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{ Tag Archives } chronicle

Using VMWare Record/Replay and VProbes for low time-distortion performance profiling

The greatest problem with performance profiling is getting as much information as possible while affecting the results as little as possible.  For my work on pecobro I used mozilla’s JavaScript DTrace probes.  Because the probes are limited to notifications of all function invocations/returns with no discretion and there is no support for JS backtraces, the […]

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2009 08 03 Andrew Sutherland Debugging
Program Execution
Thunderbird
Visualizing Comments (2)

displaying execution traces on a SIMILE timeline

chroniquery can now output JSON for display using the SIMILE timeline widget.  And I am finally done trying to figure out what was going wrong.  Click the pictures to experience the timeline sensation for yourself. Related interesting things: Supports a fancy if specific constraint mechanism.  For example, PrepareAndDispatch is only displayed in the context of […]

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2009 04 29 Andrew Sutherland clicky
Debugging
Program Execution
Visualizing Comments Off on displaying execution traces on a SIMILE timeline

understanding where unit tests go wrong with object diffs

In our last chroniquery adventure, we used roc‘s chronicle-recorder to trace the execution of an xpcshell unit test and chroniquery (repo info) to use that trace to help us understand what was happening in some particularly confusing C-ish code.  Actually, we’re doing that this time too, but the bag of tricks now contains additional tricks. […]

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2009 04 28 Andrew Sutherland Debugging
Program Execution Comments (1)

understanding libmime using chroniquery and unit tests

Mailnews’ libmime is one of the harder modules to wrap one’s head around.  8-letter filenames where the first four letters tend to be “mime”, home-grown glib-style OO rather than actual C++, and intermingling of display logic with parsing logic do not make for a fun development or even comprehension experience. Running an xpcshell unit test […]

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2009 03 15 Andrew Sutherland Debugging
Mozilla
Program Execution
Thunderbird Comments (1)

chronicle-recorder and amd64, hooray!

My personal laptop rolls amd64-style (rather than i686), and chronicle-recorder’s valgrind component was not working on it (“illegal instruction”). I have done some vendor-branch dancing to get chronicle-recorder’s valgrind sub-directory to use valgrind 3.3.0. A bzr branch of just the valgrind subdirectory (drop-in or build separately and make sure you invoke valgrind from that location) […]

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2008 01 27 Andrew Sutherland Debugging
Program Execution
Visualizing Comments (1)

Chronicle-Recorder Graph/Ring Visualization! Hooray!

Thanks to new and improved time management skills (and a holiday weekend doesn’t hurt), I’ve got a chronicle-recorder visualization going on via chroniquery: Above, we have the visualization run against the ‘fancy’ program seen in the previous chroniquery posts (with one caveat, addressed later). What does it mean? The circular nodes are functions in the […]

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2007 09 03 Andrew Sutherland Debugging
Program Execution
Visualizing Comments (4)

Hooray for dwarf location lists!

I resolved the time-stamp issues from last time. Arguments are now happy because we move to the time-stamp corresponding to when the function’s prologue had completed. The booleans were wrong because they were copied to locals during the prologue, which is where the argument list referenced them. Things like this are much easier to diagnose […]

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2007 09 01 Andrew Sutherland Debugging Comments (1)

Chroniquery slightly more chronoriffic

So, I was playing with the fantastic Chronomancer (roc‘s announcement, project link), an Eclipse GUI for chronicle-recorder, using a trace from my PyXPCOM troubles. I discovered a lack of some symbols that seemed like they should be there and decided to then run chronicle against chronicle-query and view the problem in Chronomancer so that I […]

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2007 08 23 Andrew Sutherland Debugging Comments Off on Chroniquery slightly more chronoriffic