Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 902 insertions, 0 deletions

diff --git a/src/libsystemd/sd-event/test-event.c b/src/libsystemd/sd-event/test-event.c
new file mode 100644
index 0000000..63d3ee7
--- /dev/null
+++ b/src/libsystemd/sd-event/test-event.c
@@ -0,0 +1,902 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "sd-event.h"
+
+#include "alloc-util.h"
+#include "exec-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing_syscall.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "random-util.h"
+#include "rm-rf.h"
+#include "signal-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "tests.h"
+#include "tmpfile-util.h"
+
+static int prepare_handler(sd_event_source *s, void *userdata) {
+        log_info("preparing %c", PTR_TO_INT(userdata));
+        return 1;
+}
+
+static bool got_a, got_b, got_c, got_unref;
+static unsigned got_d;
+
+static int unref_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        sd_event_source_unref(s);
+        got_unref = true;
+        return 0;
+}
+
+static int io_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+
+        log_info("got IO on %c", PTR_TO_INT(userdata));
+
+        if (userdata == INT_TO_PTR('a')) {
+                assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
+                assert_se(!got_a);
+                got_a = true;
+        } else if (userdata == INT_TO_PTR('b')) {
+                assert_se(!got_b);
+                got_b = true;
+        } else if (userdata == INT_TO_PTR('d')) {
+                got_d++;
+                if (got_d < 2)
+                        assert_se(sd_event_source_set_enabled(s, SD_EVENT_ONESHOT) >= 0);
+                else
+                        assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
+        } else
+                assert_not_reached();
+
+        return 1;
+}
+
+static int child_handler(sd_event_source *s, const siginfo_t *si, void *userdata) {
+
+        assert_se(s);
+        assert_se(si);
+
+        assert_se(si->si_uid == getuid());
+        assert_se(si->si_signo == SIGCHLD);
+        assert_se(si->si_code == CLD_EXITED);
+        assert_se(si->si_status == 78);
+
+        log_info("got child on %c", PTR_TO_INT(userdata));
+
+        assert_se(userdata == INT_TO_PTR('f'));
+
+        assert_se(sd_event_exit(sd_event_source_get_event(s), 0) >= 0);
+        sd_event_source_unref(s);
+
+        return 1;
+}
+
+static int signal_handler(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        sd_event_source *p = NULL;
+        pid_t pid;
+        siginfo_t plain_si;
+
+        assert_se(s);
+        assert_se(si);
+
+        log_info("got signal on %c", PTR_TO_INT(userdata));
+
+        assert_se(userdata == INT_TO_PTR('e'));
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGUSR2, -1) >= 0);
+
+        pid = fork();
+        assert_se(pid >= 0);
+
+        if (pid == 0) {
+                sigset_t ss;
+
+                assert_se(sigemptyset(&ss) >= 0);
+                assert_se(sigaddset(&ss, SIGUSR2) >= 0);
+
+                zero(plain_si);
+                assert_se(sigwaitinfo(&ss, &plain_si) >= 0);
+
+                assert_se(plain_si.si_signo == SIGUSR2);
+                assert_se(plain_si.si_value.sival_int == 4711);
+
+                _exit(78);
+        }
+
+        assert_se(sd_event_add_child(sd_event_source_get_event(s), &p, pid, WEXITED, child_handler, INT_TO_PTR('f')) >= 0);
+        assert_se(sd_event_source_set_enabled(p, SD_EVENT_ONESHOT) >= 0);
+        assert_se(sd_event_source_set_child_process_own(p, true) >= 0);
+
+        /* We can't use structured initialization here, since the structure contains various unions and these
+         * fields lie in overlapping (carefully aligned) unions that LLVM is allergic to allow assignments
+         * to */
+        zero(plain_si);
+        plain_si.si_signo = SIGUSR2;
+        plain_si.si_code = SI_QUEUE;
+        plain_si.si_pid = getpid_cached();
