[thirdparty/cups.git] / backend / runloop.c

/*
 * "$Id: runloop.c 6649 2007-07-11 21:46:42Z mike $"
 *
 *   Common run loop APIs for the Common UNIX Printing System (CUPS).
 *
 *   Copyright 2007 by Apple Inc.
 *   Copyright 2006-2007 by Easy Software Products, all rights reserved.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Apple Inc. and are protected by Federal copyright
 *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 *   "LICENSE" which should have been included with this file.  If this
 *   file is missing or damaged, see the license at "http://www.cups.org/".
 *
 *   This file is subject to the Apple OS-Developed Software exception.
 *
 * Contents:
 *
 *   backendDrainOutput() - Drain pending print data to the device.
 *   backendRunLoop()     - Read and write print and back-channel data.
 */

/*
 * Include necessary headers.
 */

#include "backend-private.h"
#ifdef __hpux
#  include <sys/time.h>
#else
#  include <sys/select.h>
#endif /* __hpux */


/*
 * 'backendDrainOutput()' - Drain pending print data to the device.
 */

int					/* O - 0 on success, -1 on error */
backendDrainOutput(int print_fd,	/* I - Print file descriptor */
                   int device_fd)	/* I - Device file descriptor */
{
  int		nfds;			/* Maximum file descriptor value + 1 */
  fd_set	input;			/* Input set for reading */
  ssize_t	print_bytes,		/* Print bytes read */
		bytes;			/* Bytes written */
  char		print_buffer[8192],	/* Print data buffer */
		*print_ptr;		/* Pointer into print data buffer */
  struct timeval timeout;		/* Timeout for read... */


  fprintf(stderr, "DEBUG: backendDrainOutput(print_fd=%d, device_fd=%d)\n",
          print_fd, device_fd);

 /*
  * Figure out the maximum file descriptor value to use with select()...
  */

  nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;

 /*
  * Now loop until we are out of data from print_fd...
  */

  for (;;)
  {
   /*
    * Use select() to determine whether we have data to copy around...
    */

    FD_ZERO(&input);
    FD_SET(print_fd, &input);

    timeout.tv_sec  = 0;
    timeout.tv_usec = 0;

    if (select(nfds, &input, NULL, NULL, &timeout) < 0)
      return (-1);

    if (!FD_ISSET(print_fd, &input))
      return (0);

    if ((print_bytes = read(print_fd, print_buffer,
			    sizeof(print_buffer))) < 0)
    {
     /*
      * Read error - bail if we don't see EAGAIN or EINTR...
      */

      if (errno != EAGAIN || errno != EINTR)
      {
	perror("ERROR: Unable to read print data");
	return (-1);
      }

      print_bytes = 0;
    }
    else if (print_bytes == 0)
    {
     /*
      * End of file, return...
      */

      return (0);
    }

    fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
	    (int)print_bytes);

    for (print_ptr = print_buffer; print_bytes > 0;)
    {
      if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
      {
       /*
        * Write error - bail if we don't see an error we can retry...
	*/

        if (errno != ENOSPC && errno != ENXIO && errno != EAGAIN &&
	    errno != EINTR && errno != ENOTTY)
	{
	  fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
	          strerror(errno));
	  return (-1);
	}
      }
      else
      {
        fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);

        print_bytes -= bytes;
	print_ptr   += bytes;
      }
    }
  }
}


/*
 * 'backendRunLoop()' - Read and write print and back-channel data.
 */

ssize_t					/* O - Total bytes on success, -1 on error */
backendRunLoop(
    int  print_fd,			/* I - Print file descriptor */
    int  device_fd,			/* I - Device file descriptor */
    int  use_bc,			/* I - Use back-channel? */
    void (*side_cb)(int, int, int))	/* I - Side-channel callback */
{
  int		nfds;			/* Maximum file descriptor value + 1 */
  fd_set	input,			/* Input set for reading */
		output;			/* Output set for writing */
  ssize_t	print_bytes,		/* Print bytes read */
		bc_bytes,		/* Backchannel bytes read */
		total_bytes,		/* Total bytes written */
		bytes;			/* Bytes written */
  int		paperout;		/* "Paper out" status */
  int		offline;		/* "Off-line" status */
  char		print_buffer[8192],	/* Print data buffer */
		*print_ptr,		/* Pointer into print data buffer */
		bc_buffer[1024];	/* Back-channel data buffer */
#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
  struct sigaction action;		/* Actions for POSIX signals */
#endif /* HAVE_SIGACTION && !HAVE_SIGSET */


  fprintf(stderr,
          "DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d, "
	  "side_cb=%p)\n",
          print_fd, device_fd, use_bc, side_cb);

