Search Results

Search found 7179 results on 288 pages for 'slow logon'.

Page 107/288 | < Previous Page | 103 104 105 106 107 108 109 110 111 112 113 114  | Next Page >

• What do I need to write a small game on Linux?

  - by Michas

  I want to make a simple game: 2d, single-player, without tons of animations and special effects. I am not interested in ready to use game engines, I want to learn to write some code in a quite universal language. I am using Linux (AMD64) and looking for something easy with nice library for games. I do not want to mix few languages, most of them are in fact fast enough themselves for my needs. Cross platform would be an advantage, however all I need is a good Linux support. I have been considering few solutions. Ruby + Language looks very nice. + I am going to learn Ruby. - I am afraid I can have problems with additional libraries. - This thread about game libraries for Ruby could be longer. SDL + C + It is used for games. + It is very easy to set up. + There is a lot of additional libraries. + It is cross-platform. - The solution is quite low level. - The language is sometimes quite hard to read. QT + C++ + It is very easy to set up. + The standard QT libraries supports everything I can possibly need. + It is cross-platform. + The documentation is good. - The compilation is slow. - The language looks horrible. - The size of standard QT libraries is too big to comprehend. Environment of web browser + I am going to learn something more about this environment. + It is somewhat used for games. + It is quite cross-platform. - It would be too much experimental. Java + It is used for games. + The standard Java libraries supports everything I can possibly need. + It is cross-platform. - It is quite hard to set up. - The size of standard Java libraries is too big to comprehend. - The source code in Java could look better. - I think I do not want to learn Java. Google Go + I am going to learn Google Go. - There is big problem with libraries. - The solution would be quite low level. Python + It looks some people do games in Python, according to this thread. + It looks there are probably more libraries than for Ruby. - The Ruby language looks better. - I think I do not want to learn Python. C++ + something else + It is used for games. + It would be probably cross-platform. + There is a lot of libraries. - I do not need C++ extensions over C. - Compilation could be slow, there are fast compilers for C, not for C++. Haskell + I am going to learn Haskell. - Many things about programming computer games looks too much imperative. - It looks I can have some problems with libraries. - Compilation (GHC) looks slow. There is probably something more to consider. Does anyone have experience in making small games for Linux in non mainstream solutions? Does anyone have an advice for me?

  Read the article

• Why always fires OnFailure when return View() to Ajax Form ?

  - by Wahid Bitar

  I'm trying to make a log-in log-off with Ajax supported. I made some logic in my controller to sign the user in and then return simple partial containing welcome message and log-Off ActionLink my Action method looks like this : public ActionResult LogOn(LogOnModel model, string returnUrl) { if (ModelState.IsValid) { if (MembershipService.ValidateUser(model.UserName, model.Password)) { FormsService.SignIn(model.UserName, model.RememberMe); if (Request.IsAjaxRequest()) { //HERE IS THE PROBLEM :( return View("LogedInForm"); } else { if (!String.IsNullOrEmpty(returnUrl)) return Redirect(returnUrl); else return RedirectToAction("Index", "Home"); } } else { ModelState.AddModelError("", "The user name or password provided is incorrect."); if (Request.IsAjaxRequest()) { return Content("There were an error !"); } } } return View(model); } and I'm trying to return this simple partial : Welcome <b><%= Html.Encode(Model.UserName)%></b>! <%= Html.ActionLink("Log Off", "LogOff", "Account") %> and of-course the two partial are strongly-typed to LogOnModel. But if i returned View("PartialName") i always get OnFailure with status code 500. While if i returned Content("My Message") everything is going right. so please tell me why i always get this "StatusCode = 500" ??. where is the big mistake ??. By the way in my Site MasterPage i rendered partial to show long-on simple form this partial looks like this : <script type="text/javascript"> function ShowErrorMessage(ajaxContext) { var response = ajaxContext.get_response(); var statusCode = response.get_statusCode(); alert("Sorry, the request failed with status code " + statusCode); } function ShowSuccessMessage() { alert("Hey everything is OK!"); } </script> <div id="logedInDiv"> </div> <% using (Ajax.BeginForm("LogOn", "Account", new AjaxOptions { UpdateTargetId = "logedInDiv", InsertionMode = InsertionMode.Replace, OnSuccess = "ShowSuccessMessage", OnFailure = "ShowErrorMessage" })) { %> <%= Html.TextBoxFor(m => m.UserName)%> <%= Html.PasswordFor(m => m.Password)%> <%= Html.CheckBoxFor(m => m.RememberMe)%> <input type="submit" value="Log On" /> < <% } %>