+        plain_si.si_uid = getuid();
+        plain_si.si_value.sival_int = 4711;
+
+        assert_se(sd_event_source_send_child_signal(p, SIGUSR2, &plain_si, 0) >= 0);
+
+        sd_event_source_unref(s);
+
+        return 1;
+}
+
+static int defer_handler(sd_event_source *s, void *userdata) {
+        sd_event_source *p = NULL;
+
+        assert_se(s);
+
+        log_info("got defer on %c", PTR_TO_INT(userdata));
+
+        assert_se(userdata == INT_TO_PTR('d'));
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGUSR1, -1) >= 0);
+
+        assert_se(sd_event_add_signal(sd_event_source_get_event(s), &p, SIGUSR1, signal_handler, INT_TO_PTR('e')) >= 0);
+        assert_se(sd_event_source_set_enabled(p, SD_EVENT_ONESHOT) >= 0);
+        raise(SIGUSR1);
+
+        sd_event_source_unref(s);
+
+        return 1;
+}
+
+static bool do_quit;
+
+static int time_handler(sd_event_source *s, uint64_t usec, void *userdata) {
+        log_info("got timer on %c", PTR_TO_INT(userdata));
+
+        if (userdata == INT_TO_PTR('c')) {
+
+                if (do_quit) {
+                        sd_event_source *p;
+
+                        assert_se(sd_event_add_defer(sd_event_source_get_event(s), &p, defer_handler, INT_TO_PTR('d')) >= 0);
+                        assert_se(sd_event_source_set_enabled(p, SD_EVENT_ONESHOT) >= 0);
+                } else {
+                        assert_se(!got_c);
+                        got_c = true;
+                }
+        } else
+                assert_not_reached();
+
+        return 2;
+}
+
+static bool got_exit = false;
+
+static int exit_handler(sd_event_source *s, void *userdata) {
+        log_info("got quit handler on %c", PTR_TO_INT(userdata));
+
+        got_exit = true;
+
+        return 3;
+}
+
+static bool got_post = false;
+
+static int post_handler(sd_event_source *s, void *userdata) {
+        log_info("got post handler");
+
+        got_post = true;
+
+        return 2;
+}
+
+static void test_basic_one(bool with_pidfd) {
+        sd_event *e = NULL;
+        sd_event_source *w = NULL, *x = NULL, *y = NULL, *z = NULL, *q = NULL, *t = NULL;
+        static const char ch = 'x';
+        int a[2] = EBADF_PAIR, b[2] = EBADF_PAIR,
+            d[2] = EBADF_PAIR, k[2] = EBADF_PAIR;
+        uint64_t event_now;
+        int64_t priority;
+
+        log_info("/* %s(pidfd=%s) */", __func__, yes_no(with_pidfd));
+
+        assert_se(setenv("SYSTEMD_PIDFD", yes_no(with_pidfd), 1) >= 0);
+
+        assert_se(pipe(a) >= 0);
+        assert_se(pipe(b) >= 0);
+        assert_se(pipe(d) >= 0);
+        assert_se(pipe(k) >= 0);
+
+        assert_se(sd_event_default(&e) >= 0);
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) > 0);
+
+        assert_se(sd_event_set_watchdog(e, true) >= 0);
+
+        /* Test whether we cleanly can destroy an io event source from its own handler */
+        got_unref = false;
+        assert_se(sd_event_add_io(e, &t, k[0], EPOLLIN, unref_handler, NULL) >= 0);
+        assert_se(write(k[1], &ch, 1) == 1);
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(got_unref);
+
+        got_a = false, got_b = false, got_c = false, got_d = 0;
+
+        /* Add a oneshot handler, trigger it, reenable it, and trigger it again. */
+        assert_se(sd_event_add_io(e, &w, d[0], EPOLLIN, io_handler, INT_TO_PTR('d')) >= 0);
+        assert_se(sd_event_source_set_enabled(w, SD_EVENT_ONESHOT) >= 0);
+        assert_se(write(d[1], &ch, 1) >= 0);
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(got_d == 1);
+        assert_se(write(d[1], &ch, 1) >= 0);
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(got_d == 2);
+
+        assert_se(sd_event_add_io(e, &x, a[0], EPOLLIN, io_handler, INT_TO_PTR('a')) >= 0);
+        assert_se(sd_event_add_io(e, &y, b[0], EPOLLIN, io_handler, INT_TO_PTR('b')) >= 0);
+
+        do_quit = false;
+        assert_se(sd_event_add_time(e, &z, CLOCK_MONOTONIC, 0, 0, time_handler, INT_TO_PTR('c')) >= 0);
