Question

我有一个在缓存中存储大列表的应用程序。为了防止多个用户同时填充此缓存，我使用了Mutex。但是，偶尔会出现错误：

System.Threading.AbandonedMutexException：由于放弃了互斥锁，所以等待已完成。

您可能会争辩说我忘记发布Mutex，但该发布位于Final块中，因此它应始终发布。下面的代码如何导致AbandonedMutexException？ “ mutex.ReleaseMutex”应该总是被触发。

    public static List<Objects.SearchListItem> GetActiveCwPropertyListItemsByCwPropertyAndCulture(CwProperty cwProperty, string cultureCode)
{
    var cacheKey = "GetActiveCwPropertyListItemsByCwPropertyAndCulture_" + cwProperty.Guid + "_" + cultureCode;
    var mutex = new Mutex(true, cacheKey);
    mutex.WaitOne();
    try
    {
        var cachedValue = HttpRuntime.Cache[cacheKey];
        if (cachedValue != null) return (List<Objects.SearchListItem>)cachedValue;
        var value = new List<Objects.SearchListItem>();
        var dr = new CwDbAccess(System.Data.CommandType.StoredProcedure, "CwPropertyListItemPart_LoadByCwProperty");
        try
        {
            dr.ExecuteReader();
            while (dr.MyReader.Read())
            {
                value.Add(new Objects.SearchListItem
                {
                    Name = Utils.ProperCase(dr.MyReader["Name"].ToString()),
                    Key = dr.MyReader["CwPropertyListItem_Guid"].ToString(),
                    IsAlias = false
                });
            }
        }
        catch (Exception ex)
        {
            CwLogging.LogException("Caching.ListItems.GetActiveCwPropertyListItemsByCwPropertyAndCulture", ex, ExceptionLevel.Urgent);
        }
        finally
        {
            dr.Close();
        }
        var keys = new List<string>();
        AddDependency("CwSiteClusterKey_" + cwProperty.CachedCwEntity.CwSiteClusterGuid, keys);
        AddDependency("CwPropertyKey_" + cwProperty.Guid, keys);
        HttpRuntime.Cache.Insert(cacheKey, value, new CacheDependency(null, keys.ToArray()), Cache.NoAbsoluteExpiration, Cache.NoSlidingExpiration, CacheItemPriority.Default, null);
        return value;
    }
    catch
    {
        throw;
    }
    finally
    {
        mutex.ReleaseMutex();
    }
}

完整的堆栈跟踪为：

System.Threading.AbandonedMutexException：由于放弃了互斥，等待已完成。在System.Threading.WaitHandle.ThrowAbandonedMutexException（）在System.Threading.WaitHandle.InternalWaitOne处（SafeHandle waitableSafeHandle，Int64毫秒超时，布尔值hasThreadAffinity，布尔值exitContext）在System.Threading.WaitHandle.WaitOne处（Int32毫秒超时，布尔值exitContext）在Common.Caching.ListItems.GetActiveCwPropertyListItemsByCwPropertyAndCulture（CwProperty cwProperty，字符串cultureCode）在Model.SearchFacet.GetAllSearchListItems（CwContext cwContext）在Common.Search.SqlFacets.RetrieveSqlFacetsByGroup（CwEntity cwEntity，NameValueCollectionstoredRequestForm，SqlFacetsContainer sqlFacets，SearchFacetGroupCollection组，SearchTemplate searchTemplate，CwContext cwContext）在Common.Search.SqlFacets.RetrieveSqlFacets（CwEntity cwEntity，NameValueCollectionstoredRequestForm，CwContext cwContext，SearchResultViewType searchResultViewType）在Common.Caching.SqlFacets.GetSqlFacets（字符串哈希，NameValueCollectionstoredRequestForm，CwEntity cwEntity，CwContext cwContext，SearchResultViewType searchResultViewType）位于C：\ Projects \ Compareware \ Compareware.WebApp \ Ui \ Pages \ SearchPage.cs：line 454中的Compareware_WebApp.Ui.Pages.SearchPage.AppendSearchAndResults（StringBuilder sb）在C：\ Projects \ Compareware \ Compareware.WebApp \ Ui \ Pages \ SearchPage.cs：line 310中的Compareware_WebApp.Ui.Pages.SearchPage.get_MainContent（）在ASP.default_aspx .__ RenderContent2（HtmlTextWriter __w，控制parameterContainer）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在ASP.masters_site_master .__ RenderForm1（HtmlTextWriter __w，控制parameterContainer）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.HtmlControls.HtmlForm.RenderChildren（HtmlTextWriter writer）在System.Web.UI.HtmlControls.HtmlContainerControl.Render（HtmlTextWriter writer）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在System.Web.UI.HtmlControls.HtmlForm.RenderControl（HtmlTextWriter writer）在ASP.masters_site_master .__ RenderBody（HtmlTextWriter __w，控制parameterContainer）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.HtmlControls.HtmlContainerControl.Render（HtmlTextWriter writer）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在ASP.masters_site_master .__ Render__control1（HtmlTextWriter __w，控制parameterContainer）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在System.Web.UI.Control.RenderChildrenInternal（HtmlTextWriter writer，ICollection子级）在System.Web.UI.Page.Render（HtmlTextWriter writer）在System.Web.UI.Control.RenderControlInternal（HtmlTextWriter writer，ControlAdapter适配器）在System.Web.UI.Page.ProcessRequestMain（Boolean includeStagesBeforeAsyncPoint，Boolean includeStagesAfterAsyncPoint）

Answer 1

您应该使用单个互斥锁，而不是为每个函数调用声明一个新的互斥锁。也许在此函数所在的类的范围内声明一个静态互斥锁，然后根据需要等待/释放。检查此页面上的示例：

https://docs.microsoft.com/en-us/dotnet/api/system.threading.mutex?view=netframework-4.7.2

在finally块中释放时放弃了AbandonedMutexException

1 个答案: