Just-in-time dynamic instrumentation

Abstract

Just-in-time dynamic instrumentation of a running software system may be achieved by registering one or more instrumentation probe handlers in an inactive state wherein the probe handlers reside in a memory space associated with the software system but are not instrumented into the software system. The probe handlers may each have one or more probe handler tags representing categories to which the probe handlers have been assigned. Tag query requests are periodically received and processed in order to provide information to a caller about registered probe handlers associated with a probe handler tag specified in the tag query request. A probe handler activation request can be made by specifying a probe handler or a probe handler tag. The request can be processed by placing the specified probe handler, or probe handlers associated with the tag, in an active state. The software system thus becomes dynamically instrumented to execute the probe handler(s) as part of the software system's execution flow. The activated probe handler(s) may be returned to the inactive state in response to a probe handler deactivation request specifying a probe handler or a probe handler tag.