Replace the child process `typeperf.exe` with a daemon thread that reads the performance counters directly. This prevents the issues that arise from inherited handles in grandchild processes (see issue37531 for discussion).
We only use the load tracker when running tests in multiprocess mode. This prevents inadvertent interactions with tests expecting a single threaded environment. Displaying load is really only helpful for buildbots running in multiprocess mode anyway.
* Add log() method: add timestamp and load average prefixes
to main messages.
* WindowsLoadTracker:
* LOAD_FACTOR_1 is now computed using SAMPLING_INTERVAL
* Initialize the load to the arithmetic mean of the first 5 values
of the Processor Queue Length value (so over 5 seconds), rather
than 0.0.
* Handle BrokenPipeError and when typeperf exit.
* format_duration(1.5) now returns '1.5 sec', rather than
'1 sec 500 ms'
* Windows: Fix counter name in WindowsLoadTracker. Counter names are
localized: use the registry to get the counter name. Original
change written by Lorenz Mende.
* Regrtest.main() now ensures that the Windows load tracker is also
killed if an exception is raised
* TestWorkerProcess now ensures that worker processes are no longer
running before exiting: kill also worker processes when an
exception is raised.
* Enhance regrtest messages and warnings: include test name,
duration, add a worker identifier, etc.
* Rename MultiprocessRunner to TestWorkerProcess
* Use print_warning() to display warnings.
Co-Authored-By: Lorenz Mende <Lorenz.mende@gmail.com>
* Add TestResult and MultiprocessResult types to ensure that results
always have the same fields.
* runtest() now handles KeyboardInterrupt
* accumulate_result() and format_test_result() now takes a TestResult
* cleanup_test_droppings() is now called by runtest() and mark the
test as ENV_CHANGED if the test leaks support.TESTFN file.
* runtest() now includes code "around" the test in the test timing
* Add print_warning() in test.libregrtest.utils to standardize how
libregrtest logs warnings to ease parsing the test output.
* support.unload() is now called with abstest rather than test_name
* Rename 'test' variable/parameter to 'test_name'
* dash_R(): remove unused the_module parameter
* Remove unused imports
While Windows exposes the system processor queue length, the raw value
used for load calculations on Unix systems, it does not provide an API
to access the averaged value. Hence to calculate the load we must track
and average it ourselves. We can't use multiprocessing or a thread to
read it in the background while the tests run since using those would
conflict with test_multiprocessing and test_xxsubprocess.
Thus, we use Window's asynchronous IO API to run the tracker in the
background with it sampling at the correct rate. When we wish to access
the load we check to see if there's new data on the stream, if there is,
we update our load values.