}A CORBA Garbage Collector}{48}
\contentsline {subsection}{\numberline {5.3.3}Designing the Interfaces}{50}
\contentsline {subsection}{\numberline {5.3.4}IDL Support For Garbage Collection}{52}
\contentsline {section}{\numberline {5.4}Implementing a Collector}{54}
\contentsline {subsection}{\numberline {5.4.1}Transparency To The Programmer}{54}
\contentsline {subsection}{\numberline {5.4.2}A Collection Scenario}{55}
\contentsline {subsubsection}{The Server}{56}
\contentsline {subsubsection}{The Client}{56}
\contentsline {subsubsection}{The Garbage Collector}{56}
\contentsline {subsection}{\numberline {5.4.3}Testing The System}{57}
\contentsline {chapter}{\numberline {6}Conclusion}{59}
\contentsline {section}{\numberline {6.1}Future Work}{60}
\contentsline {chapter}{Appendix\ A\ Sample Program Code}{61}
\contentsline {section}{\numberline {A.1}Collector.idl}{61}
\contentsline {section}{\numberline {A.2}GarbageCollectorImp.java}{63}
\contentsline {section}{\numberline {A.3}AccountImp.java}{66}
\contentsline {section}{\numberline {A.4}\_tie\_Account.java}{69}
\contentsline {section}{\numberline {A.5}BankImp.java}{73}
\contentsline {section}{\numberline {A.6}BankServer.java}{74}
\contentsline {section}{\numberline {A.7}Client.java}{76}