Joe Sansalone

I'm interested in using the Metal API to perform parallel tasks. I know how to use TThread and TTask. Use them all the time. I'd like to play around with using code running on the GPU. In this case Metal API. Does anyone know of sample code using Metal API to perform calculations? Joe

Why does it work for days and then it doesn't? Strange. It's the same instance. I don't change anything. I'll install Wireshark on the server. Thanks for your help.

I got the PROBLEM again - HTTP Server stops responding. This time I logged OnConnect, OnHeadersAvailable, OnException, OnCommandError events as well as the usual OnCommandGet, OnCommandOther. There was NO activity in the above events when the problem occurred. Below is the log from Twilio's server which sends a request to my server (live.projectone.ca) : ======================================================================================== MESSAGE An attempt to retrieve content from https://live.projectone.ca/Phone returned the HTTP status code 502 SSL/TLS Handshake Error Error - 11220 SSL/TLS Handshake Error During SSL/TLS negotiation, Twilio experienced a connection reset. Possible Causes Incompatible cipher suites in use by the client and the server. This would require the client to use (or enable) a cipher suite that is supported by the server. Possible Solutions Verify cipher suites in-use are up to date. Twilio-supported ciphers can be found here Use compatible version of TLS, Twilio supports TLS 1.0,1.1,1.2. ============================================================================================ After closing/starting the application again, everything was fine. Is it possible that there's a newer version of Indy that fixes this problem? I'm thinking of running without SSL to see if this problem occurs. Joe

Ok got it. When I update to latest Indy version (either with next Delphi 11 or manually), I will make sure to change my code. Thanks!

NOTE: Twilio server receives SMSs sent to a phone number that resides in their network. They then send an HTTP request to my server indicating that they received an SMS and they put the contents of the SMS in the Body parameter. Here is an example of receiving an SMS (i.e. text on a cellular phone) Hello followed by 2 different smiley face emojis, received by Twilio and sent as a request to my server: Unparsed Param: Body=Hello+%F0%9F%98%85%F0%9F%A4%A3 Parsed Param: Body=Hello ð???ð?¤£ This is perfectly fine. But, I found that then I need to do this when receiving: Text := IndyTextEncoding_UTF8.GetString(ToBytes(aRequestInfo.Params.Values['Body'], IndyTextEncoding_8Bit)); in order to SEND the same SMS with the same Hello and 2 smiley faces using the REST components: FRestRequest.Params.AddItem('Body',TIDURI.ParamsEncode(aText, IndyTextEncoding_UTF8) , TRestRequestParameterKind.pkGETorPOST, [poDoNotEncode]); If I code it the regular way, it doesn't work. It sends the outgoing SMS with Hello .. but the 2 smiley faces are weird characters instead of 2 emojis.

I forgot to mention that each section in the CommendGet event has been tested quite a bit with no known problems. I'll have more HTTP logs the next time. Just realized that even though Checkbox.IsChecked simply accesses a boolean and does nothing else, it's possible that Windows OS may require that only the UI thread does this?? Although I thought it was because of thread-safety and avoiding weird collisions of updating the UI. In any case I have changed that code.

Unfortunately, HTTP logging was off .. I'll capture on the next time. Ok, I won't catch unhandled exceptions. So far, there has never been a log to indicate any. And logging for this is always on. Twilio sends the data in SMS texts with emoticons, emojis etc. Using aRequestInfo.Params.Values['Body'] doesn't work. It is thread-safe. However, it does block for some calls with a maximum timeout so it returns for sure. Is there a timeout where it's too much for TIdHTTPServer in terms of waiting for CommandGet event? I can change some of the blocking timeouts to be lower. Oops! I will fix that. I'm aware that UI controls need to be accessed within the main UI thread. In this specific case, I verified that cbLogPartialSpeech.IsChecked really only reads a boolean (nothing else) and I need to change it sometimes while the server is running .. so I took the liberty to do it this way. In the case of using Twilio, I need to send something to tell Twilio what to do with the "Call" or "SMS" - something that won't abruptly end the call. Thus, I send something in their XML-like language to tell them not to drop the call etc. Sending a 500 response will evoke their default behavior to thrash the existing call. We prefer otherwise. But we may change this ... I understand your concern. Thanks for the help - much appreciated! Sorry for the massive code. So much happens in the engine that the HTTP event code was left to grow without possibly making it more readable. It's the reason I simply made each section an IF then for each PathInfo, without using else's or it would really be hard to read.

