1 files changed, 153 insertions, 0 deletions
diff --git a/src/libsystemd/sd-event/event-util.c b/src/libsystemd/sd-event/event-util.c
new file mode 100644
index 0000000..a310122
--- /dev/null
+++ b/src/libsystemd/sd-event/event-util.c
@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+
+#include "event-source.h"
+#include "event-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "string-util.h"
+
+int event_reset_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,
+                int64_t priority,
+                const char *description,
+                bool force_reset) {
+
+        bool created = false;
+        int enabled, r;
+        clockid_t c;
+
+        assert(e);
+        assert(s);
+
+        if (*s) {
+                if (!force_reset) {
+                        r = sd_event_source_get_enabled(*s, &enabled);
+                        if (r < 0)
+                                return log_debug_errno(r, "sd-event: Failed to query whether event source \"%s\" is enabled or not: %m",
+                                                       strna((*s)->description ?: description));
+
+                        if (enabled != SD_EVENT_OFF)
+                                return 0;
+                }
+
+                r = sd_event_source_get_time_clock(*s, &c);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to get clock id of event source \"%s\": %m", strna((*s)->description ?: description));
+
+                if (c != clock)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "sd-event: Current clock id %i of event source \"%s\" is different from specified one %i.",
+                                               (int)c,
+                                               strna((*s)->description ?: description),
+                                               (int)clock);
+
+                r = sd_event_source_set_time(*s, usec);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to set time for event source \"%s\": %m", strna((*s)->description ?: description));
+
+                r = sd_event_source_set_time_accuracy(*s, accuracy);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to set accuracy for event source \"%s\": %m", strna((*s)->description ?: description));
+
+                /* callback function is not updated, as we do not have sd_event_source_set_time_callback(). */
+
+                (void) sd_event_source_set_userdata(*s, userdata);
+
+                r = sd_event_source_set_enabled(*s, SD_EVENT_ONESHOT);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to enable event source \"%s\": %m", strna((*s)->description ?: description));
+        } else {
+                r = sd_event_add_time(e, s, clock, usec, accuracy, callback, userdata);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to create timer event \"%s\": %m", strna(description));
+
+                created = true;
+        }
+
+        r = sd_event_source_set_priority(*s, priority);
+        if (r < 0)
+                return log_debug_errno(r, "sd-event: Failed to set priority for event source \"%s\": %m", strna((*s)->description ?: description));
+
+        if (description) {
+                r = sd_event_source_set_description(*s, description);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to set description for event source \"%s\": %m", description);
+        }
+
+        return created;
+}
+
+int event_reset_time_relative(
+                sd_event *e,
+                sd_event_source **s,
+                clockid_t clock,
+                uint64_t usec,
+                uint64_t accuracy,
+                sd_event_time_handler_t callback,
+                void *userdata,
+                int64_t priority,
+                const char *description,
+                bool force_reset) {
+
+        int r;
+
+        assert(e);
+
+        if (usec > 0) {
+                usec_t usec_now;
+
+                r = sd_event_now(e, clock, &usec_now);
+                if (r < 0)
+                        return log_debug_errno(r, "sd-event: Failed to get the current time: %m");
+
+                usec = usec_add(usec_now, usec);
+        }
+
+        return event_reset_time(e, s, clock, usec, accuracy, callback, userdata, priority, description, force_reset);
+}
+
+int event_add_time_change(sd_event *e, sd_event_source **ret, sd_event_io_handler_t callback, void *userdata) {
+        _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL;
+        _cleanup_close_ int fd = -EBADF;
+        int r;
+
+        assert(e);
+
+        /* Allocates an IO event source that gets woken up whenever the clock changes. Needs to be recreated on each event */
+
+        fd = time_change_fd();
+        if (fd < 0)
+                return fd;
+
+        r = sd_event_add_io(e, &s, fd, EPOLLIN, callback, userdata);
+        if (r < 0)
+                return r;
+
+        r = sd_event_source_set_io_fd_own(s, true);
+        if (r < 0)
+                return r;
+
+        TAKE_FD(fd);
+
+        r = sd_event_source_set_description(s, "time-change");
+        if (r < 0)
+                return r;
+
+        if (ret)
+                *ret = TAKE_PTR(s);
+        else {
+                r = sd_event_source_set_floating(s, true);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}