Search Results

Search found 1138 results on 46 pages for 'venerable garbage collector'.

Page 7/46 | < Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >

  • Email Collector / Implementation

    - by Tian
    I am implementing a simple RoR webpage that collect emails from visitors and store them as objects. I'm using it as a mini-project to try RoR and BDD. I can think of 3 features for Cucumber: 1. User submits a valid email address 2. User submits an existing email address 3. User submits an invalid email My question is, for scenarios 2 and 3, is it better to handle this via the controller? or as methods in a class? Perhaps something that throws errors if an instance is instantiated in sceanrio 2 or 3? Implementation is below, love to hear some code reviews in addition to answers to questions above. Thanks! MODEL: class Contact < ActiveRecord::Base attr_accessor :email end VIEW: <h1>Welcome To My Experiment</h1> <p>Find me in app/views/welcome/index.html.erb</p> <%= flash[:notice] %> <% form_for @contact, :url => {:action => "index"} do |f| %> <%= f.label :email %><br /> <%= f.text_field :email %> <%= submit_tag 'Submit' %> <% end %> CONTROLLER: class WelcomeController < ApplicationController def index @contact = Contact.new unless params[:contact].nil? @contact = Contact.create!(params[:contact]) flash[:notice] = "Thank you for your interest, please check your mailbox for confirmation" end end end

    Read the article

  • AS3: Weak Listener References Not Appropriate During Initialization?

    - by TheDarkIn1978
    as i currently understand, if an event listener is added to an object with useWeakReference set to true, then it is eligible for garbage collection and will be removed if and when the garbage collection does a sweep. public function myCustomSpriteClass() //constructor { this.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownListener, false, 0, true); this.addEventListener(MouseEvent.MOUSE_UP, mouseUpListener, false, 0, true); } in this case, is it not appropriate to initialize an object with weak references event listeners, incase the garbage collector does activate a sweep removing the objects event listeners since they were added during initialization of the object? in this case, would it only be appropriate to create a type of deallocate() method which removes the event listeners before the object is nullified?

    Read the article

  • Lifetime of javacript variables.

    - by The Machine
    What is the lifetime of a variable in javascript, declared with "var". I am sure, it is definitely not according to expectation. <script> function(){ var a; var fun=function(){ // a is accessed and modified } }(); </script> Here how and when does javascript garbage collect the variable a? Since 'a' is a part of the closure of the inner function, it ideally should never get garbage collected, since the inner function 'fun', may be passed as a reference to an external context.So 'fun' should still be able to access 'a', from the external context. If my understanding is correct, how does garbage collection happen then, and how does it ensure to have enough memory space, since keeping all variables in memory until the execution of the program might not be tenable ?

    Read the article

  • Are spinlocks a good choice for a memory allocator?

    - by dsimcha
    I've suggested to the maintainers of the D programming language runtime a few times that the memory allocator/garbage collector should use spinlocks instead of regular OS critical sections. This hasn't really caught on. Here are the reasons I think spinlocks would be better: At least in synthetic benchmarks that I did, it's several times faster than OS critical sections when there's contention for the memory allocator/GC lock. Edit: Empirically, using spinlocks didn't even have measurable overhead in a single-core environment, probably because locks need to be held for such a short period of time in a memory allocator. Memory allocations and similar operations usually take a small fraction of a timeslice, and even a small fraction of the time a context switch takes, making it silly to context switch in the case of contention. A garbage collection in the implementation in question stops the world anyhow. There won't be any spinning during a collection. Are there any good reasons not to use spinlocks in a memory allocator/garbage collector implementation?