+        assert_se(sd_event_add_exit(e, &q, exit_handler, INT_TO_PTR('g')) >= 0);
+
+        assert_se(sd_event_source_set_priority(x, 99) >= 0);
+        assert_se(sd_event_source_get_priority(x, &priority) >= 0);
+        assert_se(priority == 99);
+        assert_se(sd_event_source_set_enabled(y, SD_EVENT_ONESHOT) >= 0);
+        assert_se(sd_event_source_set_prepare(x, prepare_handler) >= 0);
+        assert_se(sd_event_source_set_priority(z, 50) >= 0);
+        assert_se(sd_event_source_set_enabled(z, SD_EVENT_ONESHOT) >= 0);
+        assert_se(sd_event_source_set_prepare(z, prepare_handler) >= 0);
+
+        /* Test for floating event sources */
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGRTMIN+1, -1) >= 0);
+        assert_se(sd_event_add_signal(e, NULL, SIGRTMIN+1, NULL, NULL) >= 0);
+
+        assert_se(write(a[1], &ch, 1) >= 0);
+        assert_se(write(b[1], &ch, 1) >= 0);
+
+        assert_se(!got_a && !got_b && !got_c);
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+
+        assert_se(!got_a && got_b && !got_c);
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+
+        assert_se(!got_a && got_b && got_c);
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+
+        assert_se(got_a && got_b && got_c);
+
+        sd_event_source_unref(x);
+        sd_event_source_unref(y);
+
+        do_quit = true;
+        assert_se(sd_event_add_post(e, NULL, post_handler, NULL) >= 0);
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) == 0);
+        assert_se(sd_event_source_set_time(z, event_now + 200 * USEC_PER_MSEC) >= 0);
+        assert_se(sd_event_source_set_enabled(z, SD_EVENT_ONESHOT) >= 0);
+
+        assert_se(sd_event_loop(e) >= 0);
+        assert_se(got_post);
+        assert_se(got_exit);
+
+        sd_event_source_unref(z);
+        sd_event_source_unref(q);
+
+        sd_event_source_unref(w);
+
+        sd_event_unref(e);
+
+        safe_close_pair(a);
+        safe_close_pair(b);
+        safe_close_pair(d);
+        safe_close_pair(k);
+
+        assert_se(unsetenv("SYSTEMD_PIDFD") >= 0);
+}
+
+TEST(basic) {
+        test_basic_one(true);   /* test with pidfd */
+        test_basic_one(false);  /* test without pidfd */
+}
+
+TEST(sd_event_now) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        uint64_t event_now;
+
+        assert_se(sd_event_new(&e) >= 0);
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME_ALARM, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME, &event_now) > 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME_ALARM, &event_now) > 0);
+        assert_se(sd_event_now(e, -1, &event_now) == -EOPNOTSUPP);
+        assert_se(sd_event_now(e, 900 /* arbitrary big number */, &event_now) == -EOPNOTSUPP);
+
+        assert_se(sd_event_run(e, 0) == 0);
+
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_REALTIME_ALARM, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME, &event_now) == 0);
+        assert_se(sd_event_now(e, CLOCK_BOOTTIME_ALARM, &event_now) == 0);
+        assert_se(sd_event_now(e, -1, &event_now) == -EOPNOTSUPP);
+        assert_se(sd_event_now(e, 900 /* arbitrary big number */, &event_now) == -EOPNOTSUPP);
+}
+
+static int last_rtqueue_sigval = 0;
+static int n_rtqueue = 0;
+
+static int rtqueue_handler(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        last_rtqueue_sigval = si->ssi_int;
+        n_rtqueue++;
+        return 0;
+}
+
+TEST(rtqueue) {
+        sd_event_source *u = NULL, *v = NULL, *s = NULL;
+        sd_event *e = NULL;
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGRTMIN+2, SIGRTMIN+3, SIGUSR2, -1) >= 0);
+        assert_se(sd_event_add_signal(e, &u, SIGRTMIN+2, rtqueue_handler, NULL) >= 0);
+        assert_se(sd_event_add_signal(e, &v, SIGRTMIN+3, rtqueue_handler, NULL) >= 0);
+        assert_se(sd_event_add_signal(e, &s, SIGUSR2, rtqueue_handler, NULL) >= 0);
+
+        assert_se(sd_event_source_set_priority(v, -10) >= 0);
+
+        assert_se(sigqueue(getpid_cached(), SIGRTMIN+2, (union sigval) { .sival_int = 1 }) >= 0);
