Search Results

Search found 16731 results on 670 pages for 'memory limit'.

Page 594/670 | < Previous Page | 590 591 592 593 594 595 596 597 598 599 600 601  | Next Page >

• Winsock WSAAsyncSelect sending without an infinite buffer

  - by Xexr

  Hi, This is more of a design question than a specific code question, I'm sure I am missing the obvious, I just need another set of eyes. I am writing a multi-client server based on WSAAsyncSelect, each connection is made into an object of a connection class I have written which contains associated settings and buffers etc. My question concerns FD_WRITE, I understand how it operates: One FD_WRITE is sent immediately after a connection is established. Thereafter, you should send until WSAEWOULDBLOCK is received at which point you store what is left to send in a buffer, and wait to be told that it is ok to send again. This is where I have a problem, how large do I make this holding buffer within each connections object? The amount of time until a new FD_WRITE is received is unknown, I could be attempting to send a lot of stuff during this period, all the time adding to my outgoing buffer. If I make the buffer dynamic, memory usage could spiral out of control if for whatever reason, I am unable to send() and reduce the buffer. So my question is how do you generally handle this situation? Note I am not talking about the network buffer itself which winsock uses, but one of my own creation used to "queue" up sends. Hope I explained that well enough, thanks all!

  Read the article

• Minimal assembler program for CP/M 3.1 (z80)

  - by Andrew J. Brehm

  I seem to be losing the battle against my stupidity. This site explains the system calls under various versions of CP/M. However, when I try to use call 2 (C_WRITE, console output), nothing much happens. I have the following code. ORG 100h LD E,'a' LD C,2 CALL 5 CALL 0 I recite this here from memory. If there are typos, rest assured they were not in the original since the file did compile and I had a COM file to start. I am thinking the lines mean the following: Make sure this gets loaded at address 100h (0h to FFh being the zero page). Load ASCII 'a' into E register for system call 2. Load integer 2 into C register for system call 2. Make system call (JMP to system call is at address 5 in zero page). End program (Exit command is at address 0 in zero page). The program starts and exits with no problems. If I remove the last command, it hangs the computer (which I guess is also expected and shows that CALL 0 works). However, it does not print the ASCII character. (But it does print an extra new line, but the system might have done that.) How can I get my CP/M program to do what the system call is supposed to do? What am I doing wrong?

  Read the article

• Trouble with Unions in C program.

  - by Jordan S

  I am working on a C program that uses a Union. The union definition is in FILE_A header file and looks like this... // FILE_A.h**************************************************** xdata union { long position; char bytes[4]; }CurrentPosition; If I set the value of CurrentPosition.position in FILE_A.c and then call a function in FILE_B.c that uses the union, the data in the union is back to Zero. This is demonstrated below. // FILE_A.c**************************************************** int main.c(void) { CurrentPosition.position = 12345; SomeFunctionInFileB(); } // FILE_B.c**************************************************** void SomeFunctionInFileB(void) { // After the following lines execute I see all zeros in the flash memory. WriteByteToFlash(CurrentPosition.bytes[0]; WriteByteToFlash(CurrentPosition.bytes[1]; WriteByteToFlash(CurrentPosition.bytes[2]; WriteByteToFlash(CurrentPosition.bytes[3]; } Now, If I pass a long to SomeFunctionInFileB(long temp) and then store it into CurrentPosition.bytes within that function, and finally call WriteBytesToFlash(CurrentPosition.bytes[n]... it works just fine. It appears as though the CurrentPosition Union is not global. So I tried changing the union definition in the header file to include the extern keyword like this... extern xdata union { long position; char bytes[4]; }CurrentPosition; and then putting this in the source (.c) file... xdata union { long position; char bytes[4]; }CurrentPosition; but this causes a compile error that says: C:\SiLabs\Optec Programs\AgosRot\MotionControl.c:76: error 91: extern definition for 'CurrentPosition' mismatches with declaration. C:\SiLabs\Optec Programs\AgosRot\/MotionControl.h:48: error 177: previously defined here So what am I doing wrong? How do I make the union global?

  Read the article

• Computing "average" of two colors

  - by Francisco P.

