Don't produce or expect any output from the infinite looping test -
doing so is a recipe for racey flakyness without a longer timeout to
ensure the output is received first, even though that doesn't seem
integral/important to the test. Instead have a plain, no output infinite
loop and check that that is caught and handled.
If for some reason the output is valuable for test coverage - the
timeout should be increased from 1 second to give the process time to
output the text, flush, and for that text to be received and buffered
before the test is timed out.
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
David Blaikie