This helps lit unit test performance by a lot, especially on windows. The performance gain comes from launching one gtest executable for many subtests instead of one (this is the current situation).
The shards are executed by the test runner and the results are stored in the
json format supported by the GoogleTest. Later in the test reporting stage,
all test results in the json file are retrieved to continue the test results
summary etc.
On my Win10 desktop, before this patch: `check-clang-unit`: 177s, `check-llvm-unit`: 38s; after this patch: `check-clang-unit`: 37s, `check-llvm-unit`: 11s.
On my Linux machine, before this patch: `check-clang-unit`: 46s, `check-llvm-unit`: 8s; after this patch: `check-clang-unit`: 7s, `check-llvm-unit`: 4s.
Reviewed By: yln, rnk, abrachet
Differential Revision: https://reviews.llvm.org/D122251
This should work with ShTest (executed externally or internally) and GTest
test formats.
To set the timeout a new option ``--timeout=`` has
been added which specifies the maximum run time of an individual test
in seconds. By default this 0 which causes no timeout to be enforced.
The timeout can also be set from a lit configuration file by modifying
the ``lit_config.maxIndividualTestTime`` property.
To implement a timeout we now require the psutil Python module if a
timeout is requested. This dependency is confined to the newly added
``lit.util.killProcessAndChildren()``. A note has been added into the
TODO document describing how we can remove the dependency on the
``pustil`` module in the future. It would be nice to remove this
immediately but that is a lot more work and Daniel Dunbar believes it is
better that we get a working implementation first and then improve it.
To avoid breaking the existing behaviour the psutil module will not be
imported if no timeout is requested.
The included testcases are derived from test cases provided by
Jonathan Roelofs which were in an previous attempt to add a per test
timeout to lit (http://reviews.llvm.org/D6584). Thanks Jonathan!
Reviewers: ddunbar, jroelofs, cmatthews, MatzeB
Subscribers: cmatthews, llvm-commits
Differential Revision: http://reviews.llvm.org/D14706
llvm-svn: 256471
Yuanfang Chen