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我可以在Windows上将32位DLL加载到64位进程中吗？

[英]Can I load a 32 bit DLL into a 64 bit process on Windows?

原文 2008-10-22 10:25:29 9 2 .net/ windows/ 64-bit/ x86-64

I recently upgraded ac# windows service to run as a 64 bit .net process. 我最近升级了ac #windows服务，以64位.net进程运行。 Normally, this would be trivial, but the system makes use of a 32-bit DLL written in C++. 通常，这将是微不足道的，但系统使用了用C ++编写的32位DLL。 It is not an option to convert this DLL to 64 bit, so I wrapped the DLL in a separate 32 bit .net process and exposed a .net interface via remoting. 它不能将此DLL转换为64位，因此我将DLL封装在一个单独的32位.net进程中，并通过远程处理暴露了.net接口。

This is quite a reliable solution, but I would prefer to run the system as a single process. 这是一个非常可靠的解决方案，但我更愿意将系统作为单个进程运行。 Is there any way I can load my 32 bit DLL into a 64 bit process and access it directly (perhaps through some sort of thunking layer)? 有没有什么办法可以将我的32位DLL加载到64位进程并直接访问它（可能通过某种thunking层）？

2 个解决方案

No, you can't. 不，你不能。

Both 16-bit and 32-bit Windows lived in a 32-bit linear address space. 16位和32位Windows都存在于32位线性地址空间中。 The terms 16 and 32 refer to the size of the offset relative to the selector. 术语16和32指的是相对于选择器的偏移的大小。

... ...

First, notice that a full-sized 16-bit pointer and a 32-bit flat pointer are the same size. 首先，请注意，全尺寸的16位指针和32位平面指针的大小相同。 The value 0x0123:0x467 requires 32 bits, and wow, so too does a 32-bit pointer. 值0x0123：0x467需要32位，哇，32位指针也是如此。 This means that data structures containing pointers do not change size between their 16-bit and 32-bit counterparts. 这意味着包含指针的数据结构不会改变它们的16位和32位对应的大小。 A very handy coincidence. 一个非常方便的巧合。

Neither of these two observations holds true for 32-bit to 64-bit thunking. 对于32位到64位的thunking，这两个观察结果都不适用。 The size of the pointer has changed, which means that converting a 32-bit structure to a 64-bit structure and vice versa changes the size of the structure . 指针的大小已更改，这意味着将32位结构转换为64位结构（反之亦然）会更改结构的大小 。 And the 64-bit address space is four billion times larger than the 32-bit address space. 64位地址空间比32位地址空间大40亿倍。 If there is some memory in the 64-bit address space at offset 0x000006fb`01234567, 32-bit code will be unable to access it. 如果64位地址空间中的某些内存偏移量为0x000006fb`01234567，则32位代码将无法访问它。 It's not like you can build a temporary address window, because 32-bit flat code doesn't know about these temporary address windows; 这不像你可以建立一个临时地址窗口，因为32位平面代码不知道这些临时地址窗口; they abandoned selectors, remember? 他们放弃了选择者，还记得吗？

http://blogs.msdn.com/oldnewthing/archive/2008/10/20/9006720.aspx http://blogs.msdn.com/oldnewthing/archive/2008/10/20/9006720.aspx

If your .NET application is a website running in IIS you can circumvent it. 如果您的.NET应用程序是在IIS中运行的网站，您可以绕过它。

An ASP.NET webpage running on IIS on a 64-bit machine will be hosted by a 64-bit version of the w3wp.exe process, and if your webpage uses 32-bit dlls your site will fail. 在64位计算机上的IIS上运行的ASP.NET网页将由64位版本的w3wp.exe进程托管，如果您的网页使用32位dll，则您的站点将失败。

However in IIS you can go into the Advanced Settings of the Application Pool running the site, and change "Enable 32-bit applications" to true. 但是，在IIS中，您可以进入运行该站点的应用程序池的“高级设置”，并将“启用32位应用程序”更改为true。

So it's still not able to run 32-bit dll inside 64-bit process, but rather it is running w3wp.exe as a 32-bit process instead. 所以它仍然无法在64位进程内运行32位dll，而是将w3wp.exe作为32位进程运行。