  This is only marginally programming related - has much more to do w/ colors and their representation. I am working on a very low level app. I have an array of bytes in memory. Those are characters. They were rendered with anti-aliasing: they have values from 0 to 255, 0 being fully transparent and 255 totally opaque (alpha, if you wish). I am having trouble conceiving an algorithm for the rendering of this font. I'm doing the following for each pixel: // intensity is the weight I talked about: 0 to 255 intensity = glyphs[text[i]][x + GLYPH_WIDTH*y]; if (intensity == 255) continue; // Don't draw it, fully transparent else if (intensity == 0) setPixel(x + xi, y + yi, color, base); // Fully opaque, can draw original color else { // Here's the tricky part // Get the pixel in the destination for averaging purposes pixel = getPixel(x + xi, y + yi, base); // transfer is an int for calculations transfer = (int) ((float)((float) (255.0 - (float) intensity/255.0) * (float) color.red + (float) pixel.red)/2); // This is my attempt at averaging newPixel.red = (Byte) transfer; transfer = (int) ((float)((float) (255.0 - (float) intensity/255.0) * (float) color.green + (float) pixel.green)/2); newPixel.green = (Byte) transfer; // transfer = (int) ((float) ((float) 255.0 - (float) intensity)/255.0 * (((float) color.blue) + (float) pixel.blue)/2); transfer = (int) ((float)((float) (255.0 - (float) intensity/255.0) * (float) color.blue + (float) pixel.blue)/2); newPixel.blue = (Byte) transfer; // Set the newpixel in the desired mem. position setPixel(x+xi, y+yi, newPixel, base); } The results, as you can see, are less than desirable. That is a very zoomed in image, at 1:1 scale it looks like the text has a green "aura". Any idea for how to properly compute this would be greatly appreciated. Thanks for your time!

  Read the article

• Are there pitfalls to using static class/event as an application message bus

  - by Doug Clutter

  I have a static generic class that helps me move events around with very little overhead: public static class MessageBus<T> where T : EventArgs { public static event EventHandler<T> MessageReceived; public static void SendMessage(object sender, T message) { if (MessageReceived != null) MessageReceived(sender, message); } } To create a system-wide message bus, I simply need to define an EventArgs class to pass around any arbitrary bits of information: class MyEventArgs : EventArgs { public string Message { get; set; } } Anywhere I'm interested in this event, I just wire up a handler: MessageBus<MyEventArgs>.MessageReceived += (s,e) => DoSomething(); Likewise, triggering the event is just as easy: MessageBus<MyEventArgs>.SendMessage(this, new MyEventArgs() {Message="hi mom"}); Using MessageBus and a custom EventArgs class lets me have an application wide message sink for a specific type of message. This comes in handy when you have several forms that, for example, display customer information and maybe a couple forms that update that information. None of the forms know about each other and none of them need to be wired to a static "super class". I have a couple questions: fxCop complains about using static methods with generics, but this is exactly what I'm after here. I want there to be exactly one MessageBus for each type of message handled. Using a static with a generic saves me from writing all the code that would maintain the list of MessageBus objects. Are the listening objects being kept "alive" via the MessageReceived event? For instance, perhaps I have this code in a Form.Load event: MessageBus<CustomerChangedEventArgs>.MessageReceived += (s,e) => DoReload(); When the Form is Closed, is the Form being retained in memory because MessageReceived has a reference to its DoReload method? Should I be removing the reference when the form closes: MessageBus<CustomerChangedEventArgs>.MessageReceived -= (s,e) => DoReload();

  Read the article

• Why is my UITableView not being set?

  - by Jamie L

  I checked using the debbuger in the viewDidLoad method and tracerTableView is 0x0 which i assume means it is nil. I don't understand. I should go ahaed say yes I have already checked my nib file and yes all the connections are correct. Here is the header file and the begging of the .m. ///////////// .h file //////////// @interface TrackerListController : UITableViewController { // The mutable (modifiable) dictionary days holds all the data for the days tab NSMutableArray *trackerList; UITableView *tracerTableView; } @property (nonatomic, retain) NSMutableArray *trackerList; @property (nonatomic, retain) IBOutlet UITableView. *tracerTableView; //The addPackage: method is invoked when the user taps the addbutton created at runtime. -(void) addPackage : (id) sender; @end /////////////////////////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////// .m file ////////////////////////////////////// @implementation TrackerListController @synthesize trackerList, tracerTableView; (void)viewDidLoad { [super viewDidLoad]; self.title = @"Package Tracker"; self.navigationItem.leftBarButtonItem = self.editButtonItem; UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addPackage:)]; // Set up the Add custom button on the right of the navigation bar self.navigationItem.rightBarButtonItem = addButton; [addButton release]; // Release the addButton from memory since it is no longer needed }

  Read the article

• What's the most efficient query?