+        assert_se(sigqueue(getpid_cached(), SIGRTMIN+3, (union sigval) { .sival_int = 2 }) >= 0);
+        assert_se(sigqueue(getpid_cached(), SIGUSR2, (union sigval) { .sival_int = 3 }) >= 0);
+        assert_se(sigqueue(getpid_cached(), SIGRTMIN+3, (union sigval) { .sival_int = 4 }) >= 0);
+        assert_se(sigqueue(getpid_cached(), SIGUSR2, (union sigval) { .sival_int = 5 }) >= 0);
+
+        assert_se(n_rtqueue == 0);
+        assert_se(last_rtqueue_sigval == 0);
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(n_rtqueue == 1);
+        assert_se(last_rtqueue_sigval == 2); /* first SIGRTMIN+3 */
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(n_rtqueue == 2);
+        assert_se(last_rtqueue_sigval == 4); /* second SIGRTMIN+3 */
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(n_rtqueue == 3);
+        assert_se(last_rtqueue_sigval == 3); /* first SIGUSR2 */
+
+        assert_se(sd_event_run(e, UINT64_MAX) >= 1);
+        assert_se(n_rtqueue == 4);
+        assert_se(last_rtqueue_sigval == 1); /* SIGRTMIN+2 */
+
+        assert_se(sd_event_run(e, 0) == 0); /* the other SIGUSR2 is dropped, because the first one was still queued */
+        assert_se(n_rtqueue == 4);
+        assert_se(last_rtqueue_sigval == 1);
+
+        sd_event_source_unref(u);
+        sd_event_source_unref(v);
+        sd_event_source_unref(s);
+
+        sd_event_unref(e);
+}
+
+#define CREATE_EVENTS_MAX (70000U)
+
+struct inotify_context {
+        bool delete_self_handler_called;
+        unsigned create_called[CREATE_EVENTS_MAX];
+        unsigned create_overflow;
+        unsigned n_create_events;
+};
+
+static void maybe_exit(sd_event_source *s, struct inotify_context *c) {
+        unsigned n;
+
+        assert_se(s);
+        assert_se(c);
+
+        if (!c->delete_self_handler_called)
+                return;
+
+        for (n = 0; n < 3; n++) {
+                unsigned i;
+
+                if (c->create_overflow & (1U << n))
+                        continue;
+
+                for (i = 0; i < c->n_create_events; i++)
+                        if (!(c->create_called[i] & (1U << n)))
+                                return;
+        }
+
+        sd_event_exit(sd_event_source_get_event(s), 0);
+}
+
+static int inotify_handler(sd_event_source *s, const struct inotify_event *ev, void *userdata) {
+        struct inotify_context *c = userdata;
+        const char *description;
+        unsigned bit, n;
+
+        assert_se(sd_event_source_get_description(s, &description) >= 0);
+        assert_se(safe_atou(description, &n) >= 0);
+
+        assert_se(n <= 3);
+        bit = 1U << n;
+
+        if (ev->mask & IN_Q_OVERFLOW) {
+                log_info("inotify-handler <%s>: overflow", description);
+                c->create_overflow |= bit;
+        } else if (ev->mask & IN_CREATE) {
+                if (streq(ev->name, "sub"))
+                        log_debug("inotify-handler <%s>: create on %s", description, ev->name);
+                else {
+                        unsigned i;
+
+                        assert_se(safe_atou(ev->name, &i) >= 0);
+                        assert_se(i < c->n_create_events);
+                        c->create_called[i] |= bit;
+                }
+        } else if (ev->mask & IN_DELETE) {
+                log_info("inotify-handler <%s>: delete of %s", description, ev->name);
+                assert_se(streq(ev->name, "sub"));
+        } else
+                assert_not_reached();
+
+        maybe_exit(s, c);
+        return 1;
+}
+
+static int delete_self_handler(sd_event_source *s, const struct inotify_event *ev, void *userdata) {
+        struct inotify_context *c = userdata;
+
+        if (ev->mask & IN_Q_OVERFLOW) {
+                log_info("delete-self-handler: overflow");
+                c->delete_self_handler_called = true;
+        } else if (ev->mask & IN_DELETE_SELF) {
+                log_info("delete-self-handler: delete-self");
