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  • using haskell for "business applications"

    - by snorlaks
    Hello, I would like to know if there is any posiibility that I can use Haskell with small database like sql server compact so that client wont have to install any server on his desktop. Is there any api providing sql statements and so on ... What is the best solution to achieve small database application using haskell. thanks for help

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  • Subscribing message sent from another application

    - by tonga
    I have two Java applications: AppOne and AppTwo. In AppOne, I used a JMS sender to publish a Topic. In both AppOne and AppTwo, I used a JMS MessageListener to subscribe to the message published by AppOne. I used ActiveMQ as my JMS broker and Spring JMS. However, I can only see the echoed message received by AppOne message listener. But I can't see the echoed message received by AppTwo listener. AppOne message listener is in the same application/project as the message publisher. But AppTwo message listener is in a different application/project. The AppOne listener class is: public class CustomerStatusListener implements MessageListener { public void onMessage(Message message) { if (message instanceof TextMessage) { try { System.out.println("Subscriber 1 got you! The message is: " + ((TextMessage) message).getText()); } catch (JMSException ex) { throw new RuntimeException(ex); } } else { throw new IllegalArgumentException("Message must be of type TextMessage"); } } } It is invoked by a test calss JmsTest in AppOne: public class JmsTest { public static void main(String[] args) { ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("message-bean.xml"); CustomerStatusSender messageSender = (CustomerStatusSender) context.getBean("customerMessageSender"); messageSender.simpleSend(); context.close(); } } The AppTwo listener class is: public class CustomerStatusMessageListener implements MessageListener { public void onMessage(Message message) { if (message instanceof TextMessage) { try { System.out.println("Subscriber 2 got you! The message is: " + ((TextMessage) message).getText()); } catch (JMSException ex) { throw new RuntimeException(ex); } } else { throw new IllegalArgumentException( "Message must be of type TextMessage"); } } } The bean definition file for AppTwo where the Subscriber 2 lives in is: <bean id="connectionFactoryBean" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="tcp://localhost:61616" /> </bean> <!-- this is the Message Driven POJO (MDP) --> <bean id="customerStatusListener" class="com.mydomain.jms.CustomerStatusMessageListener" /> <!-- and this is the message listener container --> <bean id="listenerContainer" class="org.springframework.jms.listener.DefaultMessageListenerContainer"> <property name="connectionFactory" ref="connectionFactoryBean" /> <property name="destination" ref="topicBean" /> <property name="messageListener" ref="customerStatusListener" /> </bean> The bean id topicBean is the bean that is associated with the publisher. If both listener received the message sent from AppOne, I would have seen two echoed messages: Subscriber 1 got you! The message is: hello world Subscriber 2 got you! The message is: hello world But right now I only see the first line which means only the listener in AppOne got the message. So how to let the listener in AppTwo get the message? The first listener is in the same application as the sender, so it is easy to understand that it can get the message. But how about the second listener which is in a different application? What is the correct way to subscribe to a JMS Topic published in another application?

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  • Path to a file in a webapp under GlassFish

    - by Slavko
    How do I specify the path to a file in a web application? I have a folder named 'templates' under WEB-INF, I've been told that under GlassFish v3 the path should look like this: ./WebContent/WEB-INF/templates but this way I'm getting a file not found exception. What do I have to change in order to make it work?

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  • MVC alternatives: examples of MVA & AVC?

    - by Phillip Oldham
    I'm interested in learning about the alternative patterns to Model-View-Controller, specifically the Model-View-Adapter and Application-View-Controller patterns. Google results tend to be either a high-level overview or Java-based. Can anyone either provide, or point me to, an example of these patterns in either PHP, Python or JavaScript?

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  • Saving Data to Registry on Windows 7

    - by Jim Fell
    I heard that Windows 7 restricts access to its registry, so that applications cannot write directly to it. Is this so? I am developing an application in C#, and I would like to be able to save things such as port settings, last file used, etc. between sessions. Is the registry still a good option, or is there another preferred means of doing this now? Thanks.

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  • Do you know any mainstream desktop applications developed with Python and Qt?

    - by systempuntoout
    Hi i'm developing a small prototype of a desktop application using Qt and Python because i would like to distribute it in a multiplatform way. A friend of mine is annoying me on messenger because he claims that there are not known cool mainstream desktop apps developed with Qt and python technologies so, what i am doing, is just an exercise without future. Do you know any cool apps developed in python+Qt? thanks

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  • How can I setup a flexible local web development environment I can easily sync with a production, Amazon AWS based environment?

    - by user607057
    I'm running on an OS X environment and would like to create a flexible web development environment locally... including the option to run on an Nginx server for my PHP-based application. At the end of the day (or, development cycle), I'd like to be able to hit a switch and have it all sync over to Amazon AWS hosting (EC2, S3) - instances, databases, files, configurations, and all. Are there any simple ways to do this?

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  • How to do logout functionality in C# smart device application?