 /*
  * If we are printing data from a print driver on stdin, ignore SIGTERM
  * so that the driver can finish out any page data, e.g. to eject the
  * current page.  We only do this for stdin printing as otherwise there
  * is no way to cancel a raw print job...
  */

  if (!print_fd)
  {
#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
    sigset(SIGTERM, SIG_IGN);
#elif defined(HAVE_SIGACTION)
    memset(&action, 0, sizeof(action));

    sigemptyset(&action.sa_mask);
    action.sa_handler = SIG_IGN;
    sigaction(SIGTERM, &action, NULL);
#else
    signal(SIGTERM, SIG_IGN);
#endif /* HAVE_SIGSET */
  }

 /*
  * Figure out the maximum file descriptor value to use with select()...
  */

  nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;

 /*
  * Now loop until we are out of data from print_fd...
  */

  for (print_bytes = 0, print_ptr = print_buffer, offline = -1,
           paperout = -1, total_bytes = 0;;)
  {
   /*
    * Use select() to determine whether we have data to copy around...
    */

    FD_ZERO(&input);
    if (!print_bytes)
      FD_SET(print_fd, &input);
    if (use_bc)
      FD_SET(device_fd, &input);
    if (side_cb)
      FD_SET(CUPS_SC_FD, &input);

    FD_ZERO(&output);
    if (print_bytes || !use_bc)
      FD_SET(device_fd, &output);

    if (use_bc || side_cb)
    {
      if (select(nfds, &input, &output, NULL, NULL) < 0)
      {
       /*
	* Pause printing to clear any pending errors...
	*/

	if (errno == ENXIO && offline != 1)
	{
	  fputs("STATE: +offline-error\n", stderr);
	  fputs(_("INFO: Printer is currently off-line.\n"), stderr);
	  offline = 1;
	}
	else if (errno == EINTR && total_bytes == 0)
	{
	  fputs("DEBUG: Received an interrupt before any bytes were "
	        "written, aborting!\n", stderr);
          return (0);
	}

	sleep(1);
	continue;
      }
    }

   /*
    * Check if we have a side-channel request ready...
    */

    if (side_cb && FD_ISSET(CUPS_SC_FD, &input))
      (*side_cb)(print_fd, device_fd, use_bc);

   /*
    * Check if we have back-channel data ready...
    */

    if (FD_ISSET(device_fd, &input))
    {
      if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)
      {
	fprintf(stderr,
	        "DEBUG: Received " CUPS_LLFMT " bytes of back-channel data!\n",
	        CUPS_LLCAST bc_bytes);
        cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);
      }
    }

   /*
    * Check if we have print data ready...
    */

    if (FD_ISSET(print_fd, &input))
    {
      if ((print_bytes = read(print_fd, print_buffer,
                              sizeof(print_buffer))) < 0)
      {
       /*
        * Read error - bail if we don't see EAGAIN or EINTR...
	*/

	if (errno != EAGAIN || errno != EINTR)
	{
	  perror("ERROR: Unable to read print data");
	  return (-1);
	}

        print_bytes = 0;
      }
      else if (print_bytes == 0)
      {
       /*
        * End of file, break out of the loop...
	*/

        break;
      }

      print_ptr = print_buffer;

      fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
              (int)print_bytes);
    }

   /*
    * Check if the device is ready to receive data and we have data to
    * send...
    */

    if (print_bytes && FD_ISSET(device_fd, &output))
    {
      if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
      {
       /*
        * Write error - bail if we don't see an error we can retry...
	*/

        if (errno == ENOSPC)
	{
	  if (paperout != 1)
	  {
	    fputs("STATE: +media-empty-error\n", stderr);
	    fputs(_("ERROR: Out of paper!\n"), stderr);
	    paperout = 1;
	  }
        }
	else if (errno == ENXIO)
	{
	  if (offline != 1)
	  {
	    fputs("STATE: +offline-error\n", stderr);
	    fputs(_("INFO: Printer is currently off-line.\n"), stderr);
	    offline = 1;
	  }
	}
	else if (errno != EAGAIN && errno != EINTR && errno != ENOTTY)
	{
	  fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
	          strerror(errno));
	  return (-1);
	}
      }
      else
      {
        if (paperout)
	{
	  fputs("STATE: -media-empty-error\n", stderr);
	  paperout = 0;
	}

	if (offline)
	{
	  fputs("STATE: -offline-error\n", stderr);
	  fputs(_("INFO: Printer is now on-line.\n"), stderr);
	  offline = 0;
	}

        fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);

        print_bytes -= bytes;
	print_ptr   += bytes;
	total_bytes += bytes;
      }
    }
  }