    Read the article

  • C file read leaves garbage characters

    - by KJ
    Hi. I'm trying to read the contents of a file into my program but I keep occasionally getting garbage characters at the end of the buffers. I haven't been using C a lot (rather I've been using C++) but I assume it has something to do with streams. I don't really know what to do though. I'm using MinGW. Here is the code (this gives me garbage at the end of the second read): include include char* filetobuf(char *file) { FILE *fptr; long length; char *buf; fptr = fopen(file, "r"); /* Open file for reading */ if (!fptr) /* Return NULL on failure */ return NULL; fseek(fptr, 0, SEEK_END); /* Seek to the end of the file */ length = ftell(fptr); /* Find out how many bytes into the file we are */ buf = (char*)malloc(length+1); /* Allocate a buffer for the entire length of the file and a null terminator */ fseek(fptr, 0, SEEK_SET); /* Go back to the beginning of the file */ fread(buf, length, 1, fptr); /* Read the contents of the file in to the buffer */ fclose(fptr); /* Close the file */ buf[length] = 0; /* Null terminator */ return buf; /* Return the buffer */ } int main() { char* vs; char* fs; vs = filetobuf("testshader.vs"); fs = filetobuf("testshader.fs"); printf("%s\n\n\n%s", vs, fs); free(vs); free(fs); return 0; } The filetobuf function is from this example http://www.opengl.org/wiki/Tutorial2:_VAOs,_VBOs,_Vertex_and_Fragment_Shaders_%28C_/_SDL%29. It seems right to me though. So anyway, what's up with that?

    Read the article

  • Proper use of the IDisposable interface

    - by cwick
    I know from reading the MSDN documentation that the "primary" use of the IDisposable interface is to clean up unmanaged resources http://msdn.microsoft.com/en-us/library/system.idisposable.aspx. To me, "unmanaged" means things like database connections, sockets, window handles, etc. But, I've seen code where the Dispose method is implemented to free managed resources, which seems redundant to me, since the garbage collector should take care of that for you. For example: public class MyCollection : IDisposable { private List<String> _theList = new List<String>(); private Dictionary<String, Point> _theDict = new Dictionary<String, Point>(); // Die, you gravy sucking pig dog! public void Dispose() { _theList.clear(); _theDict.clear(); _theList = null; _theDict = null; } My question is, does this make the garbage collector free memory used by MyCollection any faster than it normally would? edit: So far people have posted some good examples of using IDisposable to clean up unmanaged resources such as database connections and bitmaps. But suppose that _theList in the above code contained a million strings, and you wanted to free that memory now, rather than waiting for the garbage collector. Would the above code accomplish that?

    Read the article

  • How to keep track of objects for garbage collection

    - by Yman
    May I know what is the proper way to keep track of display objects created and hence allow me to remove it efficiently later, for garbage collection. For example: for(i=0; i<100; i++){ var dobj = new myClass(); //a sprite addChild(dobj); } From what i know, flash's garbage collection will only collect the objects without strong references and event listeners attached to it. Since the var dobj is strongly referenced to the new object created, I will have to "nullify" it too, am I correct? Should I create an array to keep track of all the objects created in the loop such as: var objectList:Array = new Array(); for(i=0; i<100; i++) { var dobj = new myClass(); //a sprite addChild(dobj); objectList.push(dobj); } //remove all children for each (var key in objectList) { removeChild(key as myClass); } Does this allow GC to collect it on sweep?

    Read the article

  • C++ class with char pointers returning garbage

    - by JMP
    I created a class "Entry" to handle Dictionary entries, but in my main(), I create the Entry() and try to cout the char typed public members, but I get garbage. When I look at the Watch list in debugger, I see the values being set, but as soon as I access the values, there is garbage. Can anyone elaborate on what I might be missing? #include <iostream> using namespace std; class Entry { public: Entry(const char *line); char *Word; char *Definition; }; Entry::Entry(const char *line) { char tmp[100]; strcpy(tmp, line); Word = strtok(tmp, ",") + '\0'; Definition = strtok(0,",") + '\0'; } int main() { Entry *e = new Entry("drink,What you need after a long day's work"); cout << "Word: " << e->Word << endl; cout << "Def: " << e->Definition << endl; cout << endl; delete e; e = 0; return 0; }

    Read the article

  • JAVA_OPTS -XX:+PrintGCDetails affect on performance?

