Search Results

Search found 4735 results on 190 pages for 'handling interruptions'.

Page 1/190 | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• what is difference between Exception handling Application block & Exception handling

  - by Lalit

  what is difference between Exception handling Application block & Exception handling in regular dot net classes ? i don't think it is beneficial to use of Exception handling Application block. What is exact use of that block ??

  Read the article

• Strengthening code with possibly useless exception handling

  - by rdurand

  Is it a good practice to implement useless exception handling, just in case another part of the code is not coded correctly? Basic example A simple one, so I don't loose everybody :). Let's say I'm writing an app that will display a person's information (name, address, etc.), the data being extracted from a database. Let's say I'm the one coding the UI part, and someone else is writing the DB query code. Now imagine that the specifications of your app say that if the person's information is incomplete (let's say, the name is missing in the database), the person coding the query should handle this by returning "NA" for the missing field. What if the query is poorly coded and doesn't handle this case? What if the guy who wrote the query handles you an incomplete result, and when you try to display the informations, everything crashes, because your code isn't prepared to display empty stuff? This example is very basic. I believe most of you will say "it's not your problem, you're not responsible for this crash". But, it's still your part of the code which is crashing. Another example Let's say now I'm the one writing the query. The specifications don't say the same as above, but that the guy writing the "insert" query should make sure all the fields are complete when adding a person to the database to avoid inserting incomplete information. Should I protect my "select" query to make sure I give the UI guy complete informations? The questions What if the specifications don't explicitly say "this guy is the one in charge of handling this situation"? What if a third person implements another query (similar to the first one, but on another DB) and uses your UI code to display it, but doesn't handle this case in his code? Should I do what's necessary to prevent a possible crash, even if I'm not the one supposed to handle the bad case? I'm not looking for an answer like "(s)he's the one responsible for the crash", as I'm not solving a conflict here, I'd like to know, should I protect my code against situations it's not my responsibility to handle? Here, a simple "if empty do something" would suffice. In general, this question tackles redundant exception handling. I'm asking it because when I work alone on a project, I may code 2-3 times a similar exception handling in successive functions, "just in case" I did something wrong and let a bad case come through.

  Read the article

• Error Handling without Exceptions

  - by James

  While searching SO for approaches to error handling related to business rule validation , all I encounter are examples of structured exception handling. MSDN and many other reputable development resources are very clear that exceptions are not to be used to handle routine error cases. They are only to be used for exceptional circumstances and unexpected errors that may occur from improper use by the programmer (but not the user.) In many cases, user errors such as fields that are left blank are common, and things which our program should expect, and therefore are not exceptional and not candidates for use of exceptions. QUOTE: Remember that the use of the term exception in programming has to do with the thinking that an exception should represent an exceptional condition. Exceptional conditions, by their very nature, do not normally occur; so your code should not throw exceptions as part of its everyday operations. Do not throw exceptions to signal commonly occurring events. Consider using alternate methods to communicate to a caller the occurrence of those events and leave the exception throwing for when something truly out of the ordinary happens. For example, proper use: private void DoSomething(string requiredParameter) { if (requiredParameter == null) throw new ArgumentExpcetion("requiredParameter cannot be null"); // Remainder of method body... } Improper use: // Renames item to a name supplied by the user. Name must begin with an "F". public void RenameItem(string newName) { // Items must have names that begin with "F" if (!newName.StartsWith("F")) throw new RenameException("New name must begin with /"F/""); // Remainder of method body... } In the above case, according to best practices, it would have been better to pass the error up to the UI without involving/requiring .NET's exception handling mechanisms. Using the same example above, suppose one were to need to enforce a set of naming rules against items. What approach would be best? Having the method return a enumerated result? RenameResult.Success, RenameResult.TooShort, RenameResult.TooLong, RenameResult.InvalidCharacters, etc. Using an event in a controller class to report to the UI class? The UI calls the controller's RenameItem method, and then handles an AfterRename event that the controller raises and that has rename status as part of the event args? The controlling class directly references and calls a method from the UI class that handles the error, e.g. ReportError(string text). Something else... ? Essentially, I want to know how to perform complex validation in classes that may not be the Form class itself, and pass the errors back to the Form class for display -- but I do not want to involve exception handling where it should not be used (even though it seems much easier!) Based on responses to the question, I feel that I'll have to state the problem in terms that are more concrete: UI = User Interface, BLL = Business Logic Layer (in this case, just a different class) User enters value within UI. UI reports value to BLL. BLL performs routine validation of the value. BLL discovers rule violation. BLL returns rule violation to UI. UI recieves return from BLL and reports error to user. Since it is routine for a user to enter invalid values, exceptions should not be used. What is the right way to do this without exceptions?

  Read the article

• Implement Exception Handling in ASP.NET C# Project

  - by Shrewd Demon

  hi, I have an application that has many tiers. as in, i have... Presentation Layer (PL) - contains all the html My Codes Layer (CL) - has all my code Entity Layer (EL) - has all the container entities Business Logic Layer (BLL) - has the necessary business logic Data Logic Layer (DLL) - any logic against data Data Access Layer (DAL) - one that accesses data from the database Now i want to provide error handling in my DLL since it is responsible for executing statement like ExecureScalar and all.... And i am confused as to how to go about it...i mean do i catch the error in the DLL and throw it back to the BLL and from there throw it back to my code or what.... can any one please help me how do i implement a clean and easy error handling techinque help you be really appreciated. Thank you.