The application (HTTP Server) stopped responding to requests again. This time, I simply "Stopped" and "Started" the TIdHTTPServer without restarting the application and it worked - application started responding to requests. // Stopped procedure TForm1.ButtonStopClick(Sender: TObject); begin FServer.Active := False; FServer.Bindings.Clear; end; // Started procedure TForm1.StartServer; begin if not FServer.Active then begin FServer.Bindings.Clear; FServer.Bindings.Add.Port := 443; FServer.DefaultPort := StrToInt(EditPort.Text); FServer.Bindings.Add.Port := 80; FServer.Bindings.Add.Port := 8080; // for testing FServer.Active := True; end; end; I'm either doing something strange in the TIdHTTPServer events or Indy HttpServer has a bug. BELOW is my code. It's just a bunch of "If then begin end" to handle each Pathinfo differently. And all of it is wrapped in a Try/Except procedure TForm1.FServerCommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo); var // engine: TSMSEngineIn; DB: TDynamicDBSession; task, numMedia, numSegments, profile_id: integer; PathInfo, id, temp, DID, NoResponse, callerID, main, mapped, PathInfoUser: string; ms: TMemoryStream; flowEngine: TFlowEngine; sms: TTwilioSMS; nexmo: TNexmoSMS; ibm: TIBMTranslator; from, toDN, text, forwardedFrom: string; FLog: TLogger; MsgStatus, InParams, tag, ip: string; CallSid, TwiMLResponse, engineID, CallStatus, SpeechResult, StableSpeechResult, UnstableSpeechResult, seqNumber, DigitsResult, Confidence: string; DialCallSid, DialCallStatus, TwilioPayResult, TwilioPayError, QueueResult, QueueTime, DequeingCallSid: string; RecordingSid, RecordingUrl, SMSSid: string; num, address: string; // form input from web isMobile, privatecall, isOptedOut: boolean; begin PathInfo := ARequestInfo.URI; PathInfoUser := UpperCase(PathInfo); // when it's a user typing url in a browser, we want to make sure they can spell it // upper, lower etc try NoResponse := '<?xml version="1.0" encoding="UTF-8"?> <Response> </Response>'; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // if incoming params are empty, it's a "fake" request InParams := ARequestInfo.Params.DelimitedText; // default Path if ((PathInfo = '/') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: path /'); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams); From := RemovePlus1(aRequestInfo.Params.Values['From']); ToDN := RemovePlus1(aRequestInfo.Params.Values['To']); // avoid hackers if ((From = '') and (ToDN='')) then begin AResponseInfo.ResponseNo := 404; AResponseInfo.ResponseText := 'Bug off'; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'IP: ' + AContext.Binding.PeerIP); Exit; end; Text := IndyTextEncoding_UTF8.GetString(ToBytes(aRequestInfo.Params.Values['Body'], IndyTextEncoding_8Bit)); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'From: ' + From + ' To: ' + ToDN); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Text: ' +StringReplace(Text, #13#10, ' ', [rfReplaceAll])); FDisplayThread.Display(TimeToStr(Now) + ': SMS From: ' + From + ' To: ' + ToDN); FDisplayThread.Display(TimeToStr(Now) + ': Text: ' + Text); try NumMedia := StrToInt(aRequestInfo.Params.Values['NumMedia']); numSegments := StrToInt(aRequestInfo.Params.Values['NumSegments']); except on E:EConvertError do begin NumMedia := 0; numSegments := 1; end; end; DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'MMS: ' + IntToStr(numMedia)); // TODO: 1st check to see if session is already active if EngineSessions.LookupSession(From + toDN, task) then begin EnginePool[task].Engine.SMSEvent(From, toDN, Text, NumMedia, numSegments); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'SMSEvent'); end else // new if EnginePool.GetEngineFromPool(task) then begin EngineSessions.AddSession(From + toDN, task); EnginePool[task].IncomingSMS(toDN, From, Text, NumMedia, numSegments, aRequestInfo.Params.Values['MediaUrl0'], // 1st Media URL for now aRequestInfo.Params.Values['MediaContentType0']); AResponseInfo.ContentText := NoResponse; end else begin DefaultLog.WriteTimeStamp(lctSMS, lptImportant, 'Unable to get an Engine from Pool'); AResponseInfo.ContentText := TTwilioML.NoCapacitySMS; // for get this // AResponseInfo.ContentText := 'Overloaded server'; // AResponseInfo.ResponseNo := 503; // busy, overloaded, not available for now end; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Nexmo SMS if ((PathInfo = '/Nexmo/SMS') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '**** Begining webmodule default action: path /Nexmo/SMS'); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams); From := Remove1(aRequestInfo.Params.Values['msisdn']); ToDN := Remove1(aRequestInfo.Params.Values['to']); Text := IndyTextEncoding_UTF8.GetString(ToBytes(aRequestInfo.Params.Values['text'], IndyTextEncoding_8Bit)); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'From: ' + From + ' To: ' + ToDN); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Text: ' +StringReplace(Text, #13#10, ' ', [rfReplaceAll])); // 1st check to see if session is already active // not needed for SMS at this time if EnginePool.GetEngineFromPool(task) then begin EngineSessions.AddSession(From + toDN, task); EnginePool[task].IncomingSMS(toDN, From, Text, 0, 1, '', ''); // no media stuff for nexmo end else DefaultLog.WriteTimeStamp(lctSMS, lptImportant, 'Unable to get an Engine from Pool'); AResponseInfo.ResponseNo := 200; AResponseInfo.ContentText := 'OK'; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Nexmo Delivery Receipt if ((PathInfo = '/Nexmo/DLR') and (InParams <> '')) then begin DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Begining webmodule default action: path /Nexmo/DLR'); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams + #13#10); if (aRequestInfo.Params.Values['status'] <> 'delivered') then begin DefaultLog.WriteTimeStamp(lctSMS, lptImportant, 'Nexmo msg not delivered'); end; AResponseInfo.ResponseNo := 200; AResponseInfo.ContentText := 