Process Pool Demo
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In an article on the Unicorn InterGlobal web site I describe my Process Pooling Demo web view.
The code for it is as follows and you can download the zip file from this link: File:ProcPoolDemo.zip.
(Note: now modified to work with DataFlex 20.0 as well as DataFlex 19.1... and possibly prior versions as well - no guarantees though. I have only tested with 19.1 and 20.0.)
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Global_Variable Integer giRandomMove (Random(10000)) to giRandom // This will be a property of oWabApp:Property Integer piRandom (Random(10000) + 10000) // Will be opened in the WebAppOpen FlexerrsClear FlexerrsMove (Random(99) + 1) to Flexerrs.RecnumFind EQ FlexErrs by Recnum //==============================================================================// This is a Modal Dialog which will be called from the View,// included directly in-line here for simplicity://==============================================================================Object oTestDialog is a cWebModalDialog Set psCaption to "Test Dialog" Set piMinWidth to 300 Set piMinHeight to 200 Set pbServerOnEscape to False // The only way out Set pbShowClose to False // is to click "OK" Set pbServerOnSubmit to True // enable the OnSubmit event Object oMainPanel is a cWebPanel Set piColumnCount to 12 Object oProcess is a cWebForm Set piColumnSpan to 0 Set peLabelAlign to alignRight Set pbReadOnly to True Set psLabel to "This Process ID:" Set piLabelOffset to 210 End_Object Object oCaller is a cWebForm Set piColumnSpan to 0 Set peLabelAlign to alignRight Set pbReadOnly to True Set psLabel to "Called from Process ID:" Set piLabelOffset to 210 End_Object Object oGlobal is a cWebForm Set piColumnSpan to 0 Set peLabelAlign to alignRight Set pbReadOnly to True Set psLabel to "Global variable giRandom was:" Set piLabelOffset to 210 End_Object Object oRegProp is a cWebForm Set piColumnSpan to 0 Set peLabelAlign to alignRight Set pbReadOnly to True Set psLabel to "Regular property piRandom was:" Set piLabelOffset to 210 End_Object End_Object Object oBottomPanel is a cWebPanel Set piColumnCount to 4 Set peRegion to prBottom Object oOkButton is a cWebButton Set psCaption to C_$OK Set piColumnSpan to 1 Set piColumnIndex to 3 Procedure OnClick Send Ok End_Procedure End_Object End_Object Procedure OnSubmit Send Ok End_Procedure Procedure PopupTheDialog Handle hReturnObj Integer iCaller Send Popup hReturnObj WebSet psValue of oProcess to (GetCurrentProcessId()) WebSet psValue of oCaller to iCaller WebSet psValue of oGlobal to giRandom WebSet psValue of oRegProp to (piRandom(Self)) End_Procedure Function DialogResult Returns String String sResult WebGet psValue of oProcess to sResult Function_Return sResult End_Function End_Object //==============================================================================// This is the actual view//==============================================================================Object oProcPoolDemo is a cWebView Set piWidth to 700 Set psCaption to "Process Pooling Effects Demo" Set pbServerOnShow to True Property Integer[] paiWebAppProcs // Display this view at start up: Delegate Set phoDefaultView to Self // Work out the web application name from the web.config // file in AppHTML, which we read into an XML object Function WebAppName Returns String Handle hoXml hoElem String sName Boolean bOK Get Create (RefClass(cXMLDOMDocument)) to hoXml Set psDocumentName of hoXml to ; (psAppHtmlPath(phoWorkspace(ghoApplication)) + "\web.config") Get LoadXMLDocument of hoXml to bOK Get FindNode of hoXml "configuration/location/system.webServer/dataflexHttpModule" to hoElem Get AttributeValue of hoElem "application" to sName Send Destroy of hoElem Send Destroy of hoXml Function_Return sName End_Function // Will be set to return value of above function at start-up. // This is a regular property because