2 * "$Id: runloop.c 10369 2012-03-21 04:31:19Z mike $"
4 * Common run loop APIs for CUPS backends.
6 * Copyright 2007-2012 by Apple Inc.
7 * Copyright 2006-2007 by Easy Software Products, all rights reserved.
9 * These coded instructions, statements, and computer programs are the
10 * property of Apple Inc. and are protected by Federal copyright
11 * law. Distribution and use rights are outlined in the file "LICENSE.txt"
12 * "LICENSE" which should have been included with this file. If this
13 * file is missing or damaged, see the license at "http://www.cups.org/".
15 * This file is subject to the Apple OS-Developed Software exception.
19 * backendDrainOutput() - Drain pending print data to the device.
20 * backendRunLoop() - Read and write print and back-channel data.
21 * backendWaitLoop() - Wait for input from stdin while handling
22 * side-channel queries.
26 * Include necessary headers.
29 #include "backend-private.h"
32 # include <sys/time.h>
34 # include <sys/select.h>
39 * 'backendDrainOutput()' - Drain pending print data to the device.
42 int /* O - 0 on success, -1 on error */
43 backendDrainOutput(int print_fd, /* I - Print file descriptor */
44 int device_fd) /* I - Device file descriptor */
46 int nfds; /* Maximum file descriptor value + 1 */
47 fd_set input; /* Input set for reading */
48 ssize_t print_bytes, /* Print bytes read */
49 bytes; /* Bytes written */
50 char print_buffer[8192], /* Print data buffer */
51 *print_ptr; /* Pointer into print data buffer */
52 struct timeval timeout; /* Timeout for read... */
55 fprintf(stderr, "DEBUG: backendDrainOutput(print_fd=%d, device_fd=%d)\n",
59 * Figure out the maximum file descriptor value to use with select()...
62 nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
65 * Now loop until we are out of data from print_fd...
71 * Use select() to determine whether we have data to copy around...
75 FD_SET(print_fd, &input);
80 if (select(nfds, &input, NULL, NULL, &timeout) < 0)
83 if (!FD_ISSET(print_fd, &input))
86 if ((print_bytes = read(print_fd, print_buffer,
87 sizeof(print_buffer))) < 0)
90 * Read error - bail if we don't see EAGAIN or EINTR...
93 if (errno != EAGAIN || errno != EINTR)
95 _cupsLangPrintError("ERROR", _("Unable to read print data"));
101 else if (print_bytes == 0)
104 * End of file, return...
110 fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
113 for (print_ptr = print_buffer; print_bytes > 0;)
115 if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
118 * Write error - bail if we don't see an error we can retry...
121 if (errno != ENOSPC && errno != ENXIO && errno != EAGAIN &&
122 errno != EINTR && errno != ENOTTY)
124 _cupsLangPrintError("ERROR", _("Unable to write print data"));
130 fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
132 print_bytes -= bytes;
141 * 'backendRunLoop()' - Read and write print and back-channel data.
144 ssize_t /* O - Total bytes on success, -1 on error */
146 int print_fd, /* I - Print file descriptor */
147 int device_fd, /* I - Device file descriptor */
148 int snmp_fd, /* I - SNMP socket or -1 if none */
149 http_addr_t *addr, /* I - Address of device */
150 int use_bc, /* I - Use back-channel? */
151 int update_state, /* I - Update printer-state-reasons? */
152 _cups_sccb_t side_cb) /* I - Side-channel callback */
154 int nfds; /* Maximum file descriptor value + 1 */
155 fd_set input, /* Input set for reading */
156 output; /* Output set for writing */
157 ssize_t print_bytes, /* Print bytes read */
158 bc_bytes, /* Backchannel bytes read */
159 total_bytes, /* Total bytes written */
160 bytes; /* Bytes written */
161 int paperout; /* "Paper out" status */
162 int offline; /* "Off-line" status */
163 char print_buffer[8192], /* Print data buffer */
164 *print_ptr, /* Pointer into print data buffer */
165 bc_buffer[1024]; /* Back-channel data buffer */
166 struct timeval timeout; /* Timeout for select() */
167 time_t curtime, /* Current time */
169 #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
170 struct sigaction action; /* Actions for POSIX signals */
171 #endif /* HAVE_SIGACTION && !HAVE_SIGSET */
175 "DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, snmp_fd=%d, "
176 "addr=%p, use_bc=%d, side_cb=%p)\n",
177 print_fd, device_fd, snmp_fd, addr, use_bc, side_cb);
180 * If we are printing data from a print driver on stdin, ignore SIGTERM
181 * so that the driver can finish out any page data, e.g. to eject the
182 * current page. We only do this for stdin printing as otherwise there
183 * is no way to cancel a raw print job...