    - by Shailesh Jaiswal
    I am developng Smart device application in C#. It is a window application. In this application I am using Login form to authenticate the users. Only authenticated users can login into the system. In this application I am calling java web services which resides on another machine. I am passing mobile number & password from mu application's login form to the java web services. The java web services returns the userid after successful authentication. I made this userid static so that it can be used frequently with other web services. I using statc variables in this application so that they can be used at application level. After deploying the application I can see that emulator provides the close button with multiplicaton symbol. In this way I can close my form as well as application. But I want to provde one logout link in my application. Can I provide logout functionality in C# window application ? If yes, how to do that ? Please make sure that all the functions of .net framework does not work with .net compact framwork? Can you provide me the code or link through which can resolve the above issue ?

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  • Application crashing on getting updated information from database using timer and storing it on loca

    - by Amit Battan
    In our multi - user application we are continuously interacting with database. We have a common class through which we are sending POST queries to database and obtaining xml files in return. We are using delegates of NSXMLParser to parse the obtained file. The problem with us is we are facing many crashes in it generally when application is idle and changed data in database is being fetched in background through timer which is invoked after every few seconds. We have also dealt with error handling through try and catch but it proves to be of no use in this case and mostly application crashes with following error : Exception Type: EXC_BAD_ACCESS (SIGBUS) Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000020 Strange thing is that many times the fetching of updated data at background works very fine, same methods being successfully executed under similar conditions but suddenly it crashes on one of them. The codes we are using is as follows: // we are using timer in this way: chkOnlineUser=[NSTimer scheduledTimerWithTimeInterval:15 target:mmObject selector:@selector(threadOnlineUser) userInfo:NULL repeats:YES]; // this method being called in timer -(void)threadOnlineUser{//HeartBeat in Thread [NSThread detachNewThreadSelector:@selector(onlineUserRefresh) toTarget:self withObject:nil]; } // this performs actual updation -(void)onlineUserRefresh{ NSAutoreleasePool *pool =[[NSAutoreleasePool alloc]init]; @try{ if(chkTimer==1){ return; } chkTimer=1; if([allUserArray count]==0){ [user parseXMLFileUser:@"all" andFlag:3]; [allUserArray removeAllObjects]; [allUserArray addObjectsFromArray:[user users]]; } [objHeartBeat parseXMLFile:[loginID intValue] timeOut:10]; NSMutableDictionary *tDictOL=[[NSMutableDictionary alloc] init]; tDictOL=[objHeartBeat onLineList]; NSArray *tArray=[[NSArray alloc] init]; tArray=[[tDictOL objectForKey:@"onlineuser"] componentsSeparatedByString:@","]; [loginUserArray removeAllObjects]; for(int l=0;l less than [tArray count] ;l++){ int t;//=[[tArray objectAtIndex:l] intValue]; if([[allUserArray valueForKey:@"Id"] containsObject:[tArray objectAtIndex:l]]){ t = [[allUserArray valueForKey:@"Id"] indexOfObject:[tArray objectAtIndex:l]]; [loginUserArray addObject:[allUserArray objectAtIndex:t]]; } } [onlineTable reloadData]; [logInUserPopUp removeAllItems]; if([loginUserArray count]==1){ [labelLoginUser setStringValue:@"Only you are online"]; [logInUserPopUp setEnabled:YES]; }else{ [labelLoginUser setStringValue:[NSString stringWithFormat:@" %d users online",[loginUserArray count]]]; [logInUserPopUp setEnabled:YES]; } NSMenu *menu = [[NSMenu alloc] initWithTitle:@"menu"]; NSMenuItem *itemOne = [[NSMenuItem alloc] initWithTitle:@"" action:NULL keyEquivalent:@""]; [menu addItem:itemOne]; for(int l=0;l less than [loginUserArray count];l++){ NSString *tempStr= [NSString stringWithFormat:@"%@ %@",[[[loginUserArray objectAtIndex:l] objectForKey:@"user_fname"] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]],[[[loginUserArray objectAtIndex:l] objectForKey:@"user_lname"] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]]; if(![tempStr isEqualToString:@""]){ NSMenuItem *itemOne = [[NSMenuItem alloc] initWithTitle:tempStr action:NULL keyEquivalent:@""]; [menu addItem:itemOne]; }else if(l==0){ NSMenuItem *itemOne = [[NSMenuItem alloc] initWithTitle:tempStr action:NULL keyEquivalent:@""]; [menu addItem:itemOne]; } } [logInUserPopUp setMenu:menu]; if([lastUpdateTime isEqualToString:@""]){ }else { [self fetchUpdatedInfo:lastUpdateTime]; [self fetchUpdatedGroup:lastUpdateTime];// function same as fetchUpdatedInfo [avObject fetchUpdatedInfo:lastUpdateTime];// function same as fetchUpdatedInfo [esTVObject fetchUpdatedInfo:lastUpdateTime];// function same as fetchUpdatedInfo } lastUpdateTime=[[tDictOL objectForKey:@"lastServerTime"] copy]; } @catch (NSException * e) { [queryByPost insertException:@"MainModule" inFun:@"onlineUserRefresh" excp:[e description] userId:[loginID intValue]]; NSRunAlertPanel(@"Error Panel", @"Main Module- onlineUserRefresh....%@", @"OK", nil, nil,e); } @finally { NSLog(@"Internal Update Before Bye"); chkTimer=0; NSLog(@"Internal Update Bye");// Some time application crashes after this log // Some time application crahses after "Internal Update Bye" log } } // The method which we are using to obtain updated data is of following form: -(void)fetchUpdatedInfo:(NSString *)UpdTime{ @try { if(initAfterLoginComplete==0){ return; } [user parseXMLFileUser:UpdTime andFlag:[loginID intValue]]; [tempUserUpdatedArray removeAllObjects]; [tempUserUpdatedArray addObjectsFromArray:[user users]]; if([tempUserUpdatedArray count]0){ if([contactsView isHidden]){ [topContactImg setImage:[NSImage imageNamed:@"btn_contacts_off_red.png"]]; }else { [topContactImg setImage:[NSImage imageNamed:@"btn_contacts_red.png"]]; } }else { return; } int chkprof=0; for(int l=0;l less than [tempUserUpdatedArray count];l++){ NSArray *tempArr1 = [allUserArray valueForKey:@"Id"]; int s; if([[[tempUserUpdatedArray objectAtIndex:l] objectForKey:@"Id"] intValue]==profile_Id){ chkprof=1; } if([tempArr1 containsObject:[[tempUserUpdatedArray objectAtIndex:l] objectForKey:@"Id"]]){ s = [tempArr1 indexOfObject:[[tempUserUpdatedArray objectAtIndex:l] objectForKey:@"Id"]]; [allUserArray replaceObjectAtIndex:s withObject:[tempUserUpdatedArray objectAtIndex:l]]; }else { [allUserArray addObject:[tempUserUpdatedArray objectAtIndex:l]]; } NSArray *tempArr2 = [tempUser valueForKey:@"Id"]; if([tempArr2 