Changed display to use list_t.

backend/drm/backend.c

@@ -4,6 +4,8 @@
 #include <string.h>
 #include <errno.h>
 
+#include <wlr/common/list.h>
+
 #include "backend/drm/backend.h"
 #include "backend/drm/drm.h"
 #include "backend/drm/session.h"
@@ -18,10 +20,16 @@ struct wlr_drm_backend *wlr_drm_backend_init(void)
 		return NULL;
 	}
 
+	backend->displays = list_create();
+	if (!backend->displays) {
+		wlr_log(L_ERROR, "Failed to allocate list");
+		goto error_backend;
+	}
+
 	backend->event_loop = wl_event_loop_create();
 	if (!backend->event_loop) {
 		wlr_log(L_ERROR, "Failed to create event loop");
-		goto error_backend;
+		goto error_list;
 	}
 
 	if (!wlr_session_start(&backend->session)) {
@@ -61,19 +69,25 @@ error_session:
 	wlr_session_end(&backend->session);
 error_loop:
 	wl_event_loop_destroy(backend->event_loop);
+error_list:
+	list_free(backend->displays);
 error_backend:
 	free(backend);
 	return NULL;
 }
 
+static void free_display(void *item)
+{
+	struct wlr_drm_display *disp = item;
+	wlr_drm_display_free(disp, true);
+}
+
 void wlr_drm_backend_free(struct wlr_drm_backend *backend)
 {
 	if (!backend)
 		return;
 
-	for (size_t i = 0; i < backend->display_len; ++i) {
-		wlr_drm_display_free(&backend->displays[i], true);
-	}
+	list_foreach(backend->displays, free_display);
 
 	wlr_drm_renderer_free(&backend->renderer);
 	wlr_udev_free(&backend->udev);
@@ -83,7 +97,7 @@ void wlr_drm_backend_free(struct wlr_drm_backend *backend)
 	wl_event_source_remove(backend->event_src.drm);
 	wl_event_loop_destroy(backend->event_loop);
 
-	free(backend->displays);
+	list_free(backend->displays);
 	free(backend);
 }
 

backend/drm/drm.c

@@ -240,6 +240,19 @@ void wlr_drm_renderer_free(struct wlr_drm_renderer *renderer)
 	gbm_device_destroy(renderer->gbm);
 }
 
+static int find_id(const void *item, const void *cmp_to)
+{
+	const struct wlr_drm_display *disp = item;
+	const uint32_t *id = cmp_to;
+
+	if (disp->connector < *id)
+		return -1;
+	else if (disp->connector > *id)
+		return 1;
+	else
+		return 0;
+}
+
 void wlr_drm_scan_connectors(struct wlr_drm_backend *backend)
 {
 	drmModeRes *res = drmModeGetResources(backend->fd);
@@ -248,39 +261,35 @@ void wlr_drm_scan_connectors(struct wlr_drm_backend *backend)
 		return;
 	}
 
-	// I don't know if this needs to be allocated with realloc like this,
-	// as it may not even be possible for the number of connectors to change.
-	// I'll just have to see how DisplayPort MST works with DRM.
-	if ((size_t)res->count_connectors > backend->display_len) {
-		struct wlr_drm_display *new = realloc(backend->displays, sizeof *new * res->count_connectors);
-		if (!new) {
-			wlr_log(L_ERROR, "Allocation failed: %s", strerror(errno));
-			goto error;
-		}
+	for (int i = 0; i < res->count_connectors; ++i) {
+		uint32_t id = res->connectors[i];
 
-		for (int i = backend->display_len; i < res->count_connectors; ++i) {
-			new[i] = (struct wlr_drm_display) {
-				.state = DRM_DISP_INVALID,
-				.renderer = &backend->renderer,
-			};
+		drmModeConnector *conn = drmModeGetConnector(backend->fd, id);
+		if (!conn) {
+			wlr_log(L_ERROR, "Failed to get DRM connector");
+			continue;
 		}
 
-		backend->display_len = res->count_connectors;
-		backend->displays = new;
-	}
+		struct wlr_drm_display *disp;
+		int index = list_seq_find(backend->displays, find_id, &id);
 
-	for (int i = 0; i < res->count_connectors; ++i) {
-		struct wlr_drm_display *disp = &backend->displays[i];
-		drmModeConnector *conn = drmModeGetConnector(backend->fd, res->connectors[i]);
-		if (!conn)
+		if (index == -1) {
+			disp = calloc(1, sizeof *disp);
+			if (!disp) {
+				wlr_log(L_ERROR, "Allocation failed: %s", strerror(errno));
+				drmModeFreeConnector(conn);
 				continue;
+			}
 
-		if (backend->displays[i].state == DRM_DISP_INVALID) {
 			disp->state = DRM_DISP_DISCONNECTED;
 			disp->connector = res->connectors[i];
 			snprintf(disp->name, sizeof disp->name, "%s-%"PRIu32,
 				 conn_name[conn->connector_type],
 				 conn->connector_type_id);
+
+			list_add(backend->displays, disp);
+		} else {
+			disp = backend->displays->items[index];
 		}
 
 		if (disp->state == DRM_DISP_DISCONNECTED &&
@@ -298,7 +307,6 @@ void wlr_drm_scan_connectors(struct wlr_drm_backend *backend)
 		drmModeFreeConnector(conn);
 	}
 
-error:
 	drmModeFreeResources(res);
 }
 

include/backend/drm/backend.h

@@ -8,6 +8,8 @@
 #include <libudev.h>
 #include <wayland-server.h>
 
+#include <wlr/common/list.h>
+
 #include "session.h"
 #include "udev.h"
 #include "event.h"
@@ -30,8 +32,7 @@ struct wlr_drm_backend {
 		struct wl_signal display_render;
 	} signals;
 
-	size_t display_len;
-	struct wlr_drm_display *displays;
+	list_t *displays;
 
 	uint32_t taken_crtcs;