@@ -186,6 +186,22 @@ appropriately before running "make".
this feature by setting the GIT_TEST_CHAIN_LINT environment
variable to "1" or "0", respectively.
+--stress::
+--stress=<N>::
+ Run the test script repeatedly in multiple parallel jobs until
+ one of them fails. Useful for reproducing rare failures in
+ flaky tests. The number of parallel jobs is, in order of
+ precedence: <N>, or the value of the GIT_TEST_STRESS_LOAD
+ environment variable, or twice the number of available
+ processors (as shown by the 'getconf' utility), or 8.
+ Implies `--verbose -x --immediate` to get the most information
+ about the failure. Note that the verbose output of each test
+ job is saved to 't/test-results/$TEST_NAME.stress-<nr>.out',
+ and only the output of the failed test job is shown on the
+ terminal. The names of the trash directories get a
+ '.stress-<nr>' suffix, and the trash directory of the failed
+ test job is renamed to end with a '.stress-failed' suffix.
+
You can also set the GIT_TEST_INSTALLED environment variable to
the bindir of an existing git installation to test that installation.
You still need to have built this git sandbox, from which various
@@ -425,7 +441,8 @@ This test harness library does the following things:
- Creates an empty test directory with an empty .git/objects database
and chdir(2) into it. This directory is 't/trash
directory.$test_name_without_dotsh', with t/ subject to change by
- the --root option documented above.
+ the --root option documented above, and a '.stress-<N>' suffix
+ appended by the --stress option.
- Defines standard test helper functions for your scripts to
use. These functions are designed to make all scripts behave
@@ -1288,8 +1288,6 @@ test_set_port () {
# root-only port, use a larger one instead.
port=$(($port + 10000))
fi
-
- eval $var=$port
;;
*[^0-9]*)
error >&7 "invalid port number: $port"
@@ -1298,4 +1296,9 @@ test_set_port () {
# The user has specified the port.
;;
esac
+
+ # Make sure that parallel '--stress' test jobs get different
+ # ports.
+ port=$(($port + ${GIT_TEST_STRESS_JOB_NR:-0}))
+ eval $var=$port
}
@@ -87,21 +87,110 @@ do
valgrind_only=${opt#--*=} ;;
--root=*)
root=${opt#--*=} ;;
+ --stress)
+ stress=t ;;
+ --stress=*)
+ stress=${opt#--*=} ;;
*)
# Other options will be handled later.
esac
done
+TEST_STRESS_JOB_SFX="${GIT_TEST_STRESS_JOB_NR:+.stress-$GIT_TEST_STRESS_JOB_NR}"
TEST_NAME="$(basename "$0" .sh)"
TEST_RESULTS_DIR="$TEST_OUTPUT_DIRECTORY/test-results"
-TEST_RESULTS_BASE="$TEST_RESULTS_DIR/$TEST_NAME"
-TRASH_DIRECTORY="trash directory.$TEST_NAME"
+TEST_RESULTS_BASE="$TEST_RESULTS_DIR/$TEST_NAME$TEST_STRESS_JOB_SFX"
+TRASH_DIRECTORY="trash directory.$TEST_NAME$TEST_STRESS_JOB_SFX"
test -n "$root" && TRASH_DIRECTORY="$root/$TRASH_DIRECTORY"
case "$TRASH_DIRECTORY" in
/*) ;; # absolute path is good
*) TRASH_DIRECTORY="$TEST_OUTPUT_DIRECTORY/$TRASH_DIRECTORY" ;;
esac
+# If --stress was passed, run this test repeatedly in several parallel loops.
+if test "$GIT_TEST_STRESS_STARTED" = "done"
+then
+ : # Don't stress test again.
+elif test -n "$stress"
+then
+ if test "$stress" != t
+ then
+ job_count=$stress
+ elif test -n "$GIT_TEST_STRESS_LOAD"
+ then
+ job_count="$GIT_TEST_STRESS_LOAD"
+ elif job_count=$(getconf _NPROCESSORS_ONLN 2>/dev/null) &&
+ test -n "$job_count"
+ then
+ job_count=$((2 * $job_count))
+ else
+ job_count=8
+ fi
+
+ mkdir -p "$TEST_RESULTS_DIR"
+ stressfail="$TEST_RESULTS_BASE.stress-failed"
+ rm -f "$stressfail"
+
+ stress_exit=0
+ trap '
+ kill $job_pids 2>/dev/null
+ wait
+ stress_exit=1
+ ' TERM INT HUP
+
+ job_pids=
+ job_nr=0
+ while test $job_nr -lt "$job_count"
+ do
+ (
+ GIT_TEST_STRESS_STARTED=done
+ GIT_TEST_STRESS_JOB_NR=$job_nr
+ export GIT_TEST_STRESS_STARTED GIT_TEST_STRESS_JOB_NR
+
+ trap '
+ kill $test_pid 2>/dev/null
+ wait
+ exit 1
+ ' TERM INT
+
+ cnt=0
+ while ! test -e "$stressfail"
+ do
+ $TEST_SHELL_PATH "$0" "$@" >"$TEST_RESULTS_BASE.stress-$job_nr.out" 2>&1 &
+ test_pid=$!