  - by Aaron Carlino

  I have a table named Projects that has the following relationships: has many Contributions has many Payments In my result set, I need the following aggregate values: Number of unique contributors (DonorID on the Contribution table) Total contributed (SUM of Amount on Contribution table) Total paid (SUM of PaymentAmount on Payment table) Because there are so many aggregate functions and multiple joins, it gets messy do use standard aggregate functions the the GROUP BY clause. I also need the ability to sort and filter these fields. So I've come up with two options: Using subqueries: SELECT Project.ID AS PROJECT_ID, (SELECT SUM(PaymentAmount) FROM Payment WHERE ProjectID = PROJECT_ID) AS TotalPaidBack, (SELECT COUNT(DISTINCT DonorID) FROM Contribution WHERE RecipientID = PROJECT_ID) AS ContributorCount, (SELECT SUM(Amount) FROM Contribution WHERE RecipientID = PROJECT_ID) AS TotalReceived FROM Project; Using a temporary table: DROP TABLE IF EXISTS Project_Temp; CREATE TEMPORARY TABLE Project_Temp (project_id INT NOT NULL, total_payments INT, total_donors INT, total_received INT, PRIMARY KEY(project_id)) ENGINE=MEMORY; INSERT INTO Project_Temp (project_id,total_payments) SELECT `Project`.ID, IFNULL(SUM(PaymentAmount),0) FROM `Project` LEFT JOIN `Payment` ON ProjectID = `Project`.ID GROUP BY 1; INSERT INTO Project_Temp (project_id,total_donors,total_received) SELECT `Project`.ID, IFNULL(COUNT(DISTINCT DonorID),0), IFNULL(SUM(Amount),0) FROM `Project` LEFT JOIN `Contribution` ON RecipientID = `Project`.ID GROUP BY 1 ON DUPLICATE KEY UPDATE total_donors = VALUES(total_donors), total_received = VALUES(total_received); SELECT * FROM Project_Temp; Tests for both are pretty comparable, in the 0.7 - 0.8 seconds range with 1,000 rows. But I'm really concerned about scalability, and I don't want to have to re-engineer everything as my tables grow. What's the best approach?

  Read the article

• Is there a difference between starting an application from the OS or from adb

  - by aruwen

  I do have a curious error in my application. My app crashes (don't mind the crash, I roughly know why - classloader) when I start the application from the OS directly, then kill it from the background via any Task Killer (this is one of the few ways to reproduce the crash consistently - simulating the OS freeing memory and closing the application) and try to restart it again. The thing is, if I start the application via adb shell using the following command: adb shell am start -a android.intent.action.MAIN -n com.my.packagename/myLaunchActivity I cannot reproduce the crash. So is there any difference in how Android OS calls the application as opposed to the above call? EDIT: added the manifest (just changed names) <?xml version="1.0" ?> <manifest android:versionCode="5" android:versionName="1.05" package="com.my.sample" xmlns:android="http://schemas.android.com/apk/res/android"> <uses-sdk android:minSdkVersion="7"/> <application android:icon="@drawable/square_my_logo" android:label="@string/app_name"> <activity android:label="@string/app_name" android:name="com.my.InfoActivity" android:screenOrientation="landscape"></activity> <activity android:label="@string/app_name" android:name="com.my2.KickStart" android:screenOrientation="landscape"/> <activity android:label="@string/app_name" android:name="com.my2.Launcher" android:screenOrientation="landscape"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> </application> <uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/></manifest> starting the com.my2.Launcher from the adb shell

  Read the article

• Null Pointer Exception in Primavera P6 8.1

  - by gwrichard

  I am getting a null pointer exception in a Primavera P6 8.1 installation. The exception only occurs in one section of the web-client: Application settings.P6 web and the P6 API are deployed on the same WebLogic (10.3.5) node running on a Windows Server 2008 R2 installation. I have done this installation using this same software stack a dozen times and don't have this issue on any of the other installs. Exact error below: Match: beginTraversal Match: digest selected JREDesc: JREDesc[version 1.6.0_20+, heap=-1--1, args=null, href=http://java.sun.com/products/autodl/j2se, sel=false, null, null], JREInfo: JREInfo for index 0: platform is: 1.7 product is: 1.7.0_17 location is: http://java.sun.com/products/autodl/j2se path is: C:\Program Files (x86)\Java\jre7\bin\javaw.exe args is: null native platform is: Windows, x86 [ x86, 32bit ] JavaFX runtime is: JavaFX 2.2.7 found at C:\Program Files (x86)\Java\jre7\ enabled is: true registered is: true system is: true Match: ignoring maxHeap: -1 Match: ignoring InitHeap: -1 Match: digesting vmargs: null Match: digested vmargs: [JVMParameters: isSecure: true, args: ] Match: JVM args after accumulation: [JVMParameters: isSecure: true, args: ] Match: digest LaunchDesc: http://localhost:7001/p6/action/jnlp/appletsjnlp.jnlp?mainClass=com.primavera.pvapplets.adminpreferences.AdminPreferencesApplet&classPath=adminpreferences.jar,prm-applets-common.jar,forms-1.0.7.jar,prm-guisupport.jar,prm-to.jar,jide.jar,tablesupport.jar,formsupport.jar,applets-bo.jar,commons-lang.jar,prm-common.jar,resource_strings.jar,prm-img.jar,commons-logging.jar&name=AdminPreferences&version=8.1.2.0.0602 Match: digest properties: [] Match: JVM args: [JVMParameters: isSecure: true, args: ] Match: endTraversal .. Match: JVM args final: Match: Running JREInfo Version match: 1.7.0.17 == 1.7.0.17 Match: Running JVM args match: have:<> satisfy want:<> Java Plug-in 10.17.2.02 Using JRE version 1.7.0_17-b02 Java HotSpot(TM) Client VM User home directory = C:\Users\gwrichard ---------------------------------------------------- c: clear console window f: finalize objects on finalization queue g: garbage collect h: display this help message l: dump classloader list m: print memory usage o: trigger logging q: hide console r: reload policy configuration s: dump system and deployment properties t: dump thread list v: dump thread stack x: clear classloader cache 0-5: set trace level to <n> ----------------------------------------------------

