Add a shared timer, remove timerfd usage from idle and announce

1 files changed, 208 insertions, 0 deletions

diff --git a/ptimer.c b/ptimer.c
new file mode 100644
index 0000000..7d8662d
--- /dev/null
+++ b/ptimer.c
@@ -0,0 +1,208 @@
+#include <inttypes.h>
+#include <sys/timerfd.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "main.h"
+#include "uring.h"
+#include "ptimer.h"
+
+struct ptimer {
+	uint64_t value;
+	time_t previous_time;
+	struct uring_task task;
+	unsigned task_count;
+	struct list_head ptasks;
+};
+
+static void
+ptimer_set(unsigned value, unsigned interval)
+{
+	struct itimerspec tspec = {
+		.it_interval = {
+			.tv_sec  = interval,
+			.tv_nsec = 0
+		},
+		.it_value = {
+			.tv_sec  = value,
+			.tv_nsec = 0
+		}
+	};
+
+	assert_return(cfg->ptimer && cfg->ptimer->task.fd >= 0);
+
+	if (timerfd_settime(cfg->ptimer->task.fd, 0, &tspec, NULL) != 0)
+		error("timerfd_settime: %m");
+}
+
+static unsigned
+gcd(unsigned a, unsigned b)
+{
+	if (a == 0)
+		return b;
+	return gcd(b % a, a);
+}
+
+static unsigned
+array_gcd(unsigned arr[], unsigned n)
+{
+	unsigned result = arr[0];
+
+	for (unsigned i = 1; i < n; i++)
+		result = gcd(arr[i], result);
+
+	return result;
+}
+
+static void
+ptimer_tick(struct ptimer *ptimer)
+{
+	time_t now = time(NULL);
+	unsigned diff = (unsigned)(now - ptimer->previous_time);
+	struct ptimer_task *ptask, *ptmp;
+
+	fprintf(stderr, "Got a tick of %u secs\n", diff);
+	list_for_each_entry_safe(ptask, ptmp, &ptimer->ptasks, list) {
+		if (ptask->remain > diff) {
+			ptask->remain -= diff;
+			continue;
+		}
+
+		ptask->cb(ptask);
+		ptask->remain = ptask->interval;
+		if (ptask->times > 0) {
+			ptask->times--;
+			if (ptask->times == 0)
+				list_del(&ptask->list);
+		}
+	}
+
+	ptimer->previous_time = now;
+}
+
+static void
+ptimer_reconfig(struct ptimer *ptimer)
+{
+	struct ptimer_task *ptask;
+	unsigned i = 0;
+	unsigned lowest = ~0;
+
+	if (list_empty(&ptimer->ptasks)) {
+		ptimer_set(0, 0);
+		return;
+	}
+
+	unsigned intervals[ptimer->task_count];
+
+	list_for_each_entry(ptask, &ptimer->ptasks, list) {
+		if (ptask->remain < lowest)
+			lowest = ptask->remain;
+		intervals[i++] = ptask->interval;
+	}
+
+	fprintf(stderr, "Lowest %u GCD is %u\n", lowest, array_gcd(intervals, i));
+	ptimer_set(lowest, array_gcd(intervals, i));
+}
+
+void
+ptimer_del_task(struct ptimer_task *ptask)
+{
+	struct ptimer *ptimer = cfg->ptimer;
+
+	assert_return(ptask && ptimer && ptimer->task_count > 0);
+
+	list_del(&ptask->list);
+	ptimer->task_count--;
+	ptimer_tick(ptimer);
+	ptimer_reconfig(ptimer);
+	uring_task_put(&ptimer->task);
+}
+
+void
+ptimer_add_task(struct ptimer_task *ptask)
+{
+	struct ptimer *ptimer = cfg->ptimer;
+
+	assert_return(ptask && ptask->interval > 0 && ptask->cb && ptimer);
+
+	uring_task_get(&ptimer->task);
+	ptask->remain = ptask->interval;
+	ptimer_tick(ptimer);
+	list_add(&ptask->list, &ptimer->ptasks);
+	ptimer->task_count++;
+	ptimer_reconfig(ptimer);
+}
+
+void
+ptimer_refdump()
+{
+	assert_return(cfg->ptimer);
+
+	uring_task_refdump(&cfg->ptimer->task);
+}
+
+static void
+ptimer_free(struct uring_task *task)
+{
+	struct ptimer *ptimer = container_of(task, struct ptimer, task);
+
+	assert_return(task);
+
+	debug(DBG_ANN, "task %p, ptimer %p", task, ptimer);
+	xfree(ptimer);
+	cfg->ptimer = NULL;
+}
+
+void
+ptimer_delete()
+{
+	assert_return(cfg->ptimer);
+
+	debug(DBG_ANN, "closing fd %i", cfg->ptimer->task.fd);
+	uring_task_destroy(&cfg->ptimer->task);
+}
+
+static void
+ptimer_cb(struct uring_task *task, int res)
+{
+	struct ptimer *ptimer = container_of(task, struct ptimer, task);
+
+	assert_return(task);
+	assert_task_alive(DBG_IGMP, task);
+
+	if (res != sizeof(ptimer->value)) {
+		error("timerfd_read: res: %i, %m", res);
+		return;
+	}
+
+	debug(DBG_IGMP, "Called");
+	ptimer_tick(ptimer);
+	uring_read(&ptimer->task, &ptimer->value, sizeof(ptimer->value), ptimer_cb);
+}
+
+void
+ptimer_init()
+{
+	struct ptimer *ptimer;
+	int tfd;
+ 
+	assert_return(!cfg->ptimer);
+
+	ptimer = zmalloc(sizeof(*ptimer));
+	if (!ptimer)
+		die("malloc: %m");
+
+	tfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
+	if (tfd < 0)
+		die("timerfd_create: %m");
+
+	ptimer->task_count = 0;
+	ptimer->previous_time = time(NULL);
+	list_init(&ptimer->ptasks);
+	uring_task_init(&ptimer->task, "ptimer", uring_parent(), ptimer_free);
+	uring_task_set_fd(&ptimer->task, tfd);
+	cfg->ptimer = ptimer;
+	uring_read(&ptimer->task, &ptimer->value, sizeof(ptimer->value), ptimer_cb);
+}
+