  Read the article

• Best exception handling practices or recommendations?

  - by user828584

  I think the two main problems with my programs are my code structure/organization and my error handling. I'm reading Code Complete 2, but I need something to read for working with potential problems. For example, on a website, if something can only happen if the user tampers with data via javascript, do you write for that? Also, when do you not catch errors? When you write a class that expects a string and an int as input, and they aren't a string and int, do you check for that, or do you let it bubble up to the calling method that passed incorrect parameters? I know this is a broad topic that can't be answered in a single answer here, so what I'm looking for is a book or resource that's commonly accepted as teaching proper exception handling practice.

  Read the article

• Handling Errors In PHP When Using MVC

  - by James Jeffery

  I've been using Codeigniter a lot recently, but one thing that gets on my nerves is handling errors and displaying them to the user. I've never been good at handling errors without it getting messy. My main concern is when returning errors to the user. Is it good practice to use exceptions and throw/catch exceptions rather than returning 0 or 1 from functions and then using if/else to handle the errors. Thus, making it easier to inform the user about the issue. I tend to go away from exceptions. My Java tutor at university some years ago told me "exceptions shouldn't be used in production code it's more for debugging". I get the feeling he was lying. But, an example, I have code that adds a user to a database. During the process more than 1 thing could go wrong, such as a database issue, a duplicate entry, a server issue, etc. When an issue happens during registration the user needs to know about it. What's the best way to handle errors in PHP, keeping in mind that I'm using an MVC framework.

  Read the article

• AVAudioRecorderDelegate Interruptions methods doesn't get called

  - by donodare

  Hi all, My AVAudioRecorderDelegate Interruptions methods doesn't get called. I set the delegate. What might be the issue here? tnx

  Read the article

• C++ Exception Handling

  - by user1413793

  So I was writing some code and I noticed that apart from syntactical, type, and other compile-time errors, C++ does not throw any other exceptions. So I decided to test this out with a very trivial program: #include<iostream> int main() { std::count<<5/0<<std::endl; return 1 } When I compiled it using g++, g++ gave me a warning saying I was dividing by 0. But it still compiled the code. Then when I ran it, it printed some really large arbitrary number. When I want to know is, how does C++ deal with exceptions? Integer division by 0 should be a very trivial example of when an exception should be thrown and the program should terminate. Do I have to essentially enclose my entire program in a huge try block and then catch certain exceptions? I know in Python when an exception is thrown, the program will immediately terminate and print out the error. What does C++ do? Are there even runtime exceptions which stop execution and kill the program?

  Read the article

• DAL Exception handling in a MVP application

  - by Chathuranga

  In a MVP win forms application I'm handling exceptions as follows in DAL. Since the user messaging is not a responsibility of DAL, I want to move it in to my Presentation class. Could you show me a standard way to do that? public bool InsertAccount(IBankAccount ba) { string selectStatement = @"IF NOT EXISTS (SELECT ac_no FROM BankAccount WHERE ac_no=@ac_no) BEGIN INSERT INTO BankAccount ..."; using (SqlConnection sqlConnection = new SqlConnection(db.ConnectionString)) { using (SqlCommand sqlCommand = new SqlCommand(selectStatement, sqlConnection)) { try { sqlConnection.Open(); sqlCommand.Parameters.Add("@ac_no", SqlDbType.Char).Value = ba.AccountNumber; // // sqlCommand.ExecuteNonQuery(); return true; } catch (Exception e) { MessageBox.Show(("Error: " + e.Message)); } if (sqlConnection.State == System.Data.ConnectionState.Open) sqlConnection.Close(); return false; } } }

  Read the article

• How does this ruby error handling module code work

  - by Michael Durrant

  Trying to get a better handle on ruby exception handling. I have this code (from a book): def err_with_msg(pattern) m = Module.new (class << m; self; end).instance_eval do define_method(:===) do |e| pattern === e.msg end end m end So ok this is a method. We're creating a new Module. I think of module as mix-ins. Not sure what it's doing here. Not we add the module to the class. Fair enough. Then we have self on its own. What that for? I guess we have a little anonymouse method this is just about self. hmmm ok, now for each of the above, check the pattern match. but for each, I thought the above for for a new Module, did the module get to use instance's by being included? A better explanation of what's going on here would be most helpful.

