/*
 *
 *	DISCLAIMER:
 *
 *	This program is provided as a service to the programmer
 *	community to demonstrate one or more features of the Amiga
 *	personal computer.  These code samples may be freely used
 *	for commercial or noncommercial purposes.
 * 
 * 	Commodore Electronics, Ltd ("Commodore") makes no
 *	warranties, either expressed or implied, with respect
 *	to the program described herein, its quality, performance,
 *	merchantability, or fitness for any particular purpose.
 *	This program is provided "as is" and the entire risk
 *	as to its quality and performance is with the user.
 *	Should the program prove defective following its
 *	purchase, the user (and not the creator of the program,
 *	Commodore, their distributors or their retailers)
 *	assumes the entire cost of all necessary damages.  In 
 *	no event will Commodore be liable for direct, indirect,
 *	incidental or consequential damages resulting from any
 *	defect in the program even if it has been advised of the 
 *	possibility of such damages.  Some laws do not allow
 *	the exclusion or limitation of implied warranties or
 *	liabilities for incidental or consequential damages,
 *	so the above limitation or exclusion may not apply.
 *
 */

/***********************************************************************
*
*	Exec Support Function -- Extended IO Request
*
***********************************************************************/

#include "exec/types.h"
#include "exec/nodes.h"
#include "exec/lists.h"
#include "exec/memory.h"
#include "exec/interrupts.h"
#include "exec/ports.h"
#include "exec/libraries.h"
#include "exec/io.h"
#include "exec/tasks.h"
#include "exec/execbase.h"

extern APTR AllocMem();

/****** exec_support/CreateExtIO **************************************
*
*   NAME	
*	CreateExtIO() -- create an Extended IO request
*
*   SYNOPSIS
*	ioReq = CreateExtIO(ioReplyPort,size);   
*
*   FUNCTION
*	Allocates memory for and initializes a new IO request block
*	of a user-specified number of bytes.
*
*   INPUTS
*	ioReplyPort - a pointer to an already initialized
*		message port to be used for this IO request's reply port.
*
*   RESULT
*	Returns a pointer to the new block.  Pointer is of the type
*	struct IORequest.
*
*	0 indicates inability to allocate enough memory for the request block
*	or not enough signals available.
*
*   EXAMPLE
*	struct IORequest *myBlock;
*	if( (myBlock = CreateExtIO(myPort,sizeof(struct IOExtTD)) == NULL)
*		exit(NO_MEM_OR_SIGNALS);
*
*	example used to allocate space for IOExtTD (trackdisk driver
*	IO Request block for extended IO operations).
*
*   SEE ALSO
*	DeleteExtIO
*
***********************************************************************/

struct IORequest *CreateExtIO(ioReplyPort,size)
    struct MsgPort *ioReplyPort;
    LONG size;
{
    struct IORequest *ioReq;

    if (ioReplyPort == 0)
	return ((struct IORequest   *) 0);

    ioReq = AllocMem (size, MEMF_CLEAR | MEMF_PUBLIC);

    if (ioReq == 0)
	return ((struct IORequest   *) 0);

    ioReq -> io_Message.mn_Node.ln_Type = NT_MESSAGE;
    ioReq -> io_Message.mn_Node.ln_Pri = 0;

    ioReq -> io_Message.mn_ReplyPort = ioReplyPort;

    return (ioReq);
}

/****** exec_support/DeleteExtIO **************************************
*
*   NAME
*	DeleteExtIO() - return memory allocated for extended IO request
*
*   SYNOPSIS
*	DeleteExtIO(ioReq,size);
*
*   FUNCTION
*	See summary line at NAME.  Also frees the signal bit which
*	had been allocated by the call to CreateExtIO.
*
*   INPUTS
*	A pointer to the IORequest block whose resources are to be freed.
*
*   RESULT
*	Frees the memory.  Returns (no error conditions shown)
*
*   EXAMPLE
*	struct IORequest *myBlock;
*	DeleteExtIO(myBlock,(sizeof(struct IOExtTD)));
*		
*	example shows that CreateExtIO had been used to create a trackdisk
*	(extended) IO Request block.
*
*   SEE ALSO
*	CreateExtIO
*
**************************************************************************/

DeleteExtIO(ioExt,size)
    struct IORequest *ioExt;
    LONG size;
{
    ioExt -> io_Message.mn_Node.ln_Type = 0xff;
    ioExt -> io_Device = (struct Device *) -1;
    ioExt -> io_Unit = (struct Unit *) -1;

    FreeMem (ioExt, size);
}