Search Results

Search found 21089 results on 844 pages for 'virtual memory'.

Page 202/844 | < Previous Page | 198 199 200 201 202 203 204 205 206 207 208 209  | Next Page >

  • Where is the VM in LLVM?

    - by anon
    Note: marked as community wiki. Where is the Low Level Virtual Machine in LLVM? I see that we have llvm-g++ and c-lang, but to me, a LLVM is something almost like Valgrind of a simulator, where instructions are executed on it, and I can write programs to instrument the running code / interrupt when certain conditions happen / etc ... Where are the tools like this built on LLVM? Thanks!

    Read the article

  • How to make Flash 'play well with others'?

    - by Sensei James
    What up fam. So this isn't a question asking about memory management schemes; for those of you who may not know, the Flash Virtual Machine relies on garbage collection by using reference counting and mark and sweep (for good coverage of these topics, check out Grant Skinner's article and presentation). And yes, Flash also provides the "delete" operator, which can (unfortunately only) be used to remove the properties of dynamic objects. What I want to know is how to make it so that Flash programs don't continue to consume CPU and memory while running in the background (save loading content or communicating remotely, for example). The motivation for this question comes in part from Apple's ban on cross compiled applications (in its SDK 4) on the grounds that they do not behave as predicted with the multitasking feature central to iPhone OS 4. My intention is not only to make Flash programs that will 'pass muster' as far as multitasking in iPhone OS 4, but also to simply make better (behaving) Flash programs. Put another way, how might a Flash application mimic the multitasking feature of iPhone OS 4? Does the Flash API provide the means for a developer to put their applications to 'sleep' while other programs run, and then to 'awaken' them just as quickly? In our own program, we might do something as crude as detecting when the user has been idle (no mouse motion or key press) for (say) four seconds: var idle_id:uint = setInterval(4000, pause_program); var current_movie_clip:MovieClip; var current_frame:uint; ... // on Mouse move or key press... clearInterval(idle_id); idle_id = setInterval(4000, pause_program); ... function pause_program():void { current_movie_clip = event.target as MovieClip; current_frame = current_movie_clip.currentFrame; MovieClip(root).gotoAndStop("program_pause_screen"); } (on the program pause screen) resume_button.addEventListener(MouseEvent.CLICK, resume_program); function resume_program(event:MouseEvent) { current_movie_clip.gotoAndPlay(current_frame); } If that's the right idea, what's the best way to detect that an application should be shelved? And, more importantly, is it possible for Flash Player to detect that some of its running programs are idle, and to similarly shelve them until the user performs an action to resume them? (Please feel free to answer as much or as little of the many questions I've posed.)

    Read the article

  • How efficient is Python substring extraction?

    - by Cameron
    I've got the entire contents of a text file (at least a few KB) in string myStr. Will the following code create a copy of the string (less the first character) in memory? myStr = myStr[1:] I'm hoping it just refers to a different location in the same internal buffer. If not, is there a more efficient way to do this? Thanks! Note: I'm using Python 2.5.

    Read the article

  • Decompressing a very large serialized object and managing memory

    - by Mike_G
    I have an object that contains tons of data used for reports. In order to get this object from the server to the client I first serialize the object in a memory stream, then compress it using the Gzip stream of .NET. I then send the compressed object as a byte[] to the client. The problem is on some clients, when they get the byte[] and try to decompress and deserialize the object, a System.OutOfMemory exception is thrown. Ive read that this exception can be caused by new() a bunch of objects, or holding on to a bunch of strings. Both of these are happening during the deserialization process. So my question is: How do I prevent the exception (any good strategies)? The client needs all of the data, and ive trimmed down the number of strings as much as i can. edit: here is the code i am using to serialize/compress (implemented as extension methods) public static byte[] SerializeObject<T>(this object obj, T serializer) where T: XmlObjectSerializer { Type t = obj.GetType(); if (!Attribute.IsDefined(t, typeof(DataContractAttribute))) return null; byte[] initialBytes; using (MemoryStream stream = new MemoryStream()) { serializer.WriteObject(stream, obj); initialBytes = stream.ToArray(); } return initialBytes; } public static byte[] CompressObject<T>(this object obj, T serializer) where T : XmlObjectSerializer { Type t = obj.GetType(); if(!Attribute.IsDefined(t, typeof(DataContractAttribute))) return null; byte[] initialBytes = obj.SerializeObject(serializer); byte[] compressedBytes; using (MemoryStream stream = new MemoryStream(initialBytes)) { using (MemoryStream output = new MemoryStream()) { using (GZipStream zipper = new GZipStream(output, CompressionMode.Compress)) { Pump(stream, zipper); } compressedBytes = output.ToArray(); } } return compressedBytes; } internal static void Pump(Stream input, Stream output) { byte[] bytes = new byte[4096]; int n; while ((n = input.Read(bytes, 0, bytes.Length)) != 0) { output.Write(bytes, 0, n); } } And here is my code for decompress/deserialize: public static T DeSerializeObject<T,TU>(this byte[] serializedObject, TU deserializer) where TU: XmlObjectSerializer { using (MemoryStream stream = new MemoryStream(serializedObject)) { return (T)deserializer.ReadObject(stream); } } public static T DecompressObject<T, TU>(this byte[] compressedBytes, TU deserializer) where TU: XmlObjectSerializer { byte[] decompressedBytes; using(MemoryStream stream = new MemoryStream(compressedBytes)) { using(MemoryStream output = new MemoryStream()) { using(GZipStream zipper = new GZipStream(stream, CompressionMode.Decompress)) { ObjectExtensions.Pump(zipper, output); } decompressedBytes = output.ToArray(); } } return decompressedBytes.DeSerializeObject<T, TU>(deserializer); } The object that I am passing is a wrapper object, it just contains all the relevant objects that hold the data. The number of objects can be a lot (depending on the reports date range), but ive seen as many as 25k strings. One thing i did forget to mention is I am using WCF, and since the inner objects are passed individually through other WCF calls, I am using the DataContract serializer, and all my objects are marked with the DataContract attribute.

