www.pudn.com > cdrecord.zip > fifo.c
/* @(#)fifo.c 1.12 98/10/17 Copyright 1989,1997 J. Schilling */
#ifndef lint
static char sccsid[] =
"@(#)fifo.c 1.12 98/10/17 Copyright 1989,1997 J. Schilling";
#endif
/*
* A "fifo" that uses shared memory between two processes
*
* The actual code is a mixture of borrowed code from star's fifo.c
* and a proposal from Finn Arne Gangstad
* who had the idea to use a ring buffer to handle average size chunks.
*
* Copyright (c) 1989,1997 J. Schilling
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define DEBUG
#include
#if HAVE_MMAP
# define USE_MMAP 1
# undef USE_USGSHM
#elif HAVE_SHMAT
# undef USE_MMAP
# define USE_USGSHM 1
#endif
#if USE_MMAP || USE_USGSHM
#include
#ifdef USE_MMAP
#include
#endif
#include
#include
#include
#include
#include
#include
#include
#include
#include "cdrecord.h"
#ifdef DEBUG
#define EDEBUG(a) if (debug) error a
#else
#define EDEBUG(a)
#endif
#define palign(x, a) (((char *)(x)) + ((a) - 1 - (((unsigned)((x)-1))%(a))))
typedef enum faio_owner {
owner_none,
owner_reader,
owner_writer,
owner_faio
} fowner_t;
char *onames[] = {
"none",
"reader",
"writer",
"faio"
};
typedef struct faio {
int len;
volatile fowner_t owner;
short fd;
short saved_errno;
char *bufp;
} faio_t;
struct faio_stats {
long puts;
long gets;
long empty;
long full;
long done;
long cont_low;
} *sp;
#define MIN_BUFFERS 3
#define MSECS 1000
#define SECS (1000*MSECS)
/* microsecond delay between each buffer-ready probe by writing process */
#define WRITER_DELAY (20*MSECS)
#define WRITER_MAXWAIT (120*SECS) /* 120 seconds max wait for data */
/* microsecond delay between each buffer-ready probe by reading process */
#define READER_DELAY (80*MSECS)
#define READER_MAXWAIT (120*SECS) /* 120 seconds max wait for reader */
LOCAL char *buf;
LOCAL char *bufbase;
LOCAL char *bufend;
LOCAL long buflen;
extern int debug;
extern int lverbose;
EXPORT void init_fifo __PR((long));
#ifdef USE_MMAP
LOCAL char* mkshare __PR((int size));
#endif
#ifdef USE_USGSHM
LOCAL char* mkshm __PR((int size));
#endif
EXPORT BOOL init_faio __PR((int tracks, track_t *track, int));
EXPORT BOOL await_faio __PR((void));
EXPORT void kill_faio __PR((void));
LOCAL void faio_reader __PR((int tracks, track_t *track));
LOCAL void faio_read_track __PR((track_t *trackp));
LOCAL void faio_wait_on_buffer __PR((faio_t *f, fowner_t s,
unsigned long delay,
unsigned long max_wait));
LOCAL int faio_read_segment __PR((int fd, faio_t *f, int len));
LOCAL faio_t *faio_ref __PR((int n));
EXPORT int faio_read_buf __PR((int f, char *bp, int size));
EXPORT int faio_get_buf __PR((int f, char **bpp, int size));
EXPORT void fifo_stats __PR((void));
EXPORT int fifo_percent __PR((BOOL addone));
EXPORT void
init_fifo(fs)
long fs;
{
int pagesize;
if (fs == 0L)
return;
#ifdef _SC_PAGESIZE
pagesize = sysconf(_SC_PAGESIZE);
#else
pagesize = getpagesize();
#endif
buflen = roundup(fs, pagesize) + pagesize;
EDEBUG(("fs: %ld buflen: %ld\n", fs, buflen));
#if defined(USE_MMAP)
buf = mkshare(buflen);
#endif
#if defined(USE_USGSHM)
buf = mkshm(buflen);
#endif
bufbase = buf;
bufend = buf + buflen;
EDEBUG(("buf: %X bufend: %X, buflen: %ld\n", buf, bufend, buflen));
buf = palign(buf, pagesize);
buflen -= buf - bufbase;
EDEBUG(("buf: %X bufend: %X, buflen: %ld (align %ld)\n", buf, bufend, buflen, buf - bufbase));
/*
* Dirty the whole buffer. This can die with various signals if
* we're trying to lock too much memory
*/
fillbytes(buf, buflen, '\0');
}
#ifdef USE_MMAP
LOCAL char *
mkshare(size)
int size;
{
int f;
char *addr;
#ifdef MAP_ANONYMOUS /* HP/UX */
f = -1;
addr = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, f, 0);
#else
if ((f = open("/dev/zero", O_RDWR)) < 0)
comerr("Cannot open '/dev/zero'.\n");
addr = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, f, 0);
#endif
if (addr == (char *)-1)
comerr("Cannot get mmap for %d Bytes on /dev/zero.\n", size);
close(f);
if (debug) errmsgno(EX_BAD, "shared memory segment attached: %x\n", addr);
return (addr);
}
#endif
#ifdef USE_USGSHM
#include
#include
LOCAL char *
mkshm(size)
int size;
{
int id;
char *addr;
/*
* Unfortunately, a declaration of shmat() is missing in old
* implementations such as AT&T SVr0 and SunOS.