containsObject:[[tempUserUpdatedArray objectAtIndex:l] objectForKey:@"Id"]]){ s = [tempArr2 indexOfObject:[[tempUserUpdatedArray objectAtIndex:l] objectForKey:@"Id"]]; [tempUser replaceObjectAtIndex:s withObject:[tempUserUpdatedArray objectAtIndex:l]]; }else { [tempUser addObject:[tempUserUpdatedArray objectAtIndex:l]]; } } NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"user_fname" ascending:YES]; [tempUser sortUsingDescriptors:[NSMutableArray arrayWithObject:sortDescriptor]]; [userListTableView reloadData]; [groupsArray removeAllObjects]; for(int z=0;z less than [tempGroups count];z++){ NSMutableArray *tempMArr=[[NSMutableArray alloc] init]; for(int l=0;l less than [allUserArray count];l++){ if([[[allUserArray objectAtIndex:l] objectForKey:@"GroupId"] intValue]==[[[tempGroups objectAtIndex:z] objectForKey:@"group_id"] intValue]){ [tempMArr addObject:[allUserArray objectAtIndex:l]]; } } [groupsArray insertObject:tempMArr atIndex:z]; [tempMArr release]; tempMArr= nil; } for(int n=0;n less than [tempGroups count];n++){ [[groupsArray objectAtIndex:n] addObject:[tempGroups objectAtIndex:n]]; } [groupsListOV reloadData]; if(chkprof==1){ [self profileShow:profile_Id]; }else { } [self selectUserInTable:0]; }@catch (NSException * e) { NSRunAlertPanel(@"Error Panel", @"%@", @"OK", nil, nil,e); } } // The method which we are using to frame select query and parse obtained data is: -(void)parseXMLForUser:(int)UId stringVar:(NSString*)stringVar{ @try{ if(queryByPost) [queryByPost release]; queryByPost=[QueryByPost new]; // common class used to invoke method to send request via POST method //obtaining data for xml parsing NSString *query=[NSString stringWithFormat:@"Select * from userinfo update_time = '%@' AND NOT owner_id ='%d' ",stringVar,UId]; NSData *obtainedData=[queryByPost executeQuery:query WithAction:@"query"]; // method invoked to perform post query if(obtainedData==nil){ // data not obtained so return return; } // initializing dictionary to be obtained after parsing if(obtainedDictionary) [obtainedDictionary release]; obtainedDictionary=[NSMutableDictionary new]; // xml parsing if (updatedDataParser) // airportsListParser is an NSXMLParser instance variable [updatedDataParser release]; updatedDataParser = [[NSXMLParser alloc] initWithData:obtainedData]; [updatedDataParser setDelegate:self]; [updatedDataParser setShouldResolveExternalEntities:YES]; BOOL success = [updatedDataParser parse]; } @catch (NSException *e) { NSLog(@"wtihin parseXMLForUser- parseXMLForUser:stringVar: - %@",[e description]); } } //The method which will attempt to interact 4 times with server if interaction with it is found to be unsuccessful , is of following form: -(NSData*)executeQuery:(NSString*)query WithAction:(NSString*)doAction{ NSLog(@"within ExecuteQuery:WithAction: Query is: %@ and Action is: %@",query,doAction); NSString *returnResult; @try { NSString *returnResult; NSMutableURLRequest *postRequest; NSError *error; NSData *searchData; NSHTTPURLResponse *response; postRequest=[self directMySQLQuery:query WithAction:doAction]; // this method sends actual POST request NSLog(@"after directMYSQL in QueryByPost- performQuery... ErrorLogMsg"); searchData = [NSURLConnection sendSynchronousRequest:postRequest returningResponse:&response error:&error]; returnResult = [[NSString alloc] initWithData:searchData encoding:NSASCIIStringEncoding]; NSString *resultToBeCompared=[returnResult stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSLog(@"result obtained - %@/ resultToBeCompared - %@",returnResult,resultToBeCompared); if(![resultToBeCompared isEqualToString:@""]){ }else { sleep(10); postRequest=[self directMySQLQuery:query WithAction:doAction]; searchData = [NSURLConnection sendSynchronousRequest:postRequest returningResponse:&response error:&error]; if(![resultToBeCompared isEqualToString:@""]){ }else { sleep(10); postRequest=[self directMySQLQuery:query WithAction:doAction]; searchData = [NSURLConnection sendSynchronousRequest:postRequest returningResponse:&response error:&error]; if(![resultToBeCompared isEqualToString:@""]){ }else { sleep(10); postRequest=[self directMySQLQuery:query WithAction:doAction]; searchData = [NSURLConnection sendSynchronousRequest:postRequest returningResponse:&response error:&error]; if(![resultToBeCompared isEqualToString:@""]){ }else { sleep(10); postRequest=[self directMySQLQuery:query WithAction:doAction]; searchData = [NSURLConnection sendSynchronousRequest:postRequest returningResponse:&response error:&error]; if(![resultToBeCompared isEqualToString:@""]){ }else { return nil; } } } } } returnResult = [[NSString alloc] initWithData:searchData encoding:NSASCIIStringEncoding]; return searchData; } @catch (NSException * e) { NSLog(@"within QueryByPost , execurteQuery:WithAction - %@",[e description]); return nil; } } // The method which sends POST request to server , is of following form: -(NSMutableURLRequest *)directMySQLQuery:(NSString*)query WithAction:(NSString*)doAction{ @try{ NSLog(@"Query is: %@ and Action is: %@",query,doAction); // some pre initialization NSString *stringBoundary,*contentType; NSURL *cgiUrl ; NSMutableURLRequest *postRequest; NSMutableData *postBody; NSString *ans=@"434"; cgiUrl = [NSURL URLWithString:@"http://keysoftwareservices.com/API.php"]; postRequest = [NSMutableURLRequest requestWithURL:cgiUrl]; [postRequest setHTTPMethod:@"POST"]; stringBoundary = [NSString stringWithString:@"0000ABCQueryxxxxxx"]; contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", stringBoundary]; [postRequest addValue:contentType forHTTPHeaderField: @"Content-Type"]; //setting up the body: postBody = [NSMutableData data]; [postBody appendData:[[NSString stringWithFormat:@"\r\n\r\n--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"code\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:ans] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"action\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:doAction] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"devmode\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:[[[NSBundle mainBundle] infoDictionary] objectForKey:@"devmode"]] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"q\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithString:query] dataUsingEncoding:NSUTF8StringEncoding]]; [postBody appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",stringBoundary] dataUsingEncoding:NSUTF8StringEncoding]]; [postRequest setHTTPBody:postBody]; NSLog(@"Direct My SQL ok");// Some time application crashes afte this log //Some time application crashes after "Direct My SQL ok" log return [postRequest mutableCopy]; }@catch (NSException * e) { NSLog(@"NSException %@",e); NSRunAlertPanel(@"Error Panel", @"Within QueryByPost- directMySQLQuery...%@", @"OK", nil, nil,e); return nil; } }

