Search Results

Search found 870 results on 35 pages for 'allocation'.

Page 11/35 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >

• Creating huge images

  - by David Rutten

  My program has the feature to export a hi-res image of the working canvas to the disk. Users will frequently try to export images of about 20,000 x 10,000 pixels @ 32bpp which equals about 800MB. Add that to the serious memory consumption already going on in your average 3D CAD program and you'll pretty much guarantee an out-of-memory crash on 32-bit platforms. So now I'm exporting tiles of 1000x1000 pixels which the user has to stitch together afterwards in a pixel editor. Is there a way I can solve this problem without the user doing any work? I figured I could probably write a small exe that gets command-lined into the process and performs the stitching automatically. It would be a separate process and it would thus have 2GB of ram all to itself. Or is there a better way still? I'd like to support jpg, png and bmp so writing the image as a bytestream to the disk is not really possible.

  Read the article

• How can I find the size of Flash and RAM used by a firmware?

  - by Asad

  Hi Fellas, Please help me in finding the size of Flash (ROM) and RAM used by the firmware. The firmware is implemented using C++. Also I have Keil microvision4, will it be helpful to find the ROM and RAM size? Or do I need to look at the MAP(.M51) file of the firmware to find the memory sizes? Or is just looking at the size of hex files (.hex) enough for locating the size of ROM? Please suggest!

  Read the article

• What is the best way to find a processed memory allocations in terms of C# objects

  - by Shantaram

  I have written various C# console based applications, some of them long running some not, which can over time have a large memory foot print. When looking at the windows perofrmance monitor via the task manager, the same question keeps cropping up in my mind; how do I get a break down of the number objects by type that are contributing to this footprint; and which of those are f-reachable and those which aren't and hence can be collected. On numerous occasions I've performed a code inspection to ensure that I am not unnecessarily holding on objects longer than required and disposing of objects with the using construct. I have also recently looked at employing the CG.Collect method when I have released a large number of objects (for example held in a collection which has just been cleared). However, I am not so sure that this made that much difference, so I threw that code away. I am guessing that there are tools in sysinternals suite than can help to resolve these memory type quiestions but I am not sure which and how to use them. The alternative would be to pay for a third party profiling tool such as JetBrains dotTrace; but I need to make sure that I've explored the free options first before going cap in hand to my manager.

  Read the article

• Does the pointer to free() have to point to beginning of the memory block, or can it point to the interior?

  - by Lambert

  The question is in the title... I searched but couldn't find anything. Edit: I don't really see any need to explain this, but because people think that what I'm saying makes no sense (and that I'm asking the wrong questions), here's the problem: Since people seem to be very interested in the "root" cause of all the problem rather than the actual question asked (since that apparently helps things get solved better, let's see if it does), here's the problem: I'm trying to make a D runtime library based on NTDLL.dll, so that I can use that library for subsystems other than the Win32 subsystem. So that forces me to only link with NTDLL.dll. Yes, I'm aware that the functions are "undocumented" and could change at any time (even though I'd bet a hundred dollars that wcstombs will still do the same exact thing 20 years from now, if it still exists). Yes, I know people (especially Microsoft) don't like developers linking to that library, and that I'll probably get criticized for the right here. And yes, those two points above mean that programs like chkdsk and defragmenters that run before the Win32 subsystem aren't even supposed to be created in the first place, because it's literally impossible to link with anything like kernel32.dll or msvcrt.dll and still have NT-native executables, so we developers should just pretend that those stages are meant to be forever out of our reaches. But no, I doubt that anyone here would like me to paste a few thousand lines of code and help me look through them and try to figure out why memory allocations that aren't failing are being rejected by the source code I'm modifying. So that's why I asked about a different problem than the "root" cause, even though that's supposedly known to be the best practice by the community. If things still don't make sense, feel free to post comments below! :)