'OK'; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Twilio Delivery Receipt if ((PathInfo = '/Status') and (InParams <> '')) then begin // DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams + #13#10); MsgStatus := ARequestInfo.Params.Values['MessageStatus']; //if ((MsgStatus <> 'sent') and (MsgStatus <> 'delivered')) then if (MsgStatus = 'delivered') then begin DefaultLog.WriteTimeStamp(lctSMS, lptNormal, '***** /Status delivered' ); SMSSid := ARequestInfo.Params.Values['SMSSid']; if EngineSessions.LookupSession(SMSSid, task) then begin EnginePool[task].Engine.SignalSMSDelivery; end end; AResponseInfo.ContentText := NoResponse; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Twilio CallStatus events if ((PathInfo = '/CallStatus') and (InParams <> '')) then begin DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** /CallStatus '); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams + #13#10); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid + ' sessions cnt:' + IntToStr(EngineSessions.Count) ); CallStatus := aRequestInfo.Params.Values['CallStatus']; if (CallStatus = 'completed') or (CallStatus = 'canceled') then begin if EngineSessions.LookupSession(CallSid, task) then begin EngineSessions.RemoveSession(CallSid); EnginePool[task].Engine.SignalHangup; //send hangup event end else DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** /CallStatus: ' + 'did not find a session '); end else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '***** /CallStatus: ' + CallStatus + ' something other than completed/canceled??'); AResponseInfo.ContentText := NoResponse; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Twilio MakeCallStatus events // we send the engine# via the url, so no need to lookup session // however, in future, we may need to lookup session to get OTHER engines that are interested in this status if ((PathInfo = '/MakeCallStatus') and (InParams <> '')) then begin DefaultLog.WriteTimeStamp(lctSMS, lptNormal, '***** /MakeCallStatus '); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams + #13#10); CallSid := aRequestInfo.Params.Values['CallSid']; engineID := aRequestInfo.Params.Values['engineid']; task := StrToInt(engineID); CallStatus := aRequestInfo.Params.Values['CallStatus']; if (CallStatus = 'completed') then // i.e. hungup after connected begin if EngineSessions.LookupSession(CallSid, task) then begin EngineSessions.RemoveSession(CallSid); EnginePool[task].Engine.SignalHangup; // send a hangup event end; end else // busy, no-answer, canceled, (possible that hangs up before connected, Red button on mobile) etc begin EnginePool[task].Engine.SignalMakeCallStatus(CallStatus); end; AResponseInfo.ContentText := NoResponse; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Twilio calls this to get MakeCall TwiML, at this point we know MakeCall is connected if ((PathInfo = '/MakeCall') and (InParams <> '')) then begin DefaultLog.WriteTimeStamp(lctSMS, lptNormal, '***** /MakeCall '); DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams + #13#10); CallSid := aRequestInfo.Params.Values['CallSid']; engineID := aRequestInfo.Params.Values['engineid']; // value that we sent Twilio via url, so that we know engine# task := StrToInt(engineID); // TODO: make sure engineid param is there EngineSessions.AddSession(CallSid, task); TwiMLResponse := NoResponse; if not(EnginePool[task].Engine.WaitingOnMakeCallTwiML(TwiMLResponse)) then begin DefaultLog.WriteTimeStamp(lctSMS, lptNormal, '***** /MakeCall, Timed out waiting for TwiML, sending Pause '); AResponseInfo.ContentText := TTwilioML.PauseResponse; end else AResponseInfo.ContentText := TwiMLResponse; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; // IMPORTANT to have no spaces in ContentType end; // Media Path if ((PathInfo = '/Media') or (PathInfo = '/MEDIA')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '****Begining MEDIA action: '); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams); // get file or FILE value // file=balls.jpg or file=sample.gif, extension determines what ContentType to return id := ARequestInfo.Params.Values['file']; if id = '' then id := ARequestInfo.Params.Values['FILE']; ms := TMemoryStream.Create; if (id <> '') then ms.LoadFromFile(id); ms.Position := 0; AResponseInfo.ContentType := FileToContentType(id); // based on filename extension AResponseInfo.ContentStream := ms; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'File sent.' + #13#10); ms.Free; // TODO: try/finally end; // "/Media" // email Path if ((PathInfo = '/Email') or (PathInfo = '/EMAIL')) then begin DataModule1.Log.WriteTimeStamp(lctHTTP, lptNormal, '****Begining EMAIL action: '); DataModule1.Log.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams); DataModule1.Log.WriteTimeStamp(lctHTTP, lptNormal, ARequestInfo.RemoteIP); DataModule1.Log.WriteTimeStamp(lctHTTP, lptNormal, ARequestInfo.UserAgent); ip := ARequestInfo.RemoteIP; SMS := TTwilioSMS.Create(cAccountSID, cTwilioPassword); sms.Log := DataModule1.Log; // get file or FILE value // file=balls.jpg or file=sample.gif, extension determines what ContentType to return id := ARequestInfo.Params.Values['info']; if id = '' then id := ARequestInfo.Params.Values['INFO']; tag := ARequestInfo.Params.Values['tag']; ms := TMemoryStream.Create; if (id <> '') then ms.LoadFromFile('balls.jpg'); ms.Position := 0; AResponseInfo.CacheControl := 'no-cache'; // don't have browser cache this image AResponseInfo.ContentType := FileToContentType(id); // based on filename extension AResponseInfo.ContentStream := ms; text := tag + #13#10 + ip; sms.SendSMS('5146295764', '4385001040', text, '', false, numSegments, isMobile, isOptedOut, SMSSid); sms.Free; ms.Free; DataModule1.Log.WriteTimeStamp(lctHTTP, lptNormal, 'Picture sent.' + #13#10); end; // Phone Path if ((PathInfo = '/Phone') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /Phone'); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams); From := aRequestInfo.Params.Values['From']; privatecall := (From = '+266696687'); // Twilio sends this number when private From := RemovePlus1(From); if privatecall then From := 'PRIVATE'; ToDN := RemovePlus1(aRequestInfo.Params.Values['To']); forwardedFrom := RemovePlus1(aRequestInfo.Params.Values['ForwardedFrom']); CallSid := aRequestInfo.Params.Values['CallSid']; FDisplayThread.Display(TimeToStr(Now) + ': Call From: ' + From + ' To: ' + ToDN); if (forwardedFrom <> '') then FDisplayThread.Display('Forwarded from: ' + forwardedFrom); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Incoming Call From: ' + From + ' To: ' + ToDN + ' forwarded from: ' + forwardedFrom); TwiMLResponse := NoResponse; // in case we can't have an engine // ONLY new calls here if EnginePool.GetEngineFromPool(task) then begin if EngineSessions.AddSession(CallSid, task) then DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Added session: ' + CallSid + ' id: ' + IntToStr(task)); TwiMLResponse := EnginePool[task].IncomingCall(ToDN, From, CallSid, forwardedFrom, privatecall); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'TwiML(sent back to http server): ' + TwiMLResponse); AResponseInfo.ContentText := TwiMLResponse; end else begin DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, 'Unable to get an Engine from Pool'); AResponseInfo.ContentText := TTwilioML.NoCapacityCall; // forget this // AResponseInfo.ContentText := 'Overloaded server'; // AResponseInfo.ResponseNo := 503; // busy, overloaded, not available for now end; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; end; // "/Phone" // Redirect after a <Say> comes here if ((PathInfo = '/SayEnd') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /SayEnd'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalSayComplete else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/SayEnd: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Redirect after a <Play> comes here if ((PathInfo = '/PlayEnd') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /PlayEnd'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalPlayComplete else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/PlayEnd: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Redirect after a <Call> comes here (non-action Dial version) // After coversation ends, busy, no answer or call failed if ((PathInfo = '/CallEnd') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /CallEnd'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalCallComplete else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/CallEnd: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // <Call> using action, provides DialCallStatus if we need OnNoAnswer, OnBusy // getting completed means Called Party hung up if ((PathInfo = '/DialCall') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /DialCall'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); DialCallSid := aRequestInfo.Params.Values['DialCallSid']; DialCallStatus := aRequestInfo.Params.Values['DialCallStatus']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'DialCallSid: ' + DialCallSid + ' DialCallStatus: ' + DialCallStatus); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalCall(DialCallStatus) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/DialCall: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Redirect after a <Gather> comes here if ((PathInfo = '/GatherTimeout') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /GatherTimeout'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalSpeech('xTimeoutx', '') // we use string "xTimeoutx" to signal user timeout else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/GatherTimeout: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Redirect after a DTMF comes here if ((PathInfo = '/DTMFTimeout') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /DTMFTimeout'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalDTMF('xTimeoutx') // we use string "xTimeoutx" to signal user timeout else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/DTMFTimeout: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Received DTMF, comes here if ((PathInfo = '/DTMF') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /DTMF'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); DigitsResult := aRequestInfo.Params.Values['Digits']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Digits: ' + DigitsResult); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalDTMF(DigitsResult) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/DTMF: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Received speech, <Gather> comes here if ((PathInfo = '/Gather') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /Gather'); // DefaultLog.WriteTimeStamp(lctSMS, lptNormal, 'Params: ' + InParams); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); Confidence := aRequestInfo.Params.Values['Confidence']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'score: ' + Confidence); SpeechResult := aRequestInfo.Params.Values['speechResult']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'speechResult: ' + SpeechResult); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalSpeech(SpeechResult, Confidence) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/Gather: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Received speech Partial, <Gather> comes here if ((PathInfo = '/GatherPartial') and (InParams <> '')) then begin CallSid := aRequestInfo.Params.Values['CallSid']; StableSpeechResult := ARequestInfo.Params.Values['StablespeechResult']; seqNumber := ARequestInfo.Params.Values['SequenceNumber']; UnStableSpeechResult := aRequestInfo.Params.Values['UnstableSpeechResult']; if (cbLogPartialSpeech.IsChecked) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /GatherPartial'); // DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Stable speechResult: ' + StablespeechResult); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Sequence