+                c->delete_self_handler_called = true;
+        } else if (ev->mask & IN_IGNORED) {
+                log_info("delete-self-handler: ignore");
+        } else
+                assert_not_reached();
+
+        maybe_exit(s, c);
+        return 1;
+}
+
+static void test_inotify_one(unsigned n_create_events) {
+        _cleanup_(rm_rf_physical_and_freep) char *p = NULL;
+        sd_event_source *a = NULL, *b = NULL, *c = NULL, *d = NULL;
+        struct inotify_context context = {
+                .n_create_events = n_create_events,
+        };
+        sd_event *e = NULL;
+        const char *q;
+        unsigned i;
+
+        log_info("/* %s(%u) */", __func__, n_create_events);
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        assert_se(mkdtemp_malloc("/tmp/test-inotify-XXXXXX", &p) >= 0);
+
+        assert_se(sd_event_add_inotify(e, &a, p, IN_CREATE|IN_ONLYDIR, inotify_handler, &context) >= 0);
+        assert_se(sd_event_add_inotify(e, &b, p, IN_CREATE|IN_DELETE|IN_DONT_FOLLOW, inotify_handler, &context) >= 0);
+        assert_se(sd_event_source_set_priority(b, SD_EVENT_PRIORITY_IDLE) >= 0);
+        assert_se(sd_event_source_set_priority(b, SD_EVENT_PRIORITY_NORMAL) >= 0);
+        assert_se(sd_event_add_inotify(e, &c, p, IN_CREATE|IN_DELETE|IN_EXCL_UNLINK, inotify_handler, &context) >= 0);
+        assert_se(sd_event_source_set_priority(c, SD_EVENT_PRIORITY_IDLE) >= 0);
+
+        assert_se(sd_event_source_set_description(a, "0") >= 0);
+        assert_se(sd_event_source_set_description(b, "1") >= 0);
+        assert_se(sd_event_source_set_description(c, "2") >= 0);
+
+        q = strjoina(p, "/sub");
+        assert_se(touch(q) >= 0);
+        assert_se(sd_event_add_inotify(e, &d, q, IN_DELETE_SELF, delete_self_handler, &context) >= 0);
+
+        for (i = 0; i < n_create_events; i++) {
+                char buf[DECIMAL_STR_MAX(unsigned)+1];
+                _cleanup_free_ char *z = NULL;
+
+                xsprintf(buf, "%u", i);
+                assert_se(z = path_join(p, buf));
+
+                assert_se(touch(z) >= 0);
+        }
+
+        assert_se(unlink(q) >= 0);
+
+        assert_se(sd_event_loop(e) >= 0);
+
+        sd_event_source_unref(a);
+        sd_event_source_unref(b);
+        sd_event_source_unref(c);
+        sd_event_source_unref(d);
+
+        sd_event_unref(e);
+}
+
+TEST(inotify) {
+        test_inotify_one(100); /* should work without overflow */
+        test_inotify_one(33000); /* should trigger a q overflow */
+}
+
+static int pidfd_handler(sd_event_source *s, const siginfo_t *si, void *userdata) {
+        assert_se(s);
+        assert_se(si);
+
+        assert_se(si->si_uid == getuid());
+        assert_se(si->si_signo == SIGCHLD);
+        assert_se(si->si_code == CLD_EXITED);
+        assert_se(si->si_status == 66);
+
+        log_info("got pidfd on %c", PTR_TO_INT(userdata));
+
+        assert_se(userdata == INT_TO_PTR('p'));
+
+        assert_se(sd_event_exit(sd_event_source_get_event(s), 0) >= 0);
+        sd_event_source_unref(s);
+
+        return 0;
+}
+
+TEST(pidfd) {
+        sd_event_source *s = NULL, *t = NULL;
+        sd_event *e = NULL;
+        int pidfd;
+        pid_t pid, pid2;
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, -1) >= 0);
+
+        pid = fork();
+        if (pid == 0)
+                /* child */
+                _exit(66);
+
+        assert_se(pid > 1);
+
+        pidfd = pidfd_open(pid, 0);
+        if (pidfd < 0) {
+                /* No pidfd_open() supported or blocked? */
+                assert_se(ERRNO_IS_NOT_SUPPORTED(errno) || ERRNO_IS_PRIVILEGE(errno));
+                (void) wait_for_terminate(pid, NULL);
+                return;
+        }
+
+        pid2 = fork();
+        if (pid2 == 0)
+                freeze();
+
+        assert_se(pid > 2);
+
+        assert_se(sd_event_default(&e) >= 0);
+        assert_se(sd_event_add_child_pidfd(e, &s, pidfd, WEXITED, pidfd_handler, INT_TO_PTR('p')) >= 0);