 /*
  * Return with success...
  */

  return (total_bytes);
}


/*
 * End of "$Id: runloop.c 6649 2007-07-11 21:46:42Z mike $".
 */
Commit	Line	Data
ed486911	1	/*
bc44d920	2	* "$Id: runloop.c 6649 2007-07-11 21:46:42Z mike $"
ed486911	3	*
09a101d6	4	* Common run loop APIs for the Common UNIX Printing System (CUPS).
ed486911	5	*
bc44d920	6	* Copyright 2007 by Apple Inc.
f7deaa1a	7	* Copyright 2006-2007 by Easy Software Products, all rights reserved.
ed486911	8	*
ed486911	9	* These coded instructions, statements, and computer programs are the
bc44d920	10	* property of Apple Inc. and are protected by Federal copyright
bc44d920	11	* law. Distribution and use rights are outlined in the file "LICENSE.txt"
ed486911	12	* "LICENSE" which should have been included with this file. If this
bc44d920	13	* file is missing or damaged, see the license at "http://www.cups.org/".
ed486911	14	*
	15	* This file is subject to the Apple OS-Developed Software exception.
	16	*
	17	* Contents:
	18	*
09a101d6	19	* backendDrainOutput() - Drain pending print data to the device.
09a101d6	20	* backendRunLoop() - Read and write print and back-channel data.
ed486911	21	*/
	22
	23	/*
	24	* Include necessary headers.
	25	*/
	26
	27	#include "backend-private.h"
d09495fa	28	#ifdef __hpux
	29	# include <sys/time.h>
	30	#else
	31	# include <sys/select.h>
	32	#endif /* __hpux */
ed486911	33
ed486911	34
09a101d6	35	/*
	36	* 'backendDrainOutput()' - Drain pending print data to the device.
	37	*/
	38
	39	int /* O - 0 on success, -1 on error */
	40	backendDrainOutput(int print_fd, /* I - Print file descriptor */
	41	int device_fd) /* I - Device file descriptor */
	42	{
	43	int nfds; /* Maximum file descriptor value + 1 */
	44	fd_set input; /* Input set for reading */
	45	ssize_t print_bytes, /* Print bytes read */
	46	bytes; /* Bytes written */
	47	char print_buffer[8192], /* Print data buffer */
	48	print_ptr; / Pointer into print data buffer */
	49	struct timeval timeout; /* Timeout for read... */
	50
	51
	52	fprintf(stderr, "DEBUG: backendDrainOutput(print_fd=%d, device_fd=%d)\n",
	53	print_fd, device_fd);
	54
	55	/*
	56	* Figure out the maximum file descriptor value to use with select()...
	57	*/
	58
	59	nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
	60
	61	/*
	62	* Now loop until we are out of data from print_fd...
	63	*/
	64
	65	for (;;)
	66	{
	67	/*
	68	* Use select() to determine whether we have data to copy around...
	69	*/
	70
	71	FD_ZERO(&input);
	72	FD_SET(print_fd, &input);
	73
	74	timeout.tv_sec = 0;
	75	timeout.tv_usec = 0;
	76
	77	if (select(nfds, &input, NULL, NULL, &timeout) < 0)
	78	return (-1);
	79
	80	if (!FD_ISSET(print_fd, &input))
	81	return (0);
	82
	83	if ((print_bytes = read(print_fd, print_buffer,
	84	sizeof(print_buffer))) < 0)
	85	{
	86	/*
	87	* Read error - bail if we don't see EAGAIN or EINTR...
	88	*/
	89
	90	if (errno != EAGAIN \|\| errno != EINTR)
	91	{
	92	perror("ERROR: Unable to read print data");
	93	return (-1);
	94	}
	95
	96	print_bytes = 0;
	97	}
	98	else if (print_bytes == 0)
99	{
100	/*
101	* End of file, return...
102	*/
103
104	return (0);
105	}
106
107	fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
108	(int)print_bytes);
109
110	for (print_ptr = print_buffer; print_bytes > 0;)
111	{
112	if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
113	{
114	/*
115	* Write error - bail if we don't see an error we can retry...
116	*/
117
118	if (errno != ENOSPC && errno != ENXIO && errno != EAGAIN &&
