posixworker: avoid creating workers that end up getting no work
If `workers` (the detected or configured number of CPUs) is greater
than the number of work items, then some of the workers end up getting
0 work items. Let's not create such workers.
Differential Revision: https://phab.mercurial-scm.org/D8927
#require test-repo
$ cd $TESTDIR/../contrib/fuzz
$ OUT=$TESTTMP ; export OUT
which(1) could exit nonzero, but that's fine because we'll still end
up without a valid executable, so we don't need to check $? here.
$ if which gmake >/dev/null 2>&1; then
> MAKE=gmake
> else
> MAKE=make
> fi
$ havefuzz() {
> cat > $TESTTMP/dummy.cc <<EOF
> #include <stdlib.h>
> #include <stdint.h>
> int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { return 0; }
> int main(int argc, char **argv) {
> const char data[] = "asdf";
> return LLVMFuzzerTestOneInput((const uint8_t *)data, 4);
> }
> EOF
> $CXX $TESTTMP/dummy.cc -o $TESTTMP/dummy \
> -fsanitize=fuzzer-no-link,address || return 1
> }
#if clang-libfuzzer
$ CXX=clang++ havefuzz || exit 80
$ $MAKE -s clean all PYTHON_CONFIG=`which python-config`
#endif
#if no-clang-libfuzzer clang-6.0
$ CXX=clang++-6.0 havefuzz || exit 80
$ $MAKE -s clean all CC=clang-6.0 CXX=clang++-6.0 PYTHON_CONFIG=`which python-config`
#endif
#if no-clang-libfuzzer no-clang-6.0
$ exit 80
#endif
$ cd $TESTTMP
Run each fuzzer using dummy.cc as a fake input, to make sure it runs
at all. In the future we should instead unpack the corpus for each
fuzzer and use that instead.
$ for fuzzer in `ls *_fuzzer | sort` ; do
> echo run $fuzzer...
> ./$fuzzer dummy.cc > /dev/null 2>&1
> done
run bdiff_fuzzer...
run dirs_fuzzer...
run dirstate_fuzzer...
run fm1readmarkers_fuzzer...
run fncache_fuzzer...
run jsonescapeu8fast_fuzzer...
run manifest_fuzzer...
run mpatch_fuzzer...
run revlog_fuzzer...
run xdiff_fuzzer...
Clean up.
$ cd $TESTDIR/../contrib/fuzz
$ $MAKE -s clean