Abstract: Guarded file access operations are provided for creating and using guarded file descriptors, which can detect and prevent erroneous file access operations in computer programs. A file descriptor can be associated with a guard identifier to create a guarded file descriptor. The association can be established when the file is opened, and can be maintained independently of the computer program, which ordinarily maintains its own association between files, file descriptors, and guard identifiers. Subsequent file operations using the guarded file descriptor check that the guard identifier previously associated with that file descriptor is presented, and generate errors without performing the requested file operations if the correct guard identifier is not presented. This check serves as a validation of the computer program's use of file descriptors. An error and stack trace can be generated for use in analyzing a cause of the guard violation.

Abstract: Guarded file access operations are provided for creating and using guarded file descriptors, which can detect and prevent erroneous file access operations in computer programs. A file descriptor can be associated with a guard identifier to create a guarded file descriptor. The association can be established when the file is opened, and can be maintained independently of the computer program, which ordinarily maintains its own association between files, file descriptors, and guard identifiers. Subsequent file operations using the guarded file descriptor check that the guard identifier previously associated with that file descriptor is presented, and generate errors without performing the requested file operations if the correct guard identifier is not presented. This check serves as a validation of the computer program's use of file descriptors. An error and stack trace can be generated for use in analyzing a cause of the guard violation.

Abstract: A system and method for tracing device drivers using a computer is described. A memory is interconnected with a processor in the computer and configured into a user memory space and a kernel memory space. An application process executes on the processor within the user memory space. An operating system kernel executes on the processor within the kernel memory space with a traced device driver. A tracing device driver executes on the processor within the kernel memory space and is interposed between the application process and the traced device driver to trace interactions occurring between the traced device driver and the application process and the kernel operating system. A tracing process executes on the processor within the user memory space and interfaces with the tracing device driver. The tracing process controls the tracing device driver in accordance with user-specified parameters and includes a display for result sets generated by the tracing device driver.

Abstract: Apparatus, methods and computer program products are disclosed that create an "agent LWP" in a target process. Creation of the agent LWP allows a controlling process to control execution of computer instructions within the target process without co-opting an existing LWP in the target process. The invention thus provides a mechanism that does not unintentionally change the state of the target process because existing partially-completed system calls do not need to be aborted and reissued.

Abstract: A devtmp device driver provides the functionality of temporary files by representing a virtual device and including the virtual device among several devices within which a file system can store files. Rather than storing data in and retrieving data from a physical device, the devtmp device driver stores data in and retrieves data from anonymous storage through a swap file system which manages anonymous storage for a virtual memory system. A file system uses the devtmp device driver in the same manner the file system uses conventional device drivers which store data in and retrieve data from secondary storage devices. Since the devtmp device driver represents a virtual device whose data are stored in anonymous storage managed by the swap file system, the total amount of storage available for storing data of temporary files is shared among the various components of a computer process to successfully satisfy various needs of various computer processes.