Re: Running out of memory on stack in C++ routine invoked within Cocoa NSOperation
Re: Running out of memory on stack in C++ routine invoked within Cocoa NSOperation
- Subject: Re: Running out of memory on stack in C++ routine invoked within Cocoa NSOperation
- From: Leo Singer <email@hidden>
- Date: Wed, 18 Feb 2009 03:52:14 -0500
OK, so there is a way to change the size of the stack for an NSThread.
But how do I do this for an NSOperationQueue?
NSThread has the following selector:
- (void) setStackSize:(NSInteger)s;
I need to find the equivalent selector for NSOperationQueue. Any
ideas out there?
Leo
#import <Cocoa/Cocoa.h>
@interface MemoryTortureController : NSObject {
}
- (IBAction)memoryTortureBackground: (id) sender;
- (IBAction)memoryTorture: (id) sender;
@end
@implementation MemoryTortureController
- (IBAction)memoryTortureBackground: (id) sender
{
NSThread* thread;
thread = [[NSThread alloc] initWithTarget: self
selector: @selector(memoryTorture:)
object: sender];
// The magic line
[thread setStackSize:256000*8];
[thread start];
}
- (IBAction)memoryTorture: (id) sender
{
int bigmem[256000];
for (int i = 0 ; i < 256000 ; i ++)
bigmem[i] = 2*i;
}
@end
On Wed, Feb 18, 2009 at 3:31 AM, Leo Singer <email@hidden> wrote:
> Actually, if the big array and the loop are moved from the C++ method
> into the Objective C selector - (void) main then the same
> EXEC_BAD_ACCESS occurs. So the problem is not related to C++. The
> following source code still exhibits the same problem:
>
> //////////////// TestOperation.h /////////////////////
> #import <Cocoa/Cocoa.h>
>
> @interface TestOperation : NSOperation {
> }
> @end
>
> //////////////// End of TestOperation.h /////////////////////
>
> //////////////// TestOperation.mm /////////////////////
> #import "TestOperation.h"
>
> @implementation TestOperation
> - (void) main
> {
> int bigArray[256000];
>
> for (int j = 0 ; j < 256000 && ![self isCancelled] ; j ++)
> {
> bigArray[j] = 2*j;
> }
> }
> @end
>
> //////////////// End of TestOperation.mm /////////////////////
>
> On Wed, Feb 18, 2009 at 3:16 AM, Leo Singer <email@hidden> wrote:
>> Hi,
>>
>> I have a C++ method that I am invoking from within the - (void) main
>> selector of an NSOperation. My Cocoa application is crashing because
>> this particular C++ method puts a huge amount of data on the stack. I
>> am getting an EXEC_BAD_ACCESS error. However, the same C++ routine
>> works fine if I call it from within a command line C++ program.
>>
>> I have contrived some sample code to illustrate the problem.
>> TestOperation is an (Objective C) subclass of NSOperation; I am
>> running the NSOperation in a separate thread by putting it into an
>> NSOperationQueue. TestOperationImpl is a C++ class. The NSOperation
>> is responsible for doing one thing only: calling the go() method on an
>> instance of TestOperationImpl.
>>
>> Note the very large array of ints that is declared inside
>> TestOperationImpl::go(). If it is changed to an array of shorts or an
>> array of chars, then this example code works fine, no EXEC_BAD_ACCESS.
>>
>> Is there any way for me to give my application more memory, or at
>> least give more memory to the thread that is running this C++ method?
>>
>> Thanks,
>> Leo
>>
>> //////////////// TestOperation.h /////////////////////
>> #import <Cocoa/Cocoa.h>
>>
>> class TestOperationImpl {
>> private:
>> bool cancelled;
>> public:
>> TestOperationImpl();
>> void go();
>> void cancel();
>> };
>>
>> @interface TestOperation : NSOperation {
>> TestOperationImpl* testOpImpl;
>> }
>> - initWithController: (TestOperationController*) controller;
>> @end
>>
>> //////////////// End of TestOperation.h /////////////////////
>>
>> //////////////// TestOperation.mm /////////////////////
>> #import "TestOperation.h"
>>
>> TestOperationImpl::TestOperationImpl(TestOperationController* controller)
>> : cancelled(false)
>> {
>> }
>>
>> void TestOperationImpl::go()
>> {
>> int bigArray[256000];
>>
>> for (int j = 0 ; j < 256000 && !cancelled ; j ++)
>> {
>> bigArray[j] = 2*j;
>> }
>> }
>>
>> void TestOperationImpl::cancel()
>> {
>> cancelled = true;
>> }
>>
>> @implementation TestOperation
>> - initWithController: (TestOperationController*) ctrl
>> {
>> if (self = [self init])
>> testOpImpl = new TestOperationImpl(ctrl);
>> controller = ctrl;
>> return self;
>> }
>> - (void) dealloc
>> {
>> delete testOpImpl;
>> [super dealloc];
>> }
>> - (void) cancel
>> {
>> testOpImpl->cancel();
>> [super cancel];
>> }
>> - (void) main
>> {
>> testOpImpl->go();
>> }
>> @end
>>
>> //////////////// End of TestOperation.mm /////////////////////
>>
>
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