phillip@cbmvax.cbm.UUCP (Phillip Lindsay) (09/05/86)
[a line is to a line as is a line]
For all those people interested in implementing AmigaDos file I/O
with an asynchronous design.
==============================================================================
Phillip Lindsay - Commodore Business Machines - Amiga Technical Support
Dirt: 1200 Wilson Drive, West Chester PA 19380
uucp: {ihnp4|seismo|caip}!cbmvax!phillip
arpa: cbmvax!phillip@seismo -or- phillip@cbmvax.UUCP@{seismo | harvard}
Tel.: (215) 431-9180
Disclaimer: [someone said I needed this] No warranty is implied or otherwise
given in the form of suggestion or example. Any opinions found here are of
my making. [unless Fred pops up (my other self)]
==============================================================================
/***CUT HERE***/
/* asendpacket.c - (asynchronous) send multiple packets to a dos- */
/* 05-SEP-86 handler */
/* Phillip Lindsay - Commodore-Amiga */
#include "exec/types.h"
#include "exec/ports.h"
#include "exec/io.h"
#include "exec/memory.h"
#include "libraries/dos.h"
#include "libraries/dosextens.h"
#include <stdio.h>
#include "functions.h" /* aztec C include */
#define DOSTRUE -1L /* AmigaDos TRUE */
#define MAXARGS 7L /* limit in packet structure (dosextens.h) */
/*
asynchronous sendpkt routine
you must supply a port for packet replies...This function returns the
address of the pending packet.
*/
long asendpkt(replyport,pid,action,args,nargs)
struct MsgPort *replyport; /* where all packet replies are sent */
struct MsgPort *pid; /* process indentifier ... (handlers message port ) */
long action, /* packet type ... (what you want handler to do ) */
args[], /* a pointer to a argument list */
nargs; /* number of arguments in list */
{
struct StandardPacket *packet;
long count, *pargs;
if(nargs > MAXARGS) exit(FALSE);
packet = (struct StandardPacket *)
AllocMem((long)sizeof(*packet),MEMF_PUBLIC | MEMF_CLEAR);
if(!packet)
{
FreeMem(packet,(long)sizeof(*packet));
return(NULL);
}
packet->sp_Msg.mn_Node.ln_Name = (char *) &(packet->sp_Pkt); /* link packet- */
packet->sp_Pkt.dp_Link = &(packet->sp_Msg); /* to message */
packet->sp_Pkt.dp_Port = replyport; /* set-up reply port */
packet->sp_Pkt.dp_Type = action; /* what to do... */
/* move all the arguments to the packet */
pargs = &(packet->sp_Pkt.dp_Arg1); /* address of first argument */
for(count=NULL;count < nargs;count++)
pargs[count]=args[count];
PutMsg(pid,packet); /* send packet */
return((long)packet); /* everything went ok...so far... give-em the packet */
}
/* end of asendpkt.c */
/*
simple packet flush with error detection ... returns ZERO for error
or DOSTRUE (-1) for a-o-k.
A packet error can be detected in most cases by "Res1" being equal
to zero--"Res2" will hold more information pertaining to the error.
The problem with handling multiple packets is detecting an error for a
particular packet. What makes things a little more difficult is the fact
that the "Res1" member of the packet structure is not generally an
indicator of an error. So depending on what type of packets you'll be
handling you might want to deal with packet replies differently.
( I was designing a elegant packet handling tool, but I found that
AmigaDos doesn't handle ports like EXEC does. So I couldn't have
a software interrupt generated on packet arrvial [sigh...] Tim? )
*/
long pktflush(rport,pkts)
struct MsgPort *rport; /* reply port for packets */
long pkts; /* number of packets to flush */
{
struct StandardPacket *apkt;
long res1,cres;
res1 = DOSTRUE;
while(pkts--) /* received all packets? */
{
WaitPort(rport); /* sleep until a packet arrives */
apkt = (struct StandardPacket *) GetMsg(rport); /* get packet */
cres = apkt->sp_Pkt.dp_Res1; /* get result */
FreeMem(apkt,(long)sizeof(*apkt)); /* free packet structure from memory */
res1 = (!cres ? cres : res1); /* error? */
}
return(res1);
}
/*
for all those people interested in implementing AmigaDos file I/O
with an asynchronous design.
