worker,src: display remaining handles if `uv_loop_close` fails

Right now, we crash the process if there are handles remaining
on the event loop when we exit (except for the main thread).

This does not provide a lot of information about causes, though;
in particular, we don’t show which handles are pending and
who own them.

This patch adds debug output to these cases to help with the
situation.

PR-URL: https://github.com/nodejs/node/pull/21238
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 97 insertions, 0 deletions

diff --git a/test/abort/test-addon-uv-handle-leak.js b/test/abort/test-addon-uv-handle-leak.js
new file mode 100644
index 0000000000..3944cb79c7
--- /dev/null
+++ b/test/abort/test-addon-uv-handle-leak.js
@@ -0,0 +1,97 @@
+// Flags: --experimental-worker
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const cp = require('child_process');
+const { Worker } = require('worker_threads');
+
+// This is a sibling test to test/addons/uv-handle-leak.
+
+const bindingPath = path.resolve(
+  __dirname, '..', 'addons', 'uv-handle-leak', 'build',
+  `${common.buildType}/binding.node`);
+
+if (!fs.existsSync(bindingPath))
+  common.skip('binding not built yet');
+
+if (process.argv[2] === 'child') {
+  new Worker(`
+  const binding = require(${JSON.stringify(bindingPath)});
+
+  binding.leakHandle();
+  binding.leakHandle(0);
+  binding.leakHandle(0x42);
+  `, { eval: true });
+} else {
+  const child = cp.spawnSync(process.execPath,
+                             ['--experimental-worker', __filename, 'child']);
+  const stderr = child.stderr.toString();
+
+  assert.strictEqual(child.stdout.toString(), '');
+
+  const lines = stderr.split('\n');
+
+  let state = 'initial';
+
+  // parse output that is formatted like this:
+
+  // uv loop at [0x559b65ed5770] has active handles
+  // [0x7f2de0018430] timer
+  //         Close callback: 0x7f2df31de220 CloseCallback(uv_handle_s*) [...]
+  //         Data: 0x7f2df33df140 example_instance [...]
+  //         (First field): 0x7f2df33dedc0 vtable for ExampleOwnerClass [...]
+  // [0x7f2de000b870] timer
+  //         Close callback: 0x7f2df31de220 CloseCallback(uv_handle_s*) [...]
+  //         Data: (nil)
+  // [0x7f2de000b910] timer
+  //         Close callback: 0x7f2df31de220 CloseCallback(uv_handle_s*) [...]
+  //         Data: 0x42
+
+  if (!(common.isFreeBSD ||
+        common.isAIX ||
+        (common.isLinux && !common.isGlibc()) ||
+        common.isWindows)) {
+    assert(stderr.includes('ExampleOwnerClass'), stderr);
+    assert(stderr.includes('CloseCallback'), stderr);
+    assert(stderr.includes('example_instance'), stderr);
+  }
+
+  while (lines.length > 0) {
+    const line = lines.shift().trim();
+
+    switch (state) {
+      case 'initial':
+        assert(/^uv loop at \[.+\] has active handles$/.test(line), line);
+        state = 'handle-start';
+        break;
+      case 'handle-start':
+        if (/Assertion .+ failed/.test(line)) {
+          state = 'done';
+          break;
+        }
+        assert(/^\[.+\] timer$/.test(line), line);
+        state = 'close-callback';
+        break;
+      case 'close-callback':
+        assert(/^Close callback:/.test(line), line);
+        state = 'data';
+        break;
+      case 'data':
+        assert(/^Data: .+$/.test(line), line);
+        state = 'maybe-first-field';
+        break;
+      case 'maybe-first-field':
+        if (/^\(First field\)$/.test(line)) {
+          lines.unshift(line);
+          state = 'handle-start';
+          break;
+        }
+        state = 'maybe-first-field';
+        break;
+      case 'done':
+        break;
+    }
+  }
+}