/*
    (C) 1995-96 AROS - The Amiga Replacement OS
    $Id: closelibrary.c,v 1.12 1997/05/12 10:32:11 aros Exp $

    Desc: Close a library.
    Lang: english
*/
#include <aros/config.h>
#include <exec/execbase.h>
#include <dos/dos.h>
#include <aros/libcall.h>
#include <proto/exec.h>

#include "exec_debug.h"
#ifndef DEBUG_CloseLibrary
#   define DEBUG_CloseLibrary 0
#endif
#if DEBUG_CloseLibrary
#   undef DEBUG
#   define DEBUG 1
#endif
#include <aros/debug.h>
#undef kprintf

#if (AROS_FLAVOUR == AROS_FLAVOUR_NATIVE)
#   define NATIVE(x)        x
#else
#   define NATIVE(x)        /* eps */
#endif

/*****************************************************************************

    NAME */

	AROS_LH1(void, CloseLibrary,

/*  SYNOPSIS */
	AROS_LHA(struct Library *, library, A1),

/*  LOCATION */
	struct ExecBase *, SysBase, 69, Exec)

/*  FUNCTION
	Closes a previously opened library. It is legal to call this function
	with a NULL pointer.

    INPUTS
	library - Pointer to library structure or NULL.

    RESULT

    NOTES

    EXAMPLE

    BUGS

    SEE ALSO
	OpenLibrary().

    INTERNALS

    HISTORY

******************************************************************************/
{
    AROS_LIBFUNC_INIT
    NATIVE(BPTR seglist;)

    D(bug("CloseLibrary $%lx (\"%s\") by \"%s\"\n", library,
	library ? library->lib_Node.ln_Name : "(null)",
	SysBase->ThisTask->tc_Node.ln_Name));

    /* Something to do? */
    if(library!=NULL)
    {
	/* Single-thread the close routine. */
	Forbid();

	/* Do the close */
	NATIVE(seglist =) AROS_LVO_CALL0(BPTR,struct Library *,library,2,);
	/*
	    Normally you'd expect the library to be expunged if this returns
	    non-zero, but this is only exec which doesn't know anything about
	    seglists - therefore dos.library has to SetFunction() into this
	    vector for the additional functionality.
	*/

	/* All done. */
	Permit();
    }
#if (AROS_FLAVOUR == AROS_FLAVOUR_NATIVE)
    else
    {
	/* Local vars not guaranteed to be initialised to 0. I initialise
	   it here to save an assignment in case the close went ok (common
	   path optimization). */
	seglist = 0;
    }

    /*
	Kludge to force the seglist to register d0. Ramlib patches this
	vector for seglist expunge capability and expects the seglist in
	d0 after it has called the original (this) function.
	Also see CloseDevice().
    */
    {
	/* Put the library base in register d0 */
	register BPTR ret __asm("d0") = seglist;

	/* Make sure the above assignment isn't optimized away */
	asm volatile("": : "r" (ret));
    }
#endif

    AROS_LIBFUNC_EXIT
} /* CloseLibrary */