Re: [patch] spinlocks: remove 'volatile'

["trajce nedev" <trajcenedev@hotmail.com>]

On Sat, 8 Jul 2006, Chase Venters wrote:
> Perhaps you should have followed this thread closely before composing your
> assault on Linus. We're not talking about "asm volatile". We're talking 
> about
> the "volatile" keyword as applied to variables. 'volatile' as applied to
> inline ASM is of course necessary in many cases -- no one is disputing 
> that.

Ok, let's port a spinlock macro that spins instead of context switches 
instead of using the pthread garbage on IA64 or AMD64:

#if ((defined (_M_IA64) || defined (_M_AMD64)) && !defined(NT_INTEREX))
#include <windows.h>
#pragma intrinsic (_InterlockedExchange)

typedef volatile LONG lock_t[1];

#define LockInit(v)	((v)[0] = 0)
#define LockFree(v)	((v)[0] = 0)
#define Unlock(v)	((v)[0] = 0)

__forceinline void Lock(volatile LONG *hPtr)
{
	int iValue;

	for (;;) {
		iValue = _InterlockedExchange((LPLONG)hPtr, 1);
		if (iValue == 0)
			return;
		while (*hPtr);
	}
}

Please show me how I can write this to spinlock without using volatile.

		Trajce Nedev
		tnedev@mail.ru

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