188 #ifdef HAVE_SIGSET /* Use System V signals over POSIX to avoid bugs */
189 sigset(SIGTERM, SIG_IGN);
190 #elif defined(HAVE_SIGACTION)
191 memset(&action, 0, sizeof(action));
193 sigemptyset(&action.sa_mask);
194 action.sa_handler = SIG_IGN;
195 sigaction(SIGTERM, &action, NULL);
197 signal(SIGTERM, SIG_IGN);
198 #endif /* HAVE_SIGSET */
200 else if (print_fd < 0)
203 * Copy print data from stdin, but don't mess with the signal handlers...
210 * Figure out the maximum file descriptor value to use with select()...
213 nfds = (print_fd > device_fd ? print_fd : device_fd) + 1;
216 * Now loop until we are out of data from print_fd...
219 for (print_bytes = 0, print_ptr = print_buffer, offline = -1,
220 paperout = -1, total_bytes = 0;;)
223 * Use select() to determine whether we have data to copy around...
228 FD_SET(print_fd, &input);
230 FD_SET(device_fd, &input);
231 if (!print_bytes && side_cb)
232 FD_SET(CUPS_SC_FD, &input);
235 if (print_bytes || (!use_bc && !side_cb))
236 FD_SET(device_fd, &output);
238 if (use_bc || side_cb)
243 if (select(nfds, &input, &output, NULL, &timeout) < 0)
246 * Pause printing to clear any pending errors...
249 if (errno == ENXIO && offline != 1 && update_state)
251 fputs("STATE: +offline-report\n", stderr);
252 _cupsLangPrintFilter(stderr, "INFO",
253 _("Printer is not currently connected."));
256 else if (errno == EINTR && total_bytes == 0)
258 fputs("DEBUG: Received an interrupt before any bytes were "
259 "written, aborting.\n", stderr);
269 * Check if we have a side-channel request ready...
272 if (side_cb && FD_ISSET(CUPS_SC_FD, &input))
275 * Do the side-channel request, then start back over in the select
276 * loop since it may have read from print_fd...
279 if ((*side_cb)(print_fd, device_fd, snmp_fd, addr, use_bc))
285 * Check if we have back-channel data ready...
288 if (FD_ISSET(device_fd, &input))
290 if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)
293 "DEBUG: Received " CUPS_LLFMT " bytes of back-channel data\n",
294 CUPS_LLCAST bc_bytes);
295 cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);
297 else if (bc_bytes < 0 && errno != EAGAIN && errno != EINTR)
299 fprintf(stderr, "DEBUG: Error reading back-channel data: %s\n",
303 else if (bc_bytes == 0)
308 * Check if we have print data ready...
311 if (FD_ISSET(print_fd, &input))
313 if ((print_bytes = read(print_fd, print_buffer,
314 sizeof(print_buffer))) < 0)
317 * Read error - bail if we don't see EAGAIN or EINTR...
320 if (errno != EAGAIN || errno != EINTR)
322 _cupsLangPrintError("ERROR", _("Unable to read print data"));
328 else if (print_bytes == 0)
331 * End of file, break out of the loop...
