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

/*
 * "$Id: runloop.c 6591 2007-06-21 20:35:28Z mike $"
 *
 *   Common run loop APIs for the Common UNIX Printing System (CUPS).
 *
 *   Copyright 2006-2007 by Easy Software Products, all rights reserved.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Easy Software Products and are protected by Federal
 *   copyright law.  Distribution and use rights are outlined in the file
 *   "LICENSE" which should have been included with this file.  If this
 *   file is missing or damaged please contact Easy Software Products
 *   at:
 *
 *       Attn: CUPS Licensing Information
 *       Easy Software Products
 *       44141 Airport View Drive, Suite 204
 *       Hollywood, Maryland 20636 USA
 *
 *       Voice: (301) 373-9600
 *       EMail: cups-info@cups.org
 *         WWW: 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 6591 2007-06-21 20:35:28Z mike $".
 */
Commit	Line	Data
ed486911	1	/*
09a101d6	2	* "$Id: runloop.c 6591 2007-06-21 20:35:28Z mike $"
ed486911	3	*
09a101d6	4	* Common run loop APIs for the Common UNIX Printing System (CUPS).
ed486911	5	*
f7deaa1a	6	* Copyright 2006-2007 by Easy Software Products, all rights reserved.
ed486911	7	*
	8	* These coded instructions, statements, and computer programs are the
	9	* property of Easy Software Products and are protected by Federal
	10	* copyright law. Distribution and use rights are outlined in the file
	11	* "LICENSE" which should have been included with this file. If this
	12	* file is missing or damaged please contact Easy Software Products
	13	* at:
	14	*
	15	* Attn: CUPS Licensing Information
	16	* Easy Software Products
	17	* 44141 Airport View Drive, Suite 204
	18	* Hollywood, Maryland 20636 USA
	19	*
	20	* Voice: (301) 373-9600
	21	* EMail: cups-info@cups.org
	22	* WWW: http://www.cups.org
	23	*
	24	* This file is subject to the Apple OS-Developed Software exception.
	25	*
	26	* Contents:
	27	*
09a101d6	28	* backendDrainOutput() - Drain pending print data to the device.
09a101d6	29	* backendRunLoop() - Read and write print and back-channel data.
ed486911	30	*/
	31
	32	/*
	33	* Include necessary headers.
	34	*/
	35
	36	#include "backend-private.h"
d09495fa	37	#ifdef __hpux
	38	# include <sys/time.h>
	39	#else
	40	# include <sys/select.h>
	41	#endif /* __hpux */
ed486911	42
ed486911	43
09a101d6	44	/*
	45	* 'backendDrainOutput()' - Drain pending print data to the device.
	46	*/
	47
	48	int /* O - 0 on success, -1 on error */
	49	backendDrainOutput(int print_fd, /* I - Print file descriptor */
	50	int device_fd) /* I - Device file descriptor */
	51	{
	52	int nfds; /* Maximum file descriptor value + 1 */
	53	fd_set input; /* Input set for reading */
	54	ssize_t print_bytes, /* Print bytes read */
	55	bytes; /* Bytes written */
	56	char print_buffer[8192], /* Print data buffer */
	57	print_ptr; / Pointer into print data buffer */
	58	struct timeval timeout; /* Timeout for read... */
	59
	60
	61	fprintf(stderr, "DEBUG: backendDrainOutput(print_fd=%d, device_fd=%d)\n",
	62	print_fd, device_fd);
	63
	64	/*
	65	* Figure out the maximum file descriptor value to use with select()...
	66	*/
	67
	68	nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
	69
	70	/*
	71	* Now loop until we are out of data from print_fd...
	72	*/
	73
	74	for (;;)
	75	{
	76	/*
	77	* Use select() to determine whether we have data to copy around...
	78	*/
	79
	80	FD_ZERO(&input);
	81	FD_SET(print_fd, &input);
	82
	83	timeout.tv_sec = 0;
	84	timeout.tv_usec = 0;
	85
	86	if (select(nfds, &input, NULL, NULL, &timeout) < 0)
	87	return (-1);
	88
	89	if (!FD_ISSET(print_fd, &input))
	90	return (0);
	91
	92	if ((print_bytes = read(print_fd, print_buffer,
	93	sizeof(print_buffer))) < 0)
	94	{
	95	/*
	96	* Read error - bail if we don't see EAGAIN or EINTR...