    - by brad
    Does anyone know if the PrintGCDetails affects java performance much? I've been monitoring our java garbage collecting on a staging server with the same setup as the production server. I assumed it was safe to say that I shouldn't have this enabled on production but I don't know if there's really any affect on performance.

    Read the article

  • Rpm removal does not remove delivered dirs and leaves garbage

    - by Jim
    I deliver an application via an RPM. This application delivers various directories and files. E.g. under /opt/internal/com a file structure is being copied. I was expecting that on rpm -e all the file structure delivered under /opt/internal/com will be removed. But it does not. There are directories in the file structure that are non-empty. Is this the reason? But these (non-empty) directories were created by the RPM installation. So I would expect that they would be "owned" by RPM and removed automatically. Is this wrong? Am I supposed to remove them manually?

    Read the article

  • Printer irregularly producing garbage output

    - by John Gardeniers
    Every now and then instead of getting the proper output we get numerous pages, mostly with just a single line, of output which appears to be the raw PCL. My theory is that this happens when the first byte or two of the document is somehow not received by the printer, which then doesn't know how to interpret the rest and does it's best by spitting it out as text. This is a problem I've seen many times over the years but has been popping up more often since we upgraded to Win 7 64 bit, which introduced a number of headaches because of the HP lack of real support for 64 bits. It also appears to happen most often when printing PDF files. We have tried several different PDF readers in addition to Adobe's own but that hasn't helped. While we mainly use HP printers, and the problem is not limited to any particular model, I've also seen it happen on other brands, albeit to a lesser extent. I've also been unable to discern a difference between printers used via a print server or those connected directly by IP address. It also happens to USB attached printers. Because of the erratic nature of this problem there is precious little I can think of to try and debug it, so I'm after any ideas that might help to eliminate it.

    Read the article

  • Sun permgen & JRockit garbage collection

    - by Striker
    In the Sun JVM, classes that are loaded by the class loader are put in permgen space and never gc'd. (Unless the class loader goes out of scope) It's my understanding that JRockit puts that same data on the heap instead. Is that data then subject to garbage collection? Thanks.

    Read the article

  • file output in python giving me garbage

    - by Richard
    When I write the following code I get garbage for an output. It is just a simple program to find prime numbers. It works when the first for loops range only goes up to 1000 but once the range becomes large the program fail's to output meaningful data output = open("output.dat", 'w') for i in range(2, 10000): prime = 1 for j in range(2, i-1): if i%j == 0: prime = 0 j = i-1 if prime == 1: output.write(str(i) + " " ) output.close() print "writing finished"

    Read the article

  • Does variable = null set it for garbage collection

    - by manyxcxi
    Help me settle a dispute with a coworker: Does setting a variable or collection to null in Java aid in garbage collection and reducing memory usage? If I have a long running program and each function may be iteratively called (potentially thousands of times): Does setting all the variables in it to null before returning a value to the parent function help reduce heap size/memory usage?

    Read the article

  • Tuning garbage collections for low latency

    - by elec
    I'm looking for arguments as to how best to size the young generation (with respect to the old generation) in an environment where low latency is critical. My own testing tends to show that latency is lowest when the young generation is fairly large (eg. -XX:NewRatio <3), however I cannot reconcile this with the intuition that the larger the young generation the more time it should take to garbage collect. The application runs on linux, jdk 6 before update 14, i.e G1 not available.

    Read the article

  • How does the CLR (.NET) internally allocate and pass around custom value types (structs)?