  Read the article

• PHP MVC error handling, view display and user permissions

  - by cen

  I am building a moderation panel from scratch in a MVC approach and a lot of questions cropped up during development. I would like to hear from others how they handle these situations. Error handling Should you handle an error inside the class method or should the method return something anyway and you handle the error in controller? What about PDO exceptions, how to handle them? For example, let's say we have a method that returns true if the user exists in a table and false if he does not exist. What do you return in the catch statement? You can't just return false because then the controller assumes that everything is alright while the truth is that something must be seriously broken. Displaying the error from the method completely breaks the whole design. Maybe a page redirect inside the method? The proper way to show a view The controller right now looks something like this: include('view/header.php'); if ($_GET['m']=='something') include('view/something.php'); elseif ($_GET['m']=='somethingelse') include('view/somethingelse.php'); include('view/foter.php'); Each view also checks if it was included from the index page to prevent it being accessed directly. There is a view file for each different document body. Is this way of including different views ok or is there a more proper way? Managing user rights Each user has his own rights, what he can see and what he can do. Which part of the system should verify that user has the permission to see the view, controller or view itself? Right now I do permission checks directly in the view because each view can contain several forms that require different permissions and I would need to make a seperate file for each of them if it was put in the controller. I also have to re-check for the permissions everytime a form is submitted because form data can be easily forged. The truth is, all this permission checking and validating the inputs just turns the controller into a huge if/then/else cluster. I feel like 90% of the time I am doing error checks/permissions/validations and very little of the actual logic. Is this normal even for popular frameworks?

  Read the article

• Exception Handling Frequency/Log Detail

  - by Cyborgx37

  I am working on a fairly complex .NET application that interacts with another application. Many single-line statements are possible culprits for throwing an Exception and there is often nothing I can do to check the state before executing them to prevent these Exceptions. The question is, based on best practices and seasoned experience, how frequently should I lace my code with try/catch blocks? I've listed three examples below, but I'm open to any advice. I'm really hoping to get some pros/cons of various approaches. I can certainly come up with some of my own (greater log granularity for the O-C approach, better performance for the Monolithic approach), so I'm looking for experience over opinion. EDIT: I should add that this application is a batch program. The only "recovery" necessary in most cases is to log the error, clean up gracefully, and quit. So this could be seen to be as much a question of log granularity as exception handling. In my mind's eye I can imagine good reasons for both, so I'm looking for some general advice to help me find an appropriate balance. Monolitich Approach class Program{ public static void Main(){ try{ Step1(); Step2(); Step3(); } catch (Exception e) { Log(e); } finally { CleanUp(); } } public static void Step1(){ ExternalApp.Dangerous1(); ExternalApp.Dangerous2(); } public static void Step2(){ ExternalApp.Dangerous3(); ExternalApp.Dangerous4(); } public static void Step3(){ ExternalApp.Dangerous5(); ExternalApp.Dangerous6(); } } Delegated Approach class Program{ public static void Main(){ try{ Step1(); Step2(); Step3(); } finally { CleanUp(); } } public static void Step1(){ try{ ExternalApp.Dangerous1(); ExternalApp.Dangerous2(); } catch (Exception e) { Log(e); throw; } } public static void Step2(){ try{ ExternalApp.Dangerous3(); ExternalApp.Dangerous4(); } catch (Exception e) { Log(e); throw; } } public static void Step3(){ try{ ExternalApp.Dangerous5(); ExternalApp.Dangerous6(); } catch (Exception e) { Log(e); throw; } } } Obsessive-Compulsive Approach class Program{ public static void Main(){ try{ Step1(); Step2(); Step3(); } finally { CleanUp(); } } public static void Step1(){ try{ ExternalApp.Dangerous1(); } catch (Exception e) { Log(e); throw; } try{ ExternalApp.Dangerous2(); } catch (Exception e) { Log(e); throw; } } public static void Step2(){ try{ ExternalApp.Dangerous3(); } catch (Exception e) { Log(e); throw; } try{ ExternalApp.Dangerous4(); } catch (Exception e) { Log(e); throw; } } public static void Step3(){ try{ ExternalApp.Dangerous5(); } catch (Exception e) { Log(e); throw; } try{ ExternalApp.Dangerous6(); } catch (Exception e) { Log(e); throw; } } } Other approaches welcomed and encouraged. Above are examples only.

  Read the article

• Good SQL error handling in Strored Procedure

  - by developerit

  When writing SQL procedures, it is really important to handle errors cautiously. Having that in mind will probably save your efforts, time and money. I have been working with MS-SQL 2000 and MS-SQL 2005 (I have not got the opportunity to work with MS-SQL 2008 yet) for many years now and I want to share with you how I handle errors in T-SQL Stored Procedure. This code has been working for many years now without a hitch. N.B.: As antoher "best pratice", I suggest using only ONE level of TRY … CATCH and only ONE level of TRANSACTION encapsulation, as doing otherwise may not be 100% sure. BEGIN TRANSACTION; BEGIN TRY -- Code in transaction go here COMMIT TRANSACTION; END TRY BEGIN CATCH -- Rollback on error ROLLBACK TRANSACTION; -- Raise the error with the appropriate message and error severity DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int; SELECT @ErrMsg = ERROR_MESSAGE(), @ErrSeverity = ERROR_SEVERITY(); RAISERROR(@ErrMsg, @ErrSeverity, 1); END CATCH; In conclusion, I will just mention that I have been using this code with .NET 2.0 and .NET 3.5 and it works like a charm. The .NET TDS parser throws back a SQLException which is ideal to work with.