  Read the article

• Improving TCP performance over a gigabit network lots of connections and high traffic for storage and streaming services

  - by Linux Guy

  I have two servers, Both servers hardware Specification are Processor : Dual Processor RAM : over 128 G.B Hard disk : SSD Hard disk Outging Traffic bandwidth : 3 Gbps network cards speed : 10 Gbps Server A : for Encoding videos Server B : for storage videos andstream videos over web interface like youtube The inbound bandwidth between two servers is 10Gbps , the outbound bandwidth internet bandwidth is 500Mpbs Both servers using public ip addresses in public and private network Both servers transfer and connection on nginx port , and the server B used for streaming media , like youtube stream videos Both servers in same network , when i do ping from Server A to Server B i got high time latency above 1.0ms , the time range time=52.7 ms to time=215.7 ms - This is the output of iftop utility 353Mb 707Mb 1.04Gb 1.38Gb 1.73Gb mqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqqvqqqqqqqqqqqqqqqqqqqqqqqqqqq server.example.com => ip.address 6.36Mb 4.31Mb 1.66Mb <= 158Kb 94.8Kb 35.1Kb server.example.com => ip.address 1.23Mb 4.28Mb 1.12Mb <= 17.1Kb 83.5Kb 21.9Kb server.example.com => ip.address 395Kb 3.89Mb 1.07Mb <= 6.09Kb 109Kb 28.6Kb server.example.com => ip.address 4.55Mb 3.83Mb 1.04Mb <= 55.6Kb 45.4Kb 13.0Kb server.example.com => ip.address 649Kb 3.38Mb 1.47Mb <= 9.00Kb 38.7Kb 16.7Kb server.example.com => ip.address 5.00Mb 3.32Mb 1.80Mb <= 65.7Kb 55.1Kb 29.4Kb server.example.com => ip.address 387Kb 3.13Mb 1.06Mb <= 18.4Kb 39.9Kb 15.0Kb server.example.com => ip.address 3.27Mb 3.11Mb 1.01Mb <= 81.2Kb 64.5Kb 20.9Kb server.example.com => ip.address 1.75Mb 3.08Mb 2.72Mb <= 16.6Kb 35.6Kb 32.5Kb server.example.com => ip.address 1.75Mb 2.90Mb 2.79Mb <= 22.4Kb 32.6Kb 35.6Kb server.example.com => ip.address 3.03Mb 2.78Mb 1.82Mb <= 26.6Kb 27.4Kb 20.2Kb server.example.com => ip.address 2.26Mb 2.66Mb 1.36Mb <= 51.7Kb 49.1Kb 24.4Kb server.example.com => ip.address 586Kb 2.50Mb 1.03Mb <= 4.17Kb 26.1Kb 10.7Kb server.example.com => ip.address 2.42Mb 2.49Mb 2.44Mb <= 31.6Kb 29.7Kb 29.9Kb server.example.com => ip.address 2.41Mb 2.46Mb 2.41Mb <= 26.4Kb 24.5Kb 23.8Kb server.example.com => ip.address 2.37Mb 2.39Mb 2.40Mb <= 28.9Kb 27.0Kb 28.5Kb server.example.com => ip.address 525Kb 2.20Mb 1.05Mb <= 7.03Kb 26.0Kb 12.8Kb qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq TX: cum: 102GB peak: 1.65Gb rates: 1.46Gb 1.44Gb 1.48Gb RX: 1.31GB 24.3Mb 19.5Mb 18.9Mb 20.0Mb TOTAL: 103GB 1.67Gb 1.48Gb 1.46Gb 1.50Gb I check the transfer speed using iperf utility From Server A to Server B # iperf -c 0.0.0.2 -p 8777 ------------------------------------------------------------ Client connecting to 0.0.0.2, TCP port 8777 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 3] local 0.0.0.1 port 38895 connected with 0.0.0.2 port 8777 [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.8 sec 528 KBytes 399 Kbits/sec My Current Connections in Server B # netstat -an|grep ":8777"|awk '/tcp/ {print $6}'|sort -nr| uniq -c 2072 TIME_WAIT 28 SYN_RECV 1 LISTEN 189 LAST_ACK 139 FIN_WAIT2 373 FIN_WAIT1 3381 ESTABLISHED 34 CLOSING Server A Network Card Information Settings for eth0: Supported ports: [ TP ] Supported link modes: 100baseT/Full 1000baseT/Full 10000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 10000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: Yes Speed: 10000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: external Auto-negotiation: on MDI-X: Unknown Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes Server B Network Card Information Settings for eth2: Supported ports: [ FIBRE ] Supported link modes: 10000baseT/Full Supported pause frame use: No Supports auto-negotiation: No Advertised link modes: 10000baseT/Full Advertised pause frame use: No Advertised auto-negotiation: No Speed: 10000Mb/s Duplex: Full Port: Direct Attach Copper PHYAD: 0 Transceiver: external Auto-negotiation: off Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes ifconfig server A eth0 Link encap:Ethernet HWaddr 00:25:90:ED:9E:AA inet addr:0.0.0.1 Bcast:0.0.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1202795665 errors:0 dropped:64334 overruns:0 frame:0 TX packets:2313161968 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:893413096188 (832.0 GiB) TX bytes:3360949570454 (3.0 TiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2207544 errors:0 dropped:0 overruns:0 frame:0 TX packets:2207544 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:247769175 (236.2 MiB) TX bytes:247769175 (236.2 MiB) ifconfig Server B eth2 Link encap:Ethernet HWaddr 00:25:90:82:C4:FE inet addr:0.0.0.2 Bcast:0.0.0.2 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:39973046980 errors:0 dropped:1828387600 overruns:0 frame:0 TX packets:69618752480 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:3013976063688 (2.7 TiB) TX bytes:102250230803933 (92.9 TiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:1049495 errors:0 dropped:0 overruns:0 frame:0 TX packets:1049495 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:129012422 (123.0 MiB) TX bytes:129012422 (123.0 MiB) Netstat -i on Server B # netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth2 9000 0 42098629968 0 2131223717 0 73698797854 0 0 0 BMRU lo 65536 0 1077908 0 0 0 1077908 0 0 0 LRU I Turn up send/receive buffers on the network card to 2048 and problem still persist I increase the MTU for server A and problem still persist and i increase the MTU for server B for better connectivity and transfer speed but it couldn't transfer at all The problem is : as you can see from iperf utility, the transfer speed from server A to server B slow when i restart network service in server B the transfer in server A at full speed, after 2 minutes , it's getting slow How could i troubleshoot slow speed issue and fix it in server B ? Notice : if there any other commands i should execute in servers for more information, so it might help resolve the problem , let me know in comments

