我需要克服这个错误:
ThreadPool中没有足够的空闲线程来完成操作。
当排队一堆Correspondence对象(带有SSRS报告)并通过Exchange WS发送它时,我得到80%的时间。使用ThreadPool生成并通过电子邮件发送报告。
这就是代码的样子,它建立在.Net 2.0上,因此没有使用TPL或Async / Await。
public static void QueueCorrespondence(ref Correspondence corr)
{
Queue corrQ = CorrespondenceQueue(corr.Medium);
// Create an AsyncOperation, using the CorrespondenceID as a unique id
AsyncOperation asOp = AsyncOperationManager.CreateOperation(corr.CorrespondenceID);
SendCorrespondencesInCurrentQueueArgs sendCorrespondencesInCurrentQueueArgs = new SendCorrespondencesInCurrentQueueArgs();
sendCorrespondencesInCurrentQueueArgs.AsOpArg = asOp;
sendCorrespondencesInCurrentQueueArgs.CorrQueueArg = corrQ;
lock (_correspondenceQs) {
if (corrQ.Count == 0) {
corrQ.Enqueue(corr);
ThreadPool.QueueUserWorkItem(new WaitCallback(SendCorrespondencesInCurrentQueue), sendCorrespondencesInCurrentQueueArgs);
} else {
corrQ.Enqueue(corr);
}
}
}
/// <summary>Do the processing necessary on the new thread</summary>
/// <param name="scicqa"></param>
/// <remarks>This runs on a background thread in the threadpool</remarks>
private static void SendCorrespondencesInCurrentQueue(SendCorrespondencesInCurrentQueueArgs scicqa)
{
Correspondence corr = null;
bool allReportsSuccessfullySent = false;
//Dequeues the correspondence from the queue and returns it (ByRef)
while (DequeueCorrespondence(ref corr, ref scicqa.CorrQueueArg)) {
try {
//This calls Exchange Web Services to send emails
Send(corr);
allReportsSuccessfullySent = true;
} catch (Exception ex) {
Incident.NewIncident("Unexpected Error", Incident.IncidentLevelEnum.ErrorLevel, ex, true, string.Format("Sending correspondence {0} via Medium {1}", corr.CorrespondenceID.ToString, corr.Medium));
} finally {
MailRoomArgs mra = new MailRoomArgs();
mra.CorrArg = corr;
mra.TransferSuccessArg = allReportsSuccessfullySent;
//Success or not, call the RaiseCorrespondenceSentEvent subroutine via this delegate.
scicqa.AsOpArg.Post(onCorrespondenceSentDelegate, mra);
}
}
}
/// <summary>Pull the next correspondence item off the queue, returning true if success</summary>
private static bool DequeueCorrespondence(ref Correspondence corr, ref Queue corrQ)
{
lock (_correspondenceQs) {
if (corrQ.Count > 0) {
corr = corrQ.Dequeue;
return true;
} else {
corr = null;
return false;
}
}
}
这是堆栈跟踪。请参阅上面的函数调用Exchange WS和BeginGetRequestStream由于ThreadPool中缺少线程而引发异常。
at System.Net.HttpWebRequest.BeginGetRequestStream(AsyncCallback callback, Object state)
at Microsoft.Exchange.WebServices.Data.EwsHttpWebRequest.Microsoft.Exchange.WebServices.Data.IEwsHttpWebRequest.BeginGetRequestStream(AsyncCallback callback, Object state)
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.GetWebRequestStream(IEwsHttpWebRequest request)
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.EmitRequest(IEwsHttpWebRequest request)
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.BuildEwsHttpWebRequest()
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ValidateAndEmitRequest(IEwsHttpWebRequest& request)
at Microsoft.Exchange.WebServices.Data.SimpleServiceRequestBase.InternalExecute()
at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.Execute()
at Microsoft.Exchange.WebServices.Data.ExchangeService.InternalCreateItems(IEnumerable`1 items, FolderId parentFolderId, Nullable`1 messageDisposition, Nullable`1 sendInvitationsMode, ServiceErrorHandling errorHandling)