* We cannot add this definition here because the return-type
* changed on newer systems.
*
* We will get a warning like this:
*
* warning: assignment of pointer from integer lacks a cast
* or
* warning: illegal combination of pointer and integer, op =
*/
/* extern char *shmat();*/
if ((id = shmget(IPC_PRIVATE, size, IPC_CREAT|0600)) == -1)
comerr("shmget failed\n");
if (debug) errmsgno(EX_BAD, "shared memory segment allocated: %d\n", id);
if ((addr = shmat(id, (char *)0, 0600)) == (char *)-1)
comerr("shmat failed\n");
if (debug) errmsgno(EX_BAD, "shared memory segment attached: %x\n", addr);
if (shmctl(id, IPC_RMID, 0) < 0)
comerr("shmctl failed to detach shared memory segment\n");
#ifdef SHM_LOCK
/*
* Although SHM_LOCK is standard, it seems that all versions of AIX
* ommit this definition.
*/
if (shmctl(id, SHM_LOCK, 0) < 0)
comerr("shmctl failed to lock shared memory segment\n");
#endif
return (addr);
}
#endif
LOCAL int faio_buffers;
LOCAL int faio_buf_size;
LOCAL int buf_idx;
LOCAL pid_t faio_pid;
/*#define faio_ref(n) (&((faio_t *)buf)[n])*/
EXPORT BOOL
init_faio(tracks, track, bufsize)
int tracks;
track_t *track;
int bufsize;
{
int n;
faio_t *f;
int pagesize;
char *base;
if (buflen == 0L)
return (FALSE);
#ifdef _SC_PAGESIZE
pagesize = sysconf(_SC_PAGESIZE);
#else
pagesize = getpagesize();
#endif
faio_buf_size = bufsize;
f = (faio_t *)buf;
/*
* Compute space for buffer headers.
*/
faio_buffers = (buflen - sizeof(*sp)) / bufsize;
EDEBUG(("bufsize: %d buffers: %d hdrsize %d\n", bufsize, faio_buffers, faio_buffers * sizeof(struct faio)));
/*
* Reduce buffer space by header space.
*/
n = sizeof(*sp) + faio_buffers * sizeof(struct faio);
n = roundup(n, pagesize);
faio_buffers = (buflen-n) / bufsize;
EDEBUG(("bufsize: %d buffers: %d hdrsize %d\n", bufsize, faio_buffers, faio_buffers * sizeof(struct faio)));
if (faio_buffers < MIN_BUFFERS) {
errmsgno(EX_BAD,
"write-buffer too small, minimum is %dk. Disabling.\n",
MIN_BUFFERS*bufsize/1024);
return (FALSE);
}
if (debug)
printf("Using %d buffers of %d bytes.\n", faio_buffers, faio_buf_size);
f = (faio_t *)buf;
base = buf + roundup(sizeof(*sp) + faio_buffers * sizeof(struct faio),
pagesize);
for (n = 0; n < faio_buffers; n++, f++, base += bufsize) {
/* Give all the buffers to the reader process */
f->owner = owner_writer;
f->bufp = base;
f->fd = -1;
}
sp = (struct faio_stats *)f; /* point past headers */
sp->gets = sp->puts = sp->done = 0L;
faio_pid = fork();
if (faio_pid < 0)
comerr("fork(2) failed");
if (faio_pid == 0) {
/* child process */
raisepri(1); /* almost max priority */
faio_reader(tracks, track);
/* NOTREACHED */
} else {
/* close all file-descriptors that only the child will use */
for (n = 1; n <= tracks; n++)
close(track[n].f);
}
return (TRUE);
}
EXPORT BOOL
await_faio()
{
int n;
int lastfd = -1;
faio_t *f;
/*
* Wait until the reader is active and has filled the buffer.
