I would strongly reccommend using std::vector instead of a raw array. That way you're immune from stack size issues.

Sent from my iPhone

On Feb 18, 2009, at 0:31, Leo Singer <doc.aron...@gmail.com> 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 <doc.aron...@gmail.com> 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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