CODEWITHSUNDEEP
c++atomic
Gaspard Bucher
Gaspard Bucher

Reputation: 6137

Atomic increment on mac OS X

I have googled for atomic increment and decrement operators on Mac OS X and found "OSAtomic.h", but it seems you can only use this in kernel space.

Jeremy Friesner pointed me at a cross-platform atomic counter in which they use assembly or mutex on OS X (as far as I understood the interleaving of ifdefs).

Isn't there something like InterlockedDecrement or atomic_dec() on OS X ?

Upvotes: 6

Views: 8267

Answers (4)

Taylor
Taylor

Reputation: 6410

Currently, the recommendation is to use C++11's std::atomic.

Upvotes: 2

kgriffs
kgriffs

Reputation: 4258

You can also use IncrementAtomic() and DecrementAtomic() via CoreServices:

#include <CoreServices/CoreServices.h>

int main(int argc, char** argv) 
{
  int val = 0;
  IncrementAtomic(&val);
  DecrementAtomic(&val);    

  return 0;
}

Note: the return value of these functions is the value of the integer before it is incremented, so if you want similar behavior to the Win32 InterlockedIncrement() and InterlockedDecrement() functions, you will need to create wrappers that +1 to the return value.

Upvotes: 0

imaginaryboy
imaginaryboy

Reputation: 5989

You could also check out Intel's Threaded Building Blocks for their atomic template class.

Upvotes: 0

wich
wich

Reputation: 17127

What makes you think OSAtomic is kernel space only? The following compiles and works fine.

#include <libkern/OSAtomic.h>
#include <stdio.h>

int main(int argc, char** argv) {
  int32_t foo = 1;
  OSAtomicDecrement32(&foo);
  printf("%d\n", foo);

  return 0;
}

Upvotes: 9

Related Questions