sd-event: rework API to support CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM, too

22 files changed, 443 insertions, 239 deletions

diff --git a/src/core/job.c b/src/core/job.c
index 8e98bd93ab..35a9de6ee3 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -873,7 +873,12 @@ int job_start_timer(Job *j) {
         if (j->unit->job_timeout <= 0)
                 return 0;
 
-        r = sd_event_add_monotonic(j->manager->event, &j->timer_event_source, j->begin_usec + j->unit->job_timeout, 0, job_dispatch_timer, j);
+        r = sd_event_add_time(
+                        j->manager->event,
+                        &j->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        j->begin_usec + j->unit->job_timeout, 0,
+                        job_dispatch_timer, j);
         if (r < 0)
                 return r;
 
@@ -1061,7 +1066,12 @@ int job_coldplug(Job *j) {
         if (j->timer_event_source)
                 j->timer_event_source = sd_event_source_unref(j->timer_event_source);
 
-        r = sd_event_add_monotonic(j->manager->event, &j->timer_event_source, j->begin_usec + j->unit->job_timeout, 0, job_dispatch_timer, j);
+        r = sd_event_add_time(
+                        j->manager->event,
+                        &j->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        j->begin_usec + j->unit->job_timeout, 0,
+                        job_dispatch_timer, j);
         if (r < 0)
                 log_debug("Failed to restart timeout for job: %s", strerror(-r));
 
diff --git a/src/core/manager.c b/src/core/manager.c
index fd22d4863b..360a65a492 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -102,7 +102,12 @@ static int manager_watch_jobs_in_progress(Manager *m) {
                 return 0;
 
         next = now(CLOCK_MONOTONIC) + JOBS_IN_PROGRESS_WAIT_USEC;
-        return sd_event_add_monotonic(m->event, &m->jobs_in_progress_event_source, next, 0, manager_dispatch_jobs_in_progress, m);
+        return sd_event_add_time(
+                        m->event,
+                        &m->jobs_in_progress_event_source,
+                        CLOCK_MONOTONIC,
+                        next, 0,
+                        manager_dispatch_jobs_in_progress, m);
 }
 
 #define CYLON_BUFFER_EXTRA (2*(sizeof(ANSI_RED_ON)-1) + sizeof(ANSI_HIGHLIGHT_RED_ON)-1 + 2*(sizeof(ANSI_HIGHLIGHT_OFF)-1))
diff --git a/src/core/mount.c b/src/core/mount.c
index 21b7942946..a979837071 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -163,7 +163,12 @@ static int mount_arm_timer(Mount *m) {
                 return sd_event_source_set_enabled(m->timer_event_source, SD_EVENT_ONESHOT);
         }
 
-        return sd_event_add_monotonic(UNIT(m)->manager->event, &m->timer_event_source, now(CLOCK_MONOTONIC) + m->timeout_usec, 0, mount_dispatch_timer, m);
+        return sd_event_add_time(
+                        UNIT(m)->manager->event,
+                        &m->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + m->timeout_usec, 0,
+                        mount_dispatch_timer, m);
 }
 
 static void mount_unwatch_control_pid(Mount *m) {
diff --git a/src/core/scope.c b/src/core/scope.c
index aa4978de4c..e8f9e8dd73 100644
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -83,7 +83,12 @@ static int scope_arm_timer(Scope *s) {
                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
         }
 
-        return sd_event_add_monotonic(UNIT(s)->manager->event, &s->timer_event_source, now(CLOCK_MONOTONIC) + s->timeout_stop_usec, 0, scope_dispatch_timer, s);
+        return sd_event_add_time(
+                        UNIT(s)->manager->event,
+                        &s->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + s->timeout_stop_usec, 0,
+                        scope_dispatch_timer, s);
 }
 
 static void scope_set_state(Scope *s, ScopeState state) {
diff --git a/src/core/service.c b/src/core/service.c
index 78a2e06fff..67467b2d6d 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -257,7 +257,12 @@ static void service_start_watchdog(Service *s) {
 
                 r = sd_event_source_set_enabled(s->watchdog_event_source, SD_EVENT_ONESHOT);
         } else {
-                r = sd_event_add_monotonic(UNIT(s)->manager->event, &s->watchdog_event_source, s->watchdog_timestamp.monotonic + s->watchdog_usec, 0, service_dispatch_watchdog, s);
+                r = sd_event_add_time(
+                                UNIT(s)->manager->event,
+                                &s->watchdog_event_source,
+                                CLOCK_MONOTONIC,
+                                s->watchdog_timestamp.monotonic + s->watchdog_usec, 0,
+                                service_dispatch_watchdog, s);
                 if (r < 0) {
                         log_warning_unit(UNIT(s)->id, "%s failed to add watchdog timer: %s", UNIT(s)->id, strerror(-r));
                         return;
@@ -345,7 +350,12 @@ static int service_arm_timer(Service *s, usec_t usec) {
                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
         }
 
-        return sd_event_add_monotonic(UNIT(s)->manager->event, &s->timer_event_source, now(CLOCK_MONOTONIC) + usec, 0, service_dispatch_timer, s);
+        return sd_event_add_time(
+                        UNIT(s)->manager->event,
+                        &s->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + usec, 0,
+                        service_dispatch_timer, s);
 }
 
 #ifdef HAVE_SYSV_COMPAT
diff --git a/src/core/socket.c b/src/core/socket.c
index 3708a86f4d..7c18a2b75c 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -168,7 +168,12 @@ static int socket_arm_timer(Socket *s) {
                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
         }
 
-        return sd_event_add_monotonic(UNIT(s)->manager->event, &s->timer_event_source, now(CLOCK_MONOTONIC) + s->timeout_usec, 0, socket_dispatch_timer, s);
+        return sd_event_add_time(
+                        UNIT(s)->manager->event,
+                        &s->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + s->timeout_usec, 0,
+                        socket_dispatch_timer, s);
 }
 
 static int socket_instantiate_service(Socket *s) {
diff --git a/src/core/swap.c b/src/core/swap.c
index 7da742e873..10eed6d25f 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -179,7 +179,12 @@ static int swap_arm_timer(Swap *s) {
                 return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT);
         }
 
-        return sd_event_add_monotonic(UNIT(s)->manager->event, &s->timer_event_source, now(CLOCK_MONOTONIC) + s->timeout_usec, 0, swap_dispatch_timer, s);
+        return sd_event_add_time(
+                        UNIT(s)->manager->event,
+                        &s->timer_event_source,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + s->timeout_usec, 0,
+                        swap_dispatch_timer, s);
 }
 
 static int swap_add_device_links(Swap *s) {
diff --git a/src/core/timer.c b/src/core/timer.c
index 8ed0291ee6..95416f3e74 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -399,7 +399,12 @@ static void timer_enter_waiting(Timer *t, bool initial) {
 
                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
                 } else
-                        r = sd_event_add_monotonic(UNIT(t)->manager->event, &t->monotonic_event_source, t->next_elapse_monotonic, t->accuracy_usec, timer_dispatch, t);
+                        r = sd_event_add_time(
+                                        UNIT(t)->manager->event,
+                                        &t->monotonic_event_source,
+                                        CLOCK_MONOTONIC,
+                                        t->next_elapse_monotonic, t->accuracy_usec,
+                                        timer_dispatch, t);
                 if (r < 0)
                         goto fail;
 
