Oracle America, Inc.

Sun Microsystems, Inc.

Kinsley Wong

Oleg A Pliss

Nedim Fresko

Ioi Kim Lam

Hideya Kawahara

Bernd J W Mathiske

Bernd J Mathiske

One embodiment of the present invention provides a system that reduces the number of heap handles in a program. First, the system builds an intermediate representation of the program. The system then analyzes the intermediate representation to determine whether executing a function may cause a garbage-collection operation. If so, the system further analyzes the program to determine whether a heap handle in the program is defined and/or used in proximity to a call to the function. Next, the system determines whether the heap handle can be replaced by an ordinary pointer, in order to facilitate subsequently converting the heap handle to an ordinary pointer, if possible. Note that converting a heap handle to an ordinary pointer reduces the space requirements for the program and increases the speed and efficiency of the program and garbage collection operations.

Reducing the number of heap handles in a program

Techniques for processing native events associated with tasks that are concurrently supported in a virtual machine are disclosed. The techniques allow the user of a virtual machine to concurrently perform tasks even if these tasks require processing of platform-specific (or native) events (e.g., platform-specific input). A smart event-dispatcher is used to dispatch native events to multiple tasks that are concurrently supported by the virtual machine. The smart event-dispatcher can determine which one of a plurality of concurrent tasks should receive the native event for processing. The determination can be made based on a variety of different criteria. In mobile devices, the foreground task is typically the only task that is displayed for the user of mobile devices at any given time. Thus, dispatching events to the foreground task is especially useful for a virtual machine that support a mobile device.

Processing events for concurrent tasks in a virtual machine

One embodiment of the present invention provides a system that facilitates keeping track of memory usage of tasks in a shared heap. The system operates by performing a garbage collection operation on the shared heap, wherein the garbage collection operation is a compacting garbage collection operation which preserves the ordering of objects within the shared heap. The system determines a memory usage for each task in the shared heap by adding the memory usage for intervals containing objects for each task in the shared heap to the memory usage count for each task to produce an actual memory usage for each task. This garbage collection may or may not be a generational garbage collection operation.

Method and apparatus for keeping track of memory usage for tasks in a shared heap

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San Francisco, CA, United States of America

Kinsley Wong