Number: ' + seqNumber); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Unstable speechResult: ' + UnstableSpeechResult); end; // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.maybeSignalSpeechEnd(UnstableSpeechResult, StableSpeechResult) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/GatherPartial: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.NoResponse; end; // action for <Pay> TwiML for <TwilioPay> if ((PathInfo = '/TwilioPay') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /TwilioPay'); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Params: ' + InParams); CallSid := aRequestInfo.Params.Values['CallSid']; TwilioPayResult := aRequestInfo.Params.Values['result']; TwilioPayError := aRequestInfo.Params.Values['PaymentError']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // if Pos('insufficient funds', TwilioPayError) > 0 then TwilioPayResult := 'not-enough-funds'; // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalTwilioPay(TwilioPayResult) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/TwilioPay: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Redirect after a <Conference> comes here if ((PathInfo = '/Conference') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /Conference'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalConferenceEnd else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/Conference: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Received RecordingStatus, if ((PathInfo = '/RecordingStatus') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /RecordingStatus'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); RecordingSid := aRequestInfo.Params.Values['RecordingSid']; RecordingUrl := aRequestInfo.Params.Values['RecordingUrl']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'Recording: ' + RecordingSid + ' ' + RecordingUrl); //TODO: maybe assign Sid and URL somewhere in Engine for this task, so that // we may in real-time play it back, store it etc. // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.RecordingComplete(RecordingSid) else DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '/RecordingStatus: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // url for ModifyCall API (if we are using the url instead of TwiML parameter) if ((PathInfo = '/ModifyCall') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /ModifyCall'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then TwiMLResponse := EnginePool[task].Engine.GetModifyCallTwiML else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/ModifyCall: unable to find Call Session'); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'TwiML: ' + TwiMLResponse); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TwiMLResponse; end; // NOTE: for a user to type into a browser if (PathInfoUser = '/WEB') then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /Web'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := cWebformHTML; end; if ((PathInfo = '/webinput') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /webinput'); AResponseInfo.ContentText := 'Unsuccessful. Try again.'; num := aRequestInfo.Params.Values['num']; address := aRequestInfo.Params.Values['address']; num := Trim(num); address := Trim(address); if EngineSessions.LookupSession(num, task) then begin EnginePool[task].Engine.HTTPEvent(num,address); DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'HTTPEvent'); AResponseInfo.ContentText := 'Successful. Thank You.'; end; AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; end; // Twilio's <Enqueue> action="" comes here if ((PathInfo = '/EnqueueAction') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /EnqueueAction'); CallSid := aRequestInfo.Params.Values['CallSid']; QueueResult := aRequestInfo.Params.Values['QueueResult']; QueueTime := aRequestInfo.Params.Values['QueueTime']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid + ' QueueResult: ' + QueueResult); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalEnqueue(QueueResult, QueueTime) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/EnqueueAction: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; // Twilio's <Dial> ... <Queue url="" comes here // This is where we send back TwiML to caller waiting before connected if ((PathInfo = '/QueueAction') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /QueueAction'); DequeingCallSid := aRequestInfo.Params.Values['DequeingCallSid']; // <== this caller CallSid := aRequestInfo.Params.Values['CallSid']; // <=== caller that is waiting on hold, this caller will connect to QueueTime := aRequestInfo.Params.Values['QueueTime']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'this CallSid: ' + DequeingCallSid + ' other CallSid: + ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(DequeingCallSid, task) then EnginePool[task].Engine.SignalDequeueConnected(QueueTime, CallSid) else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/QueueAction: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.EnqueueStdResponse; end; // Redirect for our <Queue> if ((PathInfo = '/Queue') and (InParams <> '')) then begin DefaultLog.LineFeed; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, '***** Begining webmodule default action: /Queue'); CallSid := aRequestInfo.Params.Values['CallSid']; DefaultLog.WriteTimeStamp(lctHTTP, lptNormal, 'CallSid: ' + CallSid); // lookup session and deliver currentEvent if EngineSessions.LookupSession(CallSid, task) then EnginePool[task].Engine.SignalDequeueTimeout else DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, '/Queue: unable to find Call Session'); AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.PauseResponse; end; except on E:Exception do begin AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; AResponseInfo.ContentText := TTwilioML.NoResponse; DefaultLog.WriteTimeStamp(lctHTTP, lptImportant, 'Exception occurred in the HTTP server GetCommand'); end; end; end;