  Read the article

• Cisco IP Phone Call Manager handle events

  - by dankyy1

  I 'm new on cisco IP Phones. I have a cisco call manager system also a 7970 Ip phone. The phone cominicates with Cisco Call Manager application. I want to listen events when user logon and send some commands to phone., Is there any idea about this task? Is there a way to got events from cisco call manager or i have to listen up the ports of Ip phone? thanks

  Read the article

• Do git tags get pushed as well?

  - by vfclists

  Since I created my repository it appears that the tags I have been creating are not pushed to the repository. When I do git tag on the local directory all the tags are present, but when I logon to the remote repository and do a git tag, only the first few show up. What could the problem be?

  Read the article

• wcf message size causing permission issue

  - by Ferrell Carr

  silverlight 3.0 client wcf 3.0 VS.Net 2005 Web Site Win 2003 Server 50 column observable collection. return observable collection select top 975 * ... no problem return observable collection select * .... Issue On SL client after proxy.Get 50 col OC logon screen from win 2003 server pops up Mever makes it to the completed event.

  Read the article

• Applying Microsoft Management Console Policies

  - by Hipno

  Hello, I am using windows 7. i got a user on my computer a non-admin user, and i want to apply on him user policies from the Microsoft Management Console. i added group policy object editor, chose Non-admin group, set a setting, saved and close. but i when i logon to that user i applied to, it just won't effect! please tell me what i miss, thank you.