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  • JBoss admin-console fails to load - missing Log4J jar?

    - by Jack
    I downloaded JBoss 5.1 and unzipped to ~/jboss/ such that JBoss is installed into: ~/jboss/jboss-5.1.0.GA/ I run the default deployment by using the following command found in jboss/jboss-5.1.0.GA/bin ./run.sh -c default While JBoss starts (http://127.0.0.1:8080/), admin-console is not deployed. The log file: jboss/jboss-5.1.0.GA/server/default/log shows the following information: DEPLOYMENTS IN ERROR: Deployment "vfsfile:/Users/jackwootton/jboss/jboss-5.1.0.GA/server/default/deploy/admin-console.war/" is in error due to the following reason(s): org.jboss.deployers.spi.DeploymentException: URL file:/Users/jackwootton/jboss/jboss-5.1.0.GA/server/default/tmp/az6n6v-tjilfb-h32fokxn-1-h32fosuo-v/admin-console.war/ deployment failed Deployment "vfszip:/Users/jackwootton/jboss/jboss-5.1.0.GA/server/default/deploy/quartz-ra.rar/" is in error due to the following reason(s): org.apache.commons.logging.LogConfigurationException: User-specified log class 'org.apache.commons.logging.impl.Log4JLogger' cannot be found or is not useable. The Log4J jar file exists in: jboss/jboss-5.1.0.GA/lib/jboss-logging-log4j.jar I have three questions: Have I understood the problem correctly (i.e. that admin-console cannot find the required Log4j JAR file and therefore is not deployed)? What can I do to fix this problem? Why would an out-of-the-box deployment have this problem in the first place?