Now that logging is enabled on the OnException event handler of TIdHTTPServer, I'm seeing all sorts of different exceptions. However, the application is responding correctly. These are other "bad" requests hitting the server. I guess this is normal? Below is part of the log: [HTTP : Exception 08/10 07:01:51.935] OnException: Error accepting connection with SSL. EOF was observed that violates the protocol [HTTP : Exception 08/10 07:45:07.863] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:08.035] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:08.113] OnException: Error accepting connection with SSL. error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher [HTTP : Exception 08/10 07:45:08.379] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:08.582] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:08.738] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:08.926] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:09.113] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:09.348] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:09.567] OnException: Socket Error # 10054 Connection reset by peer. [HTTP : Exception 08/10 07:45:29.097] OnException: Connection Closed Gracefully. [HTTP : Exception 08/10 08:05:17.495] OnException: Connection Closed Gracefully. [HTTP : Exception 08/10 08:33:29.720] OnException: Error accepting connection with SSL. error:1408A10B:SSL routines:ssl3_get_client_hello:wrong version number [HTTP : Exception 08/10 09:01:26.542] OnException: Error accepting connection with SSL. EOF was observed that violates the protocol [HTTP : Exception 08/10 09:41:58.993] OnException: Error accepting connection with SSL. error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number [HTTP : Exception 08/10 09:57:41.154] OnException: Connection Closed Gracefully.

