test: wait for shared-isolate Worker exit

Ten thousand non-blocking loop turns can finish before the Worker has
started. Use a thirty-second deadline and yield between turns while
waiting for its exit, preserving the expected exit-code assertion.

Refs: nodejs/reliability#1687
Signed-off-by: Filip Skokan <panva.ip@gmail.com>
Assisted-by: Codex
PR-URL: #66722
Refs: nodejs/reliability#1686
Refs: nodejs/reliability#1690
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Guilherme Araújo <arauujogui@gmail.com>

Author: panva

test/cctest/test_environment_shared_isolate.cc

@@ -354,9 +354,13 @@ TEST_P(SharedIsolateTest, EnvironmentsComeAndGoWhileSiblingsRun) {
                     "  return 0;\n"
                     "})()"),
         0);
-    for (int turn = 0; turn < 10000; turn++) {
+    // Loop turns do not bound Worker startup time. Yield to the Worker and
+    // allow it to finish even when the main thread pumps the loop quickly.
+    const uint64_t deadline = uv_hrtime() + 30ULL * 1000 * 1000 * 1000;
+    while (uv_hrtime() < deadline) {
       PumpLoop(1);
       if (EvaluateInt(third.get(), "state.workerExit") == 7) break;
+      uv_sleep(1);
     }
     EXPECT_EQ(EvaluateInt(third.get(), "state.workerExit"), 7);
   }