push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
#require test-repo py3
$ 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
> }
Try to find a python3-config that's next to our sys.executable. If
that doesn't work, fall back to looking for a global python3-config
and hope that works out for the best.
$ PYBIN=`"$PYTHON" -c 'import sys, os; print(os.path.dirname(sys.executable))'`
$ if [ -x "$PYBIN/python3-config" ] ; then
> PYTHON_CONFIG="$PYBIN/python3-config"
> else
> PYTHON_CONFIG="`which python3-config`"
> fi
#if clang-libfuzzer
$ CXX=clang++ havefuzz || exit 80
$ $MAKE -s clean all PYTHON_CONFIG="$PYTHON_CONFIG"
#endif
#if no-clang-libfuzzer clang-6.0
$ CXX=clang++-6.0 havefuzz || exit 80
$ $MAKE -s clean all CC=clang-6.0 CXX=clang++-6.0 PYTHON_CONFIG="$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