+        assert_se(sd_event_source_set_child_pidfd_own(s, true) >= 0);
+
+        /* This one should never trigger, since our second child lives forever */
+        assert_se(sd_event_add_child(e, &t, pid2, WEXITED, pidfd_handler, INT_TO_PTR('q')) >= 0);
+        assert_se(sd_event_source_set_child_process_own(t, true) >= 0);
+
+        assert_se(sd_event_loop(e) >= 0);
+
+        /* Child should still be alive */
+        assert_se(kill(pid2, 0) >= 0);
+
+        t = sd_event_source_unref(t);
+
+        /* Child should now be dead, since we dropped the ref */
+        assert_se(kill(pid2, 0) < 0 && errno == ESRCH);
+
+        sd_event_unref(e);
+}
+
+static int ratelimit_io_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        unsigned *c = (unsigned*) userdata;
+        *c += 1;
+        return 0;
+}
+
+static int ratelimit_time_handler(sd_event_source *s, uint64_t usec, void *userdata) {
+        int r;
+
+        r = sd_event_source_set_enabled(s, SD_EVENT_ON);
+        if (r < 0)
+                log_warning_errno(r, "Failed to turn on notify event source: %m");
+
+        r = sd_event_source_set_time(s, usec + 1000);
+        if (r < 0)
+                log_error_errno(r, "Failed to restart watchdog event source: %m");
+
+        unsigned *c = (unsigned*) userdata;
+        *c += 1;
+
+        return 0;
+}
+
+static int expired = -1;
+static int ratelimit_expired(sd_event_source *s, void *userdata) {
+        return ++expired;
+}
+
+TEST(ratelimit) {
+        _cleanup_close_pair_ int p[2] = EBADF_PAIR;
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
+        uint64_t interval;
+        unsigned count, burst;
+
+        assert_se(sd_event_default(&e) >= 0);
+        assert_se(pipe2(p, O_CLOEXEC|O_NONBLOCK) >= 0);
+
+        assert_se(sd_event_add_io(e, &s, p[0], EPOLLIN, ratelimit_io_handler, &count) >= 0);
+        assert_se(sd_event_source_set_description(s, "test-ratelimit-io") >= 0);
+        assert_se(sd_event_source_set_ratelimit(s, 1 * USEC_PER_SEC, 5) >= 0);
+        assert_se(sd_event_source_get_ratelimit(s, &interval, &burst) >= 0);
+        assert_se(interval == 1 * USEC_PER_SEC && burst == 5);
+
+        assert_se(write(p[1], "1", 1) == 1);
+
+        count = 0;
+        for (unsigned i = 0; i < 10; i++) {
+                log_debug("slow loop iteration %u", i);
+                assert_se(sd_event_run(e, UINT64_MAX) >= 0);
+                assert_se(usleep_safe(250 * USEC_PER_MSEC) >= 0);
+        }
+
+        assert_se(sd_event_source_is_ratelimited(s) == 0);
+        assert_se(count == 10);
+        log_info("ratelimit_io_handler: called %u times, event source not ratelimited", count);
+
+        assert_se(sd_event_source_set_ratelimit(s, 0, 0) >= 0);
+        assert_se(sd_event_source_set_ratelimit(s, 1 * USEC_PER_SEC, 5) >= 0);
+
+        count = 0;
+        for (unsigned i = 0; i < 10; i++) {
+                log_debug("fast event loop iteration %u", i);
+                assert_se(sd_event_run(e, UINT64_MAX) >= 0);
+                assert_se(usleep_safe(10) >= 0);
+        }
+        log_info("ratelimit_io_handler: called %u times, event source got ratelimited", count);
+        assert_se(count < 10);
+
+        s = sd_event_source_unref(s);
+        safe_close_pair(p);
+
+        count = 0;
+        assert_se(sd_event_add_time_relative(e, &s, CLOCK_MONOTONIC, 1000, 1, ratelimit_time_handler, &count) >= 0);
+        assert_se(sd_event_source_set_ratelimit(s, 1 * USEC_PER_SEC, 10) == 0);
+
+        do {
+                assert_se(sd_event_run(e, UINT64_MAX) >= 0);
+        } while (!sd_event_source_is_ratelimited(s));
+
+        log_info("ratelimit_time_handler: called %u times, event source got ratelimited", count);
+        assert_se(count == 10);
+
+        /* In order to get rid of active rate limit client needs to disable it explicitly */
+        assert_se(sd_event_source_set_ratelimit(s, 0, 0) >= 0);
+        assert_se(!sd_event_source_is_ratelimited(s));