337 print_ptr = print_buffer;
339 fprintf(stderr, "DEBUG: Read %d bytes of print data...\n",
344 * Check if the device is ready to receive data and we have data to
348 if (print_bytes && FD_ISSET(device_fd, &output))
350 if ((bytes = write(device_fd, print_ptr, print_bytes)) < 0)
353 * Write error - bail if we don't see an error we can retry...
358 if (paperout != 1 && update_state)
360 fputs("STATE: +media-empty-warning\n", stderr);
361 fputs("DEBUG: Out of paper\n", stderr);
365 else if (errno == ENXIO)
367 if (offline != 1 && update_state)
369 fputs("STATE: +offline-report\n", stderr);
370 _cupsLangPrintFilter(stderr, "INFO",
371 _("Printer is not currently connected."));
375 else if (errno != EAGAIN && errno != EINTR && errno != ENOTTY)
377 _cupsLangPrintError("ERROR", _("Unable to write print data"));
383 if (paperout && update_state)
385 fputs("STATE: -media-empty-warning\n", stderr);
389 if (offline && update_state)
391 fputs("STATE: -offline-report\n", stderr);
392 _cupsLangPrintFilter(stderr, "INFO", _("Printer is now connected."));
396 fprintf(stderr, "DEBUG: Wrote %d bytes of print data...\n", (int)bytes);
398 print_bytes -= bytes;
400 total_bytes += bytes;
405 * Do SNMP updates periodically...
408 if (snmp_fd >= 0 && time(&curtime) >= snmp_update)
410 if (backendSNMPSupplies(snmp_fd, addr, NULL, NULL))
411 snmp_update = INT_MAX;
413 snmp_update = curtime + 5;
418 * Return with success...
421 return (total_bytes);
426 * 'backendWaitLoop()' - Wait for input from stdin while handling side-channel
430 int /* O - 1 if data is ready, 0 if not */
432 int snmp_fd, /* I - SNMP socket or -1 if none */
433 http_addr_t *addr, /* I - Address of device */
434 int use_bc, /* I - Use back-channel? */
435 _cups_sccb_t side_cb) /* I - Side-channel callback */
437 int nfds; /* Number of file descriptors */
438 fd_set input; /* Input set for reading */
439 time_t curtime, /* Current time */
440 snmp_update = 0;/* Last SNMP status update */
441 struct timeval timeout; /* Timeout for select() */
444 fprintf(stderr, "DEBUG: backendWaitLoop(snmp_fd=%d, addr=%p, side_cb=%p)\n",
445 snmp_fd, addr, side_cb);
448 * Now loop until we receive data from stdin...
452 snmp_update = time(NULL) + 5;
457 * Use select() to determine whether we have data to copy around...
463 FD_SET(CUPS_SC_FD, &input);
467 curtime = time(NULL);
468 timeout.tv_sec = curtime >= snmp_update ? 0 : snmp_update - curtime;
471 nfds = select(CUPS_SC_FD + 1, &input, NULL, NULL, &timeout);
474 nfds = select(CUPS_SC_FD + 1, &input, NULL, NULL, NULL);
479 * Pause printing to clear any pending errors...
484 fputs("DEBUG: Received an interrupt before any bytes were "
485 "written, aborting.\n", stderr);
494 * Check for input on stdin...
497 if (FD_ISSET(0, &input))
501 * Check if we have a side-channel request ready...
504 if (side_cb && FD_ISSET(CUPS_SC_FD, &input))
507 * Do the side-channel request, then start back over in the select
508 * loop since it may have read from print_fd...
511 if ((*side_cb)(0, -1, snmp_fd, addr, use_bc))
517 * Do SNMP updates periodically...
520 if (snmp_fd >= 0 && curtime >= snmp_update)
522 if (backendSNMPSupplies(snmp_fd, addr, NULL, NULL))
525 snmp_update = curtime + 5;
530 * Return with success...
538 * End of "$Id: runloop.c 10369 2012-03-21 04:31:19Z mike $".