1 files changed, 91 insertions, 0 deletions
diff --git a/backend/drm/event.c b/backend/drm/event.c
new file mode 100644
index 00000000..f20cb282
--- /dev/null
+++ b/backend/drm/event.c
@@ -0,0 +1,91 @@
+#include "otd.h"
+#include "event.h"
+#include "drm.h"
+#include "udev.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <poll.h>
+
+static inline void event_swap(struct otd_event *a, struct otd_event *b)
+{
+	struct otd_event tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+bool otd_get_event(struct otd *otd, struct otd_event *restrict ret)
+{
+	struct pollfd fds[] = {
+		{ .fd = otd->fd, .events = POLLIN },
+		{ .fd = otd->udev_fd, .events = POLLIN },
+	};
+
+	while (poll(fds, 2, 0) > 0) {
+		if (fds[0].revents)
+			get_drm_event(otd);
+		if (fds[1].revents)
+			otd_udev_event(otd);
+	}
+
+	if (otd->event_len == 0) {
+		ret->type = OTD_EV_NONE;
+		ret->display = NULL;
+		return false;
+	}
+
+	struct otd_event *ev = otd->events;
+
+	// Downheap
+	*ret = ev[0];
+	ev[0] = ev[--otd->event_len];
+
+	size_t i = 0;
+	while (i < otd->event_len / 2) {
+		size_t left = i * 2 + 1;
+		size_t right = i * 2 + 2;
+		size_t max = (ev[left].type > ev[right].type) ? left : right;
+
+		if (ev[i].type <= ev[max].type) {
+			event_swap(&ev[i], &ev[max]);
+			i = max;
+		} else {
+			break;
+		}
+	}
+
+	return true;
+}
+
+bool event_add(struct otd *otd, struct otd_display *disp, enum otd_event_type type)
+{
+	if (type == OTD_EV_NONE)
+		return true;
+
+	if (otd->event_len == otd->event_cap) {
+		size_t new_size = (otd->event_cap == 0) ? 8 : otd->event_cap * 2;
+
+		struct otd_event *new = realloc(otd->events, sizeof *new * new_size);
+		if (!new) {
+			return false;
+		}
+
+		otd->event_cap = new_size;
+		otd->events = new;
+	}
+
+	struct otd_event *ev = otd->events;
+
+	// Upheap
+	size_t i = otd->event_len++;
+	ev[i].type = type;
+	ev[i].display = disp;
+
+	size_t j;
+	while (i > 0 && ev[i].type > ev[(j = (i - 1) / 2)].type) {
+		event_swap(&ev[i], &ev[j]);
+		i = j;
+	}
+
+	return true;
+}