@@ -421,7 +426,12 @@ static void timer_enter_waiting(Timer *t, bool initial) {
 
                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
                 } else
-                        r = sd_event_add_realtime(UNIT(t)->manager->event, &t->realtime_event_source, t->next_elapse_realtime, t->accuracy_usec, timer_dispatch, t);
+                        r = sd_event_add_time(
+                                        UNIT(t)->manager->event,
+                                        &t->realtime_event_source,
+                                        CLOCK_REALTIME,
+                                        t->next_elapse_realtime, t->accuracy_usec,
+                                        timer_dispatch, t);
                 if (r < 0)
                         goto fail;
 
diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index c2a60d5e83..6da81e7cde 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -1377,14 +1377,19 @@ int server_schedule_sync(Server *s, int priority) {
         if (s->sync_interval_usec > 0) {
                 usec_t when;
 
-                r = sd_event_get_now_monotonic(s->event, &when);
+                r = sd_event_now(s->event, CLOCK_MONOTONIC, &when);
                 if (r < 0)
                         return r;
 
                 when += s->sync_interval_usec;
 
                 if (!s->sync_event_source) {
-                        r = sd_event_add_monotonic(s->event, &s->sync_event_source, when, 0, server_dispatch_sync, s);
+                        r = sd_event_add_time(
+                                        s->event,
+                                        &s->sync_event_source,
+                                        CLOCK_MONOTONIC,
+                                        when, 0,
+                                        server_dispatch_sync, s);
                         if (r < 0)
                                 return r;
 
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 0728a15550..0be6212a4f 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -300,7 +300,7 @@ static int client_send_discover(sd_dhcp_client *client) {
 
         assert(client);
 
-        r = sd_event_get_now_monotonic(client->event, &time_now);
+        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
         if (r < 0)
                 return r;
         assert(time_now >= client->start_time);
@@ -427,7 +427,7 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
         assert(client);
         assert(client->event);
 
-        r = sd_event_get_now_monotonic(client->event, &time_now);
+        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
         if (r < 0)
                 goto error;
 
@@ -476,11 +476,11 @@ static int client_timeout_resend(sd_event_source *s, uint64_t usec,
 
         client->timeout_resend = sd_event_source_unref(client->timeout_resend);
 
-        r = sd_event_add_monotonic(client->event,
-                                     &client->timeout_resend,
-                                     next_timeout,
-                                     10 * USEC_PER_MSEC,
-                                     client_timeout_resend, client);
+        r = sd_event_add_time(client->event,
+                              &client->timeout_resend,
+                              CLOCK_MONOTONIC,
+                              next_timeout, 10 * USEC_PER_MSEC,
+                              client_timeout_resend, client);
         if (r < 0)
                 goto error;
 
@@ -560,9 +560,11 @@ static int client_initialize_events(sd_dhcp_client *client,
 
         client->timeout_resend = sd_event_source_unref(client->timeout_resend);
 
-        r = sd_event_add_monotonic(client->event,
-                                   &client->timeout_resend, 0, 0,
-                                   client_timeout_resend, client);
+        r = sd_event_add_time(client->event,
+                              &client->timeout_resend,
+                              CLOCK_MONOTONIC,
+                              0, 0,
+                              client_timeout_resend, client);
         if (r < 0)
                 goto error;
 
@@ -806,7 +808,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
         if (client->lease->lifetime == 0xffffffff)
                 return 0;
 
-        r = sd_event_get_now_monotonic(client->event, &time_now);
+        r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
         if (r < 0)
                 return r;
         assert(client->request_sent <= time_now);
@@ -856,10 +858,10 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
         }
 
         /* arm lifetime timeout */
-        r = sd_event_add_monotonic(client->event,
-                                   &client->timeout_expire, lifetime_timeout,
-                                   10 * USEC_PER_MSEC,
-                                   client_timeout_expire, client);
+        r = sd_event_add_time(client->event, &client->timeout_expire,
+                              CLOCK_MONOTONIC,
+                              lifetime_timeout, 10 * USEC_PER_MSEC,
+                              client_timeout_expire, client);
         if (r < 0)
                 return r;
 
@@ -877,11 +879,12 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
                 return 0;
 
         /* arm T2 timeout */
-        r = sd_event_add_monotonic(client->event,
-                                   &client->timeout_t2,
-                                   t2_timeout,
-                                   10 * USEC_PER_MSEC,
-                                   client_timeout_t2, client);
+        r = sd_event_add_time(client->event,
+                              &client->timeout_t2,
+                              CLOCK_MONOTONIC,
+                              t2_timeout,
+                              10 * USEC_PER_MSEC,
+                              client_timeout_t2, client);
         if (r < 0)
                 return r;
 
@@ -899,11 +902,11 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) {
                 return 0;
 
         /* arm T1 timeout */
-        r = sd_event_add_monotonic(client->event,
-                                   &client->timeout_t1,
-                                   t1_timeout,
-                                   10 * USEC_PER_MSEC,
-                                   client_timeout_t1, client);
+        r = sd_event_add_time(client->event,
+                              &client->timeout_t1,
+                              CLOCK_MONOTONIC,
+                              t1_timeout, 10 * USEC_PER_MSEC,
+                              client_timeout_t1, client);
         if (r < 0)
                 return r;
 
@@ -964,10 +967,11 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
                         client->state = DHCP_STATE_REQUESTING;
                         client->attempt = 1;
 
-                        r = sd_event_add_monotonic(client->event,
-                                                   &client->timeout_resend, 0,
-                                                   0, client_timeout_resend,
-                                                   client);
+                        r = sd_event_add_time(client->event,
+                                              &client->timeout_resend,
+                                              CLOCK_MONOTONIC,
+                                              0, 0,
+                                              client_timeout_resend, client);
                         if (r < 0)
                                 goto error;
 
diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
index 7431af729e..a201139b08 100644
--- a/src/libsystemd-network/sd-ipv4ll.c
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -165,7 +165,7 @@ static int ipv4ll_timer(sd_event_source *s, uint64_t usec, void *userdata) {
         return 0;
 }
 
-static void ipv4ll_set_next_wakeup (sd_ipv4ll *ll, int sec, int random_sec) {
+static void ipv4ll_set_next_wakeup(sd_ipv4ll *ll, int sec, int random_sec) {
         usec_t next_timeout = 0;
         usec_t time_now = 0;
 
@@ -178,7 +178,7 @@ static void ipv4ll_set_next_wakeup (sd_ipv4ll *ll, int sec, int random_sec) {
         if (random_sec)
                 next_timeout += random_u32() % (random_sec * USEC_PER_SEC);
 
-        if (sd_event_get_now_monotonic(ll->event, &time_now) < 0)
+        if (sd_event_now(ll->event, CLOCK_MONOTONIC, &time_now) < 0)
                 time_now = now(CLOCK_MONOTONIC);
 
         ll->next_wakeup = time_now + next_timeout;
@@ -278,7 +278,7 @@ static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void
 
