#133 Data race on ARM multicore

[manuelbliemel]

I'm using STLPort on a DualCore CortexA9 ARM CPU with WinCE Compact 7.
I realized that the original version of STLPort lacks support for
ARM multicore platforms causing random crashes.

I propose to use _Atomic_swap to revert the lock back to 0 for platforms
where no explicit memory barrier mechanism is supported.

So the OS/Runtime Libs will take care of the instruction synchronisation.

Best regards,
Manuel