+
+        assert_se(sd_event_source_set_ratelimit(s, 1 * USEC_PER_SEC, 10) >= 0);
+
+        /* Set callback that will be invoked when we leave rate limited state. */
+        assert_se(sd_event_source_set_ratelimit_expire_callback(s, ratelimit_expired) >= 0);
+
+        do {
+                assert_se(sd_event_run(e, UINT64_MAX) >= 0);
+        } while (!sd_event_source_is_ratelimited(s));
+
+        log_info("ratelimit_time_handler: called 10 more times, event source got ratelimited");
+        assert_se(count == 20);
+
+        /* Dispatch the event loop once more and check that ratelimit expiration callback got called */
+        assert_se(sd_event_run(e, UINT64_MAX) >= 0);
+        assert_se(expired == 0);
+}
+
+TEST(simple_timeout) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        usec_t f, t, some_time;
+
+        some_time = random_u64_range(2 * USEC_PER_SEC);
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        assert_se(sd_event_prepare(e) == 0);
+
+        f = now(CLOCK_MONOTONIC);
+        assert_se(sd_event_wait(e, some_time) >= 0);
+        t = now(CLOCK_MONOTONIC);
+
+        /* The event loop may sleep longer than the specified time (timer accuracy, scheduling latencies, …),
+         * but never shorter. Let's check that. */
+        assert_se(t >= usec_add(f, some_time));
+}
+
+static int inotify_self_destroy_handler(sd_event_source *s, const struct inotify_event *ev, void *userdata) {
+        sd_event_source **p = userdata;
+
+        assert_se(ev);
+        assert_se(p);
+        assert_se(*p == s);
+
+        assert_se(FLAGS_SET(ev->mask, IN_ATTRIB));
+
+        assert_se(sd_event_exit(sd_event_source_get_event(s), 0) >= 0);
+
+        *p = sd_event_source_unref(*p); /* here's what we actually intend to test: we destroy the event
+                                         * source from inside the event source handler */
+        return 1;
+}
+
+TEST(inotify_self_destroy) {
+        _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        char path[] = "/tmp/inotifyXXXXXX";
+        _cleanup_close_ int fd = -EBADF;
+
+        /* Tests that destroying an inotify event source from its own handler is safe */
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        fd = mkostemp_safe(path);
+        assert_se(fd >= 0);
+        assert_se(sd_event_add_inotify_fd(e, &s, fd, IN_ATTRIB, inotify_self_destroy_handler, &s) >= 0);
+        fd = safe_close(fd);
+        assert_se(unlink(path) >= 0); /* This will trigger IN_ATTRIB because link count goes to zero */
+        assert_se(sd_event_loop(e) >= 0);
+}
+
+struct inotify_process_buffered_data_context {
+        const char *path[2];
+        unsigned i;
+};
+
+static int inotify_process_buffered_data_handler(sd_event_source *s, const struct inotify_event *ev, void *userdata) {
+        struct inotify_process_buffered_data_context *c = ASSERT_PTR(userdata);
+        const char *description;
+
+        assert_se(sd_event_source_get_description(s, &description) >= 0);
+
+        assert_se(c->i < 2);
+        assert_se(streq(c->path[c->i], description));
+        c->i++;
+
+        return 1;
+}
+
+TEST(inotify_process_buffered_data) {
+        _cleanup_(rm_rf_physical_and_freep) char *p = NULL, *q = NULL;
+        _cleanup_(sd_event_source_unrefp) sd_event_source *a = NULL, *b = NULL;
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        _cleanup_free_ char *z = NULL;
+
+        /* For issue #23826 */
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        assert_se(mkdtemp_malloc("/tmp/test-inotify-XXXXXX", &p) >= 0);
+        assert_se(mkdtemp_malloc("/tmp/test-inotify-XXXXXX", &q) >= 0);
+
+        struct inotify_process_buffered_data_context context = {
+                .path = { p, q },
+        };
+
+        assert_se(sd_event_add_inotify(e, &a, p, IN_CREATE, inotify_process_buffered_data_handler, &context) >= 0);
+        assert_se(sd_event_add_inotify(e, &b, q, IN_CREATE, inotify_process_buffered_data_handler, &context) >= 0);