                         if (ipv4ll_arp_conflict(ll, in_packet)) {
 
-                                r = sd_event_get_now_monotonic(ll->event, &time_now);
+                                r = sd_event_now(ll->event, CLOCK_MONOTONIC, &time_now);
                                 if (r < 0)
                                         goto out;
 
@@ -330,8 +330,8 @@ static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void
 
         if (ll->next_wakeup_valid) {
                 ll->timer = sd_event_source_unref(ll->timer);
-                r = sd_event_add_monotonic(ll->event, &ll->timer,
-                                   ll->next_wakeup, 0, ipv4ll_timer, ll);
+                r = sd_event_add_time(ll->event, &ll->timer, CLOCK_MONOTONIC,
+                                      ll->next_wakeup, 0, ipv4ll_timer, ll);
                 if (r < 0)
                         goto out;
 
@@ -530,8 +530,11 @@ int sd_ipv4ll_start (sd_ipv4ll *ll) {
         if (r < 0)
                 goto out;
 
-        r = sd_event_add_monotonic(ll->event, &ll->timer, now(CLOCK_MONOTONIC), 0,
-                                   ipv4ll_timer, ll);
+        r = sd_event_add_time(ll->event,
+                              &ll->timer,
+                              CLOCK_MONOTONIC,
+                              now(CLOCK_MONOTONIC), 0,
+                              ipv4ll_timer, ll);
 
         if (r < 0)
                 goto out;
diff --git a/src/libsystemd-network/test-dhcp-client.c b/src/libsystemd-network/test-dhcp-client.c
index 0f7adac562..2d4d59096a 100644
--- a/src/libsystemd-network/test-dhcp-client.c
+++ b/src/libsystemd-network/test-dhcp-client.c
@@ -466,9 +466,10 @@ static void test_addr_acq(sd_event *e)
 
         callback_recv = test_addr_acq_recv_discover;
 
-        assert_se(sd_event_add_monotonic(e, &test_hangcheck,
-                                         time_now + 2 * USEC_PER_SEC, 0,
-                                         test_dhcp_hangcheck, NULL) >= 0);
+        assert_se(sd_event_add_time(e, &test_hangcheck,
+                                    CLOCK_MONOTONIC,
+                                    time_now + 2 * USEC_PER_SEC, 0,
+                                    test_dhcp_hangcheck, NULL) >= 0);
 
         res = sd_dhcp_client_start(client);
         assert_se(res == 0 || res == -EINPROGRESS);
diff --git a/src/libsystemd/libsystemd.sym.m4 b/src/libsystemd/libsystemd.sym.m4
index 8589d605ab..d0ac64386e 100644
--- a/src/libsystemd/libsystemd.sym.m4
+++ b/src/libsystemd/libsystemd.sym.m4
@@ -360,8 +360,7 @@ m4_ifdef(`ENABLE_KDBUS',
         sd_event_ref;
         sd_event_unref;
         sd_event_add_io;
-        sd_event_add_monotonic;
-        sd_event_add_realtime;
+        sd_event_add_time;
         sd_event_add_signal;
         sd_event_add_child;
         sd_event_add_defer;
@@ -369,11 +368,10 @@ m4_ifdef(`ENABLE_KDBUS',
         sd_event_run;
         sd_event_loop;
         sd_event_exit;
+        sd_event_now;
         sd_event_get_state;
         sd_event_get_tid;
         sd_event_get_exit_code;
-        sd_event_get_now_realtime;
-        sd_event_get_now_monotonic;
         sd_event_set_watchdog;
         sd_event_get_watchdog;
         sd_event_source_ref;
@@ -395,6 +393,7 @@ m4_ifdef(`ENABLE_KDBUS',
         sd_event_source_set_time;
         sd_event_source_set_time_accuracy;
         sd_event_source_get_time_accuracy;
+        sd_event_source_get_time_clock;
         sd_event_source_get_signal;
         sd_event_source_get_child_pid;
         sd_event_source_get_event;
diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c
index bbe61a6a8f..3929b351e2 100644
--- a/src/libsystemd/sd-bus/sd-bus.c
+++ b/src/libsystemd/sd-bus/sd-bus.c
@@ -3065,7 +3065,7 @@ _public_ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
 
         bus->event_priority = priority;
 
-        r = sd_event_add_monotonic(bus->event, &bus->time_event_source, 0, 0, time_callback, bus);
+        r = sd_event_add_time(bus->event, &bus->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, bus);
         if (r < 0)
                 goto fail;
 
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index 3bda7f31ad..4552f4dad6 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -41,16 +41,22 @@
 
 typedef enum EventSourceType {
         SOURCE_IO,
-        SOURCE_MONOTONIC,
-        SOURCE_REALTIME,
+        SOURCE_TIME_REALTIME,
+        SOURCE_TIME_MONOTONIC,
+        SOURCE_TIME_REALTIME_ALARM,
+        SOURCE_TIME_BOOTTIME_ALARM,
         SOURCE_SIGNAL,
         SOURCE_CHILD,
         SOURCE_DEFER,
         SOURCE_POST,
         SOURCE_EXIT,
-        SOURCE_WATCHDOG
+        SOURCE_WATCHDOG,
+        _SOUFCE_EVENT_SOURCE_TYPE_MAX,
+        _SOURCE_EVENT_SOURCE_TYPE_INVALID = -1
 } EventSourceType;
 
+#define EVENT_SOURCE_IS_TIME(t) IN_SET((t), SOURCE_TIME_REALTIME, SOURCE_TIME_MONOTONIC, SOURCE_TIME_REALTIME_ALARM, SOURCE_TIME_BOOTTIME_ALARM)
+
 struct sd_event_source {
         unsigned n_ref;
 
@@ -58,7 +64,7 @@ struct sd_event_source {
         void *userdata;
         sd_event_handler_t prepare;
 
-        EventSourceType type:4;
+        EventSourceType type:5;
         int enabled:3;
         bool pending:1;
         bool dispatching:1;
@@ -107,30 +113,39 @@ struct sd_event_source {
         };
 };
 
+struct clock_data {
+        int fd;
+
+        /* For all clocks we maintain two priority queues each, one
+         * ordered for the earliest times the events may be
+         * dispatched, and one ordered by the latest times they must
+         * have been dispatched. The range between the top entries in
+         * the two prioqs is the time window we can freely schedule
+         * wakeups in */
+
+        Prioq *earliest;
+        Prioq *latest;
+        usec_t next;
+};
+
 struct sd_event {
         unsigned n_ref;
 
         int epoll_fd;
         int signal_fd;
-        int realtime_fd;
-        int monotonic_fd;
         int watchdog_fd;
 
         Prioq *pending;
         Prioq *prepare;
 
-        /* For both clocks we maintain two priority queues each, one
-         * ordered for the earliest times the events may be
-         * dispatched, and one ordered by the latest times they must
-         * have been dispatched. The range between the top entries in
-         * the two prioqs is the time window we can freely schedule
-         * wakeups in */
-        Prioq *monotonic_earliest;
-        Prioq *monotonic_latest;
-        Prioq *realtime_earliest;
-        Prioq *realtime_latest;
+        /* timerfd_create() only supports these four clocks so far. We
+         * can add support for more clocks when the kernel learns to
+         * deal with them, too. */
+        struct clock_data realtime;
+        struct clock_data monotonic;
+        struct clock_data realtime_alarm;
+        struct clock_data boottime_alarm;
 
