1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/* poll.cc. Implements poll(2) via usage of select(2) call.
Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011,
2012 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#define FD_SETSIZE 16384 // lots of fds
#include "winsup.h"
#include <sys/poll.h>
#include <stdlib.h>
#define USE_SYS_TYPES_FD_SET
#include "cygerrno.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "pinfo.h"
#include "sigproc.h"
extern "C" int
poll (struct pollfd *fds, nfds_t nfds, int timeout)
{
int max_fd = 0;
int invalid_fds = 0;
fd_set *read_fds, *write_fds, *except_fds;
struct timeval tv = { timeout / 1000, (timeout % 1000) * 1000 };
for (unsigned int i = 0; i < nfds; ++i)
if (fds[i].fd > max_fd)
max_fd = fds[i].fd;
size_t fds_size = howmany (max_fd + 1, NFDBITS) * sizeof (fd_mask);
read_fds = (fd_set *) alloca (fds_size);
write_fds = (fd_set *) alloca (fds_size);
except_fds = (fd_set *) alloca (fds_size);
if (!read_fds || !write_fds || !except_fds)
{
set_errno (EINVAL); /* According to SUSv3. */
return -1;
}
memset (read_fds, 0, fds_size);
memset (write_fds, 0, fds_size);
memset (except_fds, 0, fds_size);
for (unsigned int i = 0; i < nfds; ++i)
{
fds[i].revents = 0;
if (!cygheap->fdtab.not_open (fds[i].fd))
{
if (fds[i].events & POLLIN)
FD_SET(fds[i].fd, read_fds);
if (fds[i].events & POLLOUT)
FD_SET(fds[i].fd, write_fds);
if (fds[i].events & POLLPRI)
FD_SET(fds[i].fd, except_fds);
}
else if (fds[i].fd >= 0)
{
++invalid_fds;
fds[i].revents = POLLNVAL;
}
}
/* Invalid fds? */
if (invalid_fds > 0)
{
/* Only invalid fds? Return. */
if ((nfds_t) invalid_fds == nfds)
return invalid_fds;
/* POSIX doesn't explicitely define this behaviour, but on Linux,
the timeout is set to 0 if an error occurs, and POLLNVAL is one
of these errors. So, for Linux-compatibility's sake... */
tv.tv_sec = tv.tv_usec = 0;
}
int ret = cygwin_select (max_fd + 1, read_fds, write_fds, except_fds,
timeout < 0 ? NULL : &tv);
/* timeout, signal, whatever? Return. If invalid fds exist, return with
their number. */
if (ret <= 0)
return invalid_fds ?: ret;
/* Set revents fields and count fds with non-zero revents fields for
return value. */
ret = 0;
for (unsigned int i = 0; i < nfds; ++i)
{
if (fds[i].fd >= 0 && fds[i].revents != POLLNVAL)
{
fhandler_socket *sock;
/* Check if the descriptor has been closed, or if shutdown for the
read side has been called on a socket. */
if (cygheap->fdtab.not_open (fds[i].fd)
|| ((sock = cygheap->fdtab[fds[i].fd]->is_socket ())
&& sock->saw_shutdown_read ()))
fds[i].revents = POLLHUP;
else
{
if (FD_ISSET(fds[i].fd, read_fds))
/* This should be sufficient for sockets, too. Using
MSG_PEEK, as before, can be considered dangerous at
best. Quote from W. Richard Stevens: "The presence
of an error can be considered either normal data or
an error (POLLERR). In either case, a subsequent read
will return -1 with errno set to the appropriate value."
So it looks like there's actually no good reason to
return POLLERR. */
fds[i].revents |= POLLIN;
/* Handle failed connect. */
if (FD_ISSET(fds[i].fd, write_fds)
&& (sock = cygheap->fdtab[fds[i].fd]->is_socket ())
&& sock->connect_state () == connect_failed)
fds[i].revents |= (POLLIN | POLLERR);
else
{
if (FD_ISSET(fds[i].fd, write_fds))
fds[i].revents |= POLLOUT;
if (FD_ISSET(fds[i].fd, except_fds))
fds[i].revents |= POLLPRI;
}
}
if (fds[i].revents)
++ret;
}
}
/* Number of fds with event includes the invalid fds. */
return ret + invalid_fds;
}
extern "C" int
ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout_ts,
const sigset_t *sigmask)
{
int timeout;
sigset_t oldset = _my_tls.sigmask;
myfault efault;
if (efault.faulted (EFAULT))
return -1;
timeout = (timeout_ts == NULL)
? -1
: (timeout_ts->tv_sec * 1000 + timeout_ts->tv_nsec / 1000000);
if (sigmask)
set_signal_mask (_my_tls.sigmask, *sigmask);
int ret = poll (fds, nfds, timeout);
if (sigmask)
set_signal_mask (_my_tls.sigmask, oldset);
return ret;
}
|
