International Business Machines Corporation

James A Keniston

Gerrit Huizenga

Prasadarao Akulavenkatavara

The present invention provides a probe system and method for multithreaded user-space programs. The system includes an instrumentation module that enables single stepping out of line processing for multithreaded programs, an establish probepoint module that divides up an area of the probed program's memory into a plurality of instruction slots, an ensure slot assigned module that ensures that an instruction slot is assigned to a probepoint, a slot acquisition module that acquires the instruction slot for the probepoint, stealing a slot from another probepoint as needed, and a free slot module that relinquishes the instruction slot owned by the probepoint when the probepoint is being unregistered.

Multiplexing per-probepoint instruction slots for out-of-line execution

A computer system is provided with memory divided by the operating system into kernel space and user space. A probe function is provided in a related user-space application to support dynamic insertion of instrumentation into the application. A breakpoint instruction is provided in an area of the process's user space that will not be overwritten to support execution of an instrumentation subroutine when a probed subroutine in the application returns.

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Tigard, OR, United States of America

James A Keniston