+
+ if wait $test_pid
+ then
+ printf "OK %2d.%d\n" $GIT_TEST_STRESS_JOB_NR $cnt
+ else
+ echo $GIT_TEST_STRESS_JOB_NR >>"$stressfail"
+ printf "FAIL %2d.%d\n" $GIT_TEST_STRESS_JOB_NR $cnt
+ fi
+ cnt=$(($cnt + 1))
+ done
+ ) &
+ job_pids="$job_pids $!"
+ job_nr=$(($job_nr + 1))
+ done
+
+ wait
+
+ if test -f "$stressfail"
+ then
+ echo "Log(s) of failed test run(s):"
+ for failed_job_nr in $(sort -n "$stressfail")
+ do
+ echo "Contents of '$TEST_RESULTS_BASE.stress-$failed_job_nr.out':"
+ cat "$TEST_RESULTS_BASE.stress-$failed_job_nr.out"
+ done
+ rm -rf "$TRASH_DIRECTORY.stress-failed"
+ # Move the last one.
+ mv "$TRASH_DIRECTORY.stress-$failed_job_nr" "$TRASH_DIRECTORY.stress-failed"
+ fi
+
+ exit $stress_exit
+fi
+
# if --tee was passed, write the output not only to the terminal, but
# additionally to the file test-results/$BASENAME.out, too.
if test "$GIT_TEST_TEE_STARTED" = "done"
@@ -340,7 +429,8 @@ do
--va|--val|--valg|--valgr|--valgri|--valgrin|--valgrind|\
--valgrind=*|\
--valgrind-only=*|\
- --root=*)
+ --root=*|\
+ --stress|--stress=*)
shift ;; # These options were handled already.
*)
echo "error: unknown test option '$1'" >&2; exit 1 ;;
@@ -379,6 +469,13 @@ then
verbose=t
fi
+if test -n "$stress"
+then
+ verbose=t
+ trace=t
+ immediate=t
+fi
+
if test -n "$color"
then
# Save the color control sequences now rather than run tput
Unfortunately, we have a few flaky tests, whose failures tend to be hard to reproduce. We've found that the best we can do to reproduce such a failure is to run the test repeatedly while the machine is under load, and wait in the hope that the load creates enough variance in the timing of the test's commands that a failure is evenually triggered. I have a command to do that, and I noticed that two other contributors have rolled their own scripts to do the same, all choosing slightly different approaches. To help reproduce failures in flaky tests, introduce the '--stress' option to run a test script repeatedly in multiple parallel jobs until one of them fails, thereby using the test script itself to increase the load on the machine. The number of parallel jobs is determined by, in order of precedence: the number specified as '--stress=<N>', or the value of the GIT_TEST_STRESS_LOAD environment variable, or twice the number of available processors (as reported by the 'getconf' utility), or 8. Make '--stress' imply '--verbose -x --immediate' to get the most information about rare failures; there is really no point in spending all the extra effort to reproduce such a failure, and then not know which command failed and why. To prevent the several parallel invocations of the same test from interfering with each other: - Include the parallel job's number in the name of the trash directory and the various output files under 't/test-results/' as a '.stress-<Nr>' suffix. - Add the parallel job's number to the port number specified by the user or to the test number, so even tests involving daemons listening on a TCP socket can be stressed. - Redirect each parallel test run's output to 't/test-results/$TEST_NAME.stress-<nr>.out', because dumping the output of several parallel running tests to the terminal would create a big ugly mess. For convenience, print the output of the failed test job at the end, and rename its trash directory to end with the '.stress-failed' suffix, so it's easy to find in a predictable path. If, in an unlikely case, more than one jobs were to fail nearly at the same time, then print the output of all failed jobs, and rename the trash directory of only the last one (i.e. with the highest job number), as it is the trash directory of the test whose output will be at the bottom of the user's terminal. Based on Jeff King's 'stress' script. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> --- t/README | 19 +++++++- t/test-lib-functions.sh | 7 ++- t/test-lib.sh | 103 ++++++++++++++++++++++++++++++++++++++-- 3 files changed, 123 insertions(+), 6 deletions(-)