    - by stakx
    Question: Do all CLR value types, including user-defined structs, live on the evaluation stack exclusively, meaning that they will never need to be reclaimed by the garbage-collector, or are there cases where they are garbage-collected? Background: I have previously asked a question on SO about the impact that a fluent interface has on the runtime performance of a .NET application. I was particuarly worried that creating a large number of very short-lived temporary objects would negatively affect runtime performance through more frequent garbage-collection. Now it has occured to me that if I declared those temporary objects' types as struct (ie. as user-defined value types) instead of class, the garbage collector might not be involved at all if it turns out that all value types live exclusively on the evaluation stack. What I've found out so far: I did a brief experiment to see what the differences are in the CIL generated for user-defined value types and reference types. This is my C# code: struct SomeValueType { public int X; } class SomeReferenceType { public int X; } . . static void TryValueType(SomeValueType vt) { ... } static void TryReferenceType(SomeReferenceType rt) { ... } . . var vt = new SomeValueType { X = 1 }; var rt = new SomeReferenceType { X = 2 }; TryValueType(vt); TryReferenceType(rt); And this is the CIL generated for the last four lines of code: .locals init ( [0] valuetype SomeValueType vt, [1] class SomeReferenceType rt, [2] valuetype SomeValueType <>g__initLocal0, // [3] class SomeReferenceType <>g__initLocal1, // why are these generated? [4] valuetype SomeValueType CS$0$0000 // ) L_0000: ldloca.s CS$0$0000 L_0002: initobj SomeValueType // no newobj required, instance already allocated L_0008: ldloc.s CS$0$0000 L_000a: stloc.2 L_000b: ldloca.s <>g__initLocal0 L_000d: ldc.i4.1 L_000e: stfld int32 SomeValueType::X L_0013: ldloc.2 L_0014: stloc.0 L_0015: newobj instance void SomeReferenceType::.ctor() L_001a: stloc.3 L_001b: ldloc.3 L_001c: ldc.i4.2 L_001d: stfld int32 SomeReferenceType::X L_0022: ldloc.3 L_0023: stloc.1 L_0024: ldloc.0 L_0025: call void Program::TryValueType(valuetype SomeValueType) L_002a: ldloc.1 L_002b: call void Program::TryReferenceType(class SomeReferenceType) What I cannot figure out from this code is this: Where are all those local variables mentioned in the .locals block allocated? How are they allocated? How are they freed? Why are so many anonymous local variables needed and copied to-and-fro only to initialize my two local variables rt and vt?

    Read the article

  • WeakHashMap iteration and garbage collection

    - by Shamik
    I am using a WeaekHashMap to implement a Cache. I am wondering if I am iterating over the keys of this map, and at the same time garbage collector is actively removing keys from this map, would I receive a ConcurrentModificationException ? I do not think so, because as far as I understand, concurrentmodificationexception happens because of bugs in the application code where the developer forgot to understand that the same map is shared/used by other threads and in this case, it should not happen. But wondering how would JVM handle this when WeakHashMap is not synchronized ?

    Read the article

  • Automatically calling OnDetaching() for Silverlight Behaviors

    - by Dan Auclair
    I am using several Blend behaviors and triggers on a silverlight control. I am wondering if there is any mechanism for automatically detaching or ensuring that OnDetaching() is called for a behavior or trigger when the control is no longer being used (i.e. removed from the visual tree). My problem is that there is a managed memory leak with the control because of one of the behaviors. The behavior subscribes to an event on some long-lived object in the OnAttached() override and should be unsubscribing to that event in the OnDetaching() override so that it can become a candidate for garbage collection. However, OnDetaching() never seems to be getting called when I remove the control from the visual tree... the only way I can get it to happen is by explicit detaching the behavior BEFORE removing the control and then it is properly garbage collected. Right now my only solution was to create a public method in the code-behind for the control that can go through and detach any known behaviors that would cause garbage collection problems. It would be up to the client code to know to call this before removing the control from the panel. I don't really like this approach, so I am looking for some automatic way of doing this that I am overlooking or a better suggestion. public void DetachBehaviors() { foreach (var behavior in Interaction.GetBehaviors(this.LayoutRoot)) { behavior.Detach(); } //... //continue detaching all known problematic behaviors.... }

    Read the article

  • Duration of Excessive GC Time in "java.lang.OutOfMemoryError: GC overhead limit exceeded"