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  • Android SDK: hello world does not run

    - by Alex
    I have installed Java x64, Eclipse Classic Judo x64 + ADT Pluggin. OS win 7 x64. I did installation everything according to the manual. Then created first application and launched it. Emulator was launched but hello world was not. I have not idea what doing wrong. Do anyone knows of such error and my problem as a whole? thx Console log: [2012-10-06 13:35:42 - test] ------------------------------ [2012-10-06 13:35:42 - test] Android Launch! [2012-10-06 13:35:42 - test] adb is running normally. [2012-10-06 13:35:42 - test] Performing com.example.test.MainActivity activity launch [2012-10-06 13:35:42 - test] Automatic Target Mode: launching new emulator with compatible AVD 'AVD_41' [2012-10-06 13:35:42 - test] Launching a new emulator with Virtual Device 'AVD_41' [2012-10-06 13:35:42 - Emulator] Failed to create Context 0x3005 [2012-10-06 13:35:42 - Emulator] emulator: WARNING: Could not initialize OpenglES emulation, using software renderer. [2012-10-06 13:35:42 - Emulator] WARNING: Data partition already in use. Changes will not persist! [2012-10-06 13:35:42 - Emulator] WARNING: SD Card image already in use: C:\Users\Zewisa\.android\avd\AVD_41.avd/sdcard.img [2012-10-06 13:35:42 - Emulator] WARNING: Cache partition already in use. Changes will not persist! [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] could not get wglGetExtensionsStringARB [2012-10-06 13:35:42 - Emulator] emulator: warning: opening audio input failed [2012-10-06 13:35:42 - Emulator]

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  • Subterranean IL: Compiling C# exception handlers

    - by Simon Cooper
    An exception handler in C# combines the IL catch and finally exception handling clauses into a single try statement: try { Console.WriteLine("Try block") // ... } catch (IOException) { Console.WriteLine("IOException catch") // ... } catch (Exception e) { Console.WriteLine("Exception catch") // ... } finally { Console.WriteLine("Finally block") // ... } How does this get compiled into IL? Initial implementation If you remember from my earlier post, finally clauses must be specified with their own .try clause. So, for the initial implementation, we take the try/catch/finally, and simply split it up into two .try clauses (I have to use label syntax for this): StartTry: ldstr "Try block" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End EndTry: StartIOECatch: ldstr "IOException catch" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End EndIOECatch: StartECatch: ldstr "Exception catch" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End EndECatch: StartFinally: ldstr "Finally block" call void [mscorlib]System.Console::WriteLine(string) // ... endfinally EndFinally: End: // ... .try StartTry to EndTry catch [mscorlib]System.IO.IOException handler StartIOECatch to EndIOECatch catch [mscorlib]System.Exception handler StartECatch to EndECatch .try StartTry to EndTry finally handler StartFinally to EndFinally However, the resulting program isn't verifiable, and doesn't run: [IL]: Error: Shared try has finally or fault handler. Nested try blocks What's with the verification error? Well, it's a condition of IL verification that all exception handling regions (try, catch, filter, finally, fault) of a single .try clause have to be completely contained within any outer exception region, and they can't overlap with any other exception handling clause. In other words, IL exception handling clauses must to be representable in the scoped syntax, and in this example, we're overlapping catch and finally clauses. Not only is this example not verifiable, it isn't semantically correct. The finally handler is specified round the .try. What happens if you were able to run this code, and an exception was thrown? Program execution enters top of try block, and exception is thrown within it CLR searches for an exception handler, finds catch Because control flow is leaving .try, finally block is run The catch block is run leave.s End inside the catch handler branches to End label. We're actually running the finally before the catch! What we do about it What we actually need to do is put the catch clauses inside the finally clause, as this will ensure the finally gets executed at the correct time (this time using scoped syntax): .try { .try { ldstr "Try block" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End } catch [mscorlib]System.IO.IOException { ldstr "IOException catch" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End } catch [mscorlib]System.Exception { ldstr "Exception catch" call void [mscorlib]System.Console::WriteLine(string) // ... leave.s End } } finally { ldstr "Finally block" call void [mscorlib]System.Console::WriteLine(string) // ... endfinally } End: ret Returning from methods There is a further semantic mismatch that the C# compiler has to deal with; in C#, you are allowed to return from within an exception handling block: public int HandleMethod() { try { // ... return 0; } catch (Exception) { // ... return -1; } } However, you can't ret inside an exception handling block in IL. So the C# compiler does a leave.s to a ret outside the exception handling area, loading/storing any return value to a local variable along the way (as leave.s clears the stack): .method public instance int32 HandleMethod() { .locals init ( int32 retVal ) .try { // ... ldc.i4.0 stloc.0 leave.s End } catch [mscorlib]System.Exception { // ... ldc.i4.m1 stloc.0 leave.s End } End: ldloc.0 ret } Conclusion As you can see, the C# compiler has quite a few hoops to jump through to translate C# code into semantically-correct IL, and hides the numerous conditions on IL exception handling blocks from the C# programmer. Next up: catch-all blocks, and how the runtime deals with non-Exception exceptions.