  Read the article

• Page Redirect when session end in ASP.Net MVC

  - by Kaung Sitt Thu

  I would like to do redirect to login when current session end and that config must be working at any View and Controller. ///My current code in Global.asax protected void Session_End(object sender, EventArgs e) { Session.Abandon(); //GetPath() is getting currently path // eg. http://localhost/mymvcproject Response.Redirect(PATH.GetPath() + "User/LogOn"); }

  Read the article

• Joomla + CB (Community Builder) + Google Apps

  I started wondering today if it would be possible to integrate Joomla+CB with Google apps. If that would be possible we could have one great product! The first thing that I would want to integrate is the logon-process, one login for Joomla+Google apps. Then it would be great to have some Google apps modules: - your latest e-mails - your next calendar entries - your google talk buddies online/offline - your most recent docs and spreadsheets

  Read the article

• How can I setup a mailing list that publishes and email to all members when logs in and presses a bu

  - by kjm

  I want to setup a site where users can register and then simply logon and press a button on a web page (that I will need to build) that then post a generic email to everyone. I want a button on the page that the user can press that will result in an email being sent to all members of the list/group I am looking at mail man. Any ideas?

  Read the article

• ASP.Net Email and Account validation

  - by c11ada

  hey all, i was wondering if any one can advise me on how i can go about implementing a email and account validation feature in my ASP.net website. so when a user creates an account, an email is sent to the email address used, and the user needs to verify that email address to be able to logon. thanks

  Read the article

• SQL server Agent - Not starting - Automatic start enabled

  - by user130561

  SQL server agent is not starting automatically even when it is set to "Automatic". We have a weekend reboot of the server and usually it should come up automatically since it is set to "Automatic". SQL Agent Logs: [298] SQLServer Error: 831, Client unable to establish connection [SQLSTATE 08001] [382] Logon to server '(local)' failed (SubSystemStepHistoryLogger) [165] ODBC Error: 0, Driver's SQLAllocHandle on SQL_HANDLE_ENV failed [SQLSTATE IM004]

  Read the article

• Deploy .net MVC 2 appication on IIS6

  - by munish

  I want to deploy my .net MVC 2 appication on IIS6.0. Will it require to change route path in global.asax file. In my application i have used html link, ajax request and Html.ActionLink. The code lines in the Global.asax file are: routes.MapRoute( "LogOn", "{controller}/{action}/{id}", new { controller = "Account", action = "Index", id = UrlParameter.Optional } ); Please suggest me. Thanks and Regards Munish

  Read the article

• Oracle database link

  - by Sunit

  I'm currently using Windows Authentication with 2 Oracle servers - SP3DSMP1 & SP3DSMP4. I created a database link on SMP1 to connect to SMP4 as: SQL create public database link LINK_SMP4 2 connect to CURRENT_USER 3 using 'SP3DSMP4'; Database link created. However when I try to do a query, I get the error: ERROR at line 1: ORA-01017: invalid username/password; logon denied Any ideas what might be wrong here? thanks Sunit

  Read the article

• Check if a username has been registered

  - by Testing123

  I am using the builtin ASP.NET logon and user management features. Is there a way to just identify if a username or email address is already registered? I would've thought it's part of FormsAuthentication or similar, but can't find such a function.

  Read the article

• ASP.NET Dashboard / Widgets

  - by davemackey

  I'd like to build a dashboard interface for an application I am working on. I want users to logon and get a birds eye view of the status of applications, outstanding issues, etc. I'm wondering if there are some good, pre-made controls rather than writing these from the ground up?

  Read the article

• Is there any analog of TCPvcon which allows to close TCP connection on remote machine?

  - by Miollnyr

  Hi, I started to use SysInternals suite, and it is great. But I wonder, whether there is any analog of TCPvcon, which allows to logon to remote machine, like psexec does, and then get list of TCP connections from there (similar to pslist functionality), and then to close some of connections (similar to pskill functionality). I am speaking about windows console tools and I would like to avoid installing something on remote machine is this is possible.

  Read the article

• How can I get an Active Directory data code from System.DirectoryServices[.Protocols]?