the web app name can't // change while the program is running. Property String psWebAppName (WebAppName(Self)) // This uses three external functions to find all the processes in the // current WebApp's process pool - it will get updated on every refresh // so if you change the number of processes in the pool while the WebApp is // running you will see it in the view. // // It first uses EnumProcesses to find all the running processes on the // machine. // // It then iterates through that list and tries OpenProcess to get a handle // to it (for some permissions will not allow that, so those are skipped). // // Finally it calls ProcessImageFileName to see if that is one of the // processes running for THIS WebApp. However ProcessImageFileName // returns a file-path starting with the disk identifer in a slightly odd // form, i.e. "\DEVICE\HARDDISKVOLUMEn" (n is "1" for my C: drive) and even // spookier things for mapped drives, so we strip off the "C:\", or whatever, // from the application file name DataFlex returns and uppercase both, then // compare THAT to the same length of the right-portion of the image name. // This may screw up if you have more than one identically pathed web-apps // on different drives - just so you know. <g> // // Note: that although the docs (and the declarations) use DWords, // on Vincent's advice we are using UIntegers in our code (the same // thing in reality) because you can use SizeOfType(UInteger) in the // Watches window when debugging, which you can't for DWord. Procedure FindWebAppProcs Integer[] aiWebAppProcs UInteger[] auiProcs UInteger uiCb uiNeeded uiSize uiErr Integer iOK i iLast iPos iSize iPathLen Handle hProc UChar[] ucaFile String sPath sImage Move (Uppercase(GetApplicationFileName(ghoApplication))) to sPath // Strip off drive designation: Move (Pos("\", sPath)) to iPos Move (Right(sPath, (Length(sPath) - iPos))) to sPath Move (Length(sPath)) to iPathLen Move 4096 to iSize Move (ResizeArray(auiProcs, iSize)) to auiProcs Move (iSize * SizeOfType(UInteger)) to uiCb Move 0 to uiNeeded Move (EnumProcesses(AddressOf(auiProcs), ; uiCb, ; AddressOf(uiNeeded))) to iOK // Just for debugging: If not iOK ; Move (GetLastError()) to uiErr Move (uiNeeded / SizeOfType(UInteger)) to iSize Move (ResizeArray(auiProcs, iSize)) to auiProcs Decrement iSize For i from 0 to iSize Move (OpenProcess(PROCESS_VM_READ + PROCESS_QUERY_INFORMATION, ; True, auiProcs[i])) to hProc If (hProc <> 0) Begin // We DID get a handle to the process Move (ResizeArray(ucaFile, 0)) to ucaFile Move (ResizeArray(ucaFile, 2048)) to ucaFile Move (ProcessImageFileName(hProc, ; AddressOf(ucaFile), 2048)) to uiSize Move (ResizeArray(ucaFile, uiSize)) to ucaFile Move (Uppercase(UCharArrayToString(ucaFile))) to sImage Move (Right(sImage, iPathLen)) to sImage If (sImage = sPath) ; Move auiProcs[i] to aiWebAppProcs[SizeOfArray(aiWebAppProcs)] End Loop Set paiWebAppProcs to aiWebAppProcs End_Procedure Procedure OnShow Send UpdateProcInfo End_Procedure // Registry object for getting the WebApp info from the registry: Object oReg is a cRegistry Set phRootKey to HKEY_LOCAL_MACHINE Set pfAccessRights to (KEY_WOW64_64KEY ior KEY_READ) Function BaseKey Returns String String[] asParts Move "SOFTWARE" to asParts[0] Move "Data Access Worldwide" to asParts[1] Move "DataFlex" to asParts[2] Move C_DFVersion to asParts[3] Move "WebApp Server" to asParts[4] Move "Web Applications" to asParts[5] // If it is a 64-bit machine and running on a DF version PRIOR to 20 // Insert "Wow6432Node just after "SOFTWARE": If (KeyExists(Self, "SOFTWARE\Wow6432Node") and ; (Number(C_DFVersion) < 20)) ; Move (InsertInArray(asParts, 1, "Wow6432Node")) to asParts Function_Return (StrJoinFromArray(asParts, "\")) End_Function Function DWKeyValue String sApp String sVal Returns Integer Boolean bOK Integer iVal String sKey Move (BaseKey(Self) + "\" + sApp) to sKey Get KeyExists sKey to bOK If not bOK ; Function_Return 0 Get OpenKey sKey to bOK If not bOK ; Function_Return 0 Move (ReadDWord(Self, sVal)) to iVal Send CloseKey Function_Return iVal End_Function End_Object // Refresh all the displayed information Procedure UpdateProcInfo String sApp Integer iMin iMax Get psWebAppName to sApp WebSet psValue of oMinProc to (DWKeyValue(oReg(Self), sApp, "MinPool")) WebSet psValue of oMaxProc to (DWKeyValue(oReg(Self), sApp, "MaxPool")) WebSet psValue of oCurrProcs to "Unknown" WebSet psValue of oCurrProcess to (GetCurrentProcessId()) WebSet psValue of oGlobalVal to giRandom WebSet psValue of oRegProp to (piRandom(Self)) WebSet psValue of oDBRec to FlexErrs.Recnum Send FindWebAppProcs Send GridRefresh of oProcList Send Focus of oCallServer End_Procedure Object oWebMainPanel is a cWebPanel Set piColumnCount to 8 Object oExplanation is a cWebLabel Set piColumnSpan to 0 Set psCaption to ; ('This view demonstrates the fact that in a Process' + ; ' Pooled WebApp (which all modern WebApps generally' + ; ' are) you CANNOT rely on the values in global variables,' + ; ' regular properties and database buffers. They change' + ; ' from one server round-trip to the next. ONLY web' + ; ' properties and Data Dictionary values can be relied on.' + ; ' If you run this under the debugger you will see that' + ; ' only a single process is "in the pool" and the values' + ; ' of the things below do not change, which is why you' + ; ' MUST test Web Apps OUTSIDE the debugger.') End_Object Object oProcPoolGrp is a cWebGroup Set piColumnCount to 8 Set piColumnSpan to 0 Set psCaption to "Process Pool Information:" Object oPoolInfo is a cWebGroup Set pbShowBorder to False Set pbShowCaption to False Set piColumnCount to 12 Set piColumnSpan to 6 Object oAppName is a cWebForm Set piColumnSpan to 0 Set pbReadOnly to True Set peLabelAlign to alignRight Set psLabel to "Web Application:" Set psValue to (psWebAppName(Self)) End_Object Object oMinProc is a cWebForm Set piColumnSpan to 5 Set pbReadOnly to True Set peLabelAlign to alignRight Set psLabel to "Minimum Pool:" End_Object Object oMaxProc is a cWebForm Set piColumnSpan to 5 Set pbReadOnly to True Set peLabelAlign to alignRight Set psLabel to "Maximum Pool:" End_Object Object oCurrProcs is a cWebForm Set piColumnSpan to 5 Set pbReadOnly to True Set peLabelAlign to alignRight Set psLabel to "Current Pool:" End_Object End_Object Object oProcList is a cWebList Set piColumnIndex to 6 Set piColumnSpan to 2 Set pbDataAware to False Set pbOfflineEditing to True // DON'T call the server on RowChange // Adjust this to see more/less process numbers without scrolling: Set piHeight to 200 Object oProcsCol is a cWebColumn Set psCaption to "Pool Process IDs" Set piWidth to 100 End_Object Procedure OnManualLoadData tWebRow[] ByRef aTheRows String ByRef sCurrentRowID Integer[] aiWebProcs Integer i iLast iThis Get paiWebAppProcs of oProcPoolDemo to aiWebProcs Move (GetCurrentProcessId()) to iThis Move (SizeOfArray(aiWebProcs)) to iLast WebSet psValue of oCurrProcs to iLast Decrement iLast For i from 0 to iLast Move aiWebProcs[i] to aTheRows[i].sRowID Move aiWebProcs[i] to aTheRows[i].aCells[0].sValue If (aiWebProcs[i] = iThis) Begin Move aiWebProcs[i] to sCurrentRowID End Loop Forward Send OnManualLoadData (&aTheRows) (&sCurrentRowID) End_Procedure End_Object End_Object Object oCurrProcess is a cWebForm Set piColumnIndex to 0 Set piColumnSpan to 4 Set pbReadOnly to True Set psLabel to "Last invoked server process was:" Set peLabelAlign to alignRight Set piLabelOffset to 250 End_Object Object oGlobalVal is a cWebForm Set piColumnIndex to 0 Set piColumnSpan to 4 Set pbReadOnly to True Set psLabel to "Global variable giRandom in that was:" Set peLabelAlign to alignRight Set piLabelOffset to 250 End_Object Object oRegProp is a cWebForm Set piColumnIndex to 0 Set piColumnSpan to 4 Set pbReadOnly to True Set psLabel to "Regular property piRandom in that was:" Set