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  • C# Dev Challenge Part 1 of n &ndash; Beginner Edition

    - by mbcrump
    I developed this challenge to test one’s knowledge of C Sharp. I am planning on creating several challenges with different skill sets, so don’t get mad if this challenge doesn’t well challenge you... I noticed that most people like short quizzes so this one only contains 5 questions. All of the challenges are clear and concise of what I am asking you to do. No smoke and mirrors here, meaning that none of the code has syntax errors. The purpose of this exercise is to test several OOP concepts and see how much of the C# language you really know. Question #1 – Lets start off Easy… Will the following code snippet compile successfully? What does this question test? - Can this compile without a namespace? Do you have to have an entry point of “static void Main()”? class Test { static int Main() { System.Console.WriteLine("Developer Challenge"); return 0; } } Answer (select text in box below): Yes, it will compile successfully. Question #2 – What is the value of the Console.WriteLine statements? What does this question test? – Do I understand reference types/value types? If a variable is declared with the @ symbol and its not a reserved keyword does the application compile successfully? using System; internal struct MyStruct { public int Value; } internal class MyClass { public int Value; } class Test { static void Main() { MyStruct @struct1 = new MyStruct(); MyStruct @struct2 = @struct1; @struct2.Value = 100; MyClass @ref1 = new MyClass(); MyClass @ref2 = @ref1; @ref2.Value = 100; Console.WriteLine("Value Type: {0} {1}", @struct1.Value, @struct2.Value); Console.WriteLine("Reference Type: {0} {1}", @ref1.Value, @ref2.Value); } } Answer (select text in box below): Value Type: 0 100 Reference Type: 100 100 Question #3 – What is the value of the Console.WriteLine statements? What does this question test? – Can 2 objects reference the same point in memory? using System; class Test { static void Main() { string s1 = "Testing2"; string t1 = s1; Console.WriteLine(s1 == t1); Console.WriteLine((object)s1 == (object)t1); } } Answer (select text in box below): True True Question #4 – What is the value of the Console.WriteLine statements? What does this question test? – How does the “Stack” work – LIFO or FIFO?   using System; using System.Collections; class Test { static void Main() { Stack a = new Stack(5); a.Push("1"); a.Push("2"); a.Push("3"); a.Push("4"); a.Push("5"); foreach (var o in a) { Console.WriteLine(o); } } } Answer (select text in box below): 5 4 3 2 1 Question #5 – What is the value of the Console.WriteLine statements? What does this question test? – Array and General Looping Knowledge. using System; namespace ConsoleApplication5 { class Program { static void Main(string[] args) { int[] J_LIST = new int[5] { 1, 2, 3, 4, 5 }; int K = 10; int L = 5; foreach (var J in J_LIST) { K = K - J; L = K + 2 * J; Console.WriteLine("J = {0, 5} K = {1, 5} L = {2, 5}", J, K, L); } Console.ReadLine(); } } } Answer (select text in box below): J = 1 K = 9 L = 11 J = 2 K = 7 L = 11 J = 3 K = 4 L = 10 J = 4 K = 0 L = 8 J = 5 K = -5 L = 5 Stay Tuned for more challenges!

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  • Deploying MVC2 application to IIS7.5 - Ninject asked to provide controllers for content files

    - by Rune Jacobsen
    I have an application that started life as an MVC (1.0) app in Visual Studio 2008 Sp1 with a bunch of Silverlight 3 projects as part of the site. Nothing fancy at all. Using Ninject for dependency injection (first version 2 beta, now the released version 2 with the MVC extensions). With the release of .Net 4.0, VS2010, MVC2 etc., we decided to move the application to the newest platform. The conversion wizard in VS2010 apparently took care of everything, with one exception - it didn't change references to mvc1 to now point to mvc2, so I had to do that manually. Of course, this makes me think about other MVC2 things that could be missing from my app, that would be there if I did File - New Project... But that is not the focus of this question. When I deploy this application to the IIS 7.5 server (running on Win2008 R2 x64), the application as such works. However, images, scripts and other static content doesn't seem to exist. Of course they are there on disk on the server, but they don't show up in the client web browser. I am fairly new to IIS, so the only trick I knew is to try to open the web page in a browser on the server, as that could give me more information. And here, finally, we meet our enemy. If I try to go directly to the URL of one of the images (http://server/Content/someimage.jpg for instance), I get the following error in the browser: The IControllerFactory 'Ninject.Web.Mvc.NinjectControllerFactory' did not return a controller for a controller named 'Content'. Aha. The web server tries to feed this request to MVC, who with its' default routing setup assumes Content to be a controller, and fails. How can I get it to treat Content/ and Scripts/ (among others) as non-controllers and just pass through the static content? This of course works with Cassini on my developer machine, but as soon as I deploy, this problem hits. I am using the last version of Ninject MVC 2 where the IoC tool should pass missing controllers to the base controller factory, but this has apparently not helped. I have also tried to add ignore routes for Content etc., but this apparently has no effect either. I am not even sure I am addressing the problem on the right level. Does anyone know where to look to get this app going? I have full control of the web server so I can more or less do whatever I want to it, as long as it starts working. Thanks!

