<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/utils.js"></script>
<script src="/shared-storage/resources/util.js"></script>
<script src="/fenced-frame/resources/utils.js"></script>

<body>
<script>
'use strict';

promise_test(async t => {
  let worklet1 = await sharedStorage.createWorklet('resources/simple-module.js');
  let worklet2 = await sharedStorage.createWorklet('resources/simple-module.js');

  const ancestor_key1 = token();
  let url1_0 = generateURL("/shared-storage/resources/frame0.html",
                         [ancestor_key1]);
  let url1_1 = generateURL("/shared-storage/resources/frame1.html",
                         [ancestor_key1]);

  const ancestor_key2 = token();
  let url2_0 = generateURL("/shared-storage/resources/frame0.html",
                         [ancestor_key2]);
  let url2_1 = generateURL("/shared-storage/resources/frame1.html",
                         [ancestor_key2]);

  // Two `selectURL()`s run in parallel. Each performs the following steps:
  // 1. Acquires the lock.
  // 2. Reads the current value of the given key.
  // 3. Waits for 100ms.
  // 4. Increments the value.
  // 5. Releases the lock.
  //
  // Expected behavior: After both operations finish, the value of the given key
  // should be 2.
  //
  // This demonstrates that the lock is effective, preventing the
  // "get and increment" operations from interleaving. If the lock were not
  // used, both worklets would likely read 0 and set the value to 1.

  let select_url_result1 = await worklet1.selectURL(
      "get-wait-increment-within-lock", [{url: url1_0}, {url: url1_1}],
      {data: {'key': 'key'}, resolveToConfig: true});

  let select_url_result2 = await worklet2.selectURL(
      "get-wait-increment-within-lock", [{url: url2_0}, {url: url2_1}],
      {data: {'key': 'key'}, resolveToConfig: true});

  attachFencedFrame(select_url_result1, 'opaque-ads');
  const result1 = await nextValueFromServer(ancestor_key1);
  assert_equals(result1, "frame1_loaded");

  attachFencedFrame(select_url_result2, 'opaque-ads');
  const result2 = await nextValueFromServer(ancestor_key2);
  assert_equals(result2, "frame1_loaded");

  await verifyKeyValueForOrigin('key', '2', location.origin);

  await deleteKeyForOrigin('key', location.origin);
}, 'Basic test for Web Locks API in the shared storage worklet');

</script>
</body>