When the MATHFUNCSDLL_EXPORTS symbol is defined, the MATHFUNCSDLL_API symbol will set the _declspec(dllexport) modifier in the member function declarations in this code. #define MATHFUNCSDLL_API _declspec(dllimport) #define MATHFUNCSDLL_API _declspec(dllexport)
Because of this capability, DLL files are ideal for distributing device drivers. Its reusability is the most major advantage of DLL files.Ī DLL file can be used in other applications as long as the coder knows the names and parameters of the functions and procedures in the DLL file.
Windows recognizes the difference between DLL and EXE through PE Header in the file. The file format of DLL and exe is essentially the same.
DLLs save memory, reduce swapping, save disk space, upgrade easier, provide after-market support, provide a mechanism to extend the MFC library classes, support multi language programs, and ease the creation of international versions. Using dynamic linking instead of static linking offers several advantages. In static linking, the linker gets all of the referenced functions from the static link library and places it with our code into our executable.
exe file) to include only the information needed at run time to locate the executable code for a DLL function. Dynamic linking differs from static linking in that it allows an executable module (either a. Multiple applications can simultaneously access the contents of a single copy of a DLL in memory. The executable code for the function is located in a DLL, which contains one or more functions that are compiled, linked, and stored separately from the processes that use them.ĭLLs also facilitate the sharing of data and resources. Dynamic linking provides a way for a process to call a function that is not part of its executable code. A dynamic-link library (DLL) is an executable file that acts as a shared library of functions.