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  • StackOverflowException throws often when .net application built with Debug mode

    - by user1487950
    I have an application which access an external webservice often, when i are trying to debug it, means debuging in vistual studio. it often throws out StackOverflowException at the webserverice call point. when building in Release mode , the exception thrown out only occasionally. I checked the call stack, looks like there is no recursive call. can you please suggest? thank you very much. call statck attached. [In a sleep, wait, or join] mscorlib.dll!System.Threading.WaitHandle.InternalWaitOne(System.Runtime.InteropServices.SafeHandle waitableSafeHandle, long millisecondsTimeout, bool hasThreadAffinity, bool exitContext) + 0x2b bytes mscorlib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout, bool exitContext) + 0x2d bytes System.dll!System.Net.NetworkAddressChangePolled.CheckAndReset() + 0x9d bytes System.dll!System.Net.NclUtilities.LocalAddresses.get() + 0x49 bytes System.dll!System.Net.WebProxyScriptHelper.myIpAddress() + 0x27 bytes [Native to Managed Transition] System.dll!System.Net.WebProxyScriptHelper.MyMethodInfo.Invoke(object target, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture) + 0x6b bytes MTOqoHCT.dll!JScript 0.myIpAddress(object this, Microsoft.JScript.Vsa.VsaEngine vsa Engine, object arguments) + 0x91 bytes MTOqoHCT.dll!JScript 0.FindProxyForURL(object this, Microsoft.JScript.Vsa.VsaEngine vsa Engine, object arguments, object url, object host) + 0x3c6e bytes MTOqoHCT.dll!__WebProxyScript.__WebProxyScript.ExecuteFindProxyForURL(object url, object host) + 0x11d bytes [Native to Managed Transition] Microsoft.JScript.dll!System.Net.VsaWebProxyScript.CallMethod(object targetObject, string name, object[] args) + 0x11a bytes Microsoft.JScript.dll!System.Net.VsaWebProxyScript.Run(string url, string host) + 0x74 bytes [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage msg, int methodPtr, bool fExecuteInContext) + 0x1ef bytes mscorlib.dll!System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage msg) + 0xf bytes mscorlib.dll!System.Runtime.Remoting.Messaging.ServerObjectTerminatorSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x66 bytes mscorlib.dll!System.Runtime.Remoting.Messaging.ServerContextTerminatorSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x8a bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessageCallback(object[] args) + 0x94 bytes mscorlib.dll!System.Threading.Thread.CompleteCrossContextCallback(System.Threading.InternalCrossContextDelegate ftnToCall, object[] args) + 0x8 bytes [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0xa7 bytes mscorlib.dll!System.Runtime.Remoting.Channels.ChannelServices.SyncDispatchMessage(System.Runtime.Remoting.Messaging.IMessage msg) + 0x92 bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoDispatch(byte[] reqStmBuff, System.Runtime.Remoting.Messaging.SmuggledMethodCallMessage smuggledMcm, out System.Runtime.Remoting.Messaging.SmuggledMethodReturnMessage smuggledMrm) + 0xed bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoTransitionDispatchCallback(object[] args) + 0x8a bytes mscorlib.dll!System.Threading.Thread.CompleteCrossContextCallback(System.Threading.InternalCrossContextDelegate ftnToCall, object[] args) + 0x8 bytes [Appdomain Transition] mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoTransitionDispatch(byte[] reqStmBuff, System.Runtime.Remoting.Messaging.SmuggledMethodCallMessage smuggledMcm, out System.Runtime.Remoting.Messaging.SmuggledMethodReturnMessage smuggledMrm) + 0x74 bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0xa3 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.CallProcessMessage(System.Runtime.Remoting.Messaging.IMessageSink ms, System.Runtime.Remoting.Messaging.IMessage reqMsg, System.Runtime.Remoting.Contexts.ArrayWithSize proxySinks, System.Threading.Thread currentThread, System.Runtime.Remoting.Contexts.Context currentContext, bool bSkippingContextChain) + 0x50 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.InternalInvoke(System.Runtime.Remoting.Messaging.IMethodCallMessage reqMcmMsg, bool useDispatchMessage, int callType) + 0x1d5 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.Invoke(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x66 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref System.Runtime.Remoting.Proxies.MessageData msgData, int type) + 0xee bytes System.dll!System.Net.NetWebProxyFinder.GetProxies(System.Uri destination, out System.Collections.Generic.IList<string> proxyList) + 0x83 bytes System.dll!System.Net.AutoWebProxyScriptEngine.GetProxies(System.Uri destination, out System.Collections.Generic.IList<string> proxyList, ref int syncStatus) + 0x84 bytes System.dll!System.Net.WebProxy.GetProxiesAuto(System.Uri destination, ref int syncStatus) + 0x2e bytes System.dll!System.Net.ProxyScriptChain.GetNextProxy(out System.Uri proxy) + 0x2e bytes System.dll!System.Net.ProxyChain.ProxyEnumerator.MoveNext() + 0x98 bytes System.dll!System.Net.ServicePointManager.FindServicePoint(System.Uri address, System.Net.IWebProxy proxy, out System.Net.ProxyChain chain, ref System.Net.HttpAbortDelegate abortDelegate, ref int abortState) + 0x120 bytes System.dll!System.Net.HttpWebRequest.FindServicePoint(bool forceFind) + 0xb1 bytes System.dll!System.Net.HttpWebRequest.GetRequestStream(out System.Net.TransportContext context) + 