  Read the article

• handling a GET error properly

  - by Andrew Heath

  I have a website that takes two primary get strings: ?type=GAME&id=SomeGameID ?type=SCENARIO&id=SomeScenarioID for reasons unknown, I have recently begun receiving requests for erroneous get strings from both Yandex and Baidu. They are always in the form of: ?type=GAME&id=SomeScenarioID None of my users are triggering these errors, so I am (sort of) confident that this is not due to an HTML template error somewhere on my part. There is also no HTTP_REFER showing up in the $_SERVER array, so I'm guessing these are direct requests from bad dbase data on their part. I see two options for dealing with these bad requests, and would like to know which is recommended... or if there are other, better options I have not thought of: simply 404 the request, since it is incorrect redirect the request to ?type=SCENARIO&id=SomeScenarioID because the scenario IDs are always valid, the breakage is due to asking for the wrong type.

  Read the article

• Good practice or service for monitoring unhandled application errors for a small organization

  - by palto

  I'm working with multiple software with varying ways of monitoring for errors. When I make software, I usually send email with the stack trace to admins(usually me). Some customer software is monitored by a team who check that a particular batch run was successfull. Other software might not have any monitoring at all(someone will call when things go wrong horribly). Sending emails is good, except when things start going wrong, my mail gets filled fast. Also I don't want to solve the same problem in code for every software. Is there some relatively cheap and low maintenance software or practice to handle this. I want it to be cheap/low maintenance because usually I work alone or in teams of 5 or smaller. For example it would be great if errors would be aggregated so I don't get 10 000 emails when something unexpected happens... For clarification: By unhandled errors I mean Exceptions that were unhandled by application code that were propagated to Tomcat or Jboss. I don't need help with how to catch those errors. I need help with what to do with them. Is there any cloud application that I could send my errors to? Or some simple server to install? Or some library that can handle errors using configuration files. I use Java if that is any help.

  Read the article

• Error Handling Examples(C#)

  “The purpose of reviewing the Error Handling code is to assure that the application fails safely under all possible error conditions, expected and unexpected. No sensitive information is presented to the user when an error occurs.” (OWASP, 2011) No Error Handling The absence of error handling is still a form of error handling. Based on the code in Figure 1, if an error occurred and was not handled within either the ReadXml or BuildRequest methods the error would bubble up to the Search method. Since this method does not handle any acceptations the error will then bubble up the stack trace. If this continues and the error is not handled within the application then the environment in which the application is running will notify the user running the application that an error occurred based on what type of application. Figure 1: No Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); dt.ReadXml(BuildRequest(searchTerm, resultCount)); return dt; } Generic Error Handling One simple way to add error handling is to catch all errors by default. If you examine the code in Figure 2, you will see a try-catch block. On April 6th 2010 Louis Lazaris clearly describes a Try Catch statement by defining both the Try and Catch aspects of the statement. “The try portion is where you would put any code that might throw an error. In other words, all significant code should go in the try section. The catch section will also hold code, but that section is not vital to the running of the application. So, if you removed the try-catch statement altogether, the section of code inside the try part would still be the same, but all the code inside the catch would be removed.” (Lazaris, 2010) He also states that all errors that occur in the try section cause it to stops the execution of the try section and redirects all execution to the catch section. The catch section receives an object containing information about the error that occurred so that they system can gracefully handle the error properly. When errors occur they commonly log them in some form. This form could be an email, database entry, web service call, log file, or just an error massage displayed to the user.  Depending on the error sometimes applications can recover, while others force an application to close. Figure 2: Generic Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); try { dt.ReadXml(BuildRequest(searchTerm, resultCount)); } catch (Exception ex) { // Handle all Exceptions } return dt; } Error Specific Error Handling Like the Generic Error Handling, Error Specific error handling allows for the catching of specific known errors that may occur. For example wrapping a try catch statement around a soap web service call would allow the application to handle any error that was generated by the soap web service. Now, if the systems wanted to send a message to the web service provider every time a soap error occurred but did not want to notify them if any other type of error occurred like a network time out issue. This would be varying tedious to accomplish using the General Error Handling methodology. This brings us to the use case for using the Error Specific error handling methodology.  The Error Specific Error handling methodology allows for the TryCatch statement to catch various types of errors depending on the type of error that occurred. In Figure 3, the code attempts to handle DataException differently compared to how it potentially handles all other errors. This allows for specific error handling for each type of known error, and still allows for error handling of any unknown error that my occur during the execution of the TryCatch statement. Figure 5: Error Specific Error Handling public DataSet Search(string searchTerm, int resultCount) { DataSet dt = new DataSet(); try { dt.ReadXml(BuildRequest(searchTerm, resultCount)); } catch (TimeoutException ex) { // Handle Timeout TimeoutException Only } catch (Exception) { // Handle all Exceptions } return dt; }

  Read the article

• Isn't it better to use a single try catch instead of tons of TryParsing and other error handling sometimes?

