/*TRANSPILED*/goog.loadModule(function(exports) {'use strict';/*

 Copyright The Closure Library Authors.
 SPDX-License-Identifier: Apache-2.0
*/
'use strict';
goog.module("goog.async.WorkQueue");
goog.module.declareLegacyNamespace();
const FreeList = goog.require("goog.async.FreeList");
const {assert} = goog.require("goog.asserts");
class WorkQueue {
  constructor() {
    this.workHead_ = null;
    this.workTail_ = null;
  }
  add(fn, scope) {
    const item = this.getUnusedItem_();
    item.set(fn, scope);
    if (this.workTail_) {
      this.workTail_.next = item;
      this.workTail_ = item;
    } else {
      assert(!this.workHead_);
      this.workHead_ = item;
      this.workTail_ = item;
    }
  }
  remove() {
    let item = null;
    if (this.workHead_) {
      item = this.workHead_;
      this.workHead_ = this.workHead_.next;
      if (!this.workHead_) {
        this.workTail_ = null;
      }
      item.next = null;
    }
    return item;
  }
  returnUnused(item) {
    WorkQueue.freelist_.put(item);
  }
  getUnusedItem_() {
    return WorkQueue.freelist_.get();
  }
}
WorkQueue.DEFAULT_MAX_UNUSED = goog.define("goog.async.WorkQueue.DEFAULT_MAX_UNUSED", 100);
WorkQueue.freelist_ = new FreeList(() => new WorkItem(), item => item.reset(), WorkQueue.DEFAULT_MAX_UNUSED);
class WorkItem {
  constructor() {
    this.fn = null;
    this.scope = null;
    this.next = null;
  }
  set(fn, scope) {
    this.fn = fn;
    this.scope = scope;
    this.next = null;
  }
  reset() {
    this.fn = null;
    this.scope = null;
    this.next = null;
  }
}
exports = WorkQueue;

;return exports;});