I'll review my code looking for possible problems with synchronization (although I remember being careful when writing it). The production application now has logging on OnException, OnCommendError, OnHeadersAvailable, OnConnect. And using the updated SSL DLLs. So I'll wait and see if it happens again.

I'm using Indy 10.6.2.0 that came with Delphi 10.4.2. Details on error from Twilio: SSL/TLS Handshake Error An attempt to retrieve content from https://live.projectone.ca/Phone returned the HTTP status code 502 During SSL/TLS negotiation, Twilio experienced a connection reset. Yes, there's some synchronization. I'm pretty sure I put some timeouts to make sure that it returns. You bring up a good point. I'm assuming you are suggesting that synchronization can cause the OnCommand events to timeout, correct? Which could be a problem.

I'm using Indy 10.6.2.0. The OpenSSL DLLs were more than a year old, so I just updated the DLLs today with 1.0.2u version (Jun 25, 2021). I'm hoping these new DLLs might solve the problem - I later learned that Twilio server error logs indicated that a problem occurred during the TLS handshaking. Twilio servers send requests to my HTTP(S) application server. I am using the OnQuerySSLPort event. I only return True (use SSL) for the 443 port. I didn't get a chance to use Wireshark when the problem happened. If it happens again, I will. My OnCommand events do not create any object. They use pre-created objects with pre-connected database connections to handle requests. I was careful to make sure the code is thread-safe. In general, all requests are handled by separate threads anyway (pooled). Thanks for pointing out OnConnect, OnHeadersAvailable events ... I'll put some code there to log info so that the next time it happens, I'll see more. Also, OnException/OnCommandError ... I'll put some logging code. Thanks for your help. I will write again - either saying it's fixed OR if it happens again I'll update this thread with more logging information. Joe

(Currently trying with updated openssl DLL files to see if it fixes the problem .. although I need to wait a while to know for sure) In the meantime ... Hi, When testing a Indy Server application everything was fine. Now in production, it stops responding to requests after a while. Is it ok to bind multiple ports like this? (should bind to the same default IP, right?) if not FServer.Active then begin FServer.Bindings.Clear; FServer.Bindings.Add.Port := 443; FServer.DefaultPort := StrToInt(EditPort.Text); FServer.Bindings.Add.Port := 80; FServer.Bindings.Add.Port := 8080; // for testing FServer.Active := True; end; Another question: If an exception occurs in the OnCommandGet of the server and is not handled, would this screw things up for Indy HTTP server? Am I fine as long as I set this before end of OnCommandGet? AResponseInfo.ResponseNo := 200; AResponseInfo.ContentText := 'OK'; // or whatever appropriate response here AResponseInfo.ContentType := 'text/html;charset="UTF-8"'; What else could I be doing to get IdHTTPServer to stop responding to requests? Thanks, Joe

I see the benefit of For loop only evaluating once at initial.

I didn't realize For loop evaluates only once. Thanks for everyone's comments. I'll use a While loop.