add $config_args to perl -V display (suggested by Ilya Zakharevich)
[p5sagit/p5-mst-13.2.git] / ext / IO / poll.c
CommitLineData
cf7fe8a2 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 * try to emulate it as closely as possible using select()
10 *
11 */
12
13#include "EXTERN.h"
14#include "perl.h"
15#include "poll.h"
16#ifdef I_SYS_TIME
17# include <sys/time.h>
18#endif
19#ifdef I_TIME
20# include <time.h>
21#endif
22#include <sys/types.h>
23#if defined(HAS_SOCKET) && !defined(VMS) /* VMS handles sockets via vmsish.h */
24# include <sys/socket.h>
25#endif
26#include <sys/stat.h>
27#include <errno.h>
28
29#ifdef EMULATE_POLL_WITH_SELECT
30
31# define POLL_CAN_READ (POLLIN | POLLRDNORM )
32# define POLL_CAN_WRITE (POLLOUT | POLLWRNORM | POLLWRBAND )
33# define POLL_HAS_EXCP (POLLRDBAND | POLLPRI )
34
35# define POLL_EVENTS_MASK (POLL_CAN_READ | POLL_CAN_WRITE | POLL_HAS_EXCP)
36
37int
38poll(fds, nfds, timeout)
39struct pollfd *fds;
40unsigned long nfds;
41int timeout;
42{
43 int i,err;
44 fd_set rfd,wfd,efd,ifd;
45 struct timeval timebuf;
46 struct timeval *tbuf = (struct timeval *)0;
47 int n = 0;
48 int count;
49
50 FD_ZERO(&ifd);
51
52again:
53
54 FD_ZERO(&rfd);
55 FD_ZERO(&wfd);
56 FD_ZERO(&efd);
57
58 for(i = 0 ; i < nfds ; i++) {
59 int events = fds[i].events;
60 int fd = fds[i].fd;
61
62 fds[i].revents = 0;
63
64 if(fd < 0 || FD_ISSET(fd, &ifd))
65 continue;
66
67 if(fd > n)
68 n = fd;
69
70 if(events & POLL_CAN_READ)
71 FD_SET(fd, &rfd);
72
73 if(events & POLL_CAN_WRITE)
74 FD_SET(fd, &wfd);
75
76 if(events & POLL_HAS_EXCP)
77 FD_SET(fd, &efd);
78 }
79
80 if(timeout >= 0) {
81 timebuf.tv_sec = timeout / 1000;
82 timebuf.tv_usec = (timeout % 1000) * 1000;
83 tbuf = &timebuf;
84 }
85
86 err = select(n+1,&rfd,&wfd,&efd,tbuf);
87
88 if(err < 0) {
89#ifdef HAS_FSTAT
90 if(errno == EBADF) {
91 for(i = 0 ; i < nfds ; i++) {
92 struct stat buf;
93 if((fstat(fds[i].fd,&buf) < 0) && (errno == EBADF)) {
94 FD_SET(fds[i].fd, &ifd);
95 goto again;
96 }
97 }
98 }
99#endif /* HAS_FSTAT */
100 return err;
101 }
102
103 count = 0;
104
105 for(i = 0 ; i < nfds ; i++) {
106 int revents = (fds[i].events & POLL_EVENTS_MASK);
107 int fd = fds[i].fd;
108
109 if(fd < 0)
110 continue;
111
112 if(FD_ISSET(fd, &ifd))
113 revents = POLLNVAL;
114 else {
115 if(!FD_ISSET(fd, &rfd))
116 revents &= ~POLL_CAN_READ;
117
118 if(!FD_ISSET(fd, &wfd))
119 revents &= ~POLL_CAN_WRITE;
120
121 if(!FD_ISSET(fd, &efd))
122 revents &= ~POLL_HAS_EXCP;
123 }
124
125 if((fds[i].revents = revents) != 0)
126 count++;
127 }
128
129 return count;
130}
131
132#endif /* EMULATE_POLL_WITH_SELECT */