Oracle International Corporation

Bea Systems, Inc.

Joakim Dahlstedt

Peter Lonnebring

Mikael Vidstedt

Henrik Osterdahl

A system and method for providing hardware virtualization and resource management in a virtual machine environment. An application server environment is extended to provide an interface from the higher layers in the application server environment to the system's actual processing power, such that the allocation of processing can be made in a machine-independent way. A layer of software can be placed between the virtual machine and the hardware that improves the efficiency of the virtualized Java execution system. The system comprises two main components: a first, lower-level, execution environment that replaces the usual operating system; and a second, higher-level, resource broker that is responsible for handing out new virtual machines to the above layers, and for monitoring the current resource usage of the running virtual machines.

System and method for providing hardware virtualization in a virtual machine environment

A system and method to improve memory usage in virtual machines running as hypervisor guests. In accordance with an embodiment, the invention provides a system for changing the memory usage of a virtual machine on request from a hypervisor, comprising: a hypervisor; a guest operating system executing inside the hypervisor; a communication channel between the hypervisor and the guest operating system; a balloon driver in the guest operating system; a virtual machine for executing a software application; a communication channel between the balloon driver and the virtual machine; a memory space or heap for use by the virtual machine in storing software objects and pointers as part of the software application; and a compacting garbage collector for use by the virtual machine.

System and method to improve memory usage in virtual machines running as hypervisor guests

A system and method for providing hardware virtualization and resource management in a virtual machine environment. In accordance with an embodiment, an application server environment includes a computer system, application server, and virtual machine (for example, a Java Virtual Machine or JVM). In accordance with an embodiment, a virtualization layer is provided at each physical machine, including a hypervisor for partitioning virtual machines over the machine. An execution layer runs a single Java-based application, focusing on running that application as efficiently as possible. In accordance with another embodiment, the system comprises two main components: a lower-level, execution environment that replaces the usual operating system; and a higher-level, resource broker that is responsible for handing out new virtual machines to the above layers, and for monitoring the current resource usage of the running virtual machines.

A system for thread local garbage collection in a virtual machine environment, comprising: a virtual machine for executing a software application; a memory space for use by the virtual machine in storing software objects and pointers as part of the software application, divided into a global heap and several thread local heaps; a heap maintaining logic that keeps the global heap and the thread local heaps in a state suitable for efficient garbage collecting; and a garbage collector that can collect the thread local heaps in parallel with only the stop-the-world pauses for the global heap.

System and method for optimistic creation of thread local objects in a virtual machine environment

A system and method for detecting memory leaks in a garbage collected environment. In particular, the present invention provides a mechanism by which objects in the memory space of a virtual machine are analyzed as to whether they are warm or cold, i.e., how long they have persisted in memory without being accessed or referenced by another object. Following this analysis, the objects are clustered into groups of warm or cold objects, and any links from warm clusters to cold clusters are determined. This information is then provided to the software developer for use in detecting and analyzing potential memory leaks.

System and method for memory leak detection in a virtual machine environment

A method for improving the effectiveness of a data processing application when using a virtual machine, wherein the program includes a large number of methods, i.e. program sections, that are stored in the memory of the computer used, and wherein the program uses a garbage collecting procedure. The invention is characterized by analysing in a first step all so called thread stacks with respect to the procedures required thereby; causing each of said requisite methods to be regenerated in a second step, wherein occurring references to a method prior to the regeneration are replaced with references to regenerated methods; and by erasing all non-regenerated methods in a third step and placing corresponding memory space at the disposal of the program.

Method for garbage collection of unused methods

A system and a method for interpreting native code to move threads to a safe state in a run-time environment. In a runtime system or virtual machine (VM) environment, threads process requests to the VM. In many instances such as garbage collection, context switching, and single CPU locking, the threads must be stopped in a safe state for the operation to successfully complete. The invention can be used to ensure that a thread is stopped in such a safe state. In accordance with an embodiment of the invention, when a first thread A is stopped by a second thread B, if A is not in a safe state the invention allows thread B to roll thread A forward to a safe state by interpreting the machine instruction currently is at A. A's state is then updated accordingly.

System and method for using native code interpretation to move threads to a safe state in a run-time environment

The present invention provides a system and method for improving the effectiveness of a data processing application when using a virtual machine, where the program includes many methods, i.e. program sections, that are stored in the memory of the computer used, and where garbage collecting is used by said program. Thread stacks are first analyzed with respect to methods required thereby. Each of the methods required is caused to be regenerated where occurrent references to a method are replaced with reference to regenerated methods prior to the regeneration of a method. All non-regenerated methods are then erased, wherein the corresponding memory space is placed at the disposal of said program. Various means of locking and garbage collection can be used.

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Stockholm, Sweden

Joakim Dahlstedt