  - by Ryan Peschel

  I know people say it's bad to use exceptions for flow control and to only use exceptions for exceptional situations, but sometimes isn't it just cleaner and more elegant to wrap the entire block in a try-catch? For example, let's say I have a dialog window with a TextBox where the user can type input in to be parsed in a key-value sort of manner. This situation is not as contrived as you might think because I've inherited code that has to handle this exact situation (albeit not with farm animals). Consider this wall of code: class Animals { public int catA, catB; public float dogA, dogB; public int mouseA, mouseB, mouseC; public double cow; } class Program { static void Main(string[] args) { string input = "Sets all the farm animals CAT 3 5 DOG 21.3 5.23 MOUSE 1 0 1 COW 12.25"; string[] splitInput = input.Split(' '); string[] animals = { "CAT", "DOG", "MOUSE", "COW", "CHICKEN", "GOOSE", "HEN", "BUNNY" }; Animals animal = new Animals(); for (int i = 0; i < splitInput.Length; i++) { string token = splitInput[i]; if (animals.Contains(token)) { switch (token) { case "CAT": animal.catA = int.Parse(splitInput[i + 1]); animal.catB = int.Parse(splitInput[i + 2]); break; case "DOG": animal.dogA = float.Parse(splitInput[i + 1]); animal.dogB = float.Parse(splitInput[i + 2]); break; case "MOUSE": animal.mouseA = int.Parse(splitInput[i + 1]); animal.mouseB = int.Parse(splitInput[i + 2]); animal.mouseC = int.Parse(splitInput[i + 3]); break; case "COW": animal.cow = double.Parse(splitInput[i + 1]); break; } } } } } In actuality there are a lot more farm animals and more handling than that. A lot of things can go wrong though. The user could enter in the wrong number of parameters. The user can enter the input in an incorrect format. The user could specify numbers too large or too small for the data type to handle. All these different errors could be handled without exceptions through the use of TryParse, checking how many parameters the user tried to use for a specific animal, checking if the parameter is too large or too small for the data type (because TryParse just returns 0), but every one should result in the same thing: A MessageBox appearing telling the user that the inputted data is invalid and to fix it. My boss doesn't want different message boxes for different errors. So instead of doing all that, why not just wrap the block in a try-catch and in the catch statement just display that error message box and let the user try again? Maybe this isn't the best example but think of any other scenario where there would otherwise be tons of error handling that could be substituted for a single try-catch. Is that not the better solution?

  Read the article

• How to add global exception handling to a add-in dll?

  - by redjackwong

  Here's my context: I am writing a WPF add-in for an application. This Application's main thread is unmanaged. I want to add a global exception handling system for this add-in to handle any unhandled exceptions. Here's what I've tried but not working: I cannot add a try-catch block to my Application.Run() code line. Because I am an add-in, that code fragment is in the application. System.Windows.Forms.Application.ThreadException is not working too. There might not be an WinForm Application exists. (WPF hosting in unmanaged code.) AppDomain.CurrentDomain.UnhandledException is not working too. Because maybe it's handled by the Application itself. It just doesn't enter my code. So, any ideas for this situation?

  Read the article

• Processing a list of atomic operations, allowing for interruptions

  - by JDB

  I'm looking for a design pattern that addresses the following situation: There exists a list of tasks that must be processed. Tasks may be added at any time. Each task is wholly independent from all other tasks. The order in which tasks are processed has no effect on the overall system or on the tasks themselves. Every task must be processed once and only once. The "main" process which launches the task processors may start and stop without warning. When stopped, the "main" process loses all in-memory data. Obviously this is going to involve some state, but are there any design patterns which discuss where and how to maintain that state? Are there any relevant anti-patterns? Named patterns are especially helpful so that we can discuss this topic with other organizations without having to describe the entire problem domain.

