text: // Copyright (C) 2018 Amal Hussein.  All rights reserved.
  // This code is governed by the BSD license found in the LICENSE file.
  
  /*---
  esid: sec-atomics.wait
  description: >
    New waiters should be applied to the end of the list and woken by order they entered the list (FIFO)
  info: |
    Atomics.wait( typedArray, index, value, timeout )
  
    16.Perform AddWaiter(WL, W).
      ...
      3.Add W to the end of the list of waiters in WL.
  
  includes: [atomicsHelper.js]
  features: [Atomics, SharedArrayBuffer, TypedArray]
  ---*/
  
  var NUMAGENT = 3;
  
  var WAIT_INDEX = 0;
  var RUNNING = 1;
  var LOCK_INDEX = 2;
  
  for (var i = 0; i < NUMAGENT; i++) {
    var agentNum = i;
  
    $262.agent.start(`
      $262.agent.receiveBroadcast(function(sab) {
        const i32a = new Int32Array(sab);
        Atomics.add(i32a, ${RUNNING}, 1);
  
        // Synchronize workers before reporting the initial report.
        while (Atomics.compareExchange(i32a, ${LOCK_INDEX}, 0, 1) !== 0) ;
  
        // Report the agent number before waiting.
        $262.agent.report(${agentNum});
  
        // Wait until restarted by main thread.
        var status = Atomics.wait(i32a, ${WAIT_INDEX}, 0);
  
        // Report wait status.
        $262.agent.report(status);
  
        // Report the agent number after waiting.
        $262.agent.report(${agentNum});
  
        $262.agent.leaving();
      });
    `);
  }
  
  const i32a = new Int32Array(
    new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
  );
  
  $262.agent.safeBroadcast(i32a);
  
  // Wait until all agents started.
  $262.agent.waitUntil(i32a, RUNNING, NUMAGENT);
  
  // Agents may be started in any order.
  const started = [];
  for (var i = 0; i < NUMAGENT; i++) {
    // Wait until an agent entered its critical section.
    $262.agent.waitUntil(i32a, LOCK_INDEX, 1);
  
    // Record the agent number.
    started.push($262.agent.getReport());
  
    // The agent may have been interrupted between reporting its initial report
    // and the `Atomics.wait` call. Try to yield control to ensure the agent
    // actually started to wait.
    $262.agent.tryYield();
  
    // Now continue with the next agent.
    Atomics.store(i32a, LOCK_INDEX, 0);
  }
  
  // Agents must notify in the order they waited.
  for (var i = 0; i < NUMAGENT; i++) {
    var woken = 0;
    while ((woken = Atomics.notify(i32a, WAIT_INDEX, 1)) === 0) ;
  
    assert.sameValue(woken, 1,
                     'Atomics.notify(i32a, WAIT_INDEX, 1) returns 1, at index = ' + i);
  
    assert.sameValue($262.agent.getReport(), 'ok',
                     '$262.agent.getReport() returns "ok", at index = ' + i);
  
    assert.sameValue($262.agent.getReport(), started[i],
                     '$262.agent.getReport() returns the value of `started[' + i + ']`');
  }
  