  Read the article

• overloading new/delete problem

  - by hidayat

  This is my scenario, Im trying to overload new and delete globally. I have written my allocator class in a file called allocator.h. And what I am trying to achieve is that if a file is including this header file, my version of new and delete should be used. So in a header file "allocator.h" i have declared the two functions extern void* operator new(std::size_t size); extern void operator delete(void *p, std::size_t size); I the same header file I have a class that does all the allocator stuff, class SmallObjAllocator { ... }; I want to call this class from the new and delete functions and I would like the class to be static, so I have done this: template<unsigned dummy> struct My_SmallObjectAllocatorImpl { static SmallObjAllocator myAlloc; }; template<unsigned dummy> SmallObjAllocator My_SmallObjectAllocatorImpl<dummy>::myAlloc(DEFAULT_CHUNK_SIZE, MAX_OBJ_SIZE); typedef My_SmallObjectAllocatorImpl<0> My_SmallObjectAllocator; and in the cpp file it looks like this: allocator.cc void* operator new(std::size_t size) { std::cout << "using my new" << std::endl; if(size > MAX_OBJ_SIZE) return malloc(size); else return My_SmallObjectAllocator::myAlloc.allocate(size); } void operator delete(void *p, std::size_t size) { if(size > MAX_OBJ_SIZE) free(p); else My_SmallObjectAllocator::myAlloc.deallocate(p, size); } The problem is when I try to call the constructor for the class SmallObjAllocator which is a static object. For some reason the compiler are calling my overloaded function new when initializing it. So it then tries to use My_SmallObjectAllocator::myAlloc.deallocate(p, size); which is not defined so the program crashes. So why are the compiler calling new when I define a static object? and how can I solve it?

  Read the article

• Is this 2D array initialization a bad idea?

  - by Brendan Long

  I have something I need a 2D array for, but for better cache performance, I'd rather have it actually be a normal array. Here's the idea I had but I don't know if it's a terrible idea: const int XWIDTH = 10, YWIDTH = 10; int main(){ int * tempInts = new int[XWIDTH * YWIDTH]; int ** ints = new int*[XWIDTH]; for(int i=0; i<XWIDTH; i++){ ints[i] = &tempInts[i*YWIDTH]; } // do things with ints delete[] ints[0]; delete[] ints; return 0; } So the idea is that instead of newing a bunch of arrays (and having them placed in different places in memory), I just point to an array I made all at once. The reason for the delete[] (int*) ints; is because I'm actually doing this in a class and it would save [trivial amounts of] memory to not save the original pointer. Just wondering if there's any reasons this is a horrible idea. Or if there's an easier/better way. The goal is to be able to access the array as ints[x][y] rather than ints[x*YWIDTH+y].

  Read the article

• EXC_BAD_ACCESS when simply casting a pointer in Obj-C

  - by AlexChilcott

  Hi all, Frequent visitor but first post here on StackOverflow, I'm hoping that you guys might be able to help me out with this. I'm fairly new to Obj-C and XCode, and I'm faced with this really... weird... problem. Googling hasn't turned up anything whatsoever. Basically, I get an EXC_BAD_ACCESS signal on a line that doesn't do any dereferencing or anything like that that I can see. Wondering if you guys have any idea where to look for this. I've found a work around, but no idea why this works... The line the broken version barfs out on is the line: LevelEntity *le = entity; where I get my bad access signal. Here goes: THIS VERSION WORKS NSArray *contacts = [self.body getContacts]; for (PhysicsContact *contact in contacts) { PhysicsBody *otherBody; if (contact.bodyA == self.body) { otherBody = contact.bodyB; } if (contact.bodyB == self.body) { otherBody = contact.bodyA; } id entity = [otherBody userData]; if (entity != nil) { LevelEntity *le = entity; CGPoint point = [contact contactPointOnBody:otherBody]; } } THIS VERSION DOESNT WORK NSArray *contacts = [self.body getContacts]; for (NSUInteger i = 0; i < [contacts count]; i++) { PhysicsContact *contact = [contacts objectAtIndex:i]; PhysicsBody *otherBody; if (contact.bodyA == self.body) { otherBody = contact.bodyB; } if (contact.bodyB == self.body) { otherBody = contact.bodyA; } id entity = [otherBody userData]; if (entity != nil) { LevelEntity *le = entity; CGPoint point = [contact contactPointOnBody:otherBody]; } } Here, the only difference between the two examples is the way I enumerate through my array. In the first version (which works) I use for (... in ...), where as in the second I use for (...; ...; ...). As far as I can see, these should be the same. This is seriously weirding me out. Anyone have any similar experience or idea whats going on here? Would be really great :) Cheers, Alex