  Read the article

• Constructor and Destructors in C++ [Not a question] [closed]

  - by Jack

  I am using gcc. Please tell me if I am wrong - Lets say I have two classes A & B class A { public: A(){cout<<"A constructor"<<endl;} ~A(){cout<<"A destructor"<<endl;} }; class B:public A { public: B(){cout<<"B constructor"<<endl;} ~B(){cout<<"B destructor"<<endl;} }; 1) The first line in B's constructor should be a call to A's constructor ( I assume compiler automatically inserts it). Also the last line in B's destructor will be a call to A's destructor (compiler does it again). Why was it built this way? 2) When I say A * a = new B(); compiler creates a new B object and checks to see if A is a base class of B and if it is it allows 'a' to point to the newly created object. I guess that is why we don't need any virtual constructors. ( with help from @Tyler McHenry , @Konrad Rudolph) 3) When I write delete a compiler sees that a is an object of type A so it calls A's destructor leading to a problem which is solved by making A's destructor virtual. As user - Little Bobby Tables pointed out to me all destructors have the same name destroy() in memory so we can implement virtual destructors and now the call is made to B's destructor and all is well in C++ land. Please comment.

  Read the article

• SIGABRT on iPhone when changing xib

  - by Boz

  I've just finished off an app for the iPhone which, until today, ran fine on the iPhone simulator and actual devices. I tried changing the xib which is loaded in the applicationDidFinishLaunching method in my application delegate class - all I did was change the string in initWithNibName. When I launch the app on the simulator, the Default.png image is shown, then the app crashes with an uncaught exception. When running on a device, the Default.png image is shown for about 10 seconds, the UI is never loaded and I get 'GDB: Program received signal: "SIGABRT".' on the Xcode status bar. Debugging shows that applicationDidFinishLaunching is never actually reached before the app crashes. Setting the starting xib back to the original solves the issue, but now I've made a change and saved it in the Interface Builder and the app shows the same issues as above - I've made no code changes at all. Is this a memory issue, or a known issue of a common mistake? NOTE: I've made no code changes whatsoever, and the only changes I've made to the xib are cosmetic, the IBOutlets are all intact.

  Read the article

• Very slow guards in my monadic random implementation (haskell)

  - by danpriduha

  Hi! I was tried to write one random number generator implementation, based on number class. I also add there Monad and MonadPlus instance. What mean "MonadPlus" and why I add this instance? Because of I want to use guards like here: -- test.hs -- import RandomMonad import Control.Monad import System.Random x = Rand (randomR (1 ::Integer, 3)) ::Rand StdGen Integer y = do a <-x guard (a /=2) guard (a /=1) return a here comes RandomMonad.hs file contents: -- RandomMonad.hs -- module RandomMonad where import Control.Monad import System.Random import Data.List data RandomGen g => Rand g a = Rand (g ->(a,g)) | RandZero instance (Show g, RandomGen g) => Monad (Rand g) where return x = Rand (\g ->(x,g)) (RandZero)>>= _ = RandZero (Rand argTransformer)>>=(parametricRandom) = Rand funTransformer where funTransformer g | isZero x = funTransformer g1 | otherwise = (getRandom x g1,getGen x g1) where x = parametricRandom val (val,g1) = argTransformer g isZero RandZero = True isZero _ = False instance (Show g, RandomGen g) => MonadPlus (Rand g) where mzero = RandZero RandZero `mplus` x = x x `mplus` RandZero = x x `mplus` y = x getRandom :: RandomGen g => Rand g a ->g ->a getRandom (Rand f) g = (fst (f g)) getGen :: RandomGen g => Rand g a ->g -> g getGen (Rand f) g = snd (f g) when I run ghci interpreter, and give following command getRandom y (mkStdGen 2000000000) I can see memory overflow on my computer (1G). It's not expected, and if I delete one guard, it works very fast. Why in this case it works too slow? What I do wrong?