    Read the article

  • Impact of Multiple .ToUpper()'ing

    - by Kyle Rozendo
    Hi All, This is not a question of premature optimization per se. On the garbage collector and memory in general, what would hundreds of ToUpper() operations (many could be duplicated) do to a program, mainly in regard to the immutability of strings? Thanks, Kyle

    Read the article

  • Abstract class reference

    - by AlgoMan
    Can i have a class Class Room{ ~Room(); virtual cost() =0; } Class Hotel{ map rooms; /* */ }; will my hotel become abstract ? Can it hold the list of concrete Room objects that are derived from Room ?

    Read the article

  • Python: How efficient is subtring extraction?

    - by Cameron
    I've got the entire contents of a text file (at least a few KB) in string myStr. Will the following code create a copy of the string (less the first character) in memory? myStr = myStr[1:] I'm hoping it just refers to a different location in the same internal buffer. If not, is there a more efficient way to do this? Thanks!

    Read the article

  • Threading in python: retrieve return value when using target=

    - by Philipp Keller
    I want to get the "free memory" of a bunch of servers like this: def get_mem(servername): res = os.popen('ssh %s "grep MemFree /proc/meminfo | sed \'s/[^0-9]//g\'"' % servername) return res.read().strip() since this can be threaded I want to do something like that: import threading thread1 = threading.Thread(target=get_mem, args=("server01", )) thread1.start() But now: how can I access the return value(s) of the get_mem functions? Do I really need to go the full fledged way creating a class MemThread(threading.Thread) and overwriting __init__ and __run__?

    Read the article

  • In C, do braces act as a stack frame?

    - by Claudiu
    If I create a variable within a new set of curly braces, is that variable popped off the stack on the closing brace, or does it hang out until the end of the function? For example: void foo() { int c[100]; { int d[200]; } //code that takes a while return; } Will d be taking up memory during the code that takes a while section?

    Read the article

  • .net 4.0 creating a MemoryMappedFile with global context throws exception

    - by Christoph
    Hi all, I want to create a global MemoryMappedFile in C# 4.0 using following call: string MemoryMappedFileName = "Global\\20E9C857-C944-4C35-B937-A5941034D073"; ioBuffer = MemoryMappedFile.CreateNew(MemoryMappedFileName, totalIoBufferSize); This always throws following exception "System.UnauthorizedAccessException: Access to the path is denied." If I remove the "Global\" identifier from the memorymapped filename it works but I need a memory mapped file existing accross terminal sessions. thanks, Christoph

    Read the article

  • Crazy interview question

    - by benjamin button
    I was asked this crazy question. I was out of my wits. Can a method in base class which is declared as virtual be called using the base class pointer which is pointing to a derived class object? Is this possible?

    Read the article

  • wx paste image into panel

    - by Moayyad Yaghi
    hello i need to find a way to copy an image from a software .. ( microsoft paint for example ) and paste it into my own pain tool that i made using wxpython .. how do i read the image that has been loaded into memory ? so i can paste it hope idea is clear enough thanks in advance

    Read the article

  • iPhone - database reading method and memory leaks

    - by Do8821
    Hi, in my application, a RSS reader, I get memory leaks that I can't fix because I can't understand from where they come from. Here is the code pointed out by Instruments. -(void) readArticlesFromDatabase { [self setDatabaseInfo]; sqlite3 *database; articles = [[NSMutableArray alloc] init]; if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { const char *sqlStatement = "select * from articles"; if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { while(sqlite3_step(compiledStatement) == SQLITE_ROW) { NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)]; NSString *aDate = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; NSString *aUrl = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)]; NSString *aCategory = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 4)]; NSString *aAuthor = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 5)]; NSString *aSummary = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 6)]; NSMutableString *aContent = [NSMutableString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 7)]; NSString *aNbrComments = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 8)]; NSString *aCommentsLink = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 9)]; NSString *aPermalink = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 11)]; [aContent replaceCharactersInRange: [aContent rangeOfString: @"http://www.mywebsite.com/img/action-on.gif"] withString: @"hellocoton-action-on.gif"]; [aContent replaceCharactersInRange: [aContent rangeOfString: @"hhttp://www.mywebsite.com/img/action-on-h.gif"] withString: @"hellocoton-action-on-h.gif"]; [aContent replaceCharactersInRange: [aContent rangeOfString: @"hthttp://www.mywebsite.com/img/hellocoton.gif"] withString: @"hellocoton-hellocoton.gif"]; NSString *imageURLBrut = [self parseArticleForImages:aContent]; NSString *imageURLCache = [imageURLBrut stringByReplacingOccurrencesOfString:@":" withString:@"_"]; imageURLCache = [imageURLCache stringByReplacingOccurrencesOfString:@"/" withString:@"_"]; imageURLCache = [imageURLCache stringByReplacingOccurrencesOfString:@" " withString:@"_"]; NSString *uniquePath = [tmp stringByAppendingPathComponent: imageURLCache]; if([[NSFileManager defaultManager] fileExistsAtPath: uniquePath]) { imageURLCache = [@"../tmp/" stringByAppendingString: imageURLCache]; [aContent replaceCharactersInRange: [aContent rangeOfString: imageURLBrut ] withString: imageURLCache]; } Article *article = [[Article alloc] initWithName:aName date:aDate url:aUrl category:aCategory author:aAuthor summary:aSummary content:aContent commentsNbr:aNbrComments commentsLink:aCommentsLink commentsRSS:@"" enclosure:aPermalink enclosure2:@"" enclosure3:@""]; [articles addObject:article]; article = nil; [article release]; } } sqlite3_finalize(compiledStatement); } sqlite3_close(database); } ` I have a lot of "Article" leaked and NSString matching with these using : [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, X)]; I tried a lot of different code I always have these leaks. Anyone has got an idea to help me?

    Read the article

  • How can a 1Gb Java heap on a 64bit machine use 3Gb of VIRT space?

    - by Graeme Moss
    I run the same process on a 32bit machine as on a 64bit machine with the same memory VM settings (-Xms1024m -Xmx1024m) and similar VM version (1.6.0_05 vs 1.6.0_16). However the virtual space used by the 64bit machine (as shown in top under "VIRT") is almost three times as big as that in 32bit! I know 64bit VMs will use a little more memory for the larger references, but how can it be three times as big? Am I reading VIRT in top incorrectly? Full data shown below, showing top and then the result of jmap -heap, first for 64bit, then for 32bit. Note the VIRT for 64bit is 3319m for 32bit is 1220m. * 64bit * PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 22534 agent 20 0 3319m 163m 14m S 4.7 2.0 0:04.28 java $ jmap -heap 22534 Attaching to process ID 22534, please wait... Debugger attached successfully. Server compiler detected. JVM version is 10.0-b19 using thread-local object allocation. Parallel GC with 4 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 2686976 (2.5625MB) MaxNewSize = -65536 (-0.0625MB) OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 21757952 (20.75MB) MaxPermSize = 88080384 (84.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 268500992 (256.0625MB) used = 247066968 (235.62142181396484MB) free = 21434024 (20.441078186035156MB) 92.01715277089181% used From Space: capacity = 44695552 (42.625MB) used = 0 (0.0MB) free = 44695552 (42.625MB) 0.0% used To Space: capacity = 44695552 (42.625MB) used = 0 (0.0MB) free = 44695552 (42.625MB) 0.0% used PS Old Generation capacity = 715849728 (682.6875MB) used = 0 (0.0MB) free = 715849728 (682.6875MB) 0.0% used PS Perm Generation capacity = 21757952 (20.75MB) used = 16153928 (15.405586242675781MB) free = 5604024 (5.344413757324219MB) 74.24378912132907% used * 32bit * PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 30168 agent 20 0 1220m 175m 12m S 0.0 2.2 0:13.43 java $ jmap -heap 30168 Attaching to process ID 30168, please wait... Debugger attached successfully. Server compiler detected. JVM version is 14.2-b01 using thread-local object allocation. Parallel GC with 8 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 1048576 (1.0MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 4194304 (4.0MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 89522176 (85.375MB) used = 80626352 (76.89128112792969MB) free = 8895824 (8.483718872070312MB) 90.0629940005033% used From Space: capacity = 14876672 (14.1875MB) used = 14876216 (14.187065124511719MB) free = 456 (4.3487548828125E-4MB) 99.99693479832048% used To Space: capacity = 14876672 (14.1875MB) used = 0 (0.0MB) free = 14876672 (14.1875MB) 0.0% used PS Old Generation capacity = 954466304 (910.25MB) used = 10598496 (10.107513427734375MB) free = 943867808 (900.1424865722656MB) 1.1104107034039412% used PS Perm Generation capacity = 16777216 (16.0MB) used = 11366448 (10.839889526367188MB) free = 5410768 (5.1601104736328125MB) 67.74930953979492% used