*/
if (lverbose || debug) {
printf("Waiting for reader process to fill input-buffer ... ");
flush();
}
faio_wait_on_buffer(faio_ref(faio_buffers - 1), owner_reader,
500*MSECS, 0);
if (lverbose || debug)
printf("input-buffer ready.\n");
sp->empty = sp->full = 0L; /* set correct stat state */
sp->cont_low = faio_buffers; /* set cont to max value */
f = faio_ref(0);
for (n = 0; n < faio_buffers; n++, f++) {
if (f->fd != lastfd &&
f->fd == STDIN_FILENO && f->len == 0) {
errmsgno(EX_BAD, "Premature EOF on stdin.\n");
kill(faio_pid, SIGKILL);
return (FALSE);
}
lastfd = f->fd;
}
return (TRUE);
}
EXPORT void
kill_faio()
{
kill(faio_pid, SIGKILL);
}
LOCAL void
faio_reader(tracks, track)
int tracks;
track_t *track;
{
/* This function should not return, but _exit. */
int trackno;
if (debug)
printf("\nfaio_reader starting\n");
for (trackno = 1; trackno <= tracks; trackno++) {
if (debug)
printf("\nfaio_reader reading track %d\n", trackno);
faio_read_track(&track[trackno]);
}
sp->done++;
if (debug)
printf("\nfaio_reader all tracks read, exiting\n");
/* Prevent hang if buffer is larger than all the tracks combined */
if (sp->gets == 0)
faio_ref(faio_buffers - 1)->owner = owner_reader;
_exit(0);
}
#ifndef faio_ref
LOCAL faio_t *
faio_ref(n)
int n;
{
return (&((faio_t *)buf)[n]);
}
#endif
LOCAL void
faio_read_track(trackp)
track_t *trackp;
{
int fd = trackp->f;
int bytespt = trackp->secsize * trackp->secspt;
int l;
long tracksize = trackp->tracksize;
long bytes_read = 0L;
long bytes_to_read;
if (bytespt > faio_buf_size) {
comerrno(EX_BAD,
"faio_read_track fatal: secsize %d secspt %d, bytespt(%d) > %d !!\n",
trackp->secsize, trackp->secspt, bytespt,
faio_buf_size);
}
do {
bytes_to_read = bytespt;
if (tracksize > 0) {
bytes_to_read = tracksize - bytes_read;
if (bytes_to_read > bytespt)
bytes_to_read = bytespt;
}
l = faio_read_segment(fd, faio_ref(buf_idx), bytes_to_read);
if (++buf_idx >= faio_buffers)
buf_idx = 0;
if (l <= 0)
break;
bytes_read += l;
} while (tracksize < 0 || bytes_read < tracksize);
close(fd); /* Don't keep files open longer than neccesary */
}
LOCAL void
faio_wait_on_buffer(f, s, delay, max_wait)
faio_t *f;
fowner_t s;
unsigned long delay;
unsigned long max_wait;
{
unsigned long max_loops;
if (f->owner == s)
return; /* return immediately if the buffer is ours */
if (s == owner_reader)
sp->empty++;
else
sp->full++;
max_loops = max_wait / delay + 1;
while (max_wait == 0 || max_loops--) {
usleep(delay);
if (f->owner == s)
return;
}
if (debug) {
errmsgno(EX_BAD,
"%lu microseconds passed waiting for %d current: %d idx: %d\n",
max_wait, s, f->owner, (f - faio_ref(0))/sizeof(*f));
}
comerrno(EX_BAD, "faio_wait_on_buffer for %s timed out.\n",
(s > owner_faio || s < owner_none) ? "bad_owner" : onames[s]);
}
LOCAL int
faio_read_segment(fd, f, len)
int fd;
faio_t *f;
int len;
{
int l;