  Read the article

• When do instance variables get initialized and values assigned?

  - by AKh

  When doees the instance variable get initialized? Is it after the constructor block is done or before it? Consider this example: public abstract class Parent { public Parent(){ System.out.println("Parent Constructor"); init(); } public void init(){ System.out.println("parent Init()"); } } public class Child extends Parent { private Integer attribute1; private Integer attribute2 = null; public Child(){ super(); System.out.println("Child Constructor"); } public void init(){ System.out.println("Child init()"); super.init(); attribute1 = new Integer(100); attribute2 = new Integer(200); } public void print(){ System.out.println("attribute 1 : " +attribute1); System.out.println("attribute 2 : " +attribute2); } } public class Tester { public static void main(String[] args) { Parent c = new Child(); ((Child)c).print(); } } OUTPUT: Parent Constructor Child init() parent Init() Child Constructor attribute 1 : 100 attribute 2 : null When the memory for the atribute 1 & 2 are allocated in the heap ? Curious to know why is attribute 2 is NULL ? Are there any design flaws?

  Read the article

• ExpertPDF and Caching of URLs

  - by Josh

  We are using ExpertPDF to take URLs and turn them into PDFs. Everything we do is through memory, so we build up the request and then read the stream into ExpertPDF and then write the bits to file. All the files we have been requesting so far are just plain HTML documents. Our designers update CSS files or change the HTML and rerequest the documents as PDFs, but often times, things are getting cached. Take, for example, if I rename the only CSS file and view the HTML page through a web browser, the page looks broke because the CSS doesn't exist. But if I request that page through the PDF Generator, it still looks ok, which means somewhere the CSS is cached. Here's the relevant PDF creation code: // Create a request HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); request.UserAgent = "IE 8.0"; request.ContentType = "application/x-www-form-urlencoded"; request.Method = "GET"; // Send the request HttpWebResponse resp = (HttpWebResponse)request.GetResponse(); if (resp.IsFromCache) { System.Web.HttpContext.Current.Trace.Write("FROM THE CACHE!!!"); } else { System.Web.HttpContext.Current.Trace.Write("not from cache"); } // Read the response pdf.SavePdfFromHtmlStream(resp.GetResponseStream(), System.Text.Encoding.UTF8, "Output.pdf"); When I check the trace file, nothing is being loaded from cache. I checked the IIS log file and found a 200 response coming from the request, even after a file had been updated (I would expect a 302). We've tried putting the No-Cache attribute on all HTML pages, but still no luck. I even turned off all caching at the IIS level. Is there anything in ExpertPDF that might be caching somewhere or something I can do to the request object to do a hard refresh of all resources? UPDATE I put ?foo at the end of my style href links and this updates the CSS everytime. Is there a setting someplace that can prevent stylesheets from being cached so I don't have to do this inelegant solution?

