PowerShell seems to have a hard time when a flood of async tasks is
scheduled at the same time.
I speculated that WaitForMultipleObjects() in Windows can only take up
to 64 process handles and if you want to handle more than you should write
some additional code which can be sub-optimal. I.e to implement Wait-Job -Any.
I decided to test that suggestion and introduced a $Concurrency parameter with a default value of 62.
So in the new version the script fires up up to $Concurrency value
and wait for anything to complete before starting any more processes.
This improved matters greatly. Individual tests against ramdrive now
run in 8 minutes and all of the 200+ db_tests run in 9 minutes with concurrency
values of 8-16. About 48 is required to load a CPU on my box running against HD
but that does not improve running times much.
Other changes include respect -EnableJE for the individual test exes.
Enforce exclusions for the individual tests.
Introduce proper command line arguments so we can control the script
Add appveyor support
Add an ability to run all other (non db_tests) test executables in parallel
Use .NET HashSet instead of empty valued hashtable to improve the looks
TODO: Some of the tests do not use GTests and need to improve log parsing
Add an optimized build config switch for faster test runs
Change compiler options to introduce more opitmizations and be more inline with MS internal switches.
Make appveyor build to utilize all the avaiable cores on the VM (parallel)
Introduce new appveyor configuration for daily test runs as it would take too long
to run db_test after each checkin even in paralell.
With some exclusions we make it in 38 minutes. We currently fail to install ramdisk during the build.
Add a powershell script to faicilitate paralell run for db_test cases.
