1 files changed, 87 insertions, 0 deletions
diff --git a/libhw/host_alarmclock.c b/libhw/host_alarmclock.c
new file mode 100644
index 0000000..a89294c
--- /dev/null
+++ b/libhw/host_alarmclock.c
@@ -0,0 +1,87 @@
+/* libhw/host_alarmclock.c - <libhw/generic/alarmclock.h> implementation for POSIX hosts
+ *
+ * Copyright (C) 2024  Luke T. Shumaker <lukeshu@lukeshu.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+#include <assert.h>
+#include <time.h> /* for clock_gettime(), CLOCK_MONOTONIC, clockid_t, struct timespec */
+
+#include <libmisc/vcall.h>
+
+#define IMPLEMENTATION_FOR_LIBHW_GENERIC_ALARMCLOCK_H YES
+#include <libhw/generic/alarmclock.h>
+
+#include "host_sigrt.h"
+
+struct hostclock {
+	implements_alarmclock;
+	bool                             initialized;
+	clockid_t                        clock_id;
+	timer_t                          timer_id;
+	struct alarmclock_trigger       *queue;
+};
+
+static uint64_t hostclock_get_ns(implements_alarmclock *_alarmclock) {
+	struct hostclock *alarmclock =
+		VCALL_SELF(struct hostclock, implements_alarmclock, _alarmclock);
+	assert(alarmclock);
+
+	struct timespec ts;
+	int r;
+
+	r = clock_gettime(alarmclock->clock_id, &ts);
+	assert(r == 0);
+
+	return (((uint64_t)ts.tv_sec) * NS_PER_S) + (uint64_t)ts.tv_nsec;
+}
+
+static void hostclock_handle_sig_alarm(int UNUSED(sig), siginfo_t *info, void *UNUSED(ucontext)) {
+	struct hostclock *alarmclock = info->si_value.sival_ptr;
+	assert(alarmclock)
+
+	while (alarmclock->queue &&
+	       alarmclock->queue->fire_at_ns <= hostclock_get_ns(alarmclock)) {
+		struct alarmclock_trigger *trigger = alarmclock->queue;
+		trigger->cb(trigger->cb_arg);
+		alarmclock->queue = trigger->next;
+		trigger->alarmclock = NULL;
+		trigger->next = NULL;
+		trigger->prev = NULL;
+	}
+
+	if (alarmclock->queue) {
+		timer_settime(alarmclock
+	}
+		timer_hw->alarm[alarm_num] = (uint32_t)NS_TO_US_ROUNDUP(alarmclock->queue->fire_at_ns);
+}
+
+static bool hostclock_add_trigger(implements_alarmclock *self,
+                                      struct alarmclock_trigger *trigger,
+                                      uint64_t   fire_at_ns,
+                                      void       (*cb)(void *),
+                                      void      *cb_arg) {
+	struct hostclock *clock =
+		VCALL_SELF(struct hostclock, implements_alarmclock, _clock);
+
+
+}
+
+static void hostclock_del_trigger(implements_alarmclock *self,
+                                      struct alarmclock_trigger *trigger) {
+}
+
+/* Globals ********************************************************************/
+
+static struct alarmclock_vtable hostclock_vtable = {
+	.get_time_ns = hostclock_get_time_ns,
+	.add_trigger = hostclock_add_trigger,
+	.del_trigger = hostclock_del_trigger,
+};
+
+static struct hostclock clock_monotonic = {
+	.vtable  = hostclock_vtable,
+	.clockid = CLOCK_MONOTONIC,
+};
+
+const implements_alarmclock *bootclock = &clock_monotonic;