  Read the article

• java GC periodically enters into several full GC cycles

  - by Peter

  Environment: sun JDK 1.6.0_16 vm settings: -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -Xms1024 -Xmx1024M -XX:MaxNewSize=448m -XX:NewSize=448m -XX:SurvivorRatio=4(6 also checked) -XX:MaxPermSize=128M OS: windows server 2003 processor: 4 cores of INTEL XEON 5130, 2000 Hz my application description: high intensity of concurrent(java 5 concurrency used) operations completed each time by commit to oracle. it's about 20-30 threads run non stop, doing tasks. application runs in JBOSS web container. My GC starts work normally, I see a lot of small GCs and all that time CPU shows good load, like all 4 cores loaded to 40-50%, CPU graph is stable. Then , after 1 min of good work, CPU starts drop to 0% on 2 cores from 4, it's graph becomes unstable, goes up and down("teeth"). I see, that my threads work slower(I have monitoring), I see that GC starts produce a lot of FULL GC during that time and next 4-5 minutes this situation remains as is, then for short period of time, like 1 minute, it gets back to normal situation, but shortly after that all bad thing repeats. Question: Why I have so frequent full GC??? How to prevent that? I played with SurvivorRatio - does not help. I noticed, that application behaves normally until first FULL GC occurs, while I have enough memory. Then it runs badly. my GC LOG: starts good then long period of FULL GCs(many of them) 1027.861: [GC 942200K-623526K(991232K), 0.0887588 secs] 1029.333: [GC 803279K(991232K), 0.0927470 secs] 1030.551: [GC 967485K-625549K(991232K), 0.0823024 secs] 1030.634: [GC 625957K(991232K), 0.0763656 secs] 1033.126: [GC 969613K-632963K(991232K), 0.0850611 secs] 1033.281: [GC 649899K(991232K), 0.0378358 secs] 1035.910: [GC 813948K(991232K), 0.3540375 secs] 1037.994: [GC 967729K-637198K(991232K), 0.0826042 secs] 1038.435: [GC 710309K(991232K), 0.1370703 secs] 1039.665: [GC 980494K-972462K(991232K), 0.6398589 secs] 1040.306: [Full GC 972462K-619643K(991232K), 3.7780597 secs] 1044.093: [GC 620103K(991232K), 0.0695221 secs] 1047.870: [Full GC 991231K-626514K(991232K), 3.8732457 secs] 1053.739: [GC 942140K(991232K), 0.5410483 secs] 1056.343: [Full GC 991232K-634157K(991232K), 3.9071443 secs] 1061.257: [GC 786274K(991232K), 0.3106603 secs] 1065.229: [Full GC 991232K-641617K(991232K), 3.9565638 secs] 1071.192: [GC 945999K(991232K), 0.5401515 secs] 1073.793: [Full GC 991231K-648045K(991232K), 3.9627814 secs] 1079.754: [GC 936641K(991232K), 0.5321197 secs]

  Read the article

• activemessaging with stomp and activemq.prefetchSize=1

  - by Clint Miller

  I have a situation where I have a single activemq broker with 2 queues, Q1 and Q2. I have two ruby-based consumers using activemessaging. Let's call them C1 and C2. Both consumers subscribe to each queue. I'm setting activemq.prefetchSize=1 when subscribing to each queue. I'm also setting ack=client. Consider the following sequence of events: 1) A message that triggers a long-running job is published to queue Q1. Call this M1. 2) M1 is dispatched to consumer C1, kicking off a long operation. 3) Two messages that trigger short jobs are published to queue Q2. Call these M2 and M3. 4) M2 is dispatched to C2 which quickly runs the short job. 5) M3 is dispatched to C1, even though C1 is still running M1. It's able to dispatch to C1 because prefetchSize=1 is set on the queue subscription, not on the connection. So the fact that a Q1 message has already been dispatched doesn't stop one Q2 message from being dispatched. Since activemessaging consumers are single-threaded, the net result is that M3 sits and waits on C1 for a long time until C1 finishes processing M1. So, M3 is not processed for a long time, despite the fact that consumer C2 is sitting idle (since it quickly finishes with message M2). Essentially, whenever a long Q1 job is run and then a whole bunch of short Q2 jobs are created, exactly one of the short Q2 jobs gets stuck on a consumer waiting for the long Q1 job to finish. Is there a way to set prefetchSize at the connection level rather than at the subscription level? I really don't want any messages dispatched to C1 while it is processing M1. The other alternative is that I could create a consumer dedicated to processing Q1 and then have other consumers dedicated to processing Q2. But, I'd rather not do that since Q1 messages are infrequent--Q1's dedicated consumers would sit idle most of the day tying up memory.

  Read the article

• Pump Messages During Long Operations + C# (it is urgent)

  - by Newbie

  Hi I have a web service that is doing huge computation and is taking more than a minute. I have generated the proxy file of the web service and then from my client end I am using the dll(of course I generated the proxy dll). My client side code is TimeSeries3D t = new TimeSeries3D(); int portfolioId = 4387919; string[] str = new string[2]; str[0] = "MKT_CAP"; DateRange dr = new DateRange(); dr.mStartDate = DateTime.Today; dr.mEndDate = DateTime.Today; Service1 sc = new Service1(); t = sc.GetAttributesForPortfolio(portfolioId, true, str, dr); But since it is taking to much time for the server to compute, after 1 minute I am receiving an error message The CLR has been unable to transition from COM context 0x33caf30 to COM context 0x33cb0a0 for 60 seconds. The thread that owns the destination context/apartment is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages. This situation generally has a negative performance impact and may even lead to the application becoming non responsive or memory usage accumulating continually over time. To avoid this problem, all single threaded apartment (STA) threads should use pumping wait primitives (such as CoWaitForMultipleHandles) and routinely pump messages during long running operations. Kindly guide me what to do? It is very urgent. Thanks

  Read the article

• Should the code being tested compile to a DLL or an executable file?