-        usec_t realtime_next, monotonic_next;
         usec_t perturb;
 
         sigset_t sigset;
@@ -147,6 +162,7 @@ struct sd_event {
 
         unsigned iteration;
         dual_timestamp timestamp;
+        usec_t timestamp_boottime;
         int state;
 
         bool exit_requested:1;
@@ -234,8 +250,8 @@ static int prepare_prioq_compare(const void *a, const void *b) {
 static int earliest_time_prioq_compare(const void *a, const void *b) {
         const sd_event_source *x = a, *y = b;
 
-        assert(x->type == SOURCE_MONOTONIC || x->type == SOURCE_REALTIME);
-        assert(y->type == SOURCE_MONOTONIC || y->type == SOURCE_REALTIME);
+        assert(EVENT_SOURCE_IS_TIME(x->type));
+        assert(x->type == y->type);
 
         /* Enabled ones first */
         if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF)
@@ -267,8 +283,8 @@ static int earliest_time_prioq_compare(const void *a, const void *b) {
 static int latest_time_prioq_compare(const void *a, const void *b) {
         const sd_event_source *x = a, *y = b;
 
-        assert((x->type == SOURCE_MONOTONIC && y->type == SOURCE_MONOTONIC) ||
-               (x->type == SOURCE_REALTIME && y->type == SOURCE_REALTIME));
+        assert(EVENT_SOURCE_IS_TIME(x->type));
+        assert(x->type == y->type);
 
         /* Enabled ones first */
         if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF)
@@ -324,6 +340,14 @@ static int exit_prioq_compare(const void *a, const void *b) {
         return 0;
 }
 
+static void free_clock_data(struct clock_data *d) {
+        assert(d);
+
+        safe_close(d->fd);
+        prioq_free(d->earliest);
+        prioq_free(d->latest);
+}
+
 static void event_free(sd_event *e) {
         assert(e);
         assert(e->n_sources == 0);
@@ -333,16 +357,15 @@ static void event_free(sd_event *e) {
 
         safe_close(e->epoll_fd);
         safe_close(e->signal_fd);
-        safe_close(e->realtime_fd);
-        safe_close(e->monotonic_fd);
         safe_close(e->watchdog_fd);
 
+        free_clock_data(&e->realtime);
+        free_clock_data(&e->monotonic);
+        free_clock_data(&e->realtime_alarm);
+        free_clock_data(&e->boottime_alarm);
+
         prioq_free(e->pending);
         prioq_free(e->prepare);
-        prioq_free(e->monotonic_earliest);
-        prioq_free(e->monotonic_latest);
-        prioq_free(e->realtime_earliest);
-        prioq_free(e->realtime_latest);
         prioq_free(e->exit);
 
         free(e->signal_sources);
@@ -363,9 +386,10 @@ _public_ int sd_event_new(sd_event** ret) {
                 return -ENOMEM;
 
         e->n_ref = 1;
-        e->signal_fd = e->realtime_fd = e->monotonic_fd = e->watchdog_fd = e->epoll_fd = -1;
-        e->realtime_next = e->monotonic_next = (usec_t) -1;
+        e->signal_fd = e->watchdog_fd = e->epoll_fd = e->realtime.fd = e->monotonic.fd = e->realtime_alarm.fd = e->boottime_alarm.fd = -1;
+        e->realtime.next = e->monotonic.next = e->realtime_alarm.next = e->boottime_alarm.next = (usec_t) -1;
         e->original_pid = getpid();
+        e->perturb = (usec_t) -1;
 
         assert_se(sigemptyset(&e->sigset) == 0);
 
@@ -469,6 +493,70 @@ static int source_io_register(
         return 0;
 }
 
+static clockid_t event_source_type_to_clock(EventSourceType t) {
+
+        switch (t) {
+
+        case SOURCE_TIME_REALTIME:
+                return CLOCK_REALTIME;
+
+        case SOURCE_TIME_MONOTONIC:
+                return CLOCK_MONOTONIC;
+
+        case SOURCE_TIME_REALTIME_ALARM:
+                return CLOCK_REALTIME_ALARM;
+
+        case SOURCE_TIME_BOOTTIME_ALARM:
+                return CLOCK_BOOTTIME_ALARM;
+
+        default:
+                return (clockid_t) -1;
+        }
+}
+
+static EventSourceType clock_to_event_source_type(clockid_t clock) {
+
+        switch (clock) {
+
+        case CLOCK_REALTIME:
+                return SOURCE_TIME_REALTIME;
+
+        case CLOCK_MONOTONIC:
+                return SOURCE_TIME_MONOTONIC;
+
+        case CLOCK_REALTIME_ALARM:
+                return SOURCE_TIME_REALTIME_ALARM;
+
+        case CLOCK_BOOTTIME_ALARM:
+                return SOURCE_TIME_BOOTTIME_ALARM;
+
+        default:
+                return _SOURCE_EVENT_SOURCE_TYPE_INVALID;
+        }
+}
+
+static struct clock_data* event_get_clock_data(sd_event *e, EventSourceType t) {
+        assert(e);
+
+        switch (t) {
+
+        case SOURCE_TIME_REALTIME:
+                return &e->realtime;
+
+        case SOURCE_TIME_MONOTONIC:
+                return &e->monotonic;
+
+        case SOURCE_TIME_REALTIME_ALARM:
+                return &e->realtime_alarm;
+
+        case SOURCE_TIME_BOOTTIME_ALARM:
+                return &e->boottime_alarm;
+
+        default:
+                return NULL;
+        }
+}
+
 static void source_free(sd_event_source *s) {
         assert(s);
 
@@ -483,15 +571,19 @@ static void source_free(sd_event_source *s) {
 
                         break;
 
-                case SOURCE_MONOTONIC:
-                        prioq_remove(s->event->monotonic_earliest, s, &s->time.earliest_index);
-                        prioq_remove(s->event->monotonic_latest, s, &s->time.latest_index);
-                        break;
+                case SOURCE_TIME_REALTIME:
+                case SOURCE_TIME_MONOTONIC:
+                case SOURCE_TIME_REALTIME_ALARM:
+                case SOURCE_TIME_BOOTTIME_ALARM: {
+                        struct clock_data *d;
+
+                        d = event_get_clock_data(s->event, s->type);
+                        assert(d);
 
-                case SOURCE_REALTIME:
-                        prioq_remove(s->event->realtime_earliest, s, &s->time.earliest_index);
-                        prioq_remove(s->event->realtime_latest, s, &s->time.latest_index);
+                        prioq_remove(d->earliest, s, &s->time.earliest_index);
+                        prioq_remove(d->latest, s, &s->time.latest_index);
                         break;
+                }
 
                 case SOURCE_SIGNAL:
                         if (s->signal.sig > 0) {
@@ -531,7 +623,7 @@ static void source_free(sd_event_source *s) {
                         prioq_remove(s->event->exit, s, &s->exit.prioq_index);
                         break;
 
