Avoid unnecessary gc_collect_cycles if there's no open span

bwoebi · bwoebi · commit cd0ecca65719 · 2025-09-22T16:56:30.000+02:00
This can be significant in terms of performance during shutdown, especially if it happens for no actual reason.

Signed-off-by: Bob Weinand &lt;bob.weinand@datadoghq.com&gt;
diff --git a/ext/span.c b/ext/span.c
@@ -1132,8 +1132,10 @@ void ddtrace_serialize_closed_spans_with_cycle(ddog_TracesBytes *traces) {
     // We need to loop here, as closing the last span root stack could add other spans here
     while (DDTRACE_G(top_closed_stack)) {
         ddtrace_serialize_closed_spans(traces);
-        // Also flush possible cycles here
-        gc_collect_cycles();
+        if (DDTRACE_G(open_spans_count)) {
+            // Also flush possible cycles here, if there are remaining open spans
+            gc_collect_cycles();
+        }
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1132,8 +1132,10 @@ void ddtrace_serialize_closed_spans_with_cycle(ddog_TracesBytes *traces) {`
`1132`	`1132`	`// We need to loop here, as closing the last span root stack could add other spans here`
`1133`	`1133`	`while (DDTRACE_G(top_closed_stack)) {`
`1134`	`1134`	`ddtrace_serialize_closed_spans(traces);`
`1135`		`- // Also flush possible cycles here`
`1136`		`- gc_collect_cycles();`
	`1135`	`+ if (DDTRACE_G(open_spans_count)) {`
	`1136`	`+ // Also flush possible cycles here, if there are remaining open spans`
	`1137`	`+ gc_collect_cycles();`
	`1138`	`+ }`
`1137`	`1139`	`}`
`1138`	`1140`	`}`
`1139`	`1141`