Question

下面是我的一点点重构（+一些额外的代码，因为out-parameters）简单的方法，我尝试使用Parallel.Invoke（...）来加快速度。

（请忽略变量中的 async 字词:)）。

同步版本是相同的 - 同步调用相同的7种方法。

所有7种方法都非常简单 - 它们只是填充和返回集合。

现在 - 我发现令人惊讶的是：两种方法几乎在相同的时间（~6秒）内执行。

我怎么可能或我错过了什么？

private static void GenerateCachingHelpersAsync(
     SingleVODCache _svc,
     Dictionary<int, DataRow> _dicFirstContentsFilter,
     DataSet _ds,
     out ConcurrentDictionary<string, DataRow> _cdicValidContentCatalogPrices,
     out ConcurrentDictionary<int, DataRow> _cdicAllMetaDataHelper,
     out List<KeyValuePair<int, int>> _helperContentMetaDataSync,
     out ConcurrentDictionary<int, DataRow> _cdicAllAssetsHelper,
     out List<KeyValuePair<int, int>> _helperContentAssetsSync,
     out Dictionary<int, OneContentAllViewsHelper> _dicAllContentsViewsHelper,
     out ConcurrentDictionary<int, List<Category>> _cdicValidContentCategories
     )
  {
     ConcurrentDictionary<string, DataRow> _cdicValidContentCatalogPricesAsync = new ConcurrentDictionary<string, DataRow>();
     ConcurrentDictionary<int, DataRow> _cdicAllMetaDataHelperAsync = new ConcurrentDictionary<int, DataRow>();
     List<KeyValuePair<int, int>> _helperContentMetaDataSyncAsync = new List<KeyValuePair<int, int>>();
     ConcurrentDictionary<int, DataRow> _cdicAllAssetsHelperAsync = new ConcurrentDictionary<int, DataRow>();
     List<KeyValuePair<int, int>> _helperContentAssetsSyncAsync = new List<KeyValuePair<int, int>>();
     Dictionary<int, OneContentAllViewsHelper> _dicAllContentsViewsHelperAsync = new Dictionary<int, OneContentAllViewsHelper>();
     ConcurrentDictionary<int, List<Category>> _cdicValidContentCategoriesAsync = new ConcurrentDictionary<int, List<Category>>();

     Parallel.Invoke(
        () =>
        {
           _cdicValidContentCatalogPricesAsync = BuildValidContentCatalogPricesHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.CONTENT_CATALOG_PRICE_SYNC)]);
        },
        () =>
        {
           _cdicAllMetaDataHelperAsync = BuildAllMetaDataHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.META_DATA)]);
        },
        () =>
        {
           _helperContentMetaDataSyncAsync = BuildContentMetaDataSyncHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.CONTENT_META_DATA_SYNC)]);
        },
        () =>
        {
           _cdicAllAssetsHelperAsync = BuildAllAssetsHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.ASSETS)]);
        },
        () =>
        {
           _helperContentAssetsSyncAsync = BuildContentAssetsSyncHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.CONTENT_ASSET_SYNC)]);
        },
        () =>
        {
           _dicAllContentsViewsHelperAsync = BuildAllContensViewsVotesHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.CONTENT_VIEWS)], _dicFirstContentsFilter, _svc.MetaData.HowManyPastDaysForMostViewed);
        },
        () =>
        {
           _cdicValidContentCategoriesAsync = BuildValidContentCategoriesHelper(_ds.Tables[GetCMSDataTableIndex(m_eCMSDataTablesIndexes.CONTENT_CATEGORY_SYNC)], _dicFirstContentsFilter, _svc.AllCategories);
        }
        );

     _cdicValidContentCatalogPrices = _cdicValidContentCatalogPricesAsync;
     _cdicAllMetaDataHelper = _cdicAllMetaDataHelperAsync;
     _helperContentMetaDataSync = _helperContentMetaDataSyncAsync;
     _cdicAllAssetsHelper = _cdicAllAssetsHelperAsync;
     _helperContentAssetsSync = _helperContentAssetsSyncAsync;
     _dicAllContentsViewsHelper = _dicAllContentsViewsHelperAsync;
     _cdicValidContentCategories = _cdicValidContentCategoriesAsync;
  }

Answer 1

Parallel.Invoke方法将 possibly run the code asynchronously ，具体取决于代码是否会同步运行更快。在您的情况下，如果您只是填充集合并且没有昂贵的I / O或服务调用，那么它可能只是同步运行所有内容。

您应该做的是将低成本构造分组到一个代码块中，然后将更昂贵的调用（即DB或Web服务）分成单独的块，因为这些可能会增加更多的等待时间。

编辑：MSDN

的附加引用

不保证操作执行的顺序或它们是否并行执行。

c＃Parallel.Invoke（零速度改进）

1 个答案: