--Copyright:      Matra Datavision 1994

-- SharedLibrary:         OSD_SharedLibrary.cdl
-- Created:      August 30, 1994
-- Author:       J.P. TIRAULT    

class SharedLibrary from OSD 

    ---Purpose: Interface to dynamic library loader.
uses LoadMode,Function
is

  Create returns SharedLibrary;
     ---Purpose: Creates a SharedLibrary object with name NULL.
     ---Level: Public

  Create (aFilename : CString) returns SharedLibrary;
     ---Purpose: Creates a SharedLibrary object with name aFilename.
     ---Level: Public

  SetName (me : out ; aName : CString) 
     ---Purpose: Sets a name associated to the shared object.
     ---Level: Public
  is static;

  Name (me) 
     ---Purpose: Returns the name associated to the shared object.
     ---Level: Public
  returns CString 
  is static;
  
  DlOpen (me : out ; Mode : LoadMode)
     ---Purpose:   The DlOpen method provides an interface to the 
     --            dynamic library loader to allow shared libraries 
     --            to be loaded and called at runtime.  The DlOpen 
     --            function attempts to load Filename, in the address 
     --            space of the process, resolving symbols as appropriate.
     --            Any libraries that Filename depends upon are also loaded.
     --            If MODE is RTLD_LAZY, then the runtime loader
     --            does symbol resolution only as needed.  
     --            Typically, this means that the first call to a function 
     --            in the newly	loaded library will cause the resolution of
     --            the	address	of that	function to occur. 
     --            If Mode is RTLD_NOW, then the runtime loader must do all
     --            symbol binding during the DlOpen call.  
     --            The DlOpen method returns a	handle that is used by DlSym 
     --            or DlClose.  
     --            If there is an error, Standard_False is returned,
     --            Standard_True otherwise.
     --            If a NULL Filename is specified, DlOpen returns a handle
     --            for the main	executable, which allows access to dynamic
     --            symbols in the running program.
     ---Level: Public

     returns Boolean
     is static;

  DlSymb (me; Name : CString)
     ---Purpose: The dlsym function returns the address of the
     --          symbol name found in the shared library.  
     --          If the symbol is not found, a NULL pointer is 
     --          returned.
     ---Level: Public

     returns Function
     is static;

  DlClose (me)
     ---Purpose: Deallocates the address space for the library
     --          corresponding to the shared object.  
     --          If any user function continues to call a symbol
     --          resolved in the address space of a library 
     --          that has been since been deallocated by DlClose, 
     --          the results are undefined.
     ---Level: Public
  is static;

  DlError (me)
     ---Purpose: The dlerror function returns a string describing
     --          the last error that occurred from
     --          a call to DlOpen, DlClose or DlSym.
     ---Level: Public
  returns CString
  is static;

  Destroy (me : in out)
     ---Level: Public
     ---Purpose: Frees memory allocated.
     ---C++: alias ~
   is static;


 fields
 
   myHandle       : Address;
   myName         : PCharacter;

end SharedLibrary from OSD;