From 4a36ba4bdd094f676060a3721425abfed31828f4 Mon Sep 17 00:00:00 2001
From: emersion <contact@emersion.fr>
Date: Tue, 19 Dec 2017 18:28:47 +0100
Subject: [PATCH] Destroy multi backend on display destroy

---
 backend/backend.c           |  2 +-
 backend/multi/backend.c     | 29 ++++++++++++++++++++---------
 include/backend/multi.h     |  2 ++
 include/wlr/backend/multi.h |  5 +++--
 rootston/main.c             |  1 -
 5 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/backend/backend.c b/backend/backend.c
index ed21fa1f..f93dde38 100644
--- a/backend/backend.c
+++ b/backend/backend.c
@@ -91,7 +91,7 @@ struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
 		return NULL;
 	}
 
-	backend = wlr_multi_backend_create(session);
+	backend = wlr_multi_backend_create(display, session);
 	if (!backend) {
 		goto error_session;
 	}
diff --git a/backend/multi/backend.c b/backend/multi/backend.c
index fc0c5b81..3815a0bc 100644
--- a/backend/multi/backend.c
+++ b/backend/multi/backend.c
@@ -16,8 +16,8 @@ struct subbackend_state {
 	struct wl_list link;
 };
 
-static bool multi_backend_start(struct wlr_backend *_backend) {
-	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)_backend;
+static bool multi_backend_start(struct wlr_backend *wlr_backend) {
+	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)wlr_backend;
 	struct subbackend_state *sub;
 	wl_list_for_each(sub, &backend->backends, link) {
 		if (!wlr_backend_start(sub->backend)) {
@@ -28,8 +28,9 @@ static bool multi_backend_start(struct wlr_backend *_backend) {
 	return true;
 }
 
-static void multi_backend_destroy(struct wlr_backend *_backend) {
-	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)_backend;
+static void multi_backend_destroy(struct wlr_backend *wlr_backend) {
+	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)wlr_backend;
+	wl_list_remove(&backend->display_destroy.link);
 	struct subbackend_state *sub, *next;
 	wl_list_for_each_safe(sub, next, &backend->backends, link) {
 		wlr_backend_destroy(sub->backend);
@@ -38,8 +39,8 @@ static void multi_backend_destroy(struct wlr_backend *_backend) {
 	free(backend);
 }
 
-static struct wlr_egl *multi_backend_get_egl(struct wlr_backend *_backend) {
-	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)_backend;
+static struct wlr_egl *multi_backend_get_egl(struct wlr_backend *wlr_backend) {
+	struct wlr_multi_backend *backend = (struct wlr_multi_backend *)wlr_backend;
 	struct subbackend_state *sub;
 	wl_list_for_each(sub, &backend->backends, link) {
 		struct wlr_egl *egl = wlr_backend_get_egl(sub->backend);
@@ -53,10 +54,17 @@ static struct wlr_egl *multi_backend_get_egl(struct wlr_backend *_backend) {
 struct wlr_backend_impl backend_impl = {
 	.start = multi_backend_start,
 	.destroy = multi_backend_destroy,
-	.get_egl = multi_backend_get_egl
+	.get_egl = multi_backend_get_egl,
 };
 
-struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session) {
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_multi_backend *backend =
+		wl_container_of(listener, backend, display_destroy);
+	multi_backend_destroy(&backend->backend);
+}
+
+struct wlr_backend *wlr_multi_backend_create(struct wl_display *display,
+		struct wlr_session *session) {
 	struct wlr_multi_backend *backend =
 		calloc(1, sizeof(struct wlr_multi_backend));
 	if (!backend) {
@@ -64,10 +72,13 @@ struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session) {
 		return NULL;
 	}
 
+	backend->session = session;
 	wl_list_init(&backend->backends);
 	wlr_backend_init(&backend->backend, &backend_impl);
 
-	backend->session = session;
+	session->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &session->display_destroy);
+
 	return &backend->backend;
 }
 
diff --git a/include/backend/multi.h b/include/backend/multi.h
index 82f85016..2798048d 100644
--- a/include/backend/multi.h
+++ b/include/backend/multi.h
@@ -11,6 +11,8 @@ struct wlr_multi_backend {
 
 	struct wlr_session *session;
 	struct wl_list backends;
+
+	struct wl_listener display_destroy;
 };
 
 #endif
diff --git a/include/wlr/backend/multi.h b/include/wlr/backend/multi.h
index 5559f2c1..e56b07b1 100644
--- a/include/wlr/backend/multi.h
+++ b/include/wlr/backend/multi.h
@@ -4,9 +4,10 @@
 #include <wlr/backend.h>
 #include <wlr/backend/session.h>
 
-struct wlr_backend *wlr_multi_backend_create(struct wlr_session *session);
+struct wlr_backend *wlr_multi_backend_create(struct wl_display *display,
+	struct wlr_session *session);
 void wlr_multi_backend_add(struct wlr_backend *multi,
-		struct wlr_backend *backend);
+	struct wlr_backend *backend);
 
 bool wlr_backend_is_multi(struct wlr_backend *backend);
 
diff --git a/rootston/main.c b/rootston/main.c
index 27ff6b41..aa20dbba 100644
--- a/rootston/main.c
+++ b/rootston/main.c
@@ -73,7 +73,6 @@ int main(int argc, char **argv) {
 #endif
 
 	wl_display_run(server.wl_display);
-	wlr_backend_destroy(server.backend);
 	wl_display_destroy(server.wl_display);
 	return 0;
 }