-                case SOURCE_WATCHDOG:
+                default:
                         assert_not_reached("Wut? I shouldn't exist.");
                 }
 
@@ -570,12 +662,14 @@ static int source_set_pending(sd_event_source *s, bool b) {
         } else
                 assert_se(prioq_remove(s->event->pending, s, &s->pending_index));
 
-        if (s->type == SOURCE_REALTIME) {
-                prioq_reshuffle(s->event->realtime_earliest, s, &s->time.earliest_index);
-                prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
-        } else if (s->type == SOURCE_MONOTONIC) {
-                prioq_reshuffle(s->event->monotonic_earliest, s, &s->time.earliest_index);
-                prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
+        if (EVENT_SOURCE_IS_TIME(s->type)) {
+                struct clock_data *d;
+
+                d = event_get_clock_data(s->event, s->type);
+                assert(d);
+
+                prioq_reshuffle(d->earliest, s, &s->time.earliest_index);
+                prioq_reshuffle(d->latest, s, &s->time.latest_index);
         }
 
         return 0;
@@ -641,26 +735,25 @@ _public_ int sd_event_add_io(
 
 static int event_setup_timer_fd(
                 sd_event *e,
-                EventSourceType type,
-                int *timer_fd,
-                clockid_t id) {
+                struct clock_data *d,
+                clockid_t clock) {
 
         sd_id128_t bootid = {};
         struct epoll_event ev = {};
         int r, fd;
 
         assert(e);
-        assert(timer_fd);
+        assert(d);
 
-        if (_likely_(*timer_fd >= 0))
+        if (_likely_(d->fd >= 0))
                 return 0;
 
-        fd = timerfd_create(id, TFD_NONBLOCK|TFD_CLOEXEC);
+        fd = timerfd_create(clock, TFD_NONBLOCK|TFD_CLOEXEC);
         if (fd < 0)
                 return -errno;
 
         ev.events = EPOLLIN;
-        ev.data.ptr = INT_TO_PTR(type);
+        ev.data.ptr = INT_TO_PTR(clock_to_event_source_type(clock));
 
         r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, fd, &ev);
         if (r < 0) {
@@ -668,6 +761,8 @@ static int event_setup_timer_fd(
                 return -errno;
         }
 
+        d->fd = fd;
+
         /* When we sleep for longer, we try to realign the wakeup to
            the same time wihtin each minute/second/250ms, so that
            events all across the system can be coalesced into a single
@@ -677,55 +772,55 @@ static int event_setup_timer_fd(
            bit. Here, we calculate a perturbation usec offset from the
            boot ID. */
 
-        if (sd_id128_get_boot(&bootid) >= 0)
-                e->perturb = (bootid.qwords[0] ^ bootid.qwords[1]) % USEC_PER_MINUTE;
+        if (e->perturb == (usec_t) -1)
+                if (sd_id128_get_boot(&bootid) >= 0)
+                        e->perturb = (bootid.qwords[0] ^ bootid.qwords[1]) % USEC_PER_MINUTE;
 
-        *timer_fd = fd;
         return 0;
 }
 
-static int event_add_time_internal(
+_public_ int sd_event_add_time(
                 sd_event *e,
                 sd_event_source **ret,
-                EventSourceType type,
-                int *timer_fd,
-                clockid_t id,
-                Prioq **earliest,
-                Prioq **latest,
+                clockid_t clock,
                 uint64_t usec,
                 uint64_t accuracy,
                 sd_event_time_handler_t callback,
                 void *userdata) {
 
+        EventSourceType type;
         sd_event_source *s;
+        struct clock_data *d;
         int r;
 
         assert_return(e, -EINVAL);
-        assert_return(callback, -EINVAL);
         assert_return(ret, -EINVAL);
         assert_return(usec != (uint64_t) -1, -EINVAL);
         assert_return(accuracy != (uint64_t) -1, -EINVAL);
+        assert_return(callback, -EINVAL);
         assert_return(e->state != SD_EVENT_FINISHED, -ESTALE);
         assert_return(!event_pid_changed(e), -ECHILD);
 
-        assert(timer_fd);
-        assert(earliest);
-        assert(latest);
+        type = clock_to_event_source_type(clock);
+        assert_return(type >= 0, -ENOTSUP);
+
+        d = event_get_clock_data(e, type);
+        assert(d);
 
-        if (!*earliest) {
-                *earliest = prioq_new(earliest_time_prioq_compare);
-                if (!*earliest)
+        if (!d->earliest) {
+                d->earliest = prioq_new(earliest_time_prioq_compare);
+                if (!d->earliest)
                         return -ENOMEM;
         }
 
-        if (!*latest) {
-                *latest = prioq_new(latest_time_prioq_compare);
-                if (!*latest)
+        if (!d->latest) {
+                d->latest = prioq_new(latest_time_prioq_compare);
+                if (!d->latest)
                         return -ENOMEM;
         }
 
-        if (*timer_fd < 0) {
-                r = event_setup_timer_fd(e, type, timer_fd, id);
+        if (d->fd < 0) {
+                r = event_setup_timer_fd(e, d, clock);
                 if (r < 0)
                         return r;
         }
@@ -741,11 +836,11 @@ static int event_add_time_internal(
         s->userdata = userdata;
         s->enabled = SD_EVENT_ONESHOT;
 
-        r = prioq_put(*earliest, s, &s->time.earliest_index);
+        r = prioq_put(d->earliest, s, &s->time.earliest_index);
         if (r < 0)
                 goto fail;
 
-        r = prioq_put(*latest, s, &s->time.latest_index);
+        r = prioq_put(d->latest, s, &s->time.latest_index);
         if (r < 0)
                 goto fail;
 
@@ -757,26 +852,6 @@ fail:
         return r;
 }
 
-_public_ int sd_event_add_monotonic(sd_event *e,
-                                    sd_event_source **ret,
-                                    uint64_t usec,
-                                    uint64_t accuracy,
-                                    sd_event_time_handler_t callback,
-                                    void *userdata) {
-
-        return event_add_time_internal(e, ret, SOURCE_MONOTONIC, &e->monotonic_fd, CLOCK_MONOTONIC, &e->monotonic_earliest, &e->monotonic_latest, usec, accuracy, callback, userdata);
-}
-
-_public_ int sd_event_add_realtime(sd_event *e,
-                                   sd_event_source **ret,
-                                   uint64_t usec,
-                                   uint64_t accuracy,
-                                   sd_event_time_handler_t callback,
-                                   void *userdata) {
-
-        return event_add_time_internal(e, ret, SOURCE_REALTIME, &e->realtime_fd, CLOCK_REALTIME, &e->realtime_earliest, &e->realtime_latest, usec, accuracy, callback, userdata);
-}
-
 static int event_update_signal_fd(sd_event *e) {
         struct epoll_event ev = {};
         bool add_to_epoll;
@@ -1244,17 +1319,20 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                         s->enabled = m;
                         break;
 