faio_wait_on_buffer(f, owner_writer, WRITER_DELAY, WRITER_MAXWAIT);
f->fd = fd;
l = read_buf(fd, f->bufp, len);
f->len = l;
f->saved_errno = errno;
f->owner = owner_reader;
sp->puts++;
return l;
}
EXPORT int
faio_read_buf(fd, bp, size)
int fd;
char *bp;
int size;
{
char *bufp;
int len = faio_get_buf(fd, &bufp, size);
if (len > 0) {
movebytes(bufp, bp, len);
}
return len;
}
EXPORT int
faio_get_buf(fd, bpp, size)
int fd;
char **bpp;
int size;
{
faio_t *f;
int len;
again:
f = faio_ref(buf_idx);
if (f->owner == owner_faio) {
f->owner = owner_writer;
if (++buf_idx >= faio_buffers)
buf_idx = 0;
f = faio_ref(buf_idx);
}
if ((sp->puts - sp->gets) < sp->cont_low && sp->done == 0) {
EDEBUG(("gets: %d puts: %d cont: %d low: %d\n", sp->gets, sp->puts, sp->puts - sp->gets, sp->cont_low));
sp->cont_low = sp->puts - sp->gets;
}
faio_wait_on_buffer(f, owner_reader, READER_DELAY, READER_MAXWAIT);
len = f->len;
if (f->fd != fd) {
if (f->len == 0) {
/*
* If the tracksize for this track was known, and
* the tracksize is 0 mod bytespt, this happens.
*/
goto again;
}
comerrno(EX_BAD,
"faio_get_buf fatal: fd=%d, f->fd=%d, f->len=%d f->errno=%d\n",
fd, f->fd, f->len, f->saved_errno);
}
if (size < len) {
comerrno(EX_BAD,
"unexpected short read-attempt in faio_get_buf. size = %d, len = %d\n",
size, len);
}
if (len < 0)
errno = f->saved_errno;
sp->gets++;
*bpp = f->bufp;
f->owner = owner_faio;
return len;
}
EXPORT void
fifo_stats()
{
errmsgno(EX_BAD, "fifo had %ld puts and %ld gets.\n",
sp->puts, sp->gets);
errmsgno(EX_BAD, "fifo was %ld times empty and %ld times full, min fill was %ld%%.\n",
sp->empty, sp->full, (100L*sp->cont_low)/faio_buffers);
}
EXPORT int
fifo_percent(addone)
BOOL addone;
{
int percent;
if (buflen == 0L)
return (-1);
if (sp->done)
return (100);
percent = (100*(sp->puts + 1 - sp->gets)/faio_buffers);
if (percent > 100)
return (100);
return (percent);
}
#else /* FIFO */
#include
#include
#include
#include "cdrecord.h"
EXPORT void init_fifo __PR((long));
EXPORT BOOL init_faio __PR((int tracks, track_t *track, int));
EXPORT BOOL await_faio __PR((void));
EXPORT void kill_faio __PR((void));
EXPORT int faio_read_buf __PR((int f, char *bp, int size));
EXPORT int faio_get_buf __PR((int f, char **bpp, int size));
EXPORT void fifo_stats __PR((void));
EXPORT int fifo_percent __PR((BOOL addone));
EXPORT void
init_fifo(fs)
long fs;
{
errmsgno(EX_BAD, "Fifo not supported.\n");
}
EXPORT BOOL
init_faio(tracks, track, bufsize)
int tracks;
track_t *track;
int bufsize;
{
return (FALSE);
}
EXPORT BOOL
await_faio()
{
return (TRUE);
}
EXPORT void
kill_faio()
{
}
EXPORT int
faio_read_buf(fd, bp, size)
int fd;
char *bp;
int size;
{
return (0);
}
EXPORT int
faio_get_buf(fd, bpp, size)
int fd;
char **bpp;
int size;
{
return (0);
}
EXPORT void
fifo_stats()
{
}
EXPORT int
fifo_percent(addone)
BOOL addone;
{
return (-1);
}
#endif /* FIFO */