| 1 | /* |
| 2 | * poll.c |
| 3 | * |
| 4 | * Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved. |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the same terms as Perl itself. |
| 7 | * |
| 8 | * For systems that do not have the poll() system call (for example Linux |
| 9 | * kernels < v2.1.23) try to emulate it as closely as possible using select() |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include "EXTERN.h" |
| 14 | #include "perl.h" |
| 15 | #include "XSUB.h" |
| 16 | |
| 17 | #include "poll.h" |
| 18 | #ifdef I_SYS_TIME |
| 19 | # include <sys/time.h> |
| 20 | #endif |
| 21 | #ifdef I_TIME |
| 22 | # include <time.h> |
| 23 | #endif |
| 24 | #include <sys/types.h> |
| 25 | #if defined(HAS_SOCKET) && !defined(VMS) && !defined(ultrix) /* VMS handles sockets via vmsish.h, ULTRIX dies of socket struct redefinitions */ |
| 26 | # include <sys/socket.h> |
| 27 | #endif |
| 28 | #include <sys/stat.h> |
| 29 | #include <errno.h> |
| 30 | |
| 31 | #ifdef HAS_SELECT |
| 32 | #ifdef I_SYS_SELECT |
| 33 | #include <sys/select.h> |
| 34 | #endif |
| 35 | #endif |
| 36 | |
| 37 | #ifdef EMULATE_POLL_WITH_SELECT |
| 38 | |
| 39 | # define POLL_CAN_READ (POLLIN | POLLRDNORM ) |
| 40 | # define POLL_CAN_WRITE (POLLOUT | POLLWRNORM | POLLWRBAND ) |
| 41 | # define POLL_HAS_EXCP (POLLRDBAND | POLLPRI ) |
| 42 | |
| 43 | # define POLL_EVENTS_MASK (POLL_CAN_READ | POLL_CAN_WRITE | POLL_HAS_EXCP) |
| 44 | |
| 45 | int |
| 46 | poll(struct pollfd *fds, unsigned long nfds, int timeout) |
| 47 | { |
| 48 | int i,err; |
| 49 | fd_set rfd,wfd,efd,ifd; |
| 50 | struct timeval timebuf; |
| 51 | struct timeval *tbuf = (struct timeval *)0; |
| 52 | int n = 0; |
| 53 | int count; |
| 54 | |
| 55 | FD_ZERO(&ifd); |
| 56 | |
| 57 | again: |
| 58 | |
| 59 | FD_ZERO(&rfd); |
| 60 | FD_ZERO(&wfd); |
| 61 | FD_ZERO(&efd); |
| 62 | |
| 63 | for(i = 0 ; i < (int)nfds ; i++) { |
| 64 | int events = fds[i].events; |
| 65 | int fd = fds[i].fd; |
| 66 | |
| 67 | fds[i].revents = 0; |
| 68 | |
| 69 | if(fd < 0 || FD_ISSET(fd, &ifd)) |
| 70 | continue; |
| 71 | |
| 72 | if(fd > n) |
| 73 | n = fd; |
| 74 | |
| 75 | if(events & POLL_CAN_READ) |
| 76 | FD_SET(fd, &rfd); |
| 77 | |
| 78 | if(events & POLL_CAN_WRITE) |
| 79 | FD_SET(fd, &wfd); |
| 80 | |
| 81 | if(events & POLL_HAS_EXCP) |
| 82 | FD_SET(fd, &efd); |
| 83 | } |
| 84 | |
| 85 | if(timeout >= 0) { |
| 86 | timebuf.tv_sec = timeout / 1000; |
| 87 | timebuf.tv_usec = (timeout % 1000) * 1000; |
| 88 | tbuf = &timebuf; |
| 89 | } |
| 90 | |
| 91 | err = select(n+1,&rfd,&wfd,&efd,tbuf); |
| 92 | |
| 93 | if(err < 0) { |
| 94 | #ifdef HAS_FSTAT |
| 95 | if(errno == EBADF) { |
| 96 | for(i = 0 ; i < nfds ; i++) { |
| 97 | struct stat buf; |
| 98 | if((fstat(fds[i].fd,&buf) < 0) && (errno == EBADF)) { |
| 99 | FD_SET(fds[i].fd, &ifd); |
| 100 | goto again; |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | #endif /* HAS_FSTAT */ |
| 105 | return err; |
| 106 | } |
| 107 | |
| 108 | count = 0; |
| 109 | |
| 110 | for(i = 0 ; i < (int)nfds ; i++) { |
| 111 | int revents = (fds[i].events & POLL_EVENTS_MASK); |
| 112 | int fd = fds[i].fd; |
| 113 | |
| 114 | if(fd < 0) |
| 115 | continue; |
| 116 | |
| 117 | if(FD_ISSET(fd, &ifd)) |
| 118 | revents = POLLNVAL; |
| 119 | else { |
| 120 | if(!FD_ISSET(fd, &rfd)) |
| 121 | revents &= ~POLL_CAN_READ; |
| 122 | |
| 123 | if(!FD_ISSET(fd, &wfd)) |
| 124 | revents &= ~POLL_CAN_WRITE; |
| 125 | |
| 126 | if(!FD_ISSET(fd, &efd)) |
| 127 | revents &= ~POLL_HAS_EXCP; |
| 128 | } |
| 129 | |
| 130 | if((fds[i].revents = revents) != 0) |
| 131 | count++; |
| 132 | } |
| 133 | |
| 134 | return count; |
| 135 | } |
| 136 | |
| 137 | #endif /* EMULATE_POLL_WITH_SELECT */ |
| 138 | |
| 139 | /* gcc for SunOS 4 produces code from an empty (code/symbolwise) |
| 140 | * source code file that makes the SunOS 4.x /usr/bin/ld fail with |
| 141 | * ld: poll.o: premature EOF |
| 142 | * To avoid this, have at least something in here. */ |
| 143 | #if defined(__sun) && !defined(__SVR4) && defined(__GNUC__) |
| 144 | static int dummy; |
| 145 | #endif |
| 146 | |