    Read the article

  • Serious Memory Clash: Variables clashing in C

    - by Soham
    int main(int argc, char*argv[]) { Message* newMessage; Asset* Check; //manipulation and initialization of Check, so that it holds proper values. newMessage = parser("N,2376,01/02/2011 09:15:01.342,JPASSOCIAT FUTSTK 24FEB2011,B,84.05,2000,0,0",newMessage); // MessageProcess(newMessage,AssetMap); printf("LAST TRADE ADDRESS %p LAST TRADE TIME %s\n",Check->TradeBook,Check->Time); } Message* parser(char *message,Message* new_Message) { char a[9][256]; char* tmp =message; bool inQuote=0; int counter=0; int counter2=0; new_Message = (Message*)malloc(sizeof(Message)); while(*tmp!='\0') { switch(*tmp) { case ',': if(!inQuote) { a[counter][counter2]='\0'; counter++; counter2=0; } break; case '"': inQuote=!inQuote; break; default: a[counter][counter2]=*tmp; counter2++; break; } tmp++; } a[counter][counter2]='\0'; new_Message->type = *a[0]; new_Message->Time = &a[2][11]; new_Message->asset = a[3]; if(*a[4]=='S') new_Message->BS = 0; else new_Message->BS = 1; new_Message->price1=atof(a[5]); new_Message->shares1=atol(a[6]); new_Message->price2=atof(a[7]); new_Message->shares2=atol(a[8]); new_Message->idNum = atoi(a[1]); return(new_Message); } Here there is a serious memory clash, in two variables of different scope. I have investigated using gdb and it seems the address of new_Message->Time is equalling to the address of Check->Time. They both are structures of different types I am trying to resolve this issue, because, when parser changes the value of new_Message->Time it manipulates the contents of Check-Time Please do suggest how to solve this problem. I have lost(spent) around 10 hours and counting to resolve this issue, and tons of hair. Soham

    Read the article

  • Unique_ptr compiler errors

    - by Godric Seer
    I am designing and entity-component system for a project, and C++ memory management is giving me a few issues. I just want to make sure my design is legitimate. So to start I have an Entity class which stores a vector of Components: class Entity { private: std::vector<std::unique_ptr<Component> > components; public: Entity() { }; void AddComponent(Component* component) { this -> components.push_back(std::unique_ptr<Component>(component)); } ~Entity(); }; Which if I am not mistaken means that when the destructor is called (even the default, compiler created one), the destructor for the Entity, will call ~components, which will call ~std::unique_ptr for each element in the vector, and lead to the destruction of each Component, which is what I want. The component class has virtual methods, but the important part is its constructor: Component::Component(Entity parent) { parent.addComponent(this) // I am not sure if this would work like I expect // Other things here } As long as passing this to the method works, this also does what I want. My confusion is in the factory. What I want to do is something along the lines of: std::shared_ptr<Entity> createEntity() { std::shared_ptr<Entity> entityPtr(new Entity()); new Component(*parent); // Initialize more, and other types of Components return entityPtr; } Now, I believe that this setup will leave the ownership of the Component in the hands of its Parent Entity, which is what I want. First a small question, do I need to pass the entity into the Component constructor by reference or pointer or something? If I understand C++, it would pass by value, which means it gets copied, and the copied entity would die at the end of the constructor. The second, and main question is that code based on this sample will not compile. The complete error is too large to print here, however I think I know somewhat of what is going on. The compiler's error says I can't delete an incomplete type. My Component class has a purely virtual destructor with an implementation: inline Component::~Component() { }; at the end of the header. However since the whole point is that Component is actually an interface. I know from here that a complete type is required for unique_ptr destruction. The question is, how do I work around this? For reference I am using gcc 4.4.6.

    Read the article

< Previous Page | 198 199 200 201 202 203 204 205 206 207 208 209  | Next Page >