Timing

Fast, Safe, Custom Software Engineering – Raven’s Point is focused on engineering software that delivers your solutions before you expect and with the greatest reliability.

This the Raven’s Point mission statement. What does it mean? Partly it means that I specialize in delivering more quickly than the competition individually designed and coded software that is carefully tested and documented.

It also means that the programs I deliver run extremely fast, making the best use of optimizing compilers and high speed multi-core hardware.

I enjoy re-arranging computer code so that it goes faster.

Re-arranging code is dangerous. It is very easy to break something that was previously working. An effective test framework and a good set of regression tests are vital to prevent one step forward causing ten steps backward. No-one needs the wrong results reached ten times faster.

Re-arranging code is also seductive. Even if you do not do any harm, you can spend a lot of time achieving nothing. It usually turns out that a program spends most of its time executing a very few lines of code, but it can be very difficult to guess which lines these are going to be. Before optimizing, it is necessary to measure carefully and find exactly where the bottleneck is that will repay being optimized.

::raven::set::cRunWatch is a code timing profiler which can tell exactly how long a program spends executing every piece of code.

It is just two files, so it is easy to integrate with your projects, and requires adding exactly one line to instrument a piece of code.

To start profiling:

raven::set::cRunWatch::Start();

Notes:
*  This can be done anywhere, but usually early in the main function.
*  This can be called without creating an instance of the profiler.
*  If not called, all cRunWatch methods become no-ops
*  If called with a zero parameter, all cRunWatch methods become no-ops.

To profile a code scope:

raven::set::cRunWatch runwatch("<unique name of scope>");

Notes:
*  This should be done as the first line of the scope.
*  The scope is usually a function, but can be any pair of curly braces {}

To write a report to standard output:

raven::set::cRunWatch::Report();

Notes:
*  This can be done anywhere, but usually at the end of the main function.
*  This can be called without creating an instance of the profiler.

Example of Use

void highly_optimised_subroutine()
{
raven::set::cRunWatch runwatch("highly_optimised_subroutine");
Sleep( 2 );
}

void badly_written_function()
{
raven::set::cRunWatch runwatch("badly_written_function");
for (int k = 1; k < 1000; k++ )
{
highly_optimised_subroutine();
}
}

void well_written_function()
{
raven::set::cRunWatch runwatch("well_written_function");
for (int k = 1; k < 10; k++ )
{
highly_optimised_subroutine();
}
}

int _tmain(int argc, _TCHAR* argv[])
{
raven::set::cRunWatch::Start();

well_written_function();
badly_written_function();

raven::set::cRunWatch::Report();

return 0;
}

Report produced:

raven::set::cRunWatch code timing profile
Scope                          Calls   Mean (secs)           Total
highly_optimised_subroutine     1008      0.002923        2.946213
badly_written_function             1      2.926662        2.926662
well_written_function              1      0.026161        0.026161

You can obtain raven::Set::cRunWatch from here.

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