119	errno != EINTR && errno != ENOTTY)
120	{
121	fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
122	strerror(errno));
123	return (-1);
124	}
125	}
126	else
127	{
128	fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
129
130	print_bytes -= bytes;
131	print_ptr += bytes;
132	}
133	}
134	}
135	}
136
137
ed486911	138	/*
	139	* 'backendRunLoop()' - Read and write print and back-channel data.
	140	*/
	141
	142	ssize_t /* O - Total bytes on success, -1 on error */
f7deaa1a	143	backendRunLoop(
	144	int print_fd, /* I - Print file descriptor */
	145	int device_fd, /* I - Device file descriptor */
	146	int use_bc, /* I - Use back-channel? */
	147	void (side_cb)(int, int, int)) / I - Side-channel callback */
ed486911	148	{
	149	int nfds; /* Maximum file descriptor value + 1 */
	150	fd_set input, /* Input set for reading */
	151	output; /* Output set for writing */
	152	ssize_t print_bytes, /* Print bytes read */
	153	bc_bytes, /* Backchannel bytes read */
	154	total_bytes, /* Total bytes written */
	155	bytes; /* Bytes written */
	156	int paperout; /* "Paper out" status */
8ca02f3c	157	int offline; /* "Off-line" status */
ed486911	158	char print_buffer[8192], /* Print data buffer */
	159	print_ptr, / Pointer into print data buffer */
	160	bc_buffer[1024]; /* Back-channel data buffer */
	161	#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
	162	struct sigaction action; /* Actions for POSIX signals */
	163	#endif /* HAVE_SIGACTION && !HAVE_SIGSET */
	164
	165
c0e1af83	166	fprintf(stderr,
09a101d6	167	"DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d, "
	168	"side_cb=%p)\n",
	169	print_fd, device_fd, use_bc, side_cb);
8ca02f3c	170
ed486911	171	/*
	172	* If we are printing data from a print driver on stdin, ignore SIGTERM
	173	* so that the driver can finish out any page data, e.g. to eject the
	174	* current page. We only do this for stdin printing as otherwise there
	175	* is no way to cancel a raw print job...
	176	*/
	177
	178	if (!print_fd)
	179	{
	180	#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
	181	sigset(SIGTERM, SIG_IGN);
	182	#elif defined(HAVE_SIGACTION)
	183	memset(&action, 0, sizeof(action));
	184
	185	sigemptyset(&action.sa_mask);
	186	action.sa_handler = SIG_IGN;
	187	sigaction(SIGTERM, &action, NULL);
	188	#else
	189	signal(SIGTERM, SIG_IGN);
	190	#endif /* HAVE_SIGSET */
	191	}
	192
	193	/*
	194	* Figure out the maximum file descriptor value to use with select()...
	195	*/
	196
	197	nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
	198
	199	/*
	200	* Now loop until we are out of data from print_fd...
	201	*/
	202
b94498cf	203	for (print_bytes = 0, print_ptr = print_buffer, offline = -1,
b94498cf	204	paperout = -1, total_bytes = 0;;)
ed486911	205	{
	206	/*
	207	* Use select() to determine whether we have data to copy around...
	208	*/
	209
	210	FD_ZERO(&input);
	211	if (!print_bytes)
	212	FD_SET(print_fd, &input);
	213	if (use_bc)
	214	FD_SET(device_fd, &input);
f7deaa1a	215	if (side_cb)
f7deaa1a	216	FD_SET(CUPS_SC_FD, &input);
ed486911	217
ed486911	218	FD_ZERO(&output);
8ca02f3c	219	if (print_bytes \|\| !use_bc)
ed486911	220	FD_SET(device_fd, &output);
ed486911	221
f7deaa1a	222	if (use_bc \|\| side_cb)
8ca02f3c	223	{
	224	if (select(nfds, &input, &output, NULL, NULL) < 0)
	225	{
	226	/*
	227	* Pause printing to clear any pending errors...
	228	*/
	229
b94498cf	230	if (errno == ENXIO && offline != 1)
8ca02f3c	231	{