  - by Alex Waddell

  When using .Protocols, I can run the following pseudocode to authenticate to an AD: try { LdapConnection c = new LdapConnection("User", "Password"); c.Bind(); } catch (LdapException le) { Debug.WriteLine(le.ResultCode); } This code will allow me to get the "Invalid Credentials" error string, and the AD code "49", but I need to get the additional data errors similar to an LDAP Java client : [LDAP: error code 49 - 80090308: LdapErr: DSID-0C09030F, comment: AcceptSecurityContext error, data **525**, vece ] 525 – user not found 52e – invalid credentials (bad password) 530 – logon time restriction 532 – password expired 533 – account disabled 701 – account expired 773 – user must reset password

  Read the article

• C# slowdown while creating a bitmap - calculating distances from a large List of places for each pixel

  - by user576849

  I'm creating a graphic of the glow of lights above a geographic location based upon Walkers Law: Skyglow=0.01*Population*DistanceFromCenter^-2.5 I have a CSV file of places with 66,000 records using 5 fields (id,name,population,latitude,longitude), parsed on the FormLoad event and stored it in: List<string[]> placeDataList Then I set up nested loops to fill in a bitmap using SetPixel. For each pixel on the bitmap, which represents a coordinate on a map (latitude and longitude), the program loops through placeDataList – calculating the distance from that coordinate (pixel) to each place record. The distance (along with population) is used in a calculation to find how much cumulative sky glow is contributed to the coordinate from each place record. So, for every pixel, 66,000 distance calculations must be made. The problem is, this is predictably EXTREMELY slow – on the order of one line of pixels per 30 seconds or so on a 320 pixel wide image. This is unrelated to SetPixel, which I know is also slow, because the speed is similarly slow when adding the distance calculation results to an array. I don’t actually need to test all 66,000 records for every pixel, only the records within 150 miles (i.e. no skyglow is contributed to a coordinate from a small town 3000 miles away). But to find which records are within 150 miles of my coordinate I would still need to loop through all the records for each pixel. I can't use a smaller number of records because all 66,000 places contribute to skyglow for SOME coordinate in my map as it loops. This seems like a Catch-22, so I know there must be a better method out there. Like I mentioned, the slowdown is related to how many calculations I’m making per pixel, not anything to do with the bitmap. Any suggestions? private void fillPixels(int width) { Color pixelColor; int pixel_w = width; int pixel_h = (int)Math.Floor((width * 0.424088664)); Bitmap bmp = new Bitmap(pixel_w, pixel_h); for (int i = 0; i < pixel_h; i++) for (int j = 0; j < pixel_w; j++) { pixelColor = getPixelColor(i, j); bmp.SetPixel(j, i, pixelColor); } bmp.Save("Nightfall", System.Drawing.Imaging.ImageFormat.Jpeg); pictureBox1.Image = bmp; MessageBox.Show("Done"); } private Color getPixelColor(int height, int width) { int c; double glow,d,cityLat,cityLon,cityPop; double testLat, testLon; int size_h = (int)Math.Floor((size_w * 0.424088664)); ; testLat = (height * (24.443136 / size_h)) + 24.548874; testLon = (width * (57.636853 / size_w)) -124.640767; glow = 0; for (int i = 0; i < placeDataList.Count; i++) { cityPop=Convert.ToDouble(placeDataList[i][2]); cityLat=Convert.ToDouble(placeDataList[i][3]); cityLon=Convert.ToDouble(placeDataList[i][4]); d = distance(testLat, testLon, cityLat, cityLon,"M"); if(d<150) glow = glow+(0.01 * cityPop * Math.Pow(d, -2.5)); } if (glow >= 1) glow=1; c = (int)Math.Ceiling(glow * 255); return Color.FromArgb(c, c, c); }

  Read the article

• Error message 401.2. While access Users from Active Directory

  - by Anilkumar

  While Authenticating users from Active Directory Am getting the following Error. Error message 401.2.: Unauthorized: Logon failed due to server configuration. Verify that you have permission to view this directory or page based on the credentials you supplied and the authentication methods enabled on the Web server. Contact the Web server's administrator for additional assistance.

  Read the article

• AJAX ASP.Net Remove URL ID

  - by Ioxp

  The site im working on is an Ajax enabled ASP.net/C# project and i have a URL like this: http://localhost:2531/(S(lfcvqc55wkabpp55o1x4pvq5))/Logon.aspx How do you get rid of the (S(lfcvqc55wkabpp55o1x4pvq5)) portion of the URL? I have a feeling its a web.config parameter however I'm not really sure what you call this part, GUID, Session ID?

  Read the article

• SSIS 2005 running in SQL Server Agent on local PC connecting to database on remote server produces t

  - by user317178

  Hello, I'm trying to run an SSIS 2005 package from a SQL Server Agent job on my local PC. This package is attempting to connect to a SQL Server 2005 database on a remote server, but it gets the error message, "Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'". What is the problem and how can I solve it? Thank you in advance.

