The lightweight corefile is a platform-independent format designed to contain snapshot information about the current location of a parallel application. The data elements include the current value of the program counter, the contents of invocation stack frames, and a reason code for program failure. It is flexible enough to support a wide variety of platforms, including clusters of workstations as well as parallel computers.
Although it is called a corefile, the information need not be stored as a file. The browsing tools acquire the corefile data through an abstraction layer, so that the information can be constructed on-the-fly, in addition to being provided via a conventional file.
The file format provides symbolic, high-level information on program state (not the hexadecimal notation that users must struggle with when using typical core files). It is structured as an ASCII file that is readable by humans as well as by analysis programs.
How You Can Participate
The command-line and graphical browsers are available in the form of royalty-free source code. The assistance of both users and computer vendors is needed to complete this project.
If you are a user, we need your help in reviewing the usability of the browser interfaces (e.g., are the terminology and operations self-explanatory?). The browsers have been tested on all major UNIX workstation platforms (see the Web pages for more information on obtaining a copy).
Users are also encouraged to talk with their favorite vendors, encouraging them to have their operating system generate lightweight corefiles when applications crash, or to add an LCB browsing component to their existing debuggers.
If you work for a workstation or parallel computer vendor, we would like to help you implement LCB on your company’s platform(s). See the Web pages for contact information.
Both command-line and graphical versions of the tool have been implemented. The command-line version is in ANSI C. The graphical browser is written in GNU C++ and makes use of TCL and the Tk widgets (all available in the public domain). Both versions have been tested on IBM-AIX, HP/UX, Solaris, and SunOS platforms.
The final draft of the lightweight corefile format has been completed. An Adopter’s Guide is available; it includes several modifications requested as the initial vendors have begun porting LCB to their product line.