Tests about mimalloc HOT 3 CLOSED

I added a new test target on the latest dev branch so do more API surface checks. The strategy is outlined in the new test/readme.md:

Testing allocators is difficult as bugs may only surface after particular
allocation patterns. The main approach to testing mimalloc is therefore
to have extensive internal invariant checking (see page_is_valid in page.c
for example), which is enabled in debug mode with -DMI_CHECK_FULL=ON.
The main testing strategy is then to run mimalloc-bench using full
invariant checking to catch any potential problems over a wide range of intensive
allocation benchmarks and programs.

However, this does not test well for the entire API surface and this is tested
with test-api.c when using make test (from out/debug etc). (This is
not complete yet, please add to it.)

The main.c and main-override.c are there to test if building and overriding
from a local install works and therefore these build a separate test/CMakeLists.txt.

from mimalloc.

Yes, it would be nice to have a structured test framework for the full API. However, testing allocators is very hard as only specific allocation patterns may lead to bugs. The way we chose to tackle this in mimalloc is to have extensive invariant checking in the code, for example:
https://github.com/microsoft/mimalloc/blob/master/src/page.c#L72
where all invariants on a page are checked. When building in debug mode, with the cmake option
-DCHECK_FULL=ON all these invariant checks are done on every free and allocation. We then run the
mimalloc-bench test (and SpecMark and other programs) on this to extensively check if the heap state is always valid.
I would like to add regular unit tests though for the functional testing of the whole API surface.

from mimalloc.

@daanx Regarding tests, is it normal I get (this is mimalloc-test, x64, sdk 18362):

heap stats:     peak      total      freed       unit      count
   elapsed:     0.000 s
   process: user: 0.000 s, system: 0.016 s, faults: 644, reclaims: 0, rss: 2.2 mb

from mimalloc.