OSGi平台是建構在JVM(Java Virtual Machine) 上的開放式服務平台，所以OSGi上所安裝的服務及應用程式都是以Java撰寫而成，每個服務或應用程式都稱為一個服務包(bundle)。在OSGi平台上可以同時執行多個服務包以提供不同服務，也就因此會產生每個服務包對於OSGi平台上面的共用物件的存取及獨立性問題。
本論文針對 OSGi 平台上共用資源的獨立性問題做探討，包含共用資源與空指標等問題，並對此問題提出改善方法。我們在各服務包要存取共用物件時先紀錄下來並製作備份，之後若又有其他服務包要存取同一個物件時，便給予相對應的備份，如此可以解決共用物件被有錯誤或是惡意的服務包所竄改的問題。我們以JamVM 以及Knopflerfish 做為實驗環境，實作了此機制，效能量測顯示此機制平均每執行一次putfield 指令需額外耗費0.375 毫秒。

OSGi is an open platform based on JVM (Java Virtual Machine). The applications/services installed on OSGi platforms are written in Java. Every OSGi application/service is called a bundle. An OSGi platform can execute many bundles concurrently in order to provide different services. Every bundle installed on an OSGi platform may have the isolation issue, which includes the shared object(s) issue and the null pointer issue.
In this thesis, we propose a mechanism to prevent shared resources from being modified by some buggy or malicious bundle(s). We propose that when a bundle wants to access variables of shared resources, the bundle’s name, accessed variable’s name and value are recorded and when any other bundles want to access this variable hereafter, each bundle is returned a copy of the value of the shared variable. We implemented the proposed mechanism on Knopflerfish and JamVM. Performance measure shows that it has the overhead, in average, of 0.375 ms per putfield bytecode instruction.

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