The UNIX system has a mechanism similar in essence to DLLs in Windows. Its called Shared Library. Like a DLL file, a file, a shared library is an archive file containing multiple procedures or data modules that are present in memory at run time and can be bound to multiple processes at the same time. The standard C library and much of the networking code are shared libraries. Thus you can Integrate older information systems with newer ones!
There are two ways for a program to bind to a DLL. In the first way called implicit linking, the user's program statically linked with a specific file called an import library that is generated by a utility program that extracts certain information from the DLL. A user program can be linked with multiple import libraries. When a program using implicit linking is loaded into memory for execution, Windows examines it to see which DLLs it uses and checks to see if all of them are already in memory. Those that are not in memory are loaded into memory. They also have to be mapped into the program's virtual address space.
Comments
Post a Comment