  Read the article

• The hidden cost of interrupting knowledge workers

  - by Piet

  The November issue of pragpub has an interesting article on interruptions. The article is written by Brian Tarbox, who also mentions the article on his blog. I like the subtitle: ‘Simple Strategies for Avoiding Dumping Your Mental Stack’. Brian talks about the effective cost of interrupting a ‘knowledge worker’, often with trivial questions or distractions. In the eyes of the interruptor, the interruption only costs the time the interrupted had to listen to the question and give an answer. However, depending on what the interrupted was doing at the time, getting fully immersed in their task again might take up to 15-20 minutes. Enough interruptions might even cause a knowledge worker to mentally call it a day. According to this article interruptions can consume about 28% of a knowledge worker’s time, translating in a $588 billion loss for US companies each year. Looking for a new developer to join your team? Ever thought about optimizing your team’s environment and the way they work instead? Making non knowledge workers aware You can’t. Well, I haven’t succeeded yet. And believe me: I’ve tried. When you’ve got a simple way to really increase your productivity (’give me 2 hours of uninterrupted time a day’) it wouldn’t be right not to tell your boss or team-leader about it. The problem is: only productive knowledge workers seem to understand this. People who don’t fall into this category just seem to think you’re joking, being arrogant or anti-social when you tell them the interruptions can really have an impact on your productivity. Also, knowledge workers often work in a very concentrated mental state which is described here as: It is the same mindfulness as ecstatic lovemaking, the merging of two into a fluidly harmonious one. The hallmark of flow is a feeling of spontaneous joy, even rapture, while performing a task. Yes, coding can be addictive and if you’re interrupting a programmer at the wrong moment, you’re effectively bringing down a junkie from his high in just a few seconds. This can result in seemingly arrogant, almost aggressive reactions. How to make people aware of the production-cost they’re inflicting: I’ve been often pondering that question myself. The article suggests that solutions based on that question never seem to work. To be honest: I’ve never even been able to find a half decent solution for this question. People who are not in this situations just don’t understand the issue, no matter how you try to explain it. Fun (?) thing I’ve noticed: Programmers or IT people in general who don’t get this are often the kind of people who just don’t get anything done. Interrupt handling (interruption management?) IRL Have non-urgent questions handled in a non-interruptive way It helps a bit to educate people into using non-interruptive ways to ask questions: “duh, I have no idea, but I’m a bit busy here now could you put it in an email so I don’t forget?”. Eventually, a considerable amount of people will skip interrupting you and just send an email right away. Some stubborn-headed people however will continue to just interrupt you, saying “you’re 10 meters from my desk, why can’t we just talk?”. Just remember to disable your email notifications, it can be hard to resist opening your email client when you know a new email just arrived. Use Do Not Disturb signals When working in a group of programmers, often the unofficial sign you can only be interrupted for something important is to put on headphones. And when the environment is quiet enough, often people aren’t even listening to music. Otherwise music can help to block the indirect distractions (someone else talking on the phone or tapping their feet). You might get a “they’re all just surfing and listening to music”-reaction from outsiders though. Peopleware talks about a team where the no-interruption sign was placing a shawl on the desk. If I remember correctly, I am unable to locate my copy of this really excellent must-read book. If you have all standardized on the same IM tool, maybe that tool has a ‘do not disturb’ setting. Also some phone-systems have a ‘DND’ (do not disturb) setting. Hide Brian offers a number of good suggestions, some obvious like: hide away somewhere they can’t find you. Not sure how long it’ll be till someone thinks you’re just taking a nap somewhere though. Also, this often isn’t possible or your boss might not understand this. And if you really get caught taking a nap, make sure to explain that your were powernapping. Counter-act interruptions Another suggestion he offers is when you’re being interrupted to just hold up your hand, blocking the interruption, and at least giving you time to finish your sentence or your block/line of code. The last suggestion works more as a way to make it obvious to the interruptor that they really are interrupting your work and to offload some of the cost on the interruptor. In practice, this can also helps you cool down a bit so you don’t start saying nasty things to the interruptor. Unfortunately I’ve sometimes been confronted with people who just ignore this signal and keep talking, as if they’re sure that whatever they’ve got to say is really worth listening to and without a doubt more important than anything you might be doing. This behaviour usually leaves me speechless (not good when someone just asked a question). I’ve noticed that these people are usually also the first to complain when being interrupted themselves. They’re generally not very liked as colleagues, so try not to imitate their behaviour. TDD as a way to minimize recovery time I don’t like Test Driven Development. Mainly for only one reason: It interrupts flow. At least, that’s what it does for me, but maybe I’m just not grown used to TDD yet. BUT a positive effect TDD has on me when I have to work in an interruptive environment and can’t really get into the ‘flow’ (also supposedly called ‘the zone’ by software developers, although I’ve never heard it 1st hand), TDD helps me to concentrate on the tasks at hand and helps me to get back at work after an interruption. I feel when using TDD, I can get by without the need for being totally ‘in’ the project and I can be reasonably productive without obtaining ‘flow’. Do you have a suggestion on how to make people aware of the concept of ‘flow’ and the cost of interruptions? (without looking like an arrogant ass or a weirdo)

  Read the article

• What are the definitive guidelines for custom Error Handling in ASP.NET MVC 3?

  - by RyanW

  The process of doing custom error handling in ASP.NET MVC (3 in this case) seems to be incredibly neglected. I've read through the various questions and answers here, on the web, help pages for various tools (like Elmah), but I feel like I've gone in a complete circle and still don't have the best solution. With your help, perhaps we can set a new standard approach for error handling. I'd like to keep things simple and not over-engineer this. Here are my goals: For Server errors/exceptions: Display debugging information in dev Display friendly error page in production Log errors and email them to administrator in production Return 500 HTTP Status Code For 404 Not Found errors: Display friendly error page Log errors and email them to administrator in production Return 404 HTTP Status Code Is there a way to meet these goals with ASP.NET MVC?

  Read the article

• Common programming mistakes in .Net when handling exceptions?

  - by Jared Coleson

  What are some of the most common mistakes you've seen made when handling exceptions? It seems like exception handling can be one of the hardest things to learn how to do "right" in .Net. Especially considering the currently #1 ranked answer to Common programming mistakes for .NET developers to avoid? is related to exception handling. Hopefully by listing some of the most common mistakes we can all learn to handle exceptions better.

  Read the article

• Should a Perl constructor return an undef or a "invalid" object?

  - by DVK

  Question: What is considered to be "Best practice" - and why - of handling errors in a constructor?. "Best Practice" can be a quote from Schwartz, or 50% of CPAN modules use it, etc...; but I'm happy with well reasoned opinion from anyone even if it explains why the common best practice is not really the best approach. As far as my own view of the topic (informed by software development in Perl for many years), I have seen three main approaches to error handling in a perl module (listed from best to worst in my opinion): Construct an object, set an invalid flag (usually "is_valid" method). Often coupled with setting error message via your class's error handling. Pros: Allows for standard (compared to other method calls) error handling as it allows to use $obj->errors() type calls after a bad constructor just like after any other method call. Allows for additional info to be passed (e.g. 1 error, warnings, etc...) Allows for lightweight "redo"/"fixme" functionality, In other words, if the object that is constructed is very heavy, with many complex attributes that are 100% always OK, and the only reason it is not valid is because someone entered an incorrect date, you can simply do "$obj->setDate()" instead of the overhead of re-executing entire constructor again. This pattern is not always needed, but can be enormously useful in the right design. Cons: None that I'm aware of. Return "undef". Cons: Can not achieve any of the Pros of the first solution (per-object error messages outside of global variables and lightweight "fixme" capability for heavy objects). Die inside the constructor. Outside of some very narrow edge cases, I personally consider this an awful choice for too many reasons to list on the margins of this question. UPDATE: Just to be clear, I consider the (otherwise very worthy and a great design) solution of having very simple constructor that can't fail at all and a heavy initializer method where all the error checking occurs to be merely a subset of either case #1 (if initializer sets error flags) or case #3 (if initializer dies) for the purposes of this question. Obviously, choosing such a design, you automatically reject option #2.