  Read the article

• Out-of-memory algorithms for addressing large arrays

  - by reve_etrange

  I am trying to deal with a very large dataset. I have k = ~4200 matrices (varying sizes) which must be compared combinatorially, skipping non-unique and self comparisons. Each of k(k-1)/2 comparisons produces a matrix, which must be indexed against its parents (i.e. can find out where it came from). The convenient way to do this is to (triangularly) fill a k-by-k cell array with the result of each comparison. These are ~100 X ~100 matrices, on average. Using single precision floats, it works out to 400 GB overall. I need to 1) generate the cell array or pieces of it without trying to place the whole thing in memory and 2) access its elements (and their elements) in like fashion. My attempts have been inefficient due to reliance on MATLAB's eval() as well as save and clear occurring in loops. for i=1:k [~,m] = size(data{i}); cur_var = ['H' int2str(i)]; %# if i == 1; save('FileName'); end; %# If using a single MAT file and need to create it. eval([cur_var ' = cell(1,k-i);']); for j=i+1:k [~,n] = size(data{j}); eval([cur_var '{i,j} = zeros(m,n,''single'');']); eval([cur_var '{i,j} = compare(data{i},data{j});']); end save(cur_var,cur_var); %# Add '-append' when using a single MAT file. clear(cur_var); end The other thing I have done is to perform the split when mod((i+j-1)/2,max(factor(k(k-1)/2))) == 0. This divides the result into the largest number of same-size pieces, which seems logical. The indexing is a little more complicated, but not too bad because a linear index could be used. Does anyone know/see a better way?

  Read the article

• Somewhat newb question about assy and the heap.

  - by Eric M

  Ultimately I am just trying to figure out how to dynamically allocate heap memory from within assembly. If I call Linux sbrk() from assembly code, can I use the address returned as I would use an address of a statically (ie in the .data section of my program listing) declared chunk of memory? I know Linux uses the hardware MMU if present, so I am not sure if what sbrk returns is a 'raw' pointer to real RAM, or is it a cooked pointer to RAM that may be modified by Linux's VM system? I read this: How are sbrk/brk implemented in Linux?. I suspect I can not use the return value from sbrk() without worry: the MMU fault on access-non-allocated-address must cause the VM to alter the real location in RAM being addressed. Thus assy, not linked against libc or what-have-you, would not know the address has changed. Does this make sense, or am I out to lunch?

  Read the article

• Can you catch exceeded allocated memory error before it kills the script?

  - by kristovaher

  The thing is that I want to catch memory problems before they happen. I have a system that gets rows from database and casts the returned associative array to a variable, but I never know what the size of the database result is is or how much memory it will take once the database request is made. This means that my software can fail simply because memory is exceeded. But I want to avoid that somehow. One of the ways is to obviously make database requests that are smaller, but what if this is not possible or what if I do not know the size of data that is returned from database? Is it possible to 'catch' situations where memory use is exceeded in PHP? Something like this: $requestOk=memory_test(function(){ return doSomething(); }); if($requestOk){ // Memory seems fine // $requestOk now has the value from memory_test() function } else { // Function would have exceeded memory } I just find it problematic that my script can just die at any moment because of memory issues. From what I know, try-catch cannot be used here because it is a fatal error. Any help would be appreciated!

  Read the article

• Why is NULL/0 an illegal memory location for an object?

  - by aioobe

  I understand the purpose of the NULL constant in C/C++, and I understand that it needs to be represented some way internally. My question is: Is there some fundamental reason why the 0-address would be an invalid memory-location for an object in C/C++? Or are we in theory "wasting" one byte of memory due to this reservation?

