report: move event loop object into Context

It's one of the primary objects that make up the program "context"
conceptually, hence it also should be part of the Context object. This
allows us to just have it available if the Context object is seen.

src/report/report.c

@@ -27,6 +27,7 @@ static RuntimeScope arg_runtime_scope = RUNTIME_SCOPE_SYSTEM;
 static sd_json_format_flags_t arg_json_format_flags = SD_JSON_FORMAT_PRETTY_AUTO|SD_JSON_FORMAT_COLOR_AUTO;
 
 typedef struct Context {
+        sd_event *event;
         unsigned n_open_connections;
         sd_json_variant **metrics;  /* Collected metrics for sorting */
         size_t n_metrics;
@@ -93,18 +94,17 @@ static int metrics_on_query_reply(
                 context->n_open_connections--;
 
                 if (context->n_open_connections == 0)
-                        (void) sd_event_exit(ASSERT_PTR(sd_varlink_get_event(link)), EXIT_SUCCESS);
+                        (void) sd_event_exit(context->event, EXIT_SUCCESS);
         }
 
         return 0;
 }
 
-static int metrics_call(Context *context, const char *path, sd_event *event, sd_varlink **ret) {
+static int metrics_call(Context *context, const char *path, sd_varlink **ret) {
         _cleanup_(sd_varlink_unrefp) sd_varlink *vl = NULL;
         int r;
 
         assert(path);
-        assert(event);
         assert(ret);
         assert(context);
 
@@ -118,7 +118,7 @@ static int metrics_call(Context *context, const char *path, sd_event *event, sd_
         if (r < 0)
                 return log_error_errno(r, "Failed to set varlink timeout: %m");
 
-        r = sd_varlink_attach_event(vl, event, SD_EVENT_PRIORITY_NORMAL);
+        r = sd_varlink_attach_event(vl, context->event, SD_EVENT_PRIORITY_NORMAL);
         if (r < 0)
                 return log_error_errno(r, "Failed to attach varlink connection to event loop: %m");
 
@@ -148,6 +148,7 @@ static void context_done(Context *context) {
         assert(context);
 
         sd_json_variant_unref_many(context->metrics, context->n_metrics);
+        sd_event_unref(context->event);
 }
 
 static int metrics_output_sorted(Context *context) {
@@ -183,17 +184,16 @@ static int metrics_query(void) {
 
         log_debug("Looking for reports in %s/", metrics_path);
 
-        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
-        r = sd_event_default(&event);
+        _cleanup_(context_done) Context context = {};
+
+        r = sd_event_default(&context.event);
         if (r < 0)
                 return log_error_errno(r, "Failed to get event loop: %m");
 
-        r = sd_event_set_signal_exit(event, true);
+        r = sd_event_set_signal_exit(context.event, true);
         if (r < 0)
                 return log_error_errno(r, "Failed to enable exit on SIGINT/SIGTERM: %m");
 
-        _cleanup_(context_done) Context context = {};
-
         _cleanup_closedir_ DIR *d = opendir(metrics_path);
         if (!d) {
                 if (errno != ENOENT)
@@ -216,7 +216,7 @@ static int metrics_query(void) {
                         if (!p)
                                 return log_oom();
 
-                        r = metrics_call(&context, p, event, &varlinks[context.n_open_connections]);
+                        r = metrics_call(&context, p, &varlinks[context.n_open_connections]);
                         if (r < 0)
                                 continue;
 
@@ -228,7 +228,7 @@ static int metrics_query(void) {
         }
 
         if (context.n_open_connections > 0) {
-                r = sd_event_loop(event);
+                r = sd_event_loop(context.event);
                 if (r < 0)
                         return log_error_errno(r, "Failed to run event loop: %m");
         }