.Net程序突破2G的内存访问限制的方法(4)

首先先通过VirtualAlloc函数申请一块32位虚拟内存区域

然后通过 MapUserPhysicalPages API 函数将AWE内存映射到这个虚拟内存地址区域。

以下为引用的内容：

public void Map(bool readOnly)
{
unsafe
{
if (IsMapped)
{
return;
}

if (readOnly)
{
_VirtualAddress = AweApi.VirtualAlloc(null, Capacity, AweApi.MEM_RESERVE | AweApi.MEM_PHYSICAL,
AweApi.PAGE_READONLY);
}
else
{
_VirtualAddress = AweApi.VirtualAlloc(null, Capacity, AweApi.MEM_RESERVE | AweApi.MEM_PHYSICAL,
AweApi.PAGE_READWRITE);
}

if (_VirtualAddress == null)
{
throw new AweStreamException("Cannot reserve memory.", AweStreamException.Reason.CannotReserveMemory);
}

if (!AweApi.MapUserPhysicalPages(_VirtualAddress, _NumberOfPages, _PFNArray))
{
AweApi.VirtualFree(_VirtualAddress, Capacity, AweApi.MEM_RELEASE);
_VirtualAddress = null;
throw new AweStreamException(string.Format("MapUserPhysicalPages failed ({0})", General.GetLastError()),
AweStreamException.Reason.MapUserPhysicalPagesFail);
}

_CanWrite = !readOnly;
}
}

去映射和归还AWE内存的过程是上面两个过程的逆过程，这里就不再多讲，有兴趣可以看我的代码。