  Read the article

• Set asisde space for ADT when reading integers from file

  - by That Guy

  I'm using C to make maze solver. The program should be able read a maze from a text file containing a grid of 1 and 0 representing walls and paths. This file could be of any size as the user selects which maze to use. The program should then show the maze being solved. As the maze is being solved it should show where has been walked and how many steps have been taken. I have made an ADT called Cell containing a bool for wall or path and an integer for steps taken. I now need to populate a 2D array of Cells which means I need to set aside enough space to store a Cell for every integer in the maze file. What would be the best way to do this?

  Read the article

• Looking at the C++ new[] cookie. How portable is this code?

  - by carleeto

  I came up with this as a quick solution to a debugging problem - I have the pointer variable and its type, I know it points to an array of objects allocated on the heap, but I don't know how many. So I wrote this function to look at the cookie that stores the number of bytes when memory is allocated on the heap. template< typename T > int num_allocated_items( T *p ) { return *((int*)p-4)/sizeof(T); } //test #include <iostream> int main( int argc, char *argv[] ) { using std::cout; using std::endl; typedef long double testtype; testtype *p = new testtype[ 45 ]; //prints 45 std::cout<<"num allocated = "<<num_allocated_items<testtype>(p)<<std::endl; delete[] p; return 0; } I'd like to know just how portable this code is.

  Read the article

• How much memory is reserved when i declare a string?

  - by Bhagya

  What exactly happens, in terms of memory, when i declare something like: char arr[4]; How many bytes are reserved for arr? How is null string accommodated when I 'strcpy' a string of length 4 in arr? I was writing a socket program, and when I tried to suffix NULL at arr[4] (i.e. the 5th memory location), I ended up replacing the values of some other variables of the program (overflow) and got into a big time mess. Any descriptions of how compilers (gcc is what I used) manage memory?

  Read the article

• Activator.CreateInstance uses a huge amount of memory

  - by Marco

  I have been playing a bit with Silverlight and try to port my Silverlight 3.0 application to Silverlight 4.0. My application loads different XAP files and upon a user request create an instance of a Xaml user control and adds it to the main container, in a sort of MEF approach in order I can have an extensible and pluggable application. The application is pretty huge and to keep acceptable the performances and the initial loading I have built up some helper classes to load in the background all pages and user controls that might be used later on. On Silverlight 3.0 everything was running smoothly without any problem so far. Switching to SL 4.0 I have noticed that when the process approaches to create the instances of the user controls using Activator.CreateInstance, the layout freezes unexpectedly for a minute and sometimes for more. Looking at the task manager the memory usage of IE jumps from 50MB to 400MB and sometimes to 1.5 GB. If the process won't take that much the layout is rendered properly and the memory falls back to 50 MB. Otherwise everything crashes due to out of memory exeption. Does anybody encountered the same problem? Or has anybody a solution about this tricky issue?

  Read the article

• Need to allocate memory before a Delphi string copy?

  - by Duncan

  Do I need to allocate memory when performing a Delphi string copy? I've a function which posts a Windows message to another form in my application. It looks something like this: // Note: PThreadMessage = ^TThreadMessage; TThreadMessage = String; function PostMyMessage( aStr : string ); var gMsgPtr : PThreadMessage; gStrLen : Integer; begin New(gMsgPtr); gStrLen := StrLen(PWideChar(aMsg)); gMsgPtr^ := Copy(aMsg, 0, gStrLen); PostMessage(ParentHandle, WM_LOGFILE, aLevel, Integer(gMsgPtr)); // Prevent Delphi from freeing this memory before consumed. LParam(gMsgPtr) := 0; end;

  Read the article

• Constructors for C++ objects

  - by sasquatch

  I have class Person as following : class Person { char* name; int age; }; Now I need to add two contructors. One taking no arguments, that inserts field values to dynamically allocated resources. Second taking (char*, int) arguments initialized by initialization list. Last part is to define a destructor showing information about destroying objects and deallocating dynamically allocated resources. How to perform this task ? That's what I already have : class Person { char* name; int age; public: Person(){ this->name = new *char; this->age = new int; } Person(char* c, int i){ } };

  Read the article

• Threading heap and stack

  - by DJ

  How memory is allocated in case of spawning a new thread, i.e how memory heap, memory stack, and threads are related? I know this is fundamental (.net framework concept) but somehow I am not much aware of this concept.