peLabelAlign to alignRight Set piLabelOffset to 250 End_Object Object oDBRec is a cWebForm Set piColumnIndex to 0 Set piColumnSpan to 4 Set pbReadOnly to True Set psLabel to "Flexerrs recnum in that was:" Set peLabelAlign to alignRight Set piLabelOffset to 250 End_Object Object oWebValue is a cWebForm Set piColumnIndex to 0 Set piColumnSpan to 4 Set psLabel to "Your entered value:" Set psValue to "Hello!" Set peLabelAlign to alignRight Set piLabelOffset to 250 End_Object Object oNote is a cWebLabel Set psCaption to "(This is a web property - psValue of oWebValue - so will not change unless YOU change it)" Set piColumnIndex to 4 Set piColumnSpan to 4 End_Object Object oButtonSpacer is a cWebSpacer Set piHeight to 20 End_Object Object oCallServer is a cWebButton Set piColumnIndex to 0 Set piColumnSpan to 2 Set psCaption to "Call Server" Procedure OnClick Send UpdateProcInfo End_Procedure End_Object Object oInfo is a cWebButton Set piColumnIndex to 2 Set piColumnSpan to 2 Set psCaption to "Info Box" Procedure OnClick Integer iProc Move (GetCurrentProcessId()) to iProc Send ShowInfoBox ("InfoBox in process" * String(iProc)) Send UpdateProcInfo End_Procedure End_Object Object oYesNo is a cWebButton Set piColumnIndex to 4 Set piColumnSpan to 2 Set psCaption to "Yes/No" // Web Property to hold state between browser/server round-trips { WebProperty=Client } Property stAllMyState ptState // Is called in response to user's second answer: Procedure ProcessSecondAnswer Integer eAnswer stAllMyState tState String[] asInfo WebGet ptState to tState Move (GetCurrentProcessId()) to tState.iProc3 Move (CurrentDateTime()) to tState.tmAnswered2 Move (If((eAnswer = cmYes), "Yes", "No")) to tState.SecondAnswer // Assemble results: Move ("You clicked the 'Yes/No' button at" * String(tState.tmClicked) * ; "in process" * String(tState.iProc1)) ; to asInfo[SizeOfArray(asInfo)] Move ("Your first answer was: '" + ; tState.sFirstAswer + "' at" * String(tState.tmAnswered1) * ; "in process" * String(tState.iProc2)) ; to asInfo[SizeOfArray(asInfo)] Move ("Your second answer was: '" + ; tState.SecondAnswer + "' at" * String(tState.tmAnswered2) * ; "in process" * String(tState.iProc3)) ; to asInfo[SizeOfArray(asInfo)] Send ShowInfoBox (StrJoinFromArray(asInfo, C_CRLF)) "Results" Send UpdateProcInfo End_Procedure WebPublishProcedure ProcessSecondAnswer // Publish the proc to receive control after second answer // Is called in response to user's first answer: Procedure ProcessFirstAnswer Integer eAnswer stAllMyState tState WebGet ptState to tState Move (GetCurrentProcessId()) to tState.iProc2 Move (CurrentDateTime()) to tState.tmAnswered1 Move (If((eAnswer = cmYes), "Yes", "No")) to tState.sFirstAswer WebSet ptState to tState Send ShowYesNo Self (RefProc(ProcessSecondAnswer)) ; ("Do you REALLY want to do this? (Proc:" * String(tState.iProc2) + ")") ; "Second question" End_Procedure WebPublishProcedure ProcessFirstAnswer // Publish the proc to receive control after first answer // Triggers the question cascade: Procedure OnClick stAllMyState tState Move (CurrentDateTime()) to tState.tmClicked Move (GetCurrentProcessId()) to tState.iProc1 WebSet ptState to tState Send ShowYesNo Self (RefProc(ProcessFirstAnswer)) ; ("Do you want to do this? (Proc:" * String(tState.iProc1) + ")") ; "First question" End_Procedure End_Object Object oDialog is a cWebButton Set piColumnIndex to 6 Set piColumnSpan to 2 Set psCaption to "Popup Dialog" Procedure OnCloseModalDialog Handle hoModalDialog Integer iProc1 iProc2 If (hoModalDialog = oTestDialog) Begin Get DialogResult of oTestDialog to iProc1 Move (GetCurrentProcessId()) to iProc2 Send ShowInfoBox ; ("Dialog in process" * String(iProc1) + C_CRLF + ; "Returned to process" * String(iProc2)) "Result" Send UpdateProcInfo End End_Procedure Procedure OnClick Send PopupTheDialog of oTestDialog Self (GetCurrentProcessId()) End_Procedure End_Object End_Object End_Object |