  Read the article

• What components have you built that you are reusing over and over again for your desktop application

  - by Jason

  We are building our internal library of components up, and was wondering what everybody has in their library of reusable components for your organization, for desktop applications. Our list currently includes only a couple of components: Logon, Security and User Group functionality System Tray / Service Framework Component for Internet Communications (to handle proxies, security, etc...) Billing What else do you have, that we should add to our list? If you have reusable web components, save your answers... I will open a different question if this one is successful.

  Read the article

• need help on php require

  - by user225269

  What do I need to put in a php code so that the user cannot access it even if he specified the correct url for the page they are trying to access. And redirect it to the logon page. I'm really having difficulty in this matter, everytime I click back button on the browser the user can still access the page

  Read the article

• Performance Optimization &ndash; It Is Faster When You Can Measure It

  - by Alois Kraus

  Performance optimization in bigger systems is hard because the measured numbers can vary greatly depending on the measurement method of your choice. To measure execution timing of specific methods in your application you usually use Time Measurement Method Potential Pitfalls Stopwatch Most accurate method on recent processors. Internally it uses the RDTSC instruction. Since the counter is processor specific you can get greatly different values when your thread is scheduled to another core or the core goes into a power saving mode. But things do change luckily: Intel's Designer's vol3b, section 16.11.1 "16.11.1 Invariant TSC The time stamp counter in newer processors may support an enhancement, referred to as invariant TSC. Processor's support for invariant TSC is indicated by CPUID.80000007H:EDX[8]. The invariant TSC will run at a constant rate in all ACPI P-, C-. and T-states. This is the architectural behavior moving forward. On processors with invariant TSC support, the OS may use the TSC for wall clock timer services (instead of ACPI or HPET timers). TSC reads are much more efficient and do not incur the overhead associated with a ring transition or access to a platform resource." DateTime.Now Good but it has only a resolution of 16ms which can be not enough if you want more accuracy.   Reporting Method Potential Pitfalls Console.WriteLine Ok if not called too often. Debug.Print Are you really measuring performance with Debug Builds? Shame on you. Trace.WriteLine Better but you need to plug in some good output listener like a trace file. But be aware that the first time you call this method it will read your app.config and deserialize your system.diagnostics section which does also take time.   In general it is a good idea to use some tracing library which does measure the timing for you and you only need to decorate some methods with tracing so you can later verify if something has changed for the better or worse. In my previous article I did compare measuring performance with quantum mechanics. This analogy does work surprising well. When you measure a quantum system there is a lower limit how accurately you can measure something. The Heisenberg uncertainty relation does tell us that you cannot measure of a quantum system the impulse and location of a particle at the same time with infinite accuracy. For programmers the two variables are execution time and memory allocations. If you try to measure the timings of all methods in your application you will need to store them somewhere. The fastest storage space besides the CPU cache is the memory. But if your timing values do consume all available memory there is no memory left for the actual application to run. On the other hand if you try to record all memory allocations of your application you will also need to store the data somewhere. This will cost you memory and execution time. These constraints are always there and regardless how good the marketing of tool vendors for performance and memory profilers are: Any measurement will disturb the system in a non predictable way. Commercial tool vendors will tell you they do calculate this overhead and subtract it from the measured values to give you the most accurate values but in reality it is not entirely true. After falling into the trap to trust the profiler timings several times I have got into the habit to Measure with a profiler to get an idea where potential bottlenecks are. Measure again with tracing only the specific methods to check if this method is really worth optimizing. Optimize it Measure again. Be surprised that your optimization has made things worse. Think harder Implement something that really works. Measure again Finished! - Or look for the next bottleneck. Recently I have looked into issues with serialization performance. For serialization DataContractSerializer was used and I was not sure if XML is really the most optimal wire format. After looking around I have found protobuf-net which uses Googles Protocol Buffer format which is a compact binary serialization format. What is good for Google should be good for us. A small sample app to check out performance was a matter of minutes: using ProtoBuf; using System; using System.Diagnostics; using System.IO; using System.Reflection; using System.Runtime.Serialization; [DataContract, Serializable] class Data { [DataMember(Order=1)] public int IntValue { get; set; } [DataMember(Order = 2)] public string