  Read the article

• More interruptions than cpu context switches

  - by Christopher Valles

  I have a machine running Debian GNU/Linux 5.0.8 (lenny) 8 cores and 12Gb of RAM. We have one core permanently around 40% ~ 60% wait time and trying to spot what is happening I realized that we have more interruptions than cpu context switches. I found that the normal ratio between context switch and interruptions is around 10x more context switching than interruptions but on my server the values are completely different. backend1:~# vmstat -s 12330788 K total memory 12221676 K used memory 3668624 K active memory 6121724 K inactive memory 109112 K free memory 3929400 K buffer memory 4095536 K swap cache 4194296 K total swap 7988 K used swap 4186308 K free swap 44547459 non-nice user cpu ticks 702408 nice user cpu ticks 13346333 system cpu ticks 1607583668 idle cpu ticks 374043393 IO-wait cpu ticks 4144149 IRQ cpu ticks 3994255 softirq cpu ticks 0 stolen cpu ticks 4445557114 pages paged in 2910596714 pages paged out 128642 pages swapped in 267400 pages swapped out 3519307319 interrupts 2464686911 CPU context switches 1306744317 boot time 11555115 forks Any ideas if that is an issue? And in that case, how can I spot the cause and fix it? Update Following the instructions of the comments and focusing on the core stuck in wait I checked the processes attached to that core and below you can find the list: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND 24 root RT -5 0 0 0 S 0 0.0 0:03.42 7 migration/7 25 root 15 -5 0 0 0 S 0 0.0 0:04.78 7 ksoftirqd/7 26 root RT -5 0 0 0 S 0 0.0 0:00.00 7 watchdog/7 34 root 15 -5 0 0 0 S 0 0.0 1:18.90 7 events/7 83 root 15 -5 0 0 0 S 0 0.0 1:10.68 7 kblockd/7 291 root 15 -5 0 0 0 S 0 0.0 0:00.00 7 aio/7 569 root 15 -5 0 0 0 S 0 0.0 0:00.00 7 ata/7 1545 root 15 -5 0 0 0 S 0 0.0 0:00.00 7 ksnapd 1644 root 15 -5 0 0 0 S 0 0.0 0:36.73 7 kjournald 1725 root 16 -4 16940 1152 488 S 0 0.0 0:00.00 7 udevd 2342 root 20 0 8828 1140 956 S 0 0.0 0:00.00 7 sh 2375 root 20 0 8848 1220 1016 S 0 0.0 0:00.00 7 locate 2421 root 30 10 8896 1268 1016 S 0 0.0 0:00.00 7 updatedb.findut 2430 root 30 10 58272 49m 616 S 0 0.4 0:17.44 7 sort 2431 root 30 10 3792 448 360 S 0 0.0 0:00.00 7 frcode 2682 root 15 -5 0 0 0 S 0 0.0 3:25.98 7 kjournald 2683 root 15 -5 0 0 0 S 0 0.0 0:00.64 7 kjournald 2687 root 15 -5 0 0 0 S 0 0.0 1:31.30 7 kjournald 3261 root 15 -5 0 0 0 S 0 0.0 2:30.56 7 kondemand/7 3364 root 20 0 3796 596 476 S 0 0.0 0:00.00 7 acpid 3575 root 20 0 8828 1140 956 S 0 0.0 0:00.00 7 sh 3597 root 20 0 8848 1216 1016 S 0 0.0 0:00.00 7 locate 3603 root 30 10 8896 1268 1016 S 0 0.0 0:00.00 7 updatedb.findut 3612 root 30 10 58272 49m 616 S 0 0.4 0:27.04 7 sort 3655 root 20 0 11056 2852 516 S 0 0.0 5:36.46 7 redis-server 3706 root 20 0 19832 1056 816 S 0 0.0 0:01.64 7 cron 3746 root 20 0 3796 580 484 S 0 0.0 0:00.00 7 getty 3748 root 20 0 3796 580 484 S 0 0.0 0:00.00 7 getty 7674 root 20 0 28376 1000 736 S 0 0.0 0:00.00 7 cron 7675 root 20 0 8828 1140 956 S 0 0.0 0:00.00 7 sh 7708 root 30 10 58272 49m 616 S 0 0.4 0:03.36 7 sort 22049 root 20 0 8828 1136 956 S 0 0.0 0:00.00 7 sh 22095 root 20 0 8848 1220 1016 S 0 0.0 0:00.00 7 locate 22099 root 30 10 8896 1264 1016 S 0 0.0 0:00.00 7 updatedb.findut 22108 root 30 10 58272 49m 616 S 0 0.4 0:44.55 7 sort 22109 root 30 10 3792 452 360 S 0 0.0 0:00.00 7 frcode 26927 root 20 0 8828 1140 956 S 0 0.0 0:00.00 7 sh 26947 root 20 0 8848 1216 1016 S 0 0.0 0:00.00 7 locate 26951 root 30 10 8896 1268 1016 S 0 0.0 0:00.00 7 updatedb.findut 26960 root 30 10 58272 49m 616 S 0 0.4 0:10.24 7 sort 26961 root 30 10 3792 452 360 S 0 0.0 0:00.00 7 frcode 27952 root 20 0 65948 3028 2400 S 0 0.0 0:00.00 7 sshd 30731 root 20 0 0 0 0 S 0 0.0 0:01.34 7 pdflush 31204 root 20 0 0 0 0 S 0 0.0 0:00.24 7 pdflush 21857 deploy 20 0 1227m 2240 868 S 0 0.0 2:44.22 7 nginx 21858 deploy 20 0 1228m 2784 868 S 0 0.0 2:42.45 7 nginx 21862 deploy 20 0 1228m 2732 868 S 0 0.0 2:43.90 7 nginx 21869 deploy 20 0 1228m 2840 868 S 0 0.0 2:44.14 7 nginx 27994 deploy 20 0 19372 2216 1380 S 0 0.0 0:00.00 7 bash 28493 deploy 20 0 331m 32m 16m S 4 0.3 0:00.40 7 apache2 21856 deploy 20 0 1228m 2844 868 S 0 0.0 2:43.64 7 nginx 3622 nobody 30 10 21156 10m 916 D 0 0.1 4:42.31 7 find 7716 nobody 30 10 12268 1280 888 D 0 0.0 0:43.50 7 find 22116 nobody 30 10 12612 1696 916 D 0 0.0 6:32.26 7 find 26968 nobody 30 10 12268 1284 888 D 0 0.0 1:56.92 7 find Update As suggested I take a look at /proc/interrupts and below the info there: CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 0: 35 0 0 1469085485 0 0 0 0 IO-APIC-edge timer 1: 0 0 0 8 0 0 0 0 IO-APIC-edge i8042 8: 0 0 0 1 0 0 0 0 IO-APIC-edge rtc0 9: 0 0 0 0 0 0 0 0 IO-APIC-fasteoi acpi 12: 0 0 0 105 0 0 0 0 IO-APIC-edge i8042 16: 0 0 0 0 0 0 0 580212114 IO-APIC-fasteoi 3w-9xxx, uhci_hcd:usb1 18: 0 0 142 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb6, ehci_hcd:usb7 19: 9 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb3, uhci_hcd:usb5 21: 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb2 23: 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb4, ehci_hcd:usb8 1273: 0 0 1600400502 0 0 0 0 0 PCI-MSI-edge eth0 1274: 0 0 0 0 0 0 0 0 PCI-MSI-edge ahci NMI: 0 0 0 0 0 0 0 0 Non-maskable interrupts LOC: 214252181 69439018 317298553 21943690 72562482 56448835 137923978 407514738 Local timer interrupts RES: 27516446 16935944 26430972 44957009 24935543 19881887 57746906 24298747 Rescheduling interrupts CAL: 10655 10705 10685 10567 10689 10669 10667 396 function call interrupts TLB: 529548 462587 801138 596193 922202 747313 2027966 946594 TLB shootdowns TRM: 0 0 0 0 0 0 0 0 Thermal event interrupts THR: 0 0 0 0 0 0 0 0 Threshold APIC interrupts SPU: 0 0 0 0 0 0 0 0 Spurious interrupts ERR: 0 All the values seems more or less the same for all the cores but this one IO-APIC-fasteoi 3w-9xxx, uhci_hcd:usb1 only affects to the core 7 (the same with the wait time of 40% ~ 60%) could be something attached to the usb port causing the issue? Thanks in advanced

  Read the article

• Exception handling policy in libraries

  - by Asaf R

  When building a .NET library, what's your exception handling policy? In specific, what's your policy about handling exceptions inside library calls and exposing them to calling code? Would you treat a library function as any other, thus letting all exceptions it can't handle flow out of it as-is? Would you create a custom exception for that library? Would you catch all exceptions and throw the library's exception instead? Would you set the original exception as the library's exception internal exception? How would the library dependence on a DB affect your exception-handling policy? What other guidelines and rules would you suggest?

  Read the article

1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >