| /* |
| * "$Id: runloop.c 6834 2007-08-22 18:29:25Z 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) |
| { |
| _cupsLangPrintf(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); |
| _cupsLangPuts(stderr, _("INFO: Printer is currently off-line.\n")); |
| 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); |
| _cupsLangPuts(stderr, _("ERROR: Out of paper!\n")); |
| paperout = 1; |
| } |
| } |
| else if (errno == ENXIO) |
| { |
| if (offline != 1) |
| { |
| fputs("STATE: +offline-error\n", stderr); |
| _cupsLangPuts(stderr, _("INFO: Printer is currently off-line.\n")); |
| 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); |
| _cupsLangPuts(stderr, _("INFO: Printer is now on-line.\n")); |
| 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 6834 2007-08-22 18:29:25Z mike $". |
| */ |