Calling 32-bit DLLs

The OS/2 subsystem provides a general mechanism to allow 16-bit OS/2 and PM applications to load and call any Win32 DLL. This feature could be extremely useful in the following cases:

• When you need to call from your OS/2 application some functionality available under Windows NT only as Win32 code.

  Without the ability to call Win32 DLLs, the alternative would be to split the application into an OS/2 application and a Win32 application, then communicate between them using, for example, named pipes. This would be much more complicated to implement and may not yield a good performance.

• When you want to port your OS/2 application to Win32 but would like to do so in stages, by porting only part of the application at first.

A small set of new APIs is provided. See "Win32 Thunking Mechanism" later in this chapter.