-                case SOURCE_MONOTONIC:
-                        s->enabled = m;
-                        prioq_reshuffle(s->event->monotonic_earliest, s, &s->time.earliest_index);
-                        prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
-                        break;
+                case SOURCE_TIME_REALTIME:
+                case SOURCE_TIME_MONOTONIC:
+                case SOURCE_TIME_REALTIME_ALARM:
+                case SOURCE_TIME_BOOTTIME_ALARM: {
+                        struct clock_data *d;
 
-                case SOURCE_REALTIME:
                         s->enabled = m;
-                        prioq_reshuffle(s->event->realtime_earliest, s, &s->time.earliest_index);
-                        prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
+                        d = event_get_clock_data(s->event, s->type);
+                        assert(d);
+
+                        prioq_reshuffle(d->earliest, s, &s->time.earliest_index);
+                        prioq_reshuffle(d->latest, s, &s->time.latest_index);
                         break;
+                }
 
                 case SOURCE_SIGNAL:
                         s->enabled = m;
@@ -1288,7 +1366,7 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                         s->enabled = m;
                         break;
 
-                case SOURCE_WATCHDOG:
+                default:
                         assert_not_reached("Wut? I shouldn't exist.");
                 }
 
@@ -1303,17 +1381,20 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                         s->enabled = m;
                         break;
 
-                case SOURCE_MONOTONIC:
-                        s->enabled = m;
-                        prioq_reshuffle(s->event->monotonic_earliest, s, &s->time.earliest_index);
-                        prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
-                        break;
+                case SOURCE_TIME_REALTIME:
+                case SOURCE_TIME_MONOTONIC:
+                case SOURCE_TIME_REALTIME_ALARM:
+                case SOURCE_TIME_BOOTTIME_ALARM: {
+                        struct clock_data *d;
 
-                case SOURCE_REALTIME:
                         s->enabled = m;
-                        prioq_reshuffle(s->event->realtime_earliest, s, &s->time.earliest_index);
-                        prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
+                        d = event_get_clock_data(s->event, s->type);
+                        assert(d);
+
+                        prioq_reshuffle(d->earliest, s, &s->time.earliest_index);
+                        prioq_reshuffle(d->latest, s, &s->time.latest_index);
                         break;
+                }
 
                 case SOURCE_SIGNAL:
                         s->enabled = m;
@@ -1347,7 +1428,7 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                         s->enabled = m;
                         break;
 
-                case SOURCE_WATCHDOG:
+                default:
                         assert_not_reached("Wut? I shouldn't exist.");
                 }
         }
@@ -1364,7 +1445,7 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
 _public_ int sd_event_source_get_time(sd_event_source *s, uint64_t *usec) {
         assert_return(s, -EINVAL);
         assert_return(usec, -EINVAL);
-        assert_return(s->type == SOURCE_REALTIME || s->type == SOURCE_MONOTONIC, -EDOM);
+        assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM);
         assert_return(!event_pid_changed(s->event), -ECHILD);
 
         *usec = s->time.next;
@@ -1372,9 +1453,11 @@ _public_ int sd_event_source_get_time(sd_event_source *s, uint64_t *usec) {
 }
 
 _public_ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) {
+        struct clock_data *d;
+
         assert_return(s, -EINVAL);
         assert_return(usec != (uint64_t) -1, -EINVAL);
-        assert_return(s->type == SOURCE_REALTIME || s->type == SOURCE_MONOTONIC, -EDOM);
+        assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM);
         assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE);
         assert_return(!event_pid_changed(s->event), -ECHILD);
 
@@ -1382,13 +1465,11 @@ _public_ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) {
 
         source_set_pending(s, false);
 
-        if (s->type == SOURCE_REALTIME) {
-                prioq_reshuffle(s->event->realtime_earliest, s, &s->time.earliest_index);
-                prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
-        } else {
-                prioq_reshuffle(s->event->monotonic_earliest, s, &s->time.earliest_index);
-                prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
-        }
+        d = event_get_clock_data(s->event, s->type);
+        assert(d);
+
+        prioq_reshuffle(d->earliest, s, &s->time.earliest_index);
+        prioq_reshuffle(d->latest, s, &s->time.latest_index);
 
         return 0;
 }
@@ -1396,7 +1477,7 @@ _public_ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) {
 _public_ int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec) {
         assert_return(s, -EINVAL);
         assert_return(usec, -EINVAL);
-        assert_return(s->type == SOURCE_REALTIME || s->type == SOURCE_MONOTONIC, -EDOM);
+        assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM);
         assert_return(!event_pid_changed(s->event), -ECHILD);
 
         *usec = s->time.accuracy;
@@ -1404,9 +1485,11 @@ _public_ int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *use
 }
 
 _public_ int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec) {
+        struct clock_data *d;
+
         assert_return(s, -EINVAL);
         assert_return(usec != (uint64_t) -1, -EINVAL);
-        assert_return(s->type == SOURCE_REALTIME || s->type == SOURCE_MONOTONIC, -EDOM);
+        assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM);
         assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE);
         assert_return(!event_pid_changed(s->event), -ECHILD);
 
@@ -1417,11 +1500,21 @@ _public_ int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec
 
         source_set_pending(s, false);
 
-        if (s->type == SOURCE_REALTIME)
-                prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
-        else
-                prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
+        d = event_get_clock_data(s->event, s->type);
+        assert(d);
+
+        prioq_reshuffle(d->latest, s, &s->time.latest_index);
+
+        return 0;
+}
+
+_public_ int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *clock) {
+        assert_return(s, -EINVAL);
+        assert_return(clock, -EINVAL);
+        assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM);
+        assert_return(!event_pid_changed(s->event), -ECHILD);
 
+        *clock = event_source_type_to_clock(s->type);
         return 0;
 }
 
@@ -1562,10 +1655,7 @@ static usec_t sleep_between(sd_event *e, usec_t a, usec_t b) {
 
 static int event_arm_timer(
                 sd_event *e,
-                int timer_fd,
-                Prioq *earliest,
-                Prioq *latest,
-                usec_t *next) {
+                struct clock_data *d) {
 
         struct itimerspec its = {};
         sd_event_source *a, *b;
@@ -1573,35 +1663,34 @@ static int event_arm_timer(
         int r;
 
         assert(e);
-        assert(next);
+        assert(d);
 
-        a = prioq_peek(earliest);
+        a = prioq_peek(d->earliest);
         if (!a || a->enabled == SD_EVENT_OFF) {
 
-                if (timer_fd < 0)
+                if (d->fd < 0)
                         return 0;
 
-                if (*next == (usec_t) -1)
+                if (d->next == (usec_t) -1)
                         return 0;
 
                 /* disarm */
-                r = timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &its, NULL);
+                r = timerfd_settime(d->fd, TFD_TIMER_ABSTIME, &its, NULL);
                 if (r < 0)
                         return r;
 
-                *next = (usec_t) -1;
-
+                d->next = (usec_t) -1;
                 return 0;
         }
 
-        b = prioq_peek(latest);
+        b = prioq_peek(d->latest);
         assert_se(b && b->enabled != SD_EVENT_OFF);
 
         t = sleep_between(e, a->time.next, b->time.next + b->time.accuracy);
-        if (*next == t)
+        if (d->next == t)
                 return 0;
 
