--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2014 David Herrmann <dh.herrmann@gmail.com>
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/*
+ * IPC barrier tests
+ * These tests verify the correct behavior of the IPC Barrier implementation.
+ * Note that the tests use alarm-timers to verify dead-locks and timeouts. These
+ * might not work on slow machines where 20ms are too short to perform specific
+ * operations (though, very unlikely). In case that turns out true, we have to
+ * increase it at the slightly cost of lengthen test-duration on other machines.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "barrier.h"
+#include "def.h"
+#include "util.h"
+
+/* 20ms to test deadlocks; All timings use multiples of this constant as
+ * alarm/sleep timers. If this timeout is too small for slow machines to perform
+ * the requested operations, we have to increase it. On an i7 this works fine
+ * with 1ms base-time, so 20ms should be just fine for everyone. */
+#define BASE_TIME 20
+
+static void malarm(unsigned long msecs) {
+ struct itimerval v = { };
+
+ timeval_store(&v.it_value, msecs * USEC_PER_MSEC);
+ assert_se(setitimer(ITIMER_REAL, &v, NULL) >= 0);
+}
+
+static void msleep(unsigned long msecs) {
+ assert_se(msecs < MSEC_PER_SEC);
+ usleep(msecs * USEC_PER_MSEC);
+}
+
+#define TEST_BARRIER(_FUNCTION, _CHILD_CODE, _WAIT_CHILD, _PARENT_CODE, _WAIT_PARENT) \
+ static void _FUNCTION(void) { \
+ Barrier b; \
+ pid_t pid1, pid2; \
+ \
+ assert_se(barrier_init(&b) >= 0); \
+ \
+ pid1 = fork(); \
+ assert_se(pid1 >= 0); \
+ if (pid1 == 0) { \
+ barrier_set_role(&b, BARRIER_CHILD); \
+ { _CHILD_CODE; } \
+ exit(42); \
+ } \
+ \
+ pid2 = fork(); \
+ assert_se(pid2 >= 0); \
+ if (pid2 == 0) { \
+ barrier_set_role(&b, BARRIER_PARENT); \
+ { _PARENT_CODE; } \
+ exit(42); \
+ } \
+ \
+ barrier_destroy(&b); \
+ malarm(999); \
+ { _WAIT_CHILD; } \
+ { _WAIT_PARENT; } \
+ malarm(0); \
+ }
+
+#define TEST_BARRIER_WAIT_SUCCESS(_pid) \
+ ({ \
+ int pidr, status; \
+ pidr = waitpid(_pid, &status, 0); \
+ assert_se(pidr == _pid); \
+ assert_se(WIFEXITED(status)); \
+ assert_se(WEXITSTATUS(status) == 42); \
+ })
+
+#define TEST_BARRIER_WAIT_ALARM(_pid) \
+ ({ \
+ int pidr, status; \
+ pidr = waitpid(_pid, &status, 0); \
+ assert_se(pidr == _pid); \
+ assert_se(WIFSIGNALED(status)); \
+ assert_se(WTERMSIG(status) == SIGALRM); \
+ })
+
+/*
+ * Test basic sync points
+ * This places a barrier in both processes and waits synchronously for them.
+ * The timeout makes sure the sync works as expected. The msleep() on one side
+ * makes sure the exit of the parent does not overwrite previous barriers. Due
+ * to the msleep(), we know that the parent already exited, thus there's a
+ * pending HUP on the pipe. However, the barrier_sync() prefers reads on the
+ * eventfd, thus we can safely wait on the barrier.
+ */
+TEST_BARRIER(test_barrier_sync,
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ msleep(BASE_TIME * 2);
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test wait_next()
+ * This places a barrier in the parent and syncs on it. The child sleeps while
+ * the parent places the barrier and then waits for a barrier. The wait will
+ * succeed as the child hasn't read the parent's barrier, yet. The following
+ * barrier and sync synchronize the exit.
+ */
+TEST_BARRIER(test_barrier_wait_next,
+ ({
+ msleep(100);
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(400);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test wait_next() multiple times
+ * This places two barriers in the parent and waits for the child to exit. The
+ * child sleeps 20ms so both barriers _should_ be in place. It then waits for
+ * the parent to place the next barrier twice. The first call will fetch both
+ * barriers and return. However, the second call will stall as the parent does
+ * not place a 3rd barrier (the sleep caught two barriers). wait_next() is does
+ * not look at barrier-links so this stall is expected. Thus this test times
+ * out.
+ */
+TEST_BARRIER(test_barrier_wait_next_twice,
+ ({
+ msleep(BASE_TIME);
+ malarm(BASE_TIME);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_wait_next(&b));
+ assert_se(0);
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test wait_next() with local barriers
+ * This is the same as test_barrier_wait_next_twice, but places local barriers
+ * between both waits. This does not have any effect on the wait so it times out
+ * like the other test.
+ */
+TEST_BARRIER(test_barrier_wait_next_twice_local,
+ ({
+ msleep(BASE_TIME);
+ malarm(BASE_TIME);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_wait_next(&b));
+ assert_se(0);
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test wait_next() with sync_next()
+ * This is again the same as test_barrier_wait_next_twice but uses a
+ * synced wait as the second wait. This works just fine because the local state
+ * has no barriers placed, therefore, the remote is always in sync.
+ */
+TEST_BARRIER(test_barrier_wait_next_twice_sync,
+ ({
+ msleep(BASE_TIME);
+ malarm(BASE_TIME);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_sync_next(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test wait_next() with sync_next() and local barriers
+ * This is again the same as test_barrier_wait_next_twice_local but uses a
+ * synced wait as the second wait. This works just fine because the local state
+ * is in sync with the remote.