StringValue { get; set; } [DataMember(Order = 3)] public bool IsActivated { get; set; } [DataMember(Order = 4)] public BindingFlags Flags { get; set; } } class Program { static MemoryStream _Stream = new MemoryStream(); static MemoryStream Stream { get { _Stream.Position = 0; _Stream.SetLength(0); return _Stream; } } static void Main(string[] args) { DataContractSerializer ser = new DataContractSerializer(typeof(Data)); Data data = new Data { IntValue = 100, IsActivated = true, StringValue = "Hi this is a small string value to check if serialization does work as expected" }; var sw = Stopwatch.StartNew(); int Runs = 1000 * 1000; for (int i = 0; i < Runs; i++) { //ser.WriteObject(Stream, data); Serializer.Serialize<Data>(Stream, data); } sw.Stop(); Console.WriteLine("Did take {0:N0}ms for {1:N0} objects", sw.Elapsed.TotalMilliseconds, Runs); Console.ReadLine(); } } The results are indeed promising: Serializer Time in ms N objects protobuf-net   807 1000000 DataContract 4402 1000000 Nearly a factor 5 faster and a much more compact wire format. Lets use it! After switching over to protbuf-net the transfered wire data has dropped by a factor two (good) and the performance has worsened by nearly a factor two. How is that possible? We have measured it? Protobuf-net is much faster! As it turns out protobuf-net is faster but it has a cost: For the first time a type is de/serialized it does use some very smart code-gen which does not come for free. Lets try to measure this one by setting of our performance test app the Runs value not to one million but to 1. Serializer Time in ms N objects protobuf-net 85 1 DataContract 24 1 The code-gen overhead is significant and can take up to 200ms for more complex types. The break even point where the code-gen cost is amortized by its faster serialization performance is (assuming small objects) somewhere between 20.000-40.000 serialized objects. As it turned out my specific scenario involved about 100 types and 1000 serializations in total. That explains why the good old DataContractSerializer is not so easy to take out of business. The final approach I ended up was to reduce the number of types and to serialize primitive types via BinaryWriter directly which turned out to be a pretty good alternative. It sounded good until I measured again and found that my optimizations so far do not help much. After looking more deeper at the profiling data I did found that one of the 1000 calls did take 50% of the time. So how do I find out which call it was? Normal profilers do fail short at this discipline. A (totally undeserved) relatively unknown profiler is SpeedTrace which does unlike normal profilers create traces of your applications by instrumenting your IL code at runtime. This way you can look at the full call stack of the one slow serializer call to find out if this stack was something special. Unfortunately the call stack showed nothing special. But luckily I have my own tracing as well and I could see that the slow serializer call did happen during the serialization of a bool value. When you encounter after much analysis something unreasonable you cannot explain it then the chances are good that your thread was suspended by the garbage collector. If there is a problem with excessive GCs remains to be investigated but so far the serialization performance seems to be mostly ok.  When you do profile a complex system with many interconnected processes you can never be sure that the timings you just did measure are accurate at all. Some process might be hitting the disc slowing things down for all other processes for some seconds as well. There is a big difference between warm and cold startup. If you restart all processes you can basically forget the first run because of the OS disc cache, JIT and GCs make the measured timings very flexible. When you are in need of a random number generator you should measure cold startup times of a sufficiently complex system. After the first run you can try again getting different and much lower numbers. Now try again at least two times to get some feeling how stable the numbers are. Oh and try to do the same thing the next day. It might be that the bottleneck you found yesterday is gone today. Thanks to GC and other random stuff it can become pretty hard to find stuff worth optimizing if no big bottlenecks except bloatloads of code are left anymore. When I have found a spot worth optimizing I do make the code changes and do measure again to check if something has changed. If it has got slower and I am certain that my change should have made it faster I can blame the GC again. The thing is that if you optimize stuff and you allocate less objects the GC times will shift to some other location. If you are unlucky it will make your faster working code slower because you see now GCs at times where none were before. This is where the stuff does get really tricky. A safe escape hatch is to create a repro of the slow code in an isolated application so you can change things fast in a reliable manner. Then the normal profilers do also start working again. As Vance Morrison does point out it is much more complex to profile a system against the wall clock compared to optimize for CPU time. The reason is that for wall clock time analysis you need to understand how your system does work and which threads (if you have not one but perhaps 20) are causing a visible delay to the end user and which threads can wait a long time without affecting the user experience at all. Next time: Commercial profiler shootout.

  Read the article

< Previous Page | 103 104 105 106 107 108 109 110 111 112 113 114  | Next Page >