-        assert_se(timer_fd >= 0);
+        assert_se(d->fd >= 0);
 
         if (t == 0) {
                 /* We don' want to disarm here, just mean some time looooong ago. */
@@ -1610,11 +1699,11 @@ static int event_arm_timer(
         } else
                 timespec_store(&its.it_value, t);
 
-        r = timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &its, NULL);
+        r = timerfd_settime(d->fd, TFD_TIMER_ABSTIME, &its, NULL);
         if (r < 0)
                 return -errno;
 
-        *next = t;
+        d->next = t;
         return 0;
 }
 
@@ -1666,16 +1755,16 @@ static int flush_timer(sd_event *e, int fd, uint32_t events, usec_t *next) {
 static int process_timer(
                 sd_event *e,
                 usec_t n,
-                Prioq *earliest,
-                Prioq *latest) {
+                struct clock_data *d) {
 
         sd_event_source *s;
         int r;
 
         assert(e);
+        assert(d);
 
         for (;;) {
-                s = prioq_peek(earliest);
+                s = prioq_peek(d->earliest);
                 if (!s ||
                     s->time.next > n ||
                     s->enabled == SD_EVENT_OFF ||
@@ -1686,8 +1775,8 @@ static int process_timer(
                 if (r < 0)
                         return r;
 
-                prioq_reshuffle(earliest, s, &s->time.earliest_index);
-                prioq_reshuffle(latest, s, &s->time.latest_index);
+                prioq_reshuffle(d->earliest, s, &s->time.earliest_index);
+                prioq_reshuffle(d->latest, s, &s->time.latest_index);
         }
 
         return 0;
@@ -1848,11 +1937,10 @@ static int source_dispatch(sd_event_source *s) {
                 r = s->io.callback(s, s->io.fd, s->io.revents, s->userdata);
                 break;
 
-        case SOURCE_MONOTONIC:
-                r = s->time.callback(s, s->time.next, s->userdata);
-                break;
-
-        case SOURCE_REALTIME:
+        case SOURCE_TIME_REALTIME:
+        case SOURCE_TIME_MONOTONIC:
+        case SOURCE_TIME_REALTIME_ALARM:
+        case SOURCE_TIME_BOOTTIME_ALARM:
                 r = s->time.callback(s, s->time.next, s->userdata);
                 break;
 
@@ -2038,16 +2126,25 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
         if (r < 0)
                 goto finish;
 
-        r = event_arm_timer(e, e->monotonic_fd, e->monotonic_earliest, e->monotonic_latest, &e->monotonic_next);
+        r = event_arm_timer(e, &e->realtime);
+        if (r < 0)
+                goto finish;
+
+        r = event_arm_timer(e, &e->monotonic);
+        if (r < 0)
+                goto finish;
+
+        r = event_arm_timer(e, &e->realtime_alarm);
         if (r < 0)
                 goto finish;
 
-        r = event_arm_timer(e, e->realtime_fd, e->realtime_earliest, e->realtime_latest, &e->realtime_next);
+        r = event_arm_timer(e, &e->boottime_alarm);
         if (r < 0)
                 goto finish;
 
         if (event_next_pending(e) || e->need_process_child)
                 timeout = 0;
+
         ev_queue_max = CLAMP(e->n_sources, 1U, EPOLL_QUEUE_MAX);
         ev_queue = newa(struct epoll_event, ev_queue_max);
 
@@ -2059,16 +2156,21 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
         }
 
         dual_timestamp_get(&e->timestamp);
+        e->timestamp_boottime = now(CLOCK_BOOTTIME);
 
         for (i = 0; i < m; i++) {
 
-                if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_MONOTONIC))
-                        r = flush_timer(e, e->monotonic_fd, ev_queue[i].events, &e->monotonic_next);
-                else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_REALTIME))
-                        r = flush_timer(e, e->realtime_fd, ev_queue[i].events, &e->realtime_next);
+                if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_TIME_REALTIME))
+                        r = flush_timer(e, e->realtime.fd, ev_queue[i].events, &e->realtime.next);
+                else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_TIME_MONOTONIC))
+                        r = flush_timer(e, e->monotonic.fd, ev_queue[i].events, &e->monotonic.next);
+                else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_TIME_REALTIME_ALARM))
+                        r = flush_timer(e, e->realtime_alarm.fd, ev_queue[i].events, &e->realtime_alarm.next);
+                else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_TIME_BOOTTIME_ALARM))
+                        r = flush_timer(e, e->boottime_alarm.fd, ev_queue[i].events, &e->boottime_alarm.next);
                 else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_SIGNAL))
                         r = process_signal(e, ev_queue[i].events);
-                else if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_WATCHDOG))
+                else if (ev_queue[i].data.ptr ==  INT_TO_PTR(SOURCE_WATCHDOG))
                         r = flush_timer(e, e->watchdog_fd, ev_queue[i].events, NULL);
                 else
                         r = process_io(e, ev_queue[i].data.ptr, ev_queue[i].events);
@@ -2081,11 +2183,19 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
         if (r < 0)
                 goto finish;
 
-        r = process_timer(e, e->timestamp.monotonic, e->monotonic_earliest, e->monotonic_latest);
+        r = process_timer(e, e->timestamp.realtime, &e->realtime);
+        if (r < 0)
+                goto finish;
+
+        r = process_timer(e, e->timestamp.monotonic, &e->monotonic);
+        if (r < 0)
+                goto finish;
+
+        r = process_timer(e, e->timestamp.realtime, &e->realtime_alarm);
         if (r < 0)
                 goto finish;
 
-        r = process_timer(e, e->timestamp.realtime, e->realtime_earliest, e->realtime_latest);
+        r = process_timer(e, e->timestamp_boottime, &e->boottime_alarm);
         if (r < 0)
                 goto finish;
 
@@ -2162,23 +2272,31 @@ _public_ int sd_event_exit(sd_event *e, int code) {
         return 0;
 }
 
-_public_ int sd_event_get_now_realtime(sd_event *e, uint64_t *usec) {
+_public_ int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec) {
         assert_return(e, -EINVAL);
         assert_return(usec, -EINVAL);
-        assert_return(dual_timestamp_is_set(&e->timestamp), -ENODATA);
         assert_return(!event_pid_changed(e), -ECHILD);
 
-        *usec = e->timestamp.realtime;
-        return 0;
-}
+        /* If we haven't run yet, just get the actual time */
+        if (!dual_timestamp_is_set(&e->timestamp))
+                return -ENODATA;
 
-_public_ int sd_event_get_now_monotonic(sd_event *e, uint64_t *usec) {
-        assert_return(e, -EINVAL);
-        assert_return(usec, -EINVAL);
-        assert_return(dual_timestamp_is_set(&e->timestamp), -ENODATA);
-        assert_return(!event_pid_changed(e), -ECHILD);
+        switch (clock) {
+
+        case CLOCK_REALTIME:
+        case CLOCK_REALTIME_ALARM:
+                *usec = e->timestamp.realtime;
+                break;
+
+        case CLOCK_MONOTONIC:
+                *usec = e->timestamp.monotonic;
+                break;
+
+        case CLOCK_BOOTTIME_ALARM:
+                *usec = e->timestamp_boottime;
+                break;
+        }
 