+ */
+TEST_BARRIER(test_barrier_wait_next_twice_local_sync,
+ ({
+ msleep(BASE_TIME);
+ malarm(BASE_TIME);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync_next(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test sync_next() and sync()
+ * This tests sync_*() synchronizations and makes sure they work fine if the
+ * local state is behind the remote state.
+ */
+TEST_BARRIER(test_barrier_sync_next,
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_sync_next(&b));
+ assert_se(barrier_sync(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync_next(&b));
+ assert_se(barrier_sync_next(&b));
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ msleep(BASE_TIME);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test sync_next() and sync() with local barriers
+ * This tests timeouts if sync_*() is used if local barriers are placed but the
+ * remote didn't place any.
+ */
+TEST_BARRIER(test_barrier_sync_next_local,
+ ({
+ malarm(BASE_TIME);
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync_next(&b));
+ assert_se(0);
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid1),
+ ({
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test sync_next() and sync() with local barriers and abortion
+ * This is the same as test_barrier_sync_next_local but aborts the sync in the
+ * parent. Therefore, the sync_next() succeeds just fine due to the abortion.
+ */
+TEST_BARRIER(test_barrier_sync_next_local_abort,
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(!barrier_sync_next(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ assert_se(barrier_abort(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test matched wait_abortion()
+ * This runs wait_abortion() with remote abortion.
+ */
+TEST_BARRIER(test_barrier_wait_abortion,
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_wait_abortion(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ assert_se(barrier_abort(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test unmatched wait_abortion()
+ * This runs wait_abortion() without any remote abortion going on. It thus must
+ * timeout.
+ */
+TEST_BARRIER(test_barrier_wait_abortion_unmatched,
+ ({
+ malarm(BASE_TIME);
+ assert_se(barrier_wait_abortion(&b));
+ assert_se(0);
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid1),
+ ({
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test matched wait_abortion() with local abortion
+ * This runs wait_abortion() with local and remote abortion.
+ */
+TEST_BARRIER(test_barrier_wait_abortion_local,
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_abort(&b));
+ assert_se(!barrier_wait_abortion(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ assert_se(barrier_abort(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test unmatched wait_abortion() with local abortion
+ * This runs wait_abortion() with only local abortion. This must time out.
+ */
+TEST_BARRIER(test_barrier_wait_abortion_local_unmatched,
+ ({
+ malarm(BASE_TIME);
+ assert_se(barrier_abort(&b));
+ assert_se(!barrier_wait_abortion(&b));
+ assert_se(0);
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid1),
+ ({
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test child exit
+ * Place barrier and sync with the child. The child only exits()s, which should
+ * cause an implicit abortion and wake the parent.
+ */
+TEST_BARRIER(test_barrier_exit,
+ ({
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME * 10);
+ assert_se(barrier_place(&b));
+ assert_se(!barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+/*
+ * Test child exit with sleep
+ * Same as test_barrier_exit but verifies the test really works due to the
+ * child-exit. We add a usleep() which triggers the alarm in the parent and
+ * causes the test to time out.
+ */
+TEST_BARRIER(test_barrier_no_exit,
+ ({
+ msleep(BASE_TIME * 2);
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ malarm(BASE_TIME);
+ assert_se(barrier_place(&b));
+ assert_se(!barrier_sync(&b));
+ }),
+ TEST_BARRIER_WAIT_ALARM(pid2));
+
+/*
+ * Test pending exit against sync
+ * The parent places a barrier *and* exits. The 20ms wait in the child
+ * guarantees both are pending. However, our logic prefers pending barriers over
+ * pending exit-abortions (unlike normal abortions), thus the wait_next() must
+ * succeed, same for the sync_next() as our local barrier-count is smaller than
+ * the remote. Once we place a barrier our count is equal, so the sync still
+ * succeeds. Only if we place one more barrier, we're ahead of the remote, thus
+ * we will fail due to HUP on the pipe.
+ */
+TEST_BARRIER(test_barrier_pending_exit,
+ ({
+ malarm(BASE_TIME * 4);
+ msleep(BASE_TIME * 2);
+ assert_se(barrier_wait_next(&b));
+ assert_se(barrier_sync_next(&b));
+ assert_se(barrier_place(&b));
+ assert_se(barrier_sync_next(&b));
+ assert_se(barrier_place(&b));
+ assert_se(!barrier_sync_next(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid1),
+ ({
+ assert_se(barrier_place(&b));
+ }),
+ TEST_BARRIER_WAIT_SUCCESS(pid2));
+
+int main(int argc, char *argv[]) {
+ log_parse_environment();
+ log_open();
+
+ test_barrier_sync();
+ test_barrier_wait_next();
+ test_barrier_wait_next_twice();
+ test_barrier_wait_next_twice_sync();
+ test_barrier_wait_next_twice_local();
+ test_barrier_wait_next_twice_local_sync();
+ test_barrier_sync_next();
+ test_barrier_sync_next_local();
+ test_barrier_sync_next_local_abort();
+ test_barrier_wait_abortion();
+ test_barrier_wait_abortion_unmatched();
+ test_barrier_wait_abortion_local();
+ test_barrier_wait_abortion_local_unmatched();
+ test_barrier_exit();
+ test_barrier_no_exit();
+ test_barrier_pending_exit();
+
+ return 0;
+}
~ianmdlvl / elogind.git / blobdiff