*/
/* start of example */
#define NARGS 3L /* number of arguments */
#define NBUFFS 3L /* number of buffers */
#define BUFFLEN 60L /* buffer length */
#define ESC 27L
main()
{
struct MsgPort *filehdlr; /* for process id handler */
struct MsgPort *rport; /* where all packets return */
long arg[NARGS], /* array of arguments */
rpkt, /* holds returned packet */
count; /* count messages */
struct FileHandle *filehandle; /* our file handle */
BPTR fh, /* AmigaDos file handle */
fharg1; /* Arg1 from filehandle */
UBYTE *buff; /* buffer pointer */
struct StandardPacket *pkt; /* our packet */
/* get buffers */
buff = (UBYTE *) AllocMem((BUFFLEN * NBUFFS),MEMF_PUBLIC | MEMF_CLEAR);
if(!buff) exit(TRUE);
rport = (struct MsgPort *) CreatePort(NULL,NULL); /* make reply port */
if(!rport)
{
FreeMem(buff,(BUFFLEN * NBUFFS));
exit(TRUE);
}
/* here we open a dummy file */
fh = (BPTR) Open("df1:temp",MODE_NEWFILE);
if(!fh)
{
FreeMem(buff,(BUFFLEN * NBUFFS));
DeletePort(rport);
exit(TRUE);
}
/* bring our AmigaDos file handle into the real world... */
filehandle = (struct FileHandle *) (fh << 2);
/* read your AmigaDOS Technical Reference Manual for packet requirements */
fharg1 = filehandle->fh_Arg1; /* get Arg1 */
filehdlr = filehandle->fh_Type; /* get handler for file */
/*
you could get process id of the handler this way also ...
filehdlr = (struct MsgPort *) DeviceProc("DF1:");
*/
/* give each buffer unique data */
for(count=0;count < (BUFFLEN * NBUFFS);count ++)
buff[count]= 0x31 + (count / BUFFLEN);
/* set-up arguments and send packets */
arg[0]= (long) fharg1; /* file handle Arg1 */
arg[1]= (long) &buff[0]; /* buffer */
arg[2]= BUFFLEN; /* buffer length */
puts("one");
rpkt = asendpkt(rport,filehdlr,ACTION_WRITE,arg,NARGS);
arg[1]= (long) &buff[BUFFLEN];
puts("two");
rpkt = asendpkt(rport,filehdlr,ACTION_WRITE,arg,NARGS);
arg[1]= (long) &buff[BUFFLEN + BUFFLEN];
puts("three");
rpkt = asendpkt(rport,filehdlr,ACTION_WRITE,arg,NARGS);
/* a more elegant packet flush routine would be nice */
if(!pktflush(rport,3L)) puts("Error in packets sent.");
/* done clean up... */
Close(fh);
FreeMem(buff,(BUFFLEN * NBUFFS));
DeletePort(rport);
exit(FALSE);
}
/* eof */
--
==============================================================================
Phillip Lindsay - Commodore Business Machines - Amiga Technical Support
Dirt: 1200 Wilson Drive, West Chester PA 19380
uucp: {ihnp4|seismo|caip}!cbmvax!phillip
arpa: cbmvax!phillip@seismo -or- phillip@cbmvax.UUCP@{seismo | harvard}
Tel.: (215) 431-9180
Disclaimer: [someone said I needed this] No warranty is implied or otherwise
given in the form of suggestion or example. Any opinions found here are of
my making. [unless Fred pops up (my other self)]
==============================================================================