	97	*/
	98
	99	if (errno != EAGAIN \|\| errno != EINTR)
	100	{
	101	perror("ERROR: Unable to read print data");
	102	return (-1);
	103	}
	104
	105	print_bytes = 0;
	106	}
	107	else if (print_bytes == 0)
108	{
109	/*
110	* End of file, return...
111	*/
112
113	return (0);
114	}
115
116	fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
117	(int)print_bytes);
118
119	for (print_ptr = print_buffer; print_bytes > 0;)
120	{
121	if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
122	{
123	/*
124	* Write error - bail if we don't see an error we can retry...
125	*/
126
127	if (errno != ENOSPC && errno != ENXIO && errno != EAGAIN &&
128	errno != EINTR && errno != ENOTTY)
129	{
130	fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
131	strerror(errno));
132	return (-1);
133	}
134	}
135	else
136	{
137	fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
138
139	print_bytes -= bytes;
140	print_ptr += bytes;
141	}
142	}
143	}
144	}
145
146
ed486911	147	/*
	148	* 'backendRunLoop()' - Read and write print and back-channel data.
	149	*/
	150
	151	ssize_t /* O - Total bytes on success, -1 on error */
f7deaa1a	152	backendRunLoop(
	153	int print_fd, /* I - Print file descriptor */
	154	int device_fd, /* I - Device file descriptor */
	155	int use_bc, /* I - Use back-channel? */
	156	void (side_cb)(int, int, int)) / I - Side-channel callback */
ed486911	157	{
	158	int nfds; /* Maximum file descriptor value + 1 */
	159	fd_set input, /* Input set for reading */
	160	output; /* Output set for writing */
	161	ssize_t print_bytes, /* Print bytes read */
	162	bc_bytes, /* Backchannel bytes read */
	163	total_bytes, /* Total bytes written */
	164	bytes; /* Bytes written */
	165	int paperout; /* "Paper out" status */
8ca02f3c	166	int offline; /* "Off-line" status */
ed486911	167	char print_buffer[8192], /* Print data buffer */
	168	print_ptr, / Pointer into print data buffer */
	169	bc_buffer[1024]; /* Back-channel data buffer */
	170	#if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
	171	struct sigaction action; /* Actions for POSIX signals */
	172	#endif /* HAVE_SIGACTION && !HAVE_SIGSET */
	173
	174
c0e1af83	175	fprintf(stderr,
09a101d6	176	"DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d, "
	177	"side_cb=%p)\n",
	178	print_fd, device_fd, use_bc, side_cb);
8ca02f3c	179
ed486911	180	/*
	181	* If we are printing data from a print driver on stdin, ignore SIGTERM
	182	* so that the driver can finish out any page data, e.g. to eject the
	183	* current page. We only do this for stdin printing as otherwise there
	184	* is no way to cancel a raw print job...
	185	*/
	186
	187	if (!print_fd)
	188	{
	189	#ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
	190	sigset(SIGTERM, SIG_IGN);
	191	#elif defined(HAVE_SIGACTION)
	192	memset(&action, 0, sizeof(action));
	193
	194	sigemptyset(&action.sa_mask);
	195	action.sa_handler = SIG_IGN;
	196	sigaction(SIGTERM, &action, NULL);
	197	#else
	198	signal(SIGTERM, SIG_IGN);
	199	#endif /* HAVE_SIGSET */
	200	}
	201
	202	/*
	203	* Figure out the maximum file descriptor value to use with select()...
	204	*/
	205
	206	nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
	207
	208	/*
	209	* Now loop until we are out of data from print_fd...
	210	*/
	211
b94498cf	212	for (print_bytes = 0, print_ptr = print_buffer, offline = -1,
b94498cf	213	paperout = -1, total_bytes = 0;;)
ed486911	214	{
	215	/*
	216	* Use select() to determine whether we have data to copy around...
	217	*/
	218
	219	FD_ZERO(&input);
	220	if (!print_bytes)
	221	FD_SET(print_fd, &input);
	222	if (use_bc)
	223	FD_SET(device_fd, &input);
f7deaa1a	224	if (side_cb)
f7deaa1a	225	FD_SET(CUPS_SC_FD, &input);
ed486911	226
ed486911	227	FD_ZERO(&output);
8ca02f3c	228	if (print_bytes \|\| !use_bc)
ed486911	229	FD_SET(device_fd, &output);
ed486911	230
f7deaa1a	231	if (use_bc \|\| side_cb)
8ca02f3c	232	{
	233	if (select(nfds, &input, &output, NULL, NULL) < 0)
	234	{
	235	/*
	236	* Pause printing to clear any pending errors...
