From 60ab03640affb98b3f9d79741662d8a4ff8486ff Mon Sep 17 00:00:00 2001
From: Derek Foreman <derek.foreman@collabora.com>
Date: Thu, 23 Sep 2021 14:06:57 -0500
Subject: [PATCH] compositor: Allow disabling default flight recorders

Add a command line option to disable the default flight recorders
so we can save a little bit of CPU and memory on systems where
this isn't necessary.

Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
---
 compositor/main.c | 28 ++++++++++++++++------------
 man/weston.man    |  3 ++-
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/compositor/main.c b/compositor/main.c
index 88900789..4c5807a3 100644
--- a/compositor/main.c
+++ b/compositor/main.c
@@ -69,6 +69,7 @@
 #define WINDOW_TITLE "Weston Compositor"
 /* flight recorder size (in bytes) */
 #define DEFAULT_FLIGHT_REC_SIZE (5 * 1024 * 1024)
+#define DEFAULT_FLIGHT_REC_SCOPES "log,drm-backend"
 
 struct wet_output_config {
 	int width;
@@ -3197,18 +3198,13 @@ weston_log_subscribe_to_scopes(struct weston_log_context *log_ctx,
 			       const char *log_scopes,
 			       const char *flight_rec_scopes)
 {
-	if (log_scopes)
+	if (logger && log_scopes)
 		weston_log_setup_scopes(log_ctx, logger, log_scopes);
 	else
 		weston_log_subscribe(log_ctx, logger, "log");
 
-	if (flight_rec_scopes) {
+	if (flight_rec && flight_rec_scopes)
 		weston_log_setup_scopes(log_ctx, flight_rec, flight_rec_scopes);
-	} else {
-		/* by default subscribe to 'log', and 'drm-backend' */
-		weston_log_subscribe(log_ctx, flight_rec, "log");
-		weston_log_subscribe(log_ctx, flight_rec, "drm-backend");
-	}
 }
 
 WL_EXPORT int
@@ -3305,7 +3301,12 @@ wet_main(int argc, char *argv[], const struct weston_testsuite_data *test_data)
 	weston_log_set_handler(vlog, vlog_continue);
 
 	logger = weston_log_subscriber_create_log(weston_logfile);
-	flight_rec = weston_log_subscriber_create_flight_rec(DEFAULT_FLIGHT_REC_SIZE);
+
+	if (!flight_rec_scopes)
+		flight_rec_scopes = DEFAULT_FLIGHT_REC_SCOPES;
+
+	if (flight_rec_scopes && strlen(flight_rec_scopes) > 0)
+		flight_rec = weston_log_subscriber_create_flight_rec(DEFAULT_FLIGHT_REC_SIZE);
 
 	weston_log_subscribe_to_scopes(log_ctx, logger, flight_rec,
 				       log_scopes, flight_rec_scopes);
@@ -3320,6 +3321,7 @@ wet_main(int argc, char *argv[], const struct weston_testsuite_data *test_data)
 	free(cmdline);
 	log_uname();
 
+	weston_log("Flight recorder: %s\n", flight_rec ? "enabled" : "disabled");
 	verify_xdg_runtime_dir();
 
 	display = wl_display_create();
@@ -3393,9 +3395,10 @@ wet_main(int argc, char *argv[], const struct weston_testsuite_data *test_data)
 	if (debug_protocol)
 		weston_compositor_enable_debug_protocol(wet.compositor);
 
-	weston_compositor_add_debug_binding(wet.compositor, KEY_D,
-					    flight_rec_key_binding_handler,
-					    flight_rec);
+	if (flight_rec)
+		weston_compositor_add_debug_binding(wet.compositor, KEY_D,
+						    flight_rec_key_binding_handler,
+						    flight_rec);
 
 	if (weston_compositor_init_config(wet.compositor, config) < 0)
 		goto out;
@@ -3534,7 +3537,8 @@ out_display:
 	weston_log_scope_destroy(log_scope);
 	log_scope = NULL;
 	weston_log_subscriber_destroy(logger);
-	weston_log_subscriber_destroy(flight_rec);
+	if (flight_rec)
+		weston_log_subscriber_destroy(flight_rec);
 	weston_log_ctx_destroy(log_ctx);
 	weston_log_file_close();
 
diff --git a/man/weston.man b/man/weston.man
index 5d20c03e..c453a7d3 100644
--- a/man/weston.man
+++ b/man/weston.man
@@ -157,7 +157,8 @@ start-up code.
 Specify to which scopes should subscribe to. Useful to control which streams to
 write data into the flight recorder. Flight recorder has limited space, once
 the flight recorder is full new data will overwrite the old data. Without any
-scopes specified, it subscribes to 'log' and 'drm-backend' scopes.
+scopes specified, it subscribes to 'log' and 'drm-backend' scopes. Passing
+an empty value would disable the flight recorder entirely.
 .TP
 .BR \-\-version
 Print the program version.