allow embedded null characters in diagnostics
[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
35ef4773 38poll(struct pollfd *fds, unsigned long nfds, int timeout)
cf7fe8a2 39{
40 int i,err;
41 fd_set rfd,wfd,efd,ifd;
42 struct timeval timebuf;
43 struct timeval *tbuf = (struct timeval *)0;
44 int n = 0;
45 int count;
46
47 FD_ZERO(&ifd);
48
49again:
50
51 FD_ZERO(&rfd);
52 FD_ZERO(&wfd);
53 FD_ZERO(&efd);
54
55 for(i = 0 ; i < nfds ; i++) {
56 int events = fds[i].events;
57 int fd = fds[i].fd;
58
59 fds[i].revents = 0;
60
61 if(fd < 0 || FD_ISSET(fd, &ifd))
62 continue;
63
64 if(fd > n)
65 n = fd;
66
67 if(events & POLL_CAN_READ)
68 FD_SET(fd, &rfd);
69
70 if(events & POLL_CAN_WRITE)
71 FD_SET(fd, &wfd);
72
73 if(events & POLL_HAS_EXCP)
74 FD_SET(fd, &efd);
75 }
76
77 if(timeout >= 0) {
78 timebuf.tv_sec = timeout / 1000;
79 timebuf.tv_usec = (timeout % 1000) * 1000;
80 tbuf = &timebuf;
81 }
82
83 err = select(n+1,&rfd,&wfd,&efd,tbuf);
84
85 if(err < 0) {
86#ifdef HAS_FSTAT
87 if(errno == EBADF) {
88 for(i = 0 ; i < nfds ; i++) {
89 struct stat buf;
90 if((fstat(fds[i].fd,&buf) < 0) && (errno == EBADF)) {
91 FD_SET(fds[i].fd, &ifd);
92 goto again;
93 }
94 }
95 }
96#endif /* HAS_FSTAT */
97 return err;
98 }
99
100 count = 0;
101
102 for(i = 0 ; i < nfds ; i++) {
103 int revents = (fds[i].events & POLL_EVENTS_MASK);
104 int fd = fds[i].fd;
105
106 if(fd < 0)
107 continue;
108
109 if(FD_ISSET(fd, &ifd))
110 revents = POLLNVAL;
111 else {
112 if(!FD_ISSET(fd, &rfd))
113 revents &= ~POLL_CAN_READ;
114
115 if(!FD_ISSET(fd, &wfd))
116 revents &= ~POLL_CAN_WRITE;
117
118 if(!FD_ISSET(fd, &efd))
119 revents &= ~POLL_HAS_EXCP;
120 }
121
122 if((fds[i].revents = revents) != 0)
123 count++;
124 }
125
126 return count;
127}
128
129#endif /* EMULATE_POLL_WITH_SELECT */