	237	*/
	238
b94498cf	239	if (errno == ENXIO && offline != 1)
8ca02f3c	240	{
8ca02f3c	241	fputs("STATE: +offline-error\n", stderr);
c0e1af83	242	fputs(_("INFO: Printer is currently off-line.\n"), stderr);
8ca02f3c	243	offline = 1;
8ca02f3c	244	}
b94498cf	245	else if (errno == EINTR && total_bytes == 0)
	246	{
	247	fputs("DEBUG: Received an interrupt before any bytes were "
	248	"written, aborting!\n", stderr);
	249	return (0);
	250	}
8ca02f3c	251
	252	sleep(1);
	253	continue;
	254	}
	255	}
ed486911	256
f7deaa1a	257	/*
	258	* Check if we have a side-channel request ready...
	259	*/
	260
	261	if (side_cb && FD_ISSET(CUPS_SC_FD, &input))
	262	(*side_cb)(print_fd, device_fd, use_bc);
	263
ed486911	264	/*
	265	* Check if we have back-channel data ready...
	266	*/
	267
	268	if (FD_ISSET(device_fd, &input))
	269	{
	270	if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)
	271	{
	272	fprintf(stderr,
	273	"DEBUG: Received " CUPS_LLFMT " bytes of back-channel data!\n",
	274	CUPS_LLCAST bc_bytes);
	275	cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);
	276	}
	277	}
	278
	279	/*
	280	* Check if we have print data ready...
	281	*/
	282
	283	if (FD_ISSET(print_fd, &input))
	284	{
	285	if ((print_bytes = read(print_fd, print_buffer,
	286	sizeof(print_buffer))) < 0)
	287	{
	288	/*
	289	* Read error - bail if we don't see EAGAIN or EINTR...
	290	*/
	291
	292	if (errno != EAGAIN \|\| errno != EINTR)
	293	{
	294	perror("ERROR: Unable to read print data");
	295	return (-1);
	296	}
	297
	298	print_bytes = 0;
	299	}
	300	else if (print_bytes == 0)
	301	{
	302	/*
	303	* End of file, break out of the loop...
	304	*/
	305
	306	break;
	307	}
	308
	309	print_ptr = print_buffer;
8ca02f3c	310
	311	fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
	312	(int)print_bytes);
ed486911	313	}
	314
	315	/*
	316	* Check if the device is ready to receive data and we have data to
	317	* send...
	318	*/
	319
	320	if (print_bytes && FD_ISSET(device_fd, &output))
	321	{
	322	if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
	323	{
	324	/*
	325	* Write error - bail if we don't see an error we can retry...
	326	*/
	327
	328	if (errno == ENOSPC)
	329	{
b94498cf	330	if (paperout != 1)
ed486911	331	{
b86bc4cf	332	fputs("STATE: +media-empty-error\n", stderr);
c0e1af83	333	fputs(_("ERROR: Out of paper!\n"), stderr);
ed486911	334	paperout = 1;
	335	}
	336	}
8ca02f3c	337	else if (errno == ENXIO)
8ca02f3c	338	{
b94498cf	339	if (offline != 1)
8ca02f3c	340	{
8ca02f3c	341	fputs("STATE: +offline-error\n", stderr);
c0e1af83	342	fputs(_("INFO: Printer is currently off-line.\n"), stderr);
8ca02f3c	343	offline = 1;
	344	}
	345	}
ed486911	346	else if (errno != EAGAIN && errno != EINTR && errno != ENOTTY)
ed486911	347	{
c0e1af83	348	fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
c0e1af83	349	strerror(errno));
ed486911	350	return (-1);
	351	}
	352	}
	353	else
	354	{
	355	if (paperout)
	356	{
b86bc4cf	357	fputs("STATE: -media-empty-error\n", stderr);
ed486911	358	paperout = 0;
	359	}
	360
8ca02f3c	361	if (offline)
	362	{
	363	fputs("STATE: -offline-error\n", stderr);
c0e1af83	364	fputs(_("INFO: Printer is now on-line.\n"), stderr);
8ca02f3c	365	offline = 0;
	366	}
	367
	368	fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
ed486911	369
	370	print_bytes -= bytes;
	371	print_ptr += bytes;
	372	total_bytes += bytes;
	373	}
	374	}
	375	}
	376
	377	/*
	378	* Return with success...
	379	*/
	380
	381	return (total_bytes);
	382	}
	383
	384
	385	/*
09a101d6	386	* End of "$Id: runloop.c 6591 2007-06-21 20:35:28Z mike $".
ed486911	387	*/