Trace Analysis Patterns (Part 19)

Typical software narrative history consists of requests and responses, for example, function or object method calls and returns:

#     Module PID  TID  Time         File    Function Message
26060 dllA   1604 7108 10:06:21.746 fileA.c foo      Calling bar
26232 dllA   1604 7108 10:06:22.262 fileA.c foo      bar returns 0x5

The code that generates execution history is response-complete if it traces both requests and responses. For such code (except in cases where tracing is stopped before a response) the absence of expected responses could be a sign of blocked threads or quiet exception processing. The code that generates execution history is exception-complete if it also traces exception processing. Response-complete and exception-complete code is called call-complete. If we don’t see response messages for call-complete code we have Incomplete History.

In general, we can talk about the absence of certain messages in a trace as a deviation from the standard trace sequence template corresponding to a use case. The difference there is in a missing request too. This is a topic for next patterns.

- Dmitry Vostokov @ + -

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