Sun Microsystems, Inc.

Oracle America, Inc.

Dean R Long

Nedim Fresko

Jiangli Zhou

Graham Hamilton

Christopher Jordan Plummer

Frank N Yellin

Richard D Tuck

Alan G Bishop

In general, the invention relates to a method. The method includes receiving notification, which includes context information, of a trap. The method further includes accessing, based at least partially upon the context information, a particular instruction that caused the trap, determining, based at least partially upon the context information, a particular address that is to be accessed by the particular instruction, updating a set of log information to indicate accessing of the particular address, causing subsequent accesses of the particular address to not give rise to a trap, after causing subsequent accesses of the particular address to not give rise to a trap, accessing the particular address, after accessing the particular address, causing subsequent accesses of the particular address to give rise to a trap, and causing the particular instruction to not be executed.

Trap-based mechanism for tracking accesses of object class names

Techniques for assuring thread rendezvous for a plurality of threads executing in a computing system are disclosed. Techniques can be used to assure thread rendezvous for read-only code in a manner that is more efficient than polling techniques. A Light-weight, Yet Trappable On Demand (LYTOD) instruction can be generated for code that is executed by one or more threads. Typically, a LYTOD instruction is generated at critical points of the code in order to assure safe-point thread rendezvous. The LYTOD is a lightweight instruction that can change its behavior from a lightweight instruction to an instruction that causes a trap when executed. The LYTOD can, for example, be implemented as a read-from-memory instruction that operates to load a register with a content of a valid memory location.

Thread rendezvous for read-only code in an object-oriented computing environment

A trap-based mechanism is provided for gaining greater visibility into the memory usage of a process. To detect and record the memory accesses of a process, a virtual address range (or a plurality of address ranges) of the process is set to a protected status. This address range represents the range of virtual addresses that are to be monitored for access. By setting the address range to a protected status, whenever a memory access (in one implementation, whenever a memory write) is made to a virtual address within that address range, a trap arises. When the trap arises, a trap handler is invoked. When invoked, the trap handler records the virtual address that was accessed. In this manner, the access of the virtual address is detected and recorded without having to add extensive instrumentation code to the process.

Trap-based mechanism for tracking accesses of logical components

Methods, systems, and software for efficiently creating virtual file systems including object files which contain data are described. In one aspect of the invention, a method for creating a virtual file system includes retrieving a data file from a file system. A snapshot of the data file is created and converted into an object data file. The converted object data file is linked to at least one other object file. The data file can be concatenated with at least one other data file to create the snapshot. A set of assembly instructions for creating an object file from the snapshot is generated. The assembly instructions include instructions to reserve space within the object file for data contained in the data file. The assembly instructions are converted into an object file and the snapshot of the data file is copied into the reserved space.

Method and apparatus for embedding concatenated data files into object

A method of cross-compiling computer programs includes the step of extracting constants from an inheriting computer program written in a first computer language. The extracted constants refer to a generating computer program written in a second computer language. A new program in the second computer language is then created using the constants. The new program is then compiled for a target computer to ascertain compiled constant values. The compiled constant values are then substituted into the inheriting computer program to produce a final inheriting computer program.

Apparatus and method for cross-compiling source code

A method, apparatus, and software for efficiently allocating discontiguous stack space without requiring compiler changes are described. In one aspect, a method is provided for executing a compiled function that is located in a first computer memory stack chunk such that additional memory is allocated efficiently if a determination is made that such additional memory is necessary for execution of the compiled function. In one embodiment, the method includes calling a stack checking function that includes the compiled function. A determination is made if additional memory is required for executing the compiled function. If no additional memory is required, then the compiled function is called and executed. However, if additional memory is necessary, then additional memory is allocated that is discontiguous with the original memory stack.

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Boulder Creek, CA, United States of America

Dean R Long