| 42 | */ |
| 43 | |
| 44 | ssize_t /* O - Bytes read or -1 on error */ |
| 45 | cupsBackChannelRead(char *buffer, /* I - Buffer to read into */ |
| 46 | size_t bytes, /* I - Bytes to read */ |
| 47 | double timeout) /* I - Timeout in seconds, typically 0.0 to poll */ |
| 48 | { |
| 49 | fd_set input; /* Input set */ |
| 50 | struct timeval tval; /* Timeout value */ |
| 51 | int status; /* Select status */ |
| 52 | |
| 53 | |
| 54 | /* |
| 55 | * Wait for input ready. |
| 56 | */ |
| 57 | |
| 58 | do |
| 59 | { |
| 60 | cups_setup(&input, &tval, timeout); |
| 61 | |
| 62 | if (timeout < 0.0) |
| 63 | status = select(4, &input, NULL, NULL, NULL); |
| 64 | else |
| 65 | status = select(4, &input, NULL, NULL, &tval); |
| 66 | } |
| 67 | while (status < 0 && errno != EINTR && errno != EAGAIN); |
| 68 | |
| 69 | if (status <= 0) |
| 70 | return (-1); /* Timeout! */ |
| 71 | |
| 72 | /* |
| 73 | * Read bytes from the pipe... |
| 74 | */ |
| 75 | |
| 76 | #ifdef _WIN32 |
| 77 | return ((ssize_t)_read(3, buffer, (unsigned)bytes)); |
| 78 | #else |
| 79 | return (read(3, buffer, bytes)); |
| 80 | #endif /* _WIN32 */ |
| 81 | } |
| 82 | |
| 83 | |
| 84 | /* |