at Microsoft.Exchange.WebServices.Data.ExchangeService.CreateItem(Item item, FolderId parentFolderId, Nullable`1 messageDisposition, Nullable`1 sendInvitationsMode)
at Microsoft.Exchange.WebServices.Data.Item.InternalCreate(FolderId parentFolderId, Nullable`1 messageDisposition, Nullable`1 sendInvitationsMode)
at Microsoft.Exchange.WebServices.Data.Item.Save(WellKnownFolderName parentFolderName)
at XYZ.WM.CIMS.BusinessObjects.ExchangeServer.SendCorrespondence(Correspondence& corr)
at XYZ.WM.CIMS.BusinessObjects.Email.SendCorrespondence(Correspondence& corr)
at XYZ.WM.CIMS.BusinessObjects.CorrespondenceMediumBase.Send(Correspondence& corr)
at XYZ.WM.CIMS.BusinessObjects.CorrespondenceMediumBase.SendCorrespondencesInCurrentQueue(SendCorrespondencesInCurrentQueueArgs scicqa)
在主线程上发送电子邮件可以正常工作。在这几天后,我非常肯定如果我没有在工作线程上调用Exchange WS,可以避免这个问题,如下所示。
如果我保存,发送或SendAndSave电子邮件,我仍然会收到错误:
private exchangeService = new ExchangeService(3); //Exchange2010 SP2
public void SendCorrespondence(ref Correspondence corr)
{
exchangeService.Url = new Uri("https://webmail.XYZ.com.au/EWS/Exchange.asmx");
exchangeService.UseDefaultCredentials = true;
string[] emailAddresses = corr.SubscriptionObject.SubscriptionRecipients.EmailAddresses;
EmailMessage message = default(EmailMessage);
message = new EmailMessage(exchangeService);
if (emailAddresses.Count > 1) {
message.BccRecipients.Add(string.Join(RECIPIENTS_SEPARATOR, emailAddresses));
}
else if (emailAddresses.Count == 1) {
message.ToRecipients.Add(emailAddresses(0));
}
message.Subject = corr.SubscriptionObject.EmailSubject;
EmailAddress fromSender = new EmailAddress();
fromSender.Address = _instOpsSharedOutlookMailAccount;
fromSender.Name = _instOpsSharedMailAccountName;
fromSender.MailboxType = MailboxType.Mailbox;
message.From = fromSender;
foreach (ReportBase generatedReport in corr.GeneratedReports) {
message.Attachments.AddFileAttachment(generatedReport.GeneratedDocument.FullName);
}
message.Body = new BodyType();
message.Body.BodyType = BodyType.HTML;
message.Body.Text = corr.SubscriptionObject.EmailTemplate;
if (corr.SubscriptionObject.SendToDraft) {
//Saving causes the problem !!!!!!!!!!!
message.Save(WellKnownFolderName.Drafts);
} else if (Convert.ToBoolean(Code.GetCodeTextValue(PARENT_CODE, "ExchangeSaveMsgOnSend", RETURN_DEFAULT_STRING_IF_NO_DATA, "True"))) {
//Sending and Saving causes the problem !!!!!!!!!!!
message.SendAndSaveCopy();
} else {
//Sending causes the problem !!!!!!!!!!!
message.Send();
}
}
实际上使用任何Exchange方法,例如:ExchangeService.ResolveName(logonID)
在从池中的线程调用时产生错误。
有没有人知道如何在不耗尽ThreadPool的情况下发送电子邮件?我不想过多地重新构建这个代码,但是很乐意实现一种简单的方法来避免在线程上发送电子邮件,如果有人知道的话。
Lotus Notes不会出现此问题。当外部程序使用Exchange WS发送电子邮件时,我正在使用Exchange WS来解决Outlook问题。我宁愿不使用Outlook客户端,但如果没有好的解决方案,我想我将不得不这样做。使用Smtp客户端不在卡上(因为在组文件夹中保存草稿是一个主要功能)。我也试过减少ThreadPool中的最大线程数,但我怀疑这没有什么区别。
您应该检查ThreadPool.GetAvailableThreads()并查看是否仍有可用的线程。那你有两个选择。
1)扩展最大线程数(但你应该避免它)
2)等待一些线程完成
int availableThreads = 0;
int completionPortThreads = 0;
System.Threading.ThreadPool.GetAvailableThreads(out availableThreads, out completionPortThreads);
while (!(availableThreads > 1))
{
System.Threading.Thread.Sleep(100);
System.Threading.ThreadPool.GetAvailableThreads(out availableThreads, out completionPortThreads);
}
祝好运!