    - by jilles de wit
    Occasionally, somewhere between once every 2 days to once every 2 weeks, my application crashes in a seemingly random location in the code with: java.lang.OutOfMemoryError: GC overhead limit exceeded. If I google this error I come to this SO question and that lead me to this piece of sun documentation which expains: The parallel collector will throw an OutOfMemoryError if too much time is being spent in garbage collection: if more than 98% of the total time is spent in garbage collection and less than 2% of the heap is recovered, an OutOfMemoryError will be thrown. This feature is designed to prevent applications from running for an extended period of time while making little or no progress because the heap is too small. If necessary, this feature can be disabled by adding the option -XX:-UseGCOverheadLimit to the command line. Which tells me that my application is apparently spending 98% of the total time in garbage collection to recover only 2% of the heap. But 98% of what time? 98% of the entire two weeks the application has been running? 98% of the last millisecond? I'm trying to determine a best approach to actually solving this issue rather than just using -XX:-UseGCOverheadLimit but I feel a need to better understand the issue I'm solving.

    Read the article

  • Can a conforming C# compiler optimize away a local (but unused) variable if it is the only strong re

    - by stakx
    The title says it all, but let me explain: void Case_1() { var weakRef = new WeakReference(new object()); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. if (weakRef.IsAlive) ... } In this code example, I obviously have to plan for the possibility that the new'ed object is reclaimed by the garbage collector; therefore the if statement. (Note that I'm using weakRef for the sole purpose of checking if the new'ed object is still around.) void Case_2() { var unusedLocalVar = new object(); var weakRef = new WeakReference(unusedLocalVar); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. Debug.Assert(weakReferenceToUseless.IsAlive); } The main change in this code example from the previous one is that the new'ed object is strongly referenced by a local variable (unusedLocalVar). However, this variable is never used again after the weak reference (weakRef) has been created. Question: Is a conforming C# compiler allowed to optimize the first two lines of Case_2 into those of Case_1 if it sees that unusedLocalVar is only used in one place, namely as an argument to the WeakReference constructor? i.e. is there any possibility that the assertion in Case_2 could ever fail?

    Read the article

  • How to get strptime to raise ArgumentError with garbage trailing characters

    - by Matt Briggs
    We have to handle user specified date formats in our application. We decided to go with Date.strptime for parsing and validation, which works great, except for how it just ignores any garbage data entered. Here is an irb session demonstrating the issue ree-1.8.7-2010.01 > require 'date' => true ree-1.8.7-2010.01 > d = Date.strptime '2001-01-01failfailfail', '%Y-%m-%d' => #<Date: 4903821/2,0,2299161> ree-1.8.7-2010.01 > d.to_s => "2001-01-01" what we would like, is behavior more like this ree-1.8.7-2010.01 > d = Date.strptime '2001failfailfail-01-01', '%Y-%m-%d' ArgumentError: invalid date Any suggestions would be appreciated

    Read the article

  • Java - Circular Garbage Collection

    - by aloh
    A <- B <- C <- D <- A... // A is firstNode, D is lastNode if ( length == 1 ) { firstNode = null; lastNode = null; firstNode.next = null; firstNode.prev = null; } else { Node secondNode = firstNode.next; Node secondToLast = lastNode.prev; firstNode.next = null; firstNode.prev = null; lastNode.next = null; lastNode.prev = null; secondNode.prev = null; secondToLast.next = null; firstNode = null; lastNode = null; } That should send everything in between as candidates for garbage collection, I hope?

    Read the article

  • C# Async call garbage collection

    - by Troy
    Hello. I am working on a Silverlight/WCF application and of course have numerous async calls throughout the Silverlight program. I was wondering on how is the best way to handle the creation of the client classes and subscribing. Specifically, if I subscribe to an event in a method, after it returns does it fall out of scope? internal MyClass { public void OnMyButtonClicked() { var wcfClient = new WcfClient(); wcfClient.SomeMethodFinished += OnMethodCompleted; wcfClient.SomeMethodAsync(); } private void OnMethodCompleted(object sender, EventArgs args) { //Do something with the result //After this method does the subscription to the event //fall out of scope for garbage collection? } } Will I run into problems if I call the function again and create another subscription? Thanks in advance to anyone who responds.

    Read the article

< Previous Page | 3 4 5 6 7 8 9 10 11 12 13 14  | Next Page >