多线程 – 何时使用测试和设置或测试和测试？

>单一作家和单一读者
>单读者多个作家
>多个读者和单个作家
>多个读者和多个作家

那么哪一个模型更好(更有效)来锁定共享内存区域：测试和设置或测试&测试和设置以及何时使用它！

这里我有两个简单(没有时间限制)的测试程序,用x86汇编程序在Delphi IDE下编写：

procedure TestAndSet(const oldValue,newValue: cardinal; var destination);
asm
//eax = oldValue
//edx = NewLockValue
//ecx = destination = 32 bit pointer on lock variable 4 byte aligned
@RepeatSpinLoop:
        push    eax                   //Save lock oldValue (compared)
        pause                         //CPU spin-loop hint
        lock    cmpxchg dword ptr [ecx],edx
        pop     eax                   //Restore eax as oldValue
        jnz     @RepeatSpinLoop       //Repeat if cmpxchg wasn't successful
end;

procedure TestAndTestAndSet(const oldValue,newValue: cardinal; var destination);
asm
//eax = oldValue
//edx = NewLockValue
//ecx = destination = 32 bit pointer on lock variable 4 byte aligned
@RepeatSpinLoop:
        push    eax                   //Save lock oldValue (compared)
@SpinLoop:
        pause                         //CPU spin-loop hint
        cmp     dword ptr [ecx],eax  //Test betfore test&set
        jnz     @SpinLoop
        lock    cmpxchg dword ptr [ecx],edx
        pop     eax                   //Restore eax as oldValue
        jnz     @RepeatSpinLoop       //Repeat if cmpxchg wasn't successful
end;

编辑：

英特尔在文档中提到了两种方法Test& Set或Test& Test& Set.我不会在哪种情况下建立更好的方法,所以何时使用它.检查：Intel