-        *usec = e->timestamp.monotonic;
         return 0;
 }
 
diff --git a/src/libsystemd/sd-event/test-event.c b/src/libsystemd/sd-event/test-event.c
index 0b7e2e48c4..68bb2b0ca8 100644
--- a/src/libsystemd/sd-event/test-event.c
+++ b/src/libsystemd/sd-event/test-event.c
@@ -196,7 +196,7 @@ int main(int argc, char *argv[]) {
 
         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);
-        assert_se(sd_event_add_monotonic(e, &z, 0, 0, time_handler, INT_TO_PTR('c')) >= 0);
+        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);
diff --git a/src/libsystemd/sd-rtnl/sd-rtnl.c b/src/libsystemd/sd-rtnl/sd-rtnl.c
index 6042657642..a2760d056b 100644
--- a/src/libsystemd/sd-rtnl/sd-rtnl.c
+++ b/src/libsystemd/sd-rtnl/sd-rtnl.c
@@ -838,7 +838,7 @@ int sd_rtnl_attach_event(sd_rtnl *rtnl, sd_event *event, int priority) {
         if (r < 0)
                 goto fail;
 
-        r = sd_event_add_monotonic(rtnl->event, &rtnl->time_event_source, 0, 0, time_callback, rtnl);
+        r = sd_event_add_time(rtnl->event, &rtnl->time_event_source, CLOCK_MONOTONIC, 0, 0, time_callback, rtnl);
         if (r < 0)
                 goto fail;
 
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 2ef87f72aa..0af67148af 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -1340,7 +1340,12 @@ int manager_set_lid_switch_ignore(Manager *m, usec_t until) {
 
                 r = sd_event_source_set_time(m->lid_switch_ignore_event_source, until);
         } else
-                r = sd_event_add_monotonic(m->event, &m->lid_switch_ignore_event_source, until, 0, lid_switch_ignore_handler, m);
+                r = sd_event_add_time(
+                                m->event,
+                                &m->lid_switch_ignore_event_source,
+                                CLOCK_MONOTONIC,
+                                until, 0,
+                                lid_switch_ignore_handler, m);
 
         return r;
 }
diff --git a/src/login/logind-session.c b/src/login/logind-session.c
index 8c517f46a7..4ca6b5d805 100644
--- a/src/login/logind-session.c
+++ b/src/login/logind-session.c
@@ -682,7 +682,11 @@ void session_release(Session *s) {
                 return;
 
         if (!s->timer_event_source)
-                sd_event_add_monotonic(s->manager->event, &s->timer_event_source, now(CLOCK_MONOTONIC) + RELEASE_USEC, 0, release_timeout_callback, s);
+                sd_event_add_time(s->manager->event,
+                                  &s->timer_event_source,
+                                  CLOCK_MONOTONIC,
+                                  now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
+                                  release_timeout_callback, s);
 }
 
 bool session_is_active(Session *s) {
diff --git a/src/login/logind.c b/src/login/logind.c
index db9882323f..86ce7df5d6 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -933,7 +933,12 @@ static int manager_dispatch_idle_action(sd_event_source *s, uint64_t t, void *us
 
         if (!m->idle_action_event_source) {
 
-                r = sd_event_add_monotonic(m->event, &m->idle_action_event_source, elapse, USEC_PER_SEC*30, manager_dispatch_idle_action, m);
+                r = sd_event_add_time(
+                                m->event,
+                                &m->idle_action_event_source,
+                                CLOCK_MONOTONIC,
+                                elapse, USEC_PER_SEC*30,
+                                manager_dispatch_idle_action, m);
                 if (r < 0) {
                         log_error("Failed to add idle event source: %s", strerror(-r));
                         return r;
diff --git a/src/systemd/sd-event.h b/src/systemd/sd-event.h
index 45c36086f6..c0bd03bccf 100644
--- a/src/systemd/sd-event.h
+++ b/src/systemd/sd-event.h
@@ -77,8 +77,7 @@ sd_event* sd_event_ref(sd_event *e);
 sd_event* sd_event_unref(sd_event *e);
 
 int sd_event_add_io(sd_event *e, sd_event_source **s, int fd, uint32_t events, sd_event_io_handler_t callback, void *userdata);
-int sd_event_add_monotonic(sd_event *e, sd_event_source **s, uint64_t usec, uint64_t accuracy, sd_event_time_handler_t callback, void *userdata);
-int sd_event_add_realtime(sd_event *e, sd_event_source **s, uint64_t usec, uint64_t accuracy, sd_event_time_handler_t callback, void *userdata);
+int sd_event_add_time(sd_event *e, sd_event_source **s, clockid_t clock, uint64_t usec, uint64_t accuracy, sd_event_time_handler_t callback, void *userdata);
 int sd_event_add_signal(sd_event *e, sd_event_source **s, int sig, sd_event_signal_handler_t callback, void *userdata);
 int sd_event_add_child(sd_event *e, sd_event_source **s, pid_t pid, int options, sd_event_child_handler_t callback, void *userdata);
 int sd_event_add_defer(sd_event *e, sd_event_source **s, sd_event_handler_t callback, void *userdata);
@@ -89,11 +88,11 @@ int sd_event_run(sd_event *e, uint64_t timeout);
 int sd_event_loop(sd_event *e);
 int sd_event_exit(sd_event *e, int code);
 
+int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec);
+
 int sd_event_get_state(sd_event *e);
 int sd_event_get_tid(sd_event *e, pid_t *tid);
 int sd_event_get_exit_code(sd_event *e, int *code);
-int sd_event_get_now_realtime(sd_event *e, uint64_t *usec);
-int sd_event_get_now_monotonic(sd_event *e, uint64_t *usec);
 int sd_event_set_watchdog(sd_event *e, int b);
 int sd_event_get_watchdog(sd_event *e);
 
@@ -117,6 +116,7 @@ int sd_event_source_get_time(sd_event_source *s, uint64_t *usec);
 int sd_event_source_set_time(sd_event_source *s, uint64_t usec);
 int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec);
 int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec);
+int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *clock);
 int sd_event_source_get_signal(sd_event_source *s);
 int sd_event_source_get_child_pid(sd_event_source *s, pid_t *pid);
 sd_event *sd_event_source_get_event(sd_event_source *s);
diff --git a/src/timedate/timedate-sntp.c b/src/timedate/timedate-sntp.c
index cb0bf794f1..880b467a8e 100644
--- a/src/timedate/timedate-sntp.c
+++ b/src/timedate/timedate-sntp.c
@@ -265,7 +265,12 @@ static int sntp_arm_timer(SNTPContext *sntp, usec_t next) {
         }
 
         e = sd_event_source_get_event(sntp->event_receive);
-        r = sd_event_add_monotonic(e, &sntp->event_timer, now(CLOCK_MONOTONIC) + next, 0, sntp_timer, sntp);
+        r = sd_event_add_time(
+                        e,
+                        &sntp->event_timer,
+                        CLOCK_MONOTONIC,
+                        now(CLOCK_MONOTONIC) + next, 0,
+                        sntp_timer, sntp);
         if (r < 0)
                 return r;