+
+        assert_se(z = path_join(p, "aaa"));
+        assert_se(touch(z) >= 0);
+        z = mfree(z);
+        assert_se(z = path_join(q, "bbb"));
+        assert_se(touch(z) >= 0);
+        z = mfree(z);
+
+        assert_se(sd_event_run(e, 10 * USEC_PER_SEC) > 0);
+        assert_se(sd_event_prepare(e) > 0); /* issue #23826: this was 0. */
+        assert_se(sd_event_dispatch(e) > 0);
+        assert_se(sd_event_prepare(e) == 0);
+        assert_se(sd_event_wait(e, 0) == 0);
+}
+
+TEST(fork) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        int r;
+
+        assert_se(sd_event_default(&e) >= 0);
+        assert_se(sd_event_prepare(e) == 0);
+
+        /* Check that after a fork the cleanup functions return NULL */
+        r = safe_fork("(bus-fork-test)", FORK_WAIT|FORK_LOG, NULL);
+        if (r == 0) {
+                assert_se(e);
+                assert_se(sd_event_ref(e) == NULL);
+                assert_se(sd_event_unref(e) == NULL);
+                _exit(EXIT_SUCCESS);
+        }
+
+        assert_se(r >= 0);
+}
+
+static int hup_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        unsigned *c = userdata;
+
+        assert_se(revents == EPOLLHUP);
+
+        (*c)++;
+        return 0;
+}
+
+TEST(leave_ratelimit) {
+        bool expect_ratelimit = false, manually_left_ratelimit = false;
+        _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        _cleanup_close_pair_ int pfd[2] = EBADF_PAIR;
+        unsigned c = 0;
+        int r;
+
+        assert_se(sd_event_default(&e) >= 0);
+
+        /* Create an event source that will continuously fire by creating a pipe whose write side is closed,
+         * and which hence will only see EOF and constant EPOLLHUP */
+        assert_se(pipe2(pfd, O_CLOEXEC) >= 0);
+        assert_se(sd_event_add_io(e, &s, pfd[0], EPOLLIN, hup_callback, &c) >= 0);
+        assert_se(sd_event_source_set_io_fd_own(s, true) >= 0);
+        assert_se(sd_event_source_set_ratelimit(s, 5*USEC_PER_MINUTE, 5) >= 0);
+
+        pfd[0] = -EBADF;
+        pfd[1] = safe_close(pfd[1]); /* Trigger continuous EOF */
+
+        for (;;) {
+                r = sd_event_prepare(e);
+                assert_se(r >= 0);
+
+                if (r == 0) {
+                        r = sd_event_wait(e, UINT64_MAX);
+                        assert_se(r > 0);
+                }
+
+                r = sd_event_dispatch(e);
+                assert_se(r > 0);
+
+                r = sd_event_source_is_ratelimited(s);
+                assert_se(r >= 0);
+
+                if (c < 5)
+                        /* First four dispatches should just work */
+                        assert_se(!r);
+                else if (c == 5) {
+                        /* The fifth dispatch should still work, but we now expect the ratelimit to be hit subsequently */
+                        if (!expect_ratelimit) {
+                                assert_se(!r);
+                                assert_se(sd_event_source_leave_ratelimit(s) == 0); /* this should be a NOP, and return 0 hence */
+                                expect_ratelimit = true;
+                        } else {
+                                /* We expected the ratelimit, let's leave it manually, and verify it */
+                                assert_se(r);
+                                assert_se(sd_event_source_leave_ratelimit(s) > 0); /* we are ratelimited, hence should return > 0 */
+                                assert_se(sd_event_source_is_ratelimited(s) == 0);
+
+                                manually_left_ratelimit = true;
+                        }
+
+                } else if (c == 6)
+                        /* On the sixth iteration let's just exit */
+                        break;
+        }
+
+        /* Verify we definitely hit the ratelimit and left it manually again */
+        assert_se(manually_left_ratelimit);
+}
+
+DEFINE_TEST_MAIN(LOG_DEBUG);