  - by uriDium

  I have a solution with two projects. One for project for the production code and another project for the unit tests. I did this as per the suggestions I got here from SO. I noticed that in the Debug Folder that it includes the production code in executable form. I used NUnit to run the tests after removing the executable and they all fail trying to find the executable. So it definitely is trying to find it. I then did a quick read to find out which is better, a DLL or an executable. It seems that an DLL is much faster as they share memory space where communication between executables is slower. Unforunately our production code needs to be an exectuable. So the unit tests will be slightly slower. I am not too worried about that. But the project does rely on code written in another library which is also in executable format at the moment. Should the projects that expose some sort of SDK rather be compiled to an DLL and then the projects that use the SDK be compiled to executable?

  Read the article

• Implementing java FixedTreadPool status listener

  - by InsertNickHere

  Hi there, it's about an application which is supposed to process (VAD, Loudness, Clipping) a lot of soundfiles (e.g. 100k). At this time, I create as many worker threads (callables) as I can put into memory, and then run all with a threadPool.invokeAll(), write results to file system, unload processed files and continue at step 1. Due to the fact it's an app with a GUI, i don't want to user to feel like the app "is not responding" while processing all soundfiles. (which it does at this time cause invokeAll is blocking). Im not sure what is a "good" way to fix this. It shall not be possible for the user to do other things while processing, but I'd like to show a progress bar like "10 of 100000 soundfiles are done". So how do I get there? Do I have to create a "watcher thread", so that every worker hold a callback on it? I'm quite new to multi threading, and don't get the idea of such a mechanisem.. If you need to know: I'm using SWT/JFace. Regards, InsertNickHere

  Read the article

• Why are references compacted inside Perl lists?

  - by parkan

  Putting a precompiled regex inside two different hashes referenced in a list: my @list = (); my $regex = qr/ABC/; push @list, { 'one' => $regex }; push @list, { 'two' => $regex }; use Data::Dumper; print Dumper(\@list); I'd expect: $VAR1 = [ { 'one' => qr/(?-xism:ABC)/ }, { 'two' => qr/(?-xism:ABC)/ } ]; But instead we get a circular reference: $VAR1 = [ { 'one' => qr/(?-xism:ABC)/ }, { 'two' => $VAR1->[0]{'one'} } ]; This will happen with indefinitely nested hash references and shallowly copied $regex. I'm assuming the basic reason is that precompiled regexes are actually references, and references inside the same list structure are compacted as an optimization (\$scalar behaves the same way). I don't entirely see the utility of doing this (presumably a reference to a reference has the same memory footprint), but maybe there's a reason based on the internal representation Is this the correct behavior? Can I stop it from happening? Aside from probably making GC more difficult, these circular structures create pretty serious headaches. For example, iterating over a list of queries that may sometimes contain the same regular expression will crash the MongoDB driver with a nasty segfault (see https://rt.cpan.org/Public/Bug/Display.html?id=58500)

  Read the article

• Silverlight Socket Constantly Returns With Empty Buffer

  - by Benny

  I am using Silverlight to interact with a proxy application that I have developed but, without the proxy sending a message to the Silverlight application, it executes the receive completed handler with an empty buffer ('\0's). Is there something I'm doing wrong? It is causing a major memory leak. this._rawBuffer = new Byte[this.BUFFER_SIZE]; SocketAsyncEventArgs receiveArgs = new SocketAsyncEventArgs(); receiveArgs.SetBuffer(_rawBuffer, 0, _rawBuffer.Length); receiveArgs.Completed += new EventHandler<SocketAsyncEventArgs>(ReceiveComplete); this._client.ReceiveAsync(receiveArgs); if (args.SocketError == SocketError.Success && args.LastOperation == SocketAsyncOperation.Receive) { // Read the current bytes from the stream buffer int bytesRecieved = this._client.ReceiveBufferSize; // If there are bytes to process else the connection is lost if (bytesRecieved > 0) { try { //Find out what we just received string messagePart = UTF8Encoding.UTF8.GetString(_rawBuffer, 0, _rawBuffer.GetLength(0)); //Take out any trailing empty characters from the message messagePart = messagePart.Replace('\0'.ToString(), ""); //Concatenate our current message with any leftovers from previous receipts string fullMessage = _theRest + messagePart; int seperator; //While the index of the seperator (LINE_END defined & initiated as private member) while ((seperator = fullMessage.IndexOf((char)Messages.MessageSeperator.Terminator)) > 0) { //Pull out the first message available (up to the seperator index string message = fullMessage.Substring(0, seperator); //Queue up our new message _messageQueue.Enqueue(message); //Take out our line end character fullMessage = fullMessage.Remove(0, seperator + 1); } //Save whatever was NOT a full message to the private variable used to store the rest _theRest = fullMessage; //Empty the queue of messages if there are any while (this._messageQueue.Count > 0) { ... } } catch (Exception e) { throw e; } // Wait for a new message if (this._isClosing != true) Receive(); } } Thanks in advance.

