src: fix memory leak for v8.serialize

When Buffer::New passes in existing data,
it cannot be garbage collected in js synchronous execution.

Fixes: https://github.com/nodejs/node/issues/40828
Refs: https://github.com/nodejs/node/issues/38300

PR-URL: https://github.com/nodejs/node/pull/42695
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/test/parallel/test-v8-serialize-leak.js b/test/parallel/test-v8-serialize-leak.js
new file mode 100644
index 00000000000..4e3a1d96f8a
--- /dev/null
+++ b/test/parallel/test-v8-serialize-leak.js
@@ -0,0 +1,22 @@
+'use strict';
+// Flags: --expose-gc
+
+require('../common');
+const v8 = require('v8');
+const assert = require('assert');
+
+const before = process.memoryUsage.rss();
+
+for (let i = 0; i < 1000000; i++) {
+  v8.serialize('');
+}
+
+global.gc();
+
+const after = process.memoryUsage.rss();
+
+if (process.config.variables.asan) {
+  assert(after < before * 10, `asan: before=${before} after=${after}`);
+} else {
+  assert(after < before * 2, `before=${before} after=${after}`);
+}