0x247 bytes System.dll!System.Net.HttpWebRequest.GetRequestStream() + 0xe bytes System.Web.Services.dll!System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(string methodName, object[] parameters) + 0xc0 bytes Gfinet.Config.dll!Gfinet.Config.Service.cfg_webservice.addOrUpdateProperties(string string, int intVal, Gfinet.Config.Service.PropertiesDataM[] propertiesDataMs) + 0xa3 bytes Gfinet.Config.dll!Gfinet.Config.Service.WSServiceImpl.AddOrUpdateProperties(int setId, Gfinet.Config.Service.PropertiesDataM[] properties) + 0x46 bytes [Native to Managed Transition] Gfinet.Config.dll!Gfinet.Config.Service.ServiceAspect.InvocationHandler(object target, System.Reflection.MethodBase method, object[] parameters) + 0x49e bytes Gfinet.Config.dll!Gfinet.Config.DynamicProxy.DynamicProxyImpl.Invoke(System.Runtime.Remoting.Messaging.IMessage message) + 0x110 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref System.Runtime.Remoting.Proxies.MessageData msgData, int type) + 0xee bytes Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.StoreElement(string application, string category, string id, string elementValue, bool save) Line 303 + 0x55 bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAllInternal() Line 582 + 0x6e bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAll(bool async) Line 434 + 0x8 bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAll() Line 406 + 0xa bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Container.Persistor.Save() Line 59 + 0xc bytes C# Spark.exe!Tici.Kraps.RibbonShell.OnBtnSaveWorkspaceItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e) Line 642 + 0xf bytes C# DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItem.OnClick(DevExpress.XtraBars.BarItemLink link) + 0x108 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarBaseButtonItem.OnClick(DevExpress.XtraBars.BarItemLink link) + 0x47 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkClick() + 0x245 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkAction(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0xb3 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarButtonItemLink.OnLinkAction(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0x47e bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkActionCore(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0x82 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.ViewInfo.BarSelectionInfo.ClickLink(DevExpress.XtraBars.BarItemLink link) + 0x85 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.ViewInfo.BarSelectionInfo.UnPressLink(DevExpress.XtraBars.BarItemLink link) + 0x1e5 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnUnPressItem(DevExpress.Utils.DXMouseEventArgs e, DevExpress.XtraBars.Ribbon.ViewInfo.RibbonHitInfo hitInfo) + 0xa7 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnUnPress(DevExpress.Utils.DXMouseEventArgs e, DevExpress.XtraBars.Ribbon.ViewInfo.RibbonHitInfo hitInfo) + 0x5f bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnMouseUp(DevExpress.Utils.DXMouseEventArgs e) + 0x19a bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.RibbonHandler.OnMouseUp(DevExpress.Utils.DXMouseEventArgs e) + 0x47 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.RibbonControl.OnMouseUp(System.Windows.Forms.MouseEventArgs e) + 0x95 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.WmMouseUp(ref System.Windows.Forms.Message m, System.Windows.Forms.MouseButtons button, int clicks) + 0x2d1 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x93a bytes DevExpress.Utils.v11.2.dll!DevExpress.Utils.Controls.ControlBase.WndProc(ref System.Windows.Forms.Message m) + 0x81 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.RibbonControl.WndProc(ref System.Windows.Forms.Message m) + 0x85 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x13 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x31 bytes System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x96 bytes [Native to Managed Transition] [Managed to Native Transition] DevExpress.Utils.v11.2.dll!DevExpress.Utils.Win.Hook.ControlWndHook.WindowProc(System.IntPtr hWnd, int message, System.IntPtr wParam, System.IntPtr lParam) + 0x159 bytes [Native to Managed Transition] [Managed to Native Transition] System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(System.IntPtr dwComponentID, int reason, int pvLoopData) + 0x287 bytes System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason, System.Windows.Forms.ApplicationContext context) + 0x16c bytes System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x61 bytes System.Windows.Forms.dll!System.Windows.Forms.Application.Run(System.Windows.Forms.Form mainForm) + 0x31 bytes Tici.Kraps.Services.dll!Tici.Kraps.Services.Container.DefaultApplicationRunner.Run() Line 41 + 0x17 bytes C# Kraps.exe!Tici.Kraps.Program.Main() Line 105 + 0x9 bytes C# [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.AppDomain.ExecuteAssembly(string assemblyFile, System.Security.Policy.Evidence assemblySecurity, string[] args) + 0x6d bytes Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() + 0x2a bytes mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) + 0x63 bytes mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool ignoreSyncCtx) + 0xb0 bytes mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x2c bytes mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44 bytes [Native to Managed Transition]

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