8ca02f3c	232	fputs("STATE: +offline-error\n", stderr);
c0e1af83	233	fputs(_("INFO: Printer is currently off-line.\n"), stderr);
8ca02f3c	234	offline = 1;
8ca02f3c	235	}
b94498cf	236	else if (errno == EINTR && total_bytes == 0)
	237	{
	238	fputs("DEBUG: Received an interrupt before any bytes were "
	239	"written, aborting!\n", stderr);
	240	return (0);
	241	}
8ca02f3c	242
	243	sleep(1);
	244	continue;
	245	}
	246	}
ed486911	247
f7deaa1a	248	/*
	249	* Check if we have a side-channel request ready...
	250	*/
	251
	252	if (side_cb && FD_ISSET(CUPS_SC_FD, &input))
	253	(*side_cb)(print_fd, device_fd, use_bc);
	254
ed486911	255	/*
	256	* Check if we have back-channel data ready...
	257	*/
	258
	259	if (FD_ISSET(device_fd, &input))
	260	{
	261	if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)
	262	{
	263	fprintf(stderr,
	264	"DEBUG: Received " CUPS_LLFMT " bytes of back-channel data!\n",
	265	CUPS_LLCAST bc_bytes);
	266	cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);
	267	}
	268	}
	269
	270	/*
	271	* Check if we have print data ready...
	272	*/
	273
	274	if (FD_ISSET(print_fd, &input))
	275	{
	276	if ((print_bytes = read(print_fd, print_buffer,
	277	sizeof(print_buffer))) < 0)
	278	{
	279	/*
	280	* Read error - bail if we don't see EAGAIN or EINTR...
	281	*/
	282
	283	if (errno != EAGAIN \|\| errno != EINTR)
	284	{
	285	perror("ERROR: Unable to read print data");
	286	return (-1);
	287	}
	288
	289	print_bytes = 0;
	290	}
	291	else if (print_bytes == 0)
	292	{
	293	/*
	294	* End of file, break out of the loop...
	295	*/
	296
	297	break;
	298	}
	299
	300	print_ptr = print_buffer;
8ca02f3c	301
	302	fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
	303	(int)print_bytes);
ed486911	304	}
	305
	306	/*
	307	* Check if the device is ready to receive data and we have data to
	308	* send...
	309	*/
	310
	311	if (print_bytes && FD_ISSET(device_fd, &output))
	312	{
	313	if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
	314	{
	315	/*
	316	* Write error - bail if we don't see an error we can retry...
	317	*/
	318
	319	if (errno == ENOSPC)
	320	{
b94498cf	321	if (paperout != 1)
ed486911	322	{
b86bc4cf	323	fputs("STATE: +media-empty-error\n", stderr);
c0e1af83	324	fputs(_("ERROR: Out of paper!\n"), stderr);
ed486911	325	paperout = 1;
	326	}
	327	}
8ca02f3c	328	else if (errno == ENXIO)
8ca02f3c	329	{
b94498cf	330	if (offline != 1)
8ca02f3c	331	{
8ca02f3c	332	fputs("STATE: +offline-error\n", stderr);
c0e1af83	333	fputs(_("INFO: Printer is currently off-line.\n"), stderr);
8ca02f3c	334	offline = 1;
	335	}
	336	}
ed486911	337	else if (errno != EAGAIN && errno != EINTR && errno != ENOTTY)
ed486911	338	{
c0e1af83	339	fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
c0e1af83	340	strerror(errno));
ed486911	341	return (-1);
	342	}
	343	}
	344	else
	345	{
	346	if (paperout)
	347	{
b86bc4cf	348	fputs("STATE: -media-empty-error\n", stderr);
ed486911	349	paperout = 0;
	350	}
	351
8ca02f3c	352	if (offline)
	353	{
	354	fputs("STATE: -offline-error\n", stderr);
c0e1af83	355	fputs(_("INFO: Printer is now on-line.\n"), stderr);
8ca02f3c	356	offline = 0;
	357	}
	358
	359	fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
ed486911	360
	361	print_bytes -= bytes;
	362	print_ptr += bytes;
	363	total_bytes += bytes;
	364	}
	365	}
	366	}
	367
	368	/*
	369	* Return with success...
	370	*/
	371
	372	return (total_bytes);
	373	}
	374
	375
	376	/*
bc44d920	377	* End of "$Id: runloop.c 6649 2007-07-11 21:46:42Z mike $".
ed486911	378	*/