  Read the article

• How to call functions inside a C dll which take pointers as arguments from C#

  - by AndrejaKo

  Hi people, this is my first post here! I'm trying to make a windows forms program using C# which will use a precompiled C library. It will access a smart card and provide output from it. For the library, I have a .dll, .lib and .h and no source. In the .h file there are several structs defined. Most interesting functions of the .dll expect pointers to allocated structs as arguments. I've been calling functions inside the .dll like this: For example function EID_API int WINAPI EidStartup(int nApiVersion); would be called like this [DllImport("CelikApi.dll")]//the name of the .dll public static extern int EidStartup(int nApiVersion); Now my problem is that I can't find equivalent of C's pointers which point to dynamically allocated structures in memory in C#, so I don't know what to pass as argument to functions which take C pointers. I don't have much experience in C#, but to me its use looked as the easiest way of making the program I need. I tried with C++, but Visual Studio 2010 doesn't have IntelliSense for C++/CLR. If you can point me to something better, feel free to do so.

  Read the article

• C# creating a Class, having objects as member variables? I think the objects are garbage collecte

  - by Bryan

  So I have a class that has the following member variables. I have get and set functions for every piece of data in this class. public class NavigationMesh { public Vector3 node; int weight; bool isWall; bool hasTreasure; public NavigationMesh(int x, int y, int z, bool setWall, bool setTreasure) { //default constructor //Console.WriteLine(x + " " + y + " " + z); node = new Vector3(x, y, z); //Console.WriteLine(node.X + " " + node.Y + " " + node.Z); isWall = setWall; hasTreasure = setTreasure; weight = 1; }// end constructor public float getX() { Console.WriteLine(node.X); return node.X; } public float getY() { Console.WriteLine(node.Y); return node.Y; } public float getZ() { Console.WriteLine(node.Z); return node.Z; } public bool getWall() { return isWall; } public void setWall(bool item) { isWall = item; } public bool getTreasure() { return hasTreasure; } public void setTreasure(bool item) { hasTreasure = item; } public int getWeight() { return weight; } }// end class In another class, I have a 2-Dim array that looks like this NavigationMesh[,] mesh; mesh = new NavigationMesh[502,502]; I use a double for loop to assign this, my problem is I cannot get the data I need out of the Vector3 node object after I create this object in my array with my "getters". I've tried making the Vector3 a static variable, however I think it refers to the last instance of the object. How do I keep all of these object in memory? I think there being garbage collected. Any thoughts?

  Read the article

• C/C++: feedback in analyzing a code example

  - by KaiserJohaan

  Hello, I have a piece of code from an assignment I am uncertain about. I feel confident that I know the answer, but I just want to double-check with the community incase there's something I forgot. The title is basically secure coding and the question is just to explain the results. int main() { unsigned int i = 1; unsigned int c = 1; while (i > 0) { i = i*2; c++; } printf("%d\n", c); return 0; } My reasoning is this: At first glance you could imagine the code would run forever, considering it's initialized to a positive value and ever increasing. This of course is wrong because eventually the value will grow so large it will cause an integer overflow. This in turn is not entirely true either, because eventally it will force the variable 'i' to be signed by making the last bit to 1 and therefore regarded as a negative number, therefore terminating the loop. So it is not writing to unallocated memory and therefore cause integer overflow, but rather violating the data type and therefore causing the loop to terminate. I am quite sure this is the reason, but I just want to double check. Any opinions?

  Read the article

• smallest mysql type that accomodates single decimal

  - by donpal

  Database newbie here. I'm setting up a mysql table. One of the fields will accept a value in increment of a 0.5. e.g. 0.5, 1.0, 1.5, 2.0, .... 200.5, etc. I've tried int but it doesn't capture the decimals. `value` int(10), What would be the smallest type that can accommodate this value, considering it's only a single decimal. I also was considering that because the decimal will always be 0.5 if at all, I could store it in a separate boolean field? So I would have 2 fields instead. Is this a stupid or somewhat over complicated idea? I don't know if it really saves me any memory, and it might get slower now that I'm accessing 2 fields instead of 1 `value` int(10), `half` bool, //or something similar to boolean What are your suggestions guys? Is the first option better, and what's the smallest data type in that case that would get me the 0.5?

  Read the article

< Previous Page | 590 591 592 593 594 595 596 597 598 599 600 601  | Next Page >