  Read the article

• Controling CRT memory initialization

  - by Ofek Shilon

  Occasionally you meet bugs that are reproducible only in release builds and/or only on some machines. A common (but by no means only) reason is uninitialized variables, that are subject to random behaviour. E.g, an uninitialized BOOL can be TRUE most of the time, on most machines, but randomly be initialized as FALSE. What I wish I would have is a systematic way of flushing out such bugs by modifying the behaviour of the CRT memory initialization. I'm well aware of the MS debug CRT magic numbers - at the very least I'd like to have a trigger to turn 0xCDCDCDCD (the pattern that initializes freshly allocated memory) to zeros. I suspect one would be able to easily smoke out nasty initialization pests this way, even in debug builds. Am I missing an available CRT hook (API, registry key, whatever) that enables this? Anyone has other ideas to get there?

  Read the article

• Initialization of array on heap

  - by Radek Šimko

  How do i manually initiate values in array on heap? If the array is local variable (in stack), it can be done very elegant and easy way, like this: int myArray[3] = {1,2,3}; Unfortunately, following code int * myArray = new int[3]; myArray = {1,2,3}; outputs an error by compiling error: expected primary-expression before ‘{’ token error: expected `;' before ‘{’ token Do i have to use cycle, or not-so-much-elegant way like this? myArray[0] = 1; myArray[1] = 2; myArray[2] = 3;

  Read the article

• Creating "could not reserve enough space for object heap" error

  - by Paul Reiners

  Is there a utility that uses up memory so I can create a JVM "could not reserve enough space for object heap" error?

  Read the article

• how to allocate memory for struct itself, and its members

  - by Jack

  I have this struct: struct foo { char *a; char *b; char *c; char *d; }; it's possible allocate space for struct itself and its members instead of e.g, struct foo f; f.a = malloc(); f.b = malloc(); f.c = malloc(); f.d = malloc(); strcpy(f.a, "a"); strcpy(f.b, "b"); //.. something like this(of couse that it doesn't works): struct foo f = malloc(sizeof(struct f)); strpcy(f.a, "a"); //etc

  Read the article

• Why do they initialize pointers this way?

  - by Rob

  In almost all of the books I read and examples I go through I see pointers initialized this way. Say that I have a class variable NSString *myString that I want to initialize. I will almost always see that done this way: -(id)init { if (self = [super init]) { NSString *tempString = [[NSString alloc] init]; myString = tempString; [tempString release]; } return self; } Why can't I just do the following? -(id)init { if (self = [super init]) { myString = [[NSString alloc] init]; } return self; } I don't see why the extra tempString is ever needed in the first place, but I could be missing something here with memory management. Is the way I want to do things acceptable or will it cause some kind of leak? I have read the Memory Management Guide on developer.apple.com and unless I am just missing something, I don't see the difference.

  Read the article

• Force an object to be allocated on the heap

  - by Warren Seine

  A C++ class I'm writing uses shared_from_this() to return a valid boost::shared_ptr<>. Besides, I don't want to manage memory for this kind of object. At the moment, I'm not restricting the way the user allocates the object, which causes an error if shared_from_this() is called on a stack-allocated object. I'd like to force the object to be allocated with new and managed by a smart pointer, no matter how the user declares it. I thought it could be done through a proxy or an overloaded new operator, but I can't find a proper way of doing that. Is there a common design pattern for such usage? If it's not possible, how can I test it at compile time?

  Read the article

• allocator with no template

  - by Merni

  Every stl container take an allocator as a second object, template < class T, class Allocator = allocator<T> > class vector; If you write your own class It is possible to use your own allocator. But is it possible to write your own allocator without using templates? For example, writing this function is not easy if you are not allowed to use templates pointer allocate(size_type n, const_pointer = 0) { void* p = std::malloc(n * sizeof(T)); if (!p) throw std::bad_alloc(); return static_cast<pointer>(p); } Because how could you know the size of T?

  Read the article

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18  | Next Page >