author | raf |
Mon, 10 Apr 2006 12:27:38 -0700 | |
changeset 1778 | 6357a59054f7 |
parent 0 | 68f95e015346 |
child 6515 | 10dab2b883e0 |
permissions | -rw-r--r-- |
0 | 1 |
/* |
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* CDDL HEADER START |
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* |
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* The contents of this file are subject to the terms of the |
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6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
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* Common Development and Distribution License (the "License"). |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
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* You may not use this file except in compliance with the License. |
0 | 7 |
* |
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
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* or http://www.opensolaris.org/os/licensing. |
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* See the License for the specific language governing permissions |
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* and limitations under the License. |
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* |
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* When distributing Covered Code, include this CDDL HEADER in each |
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
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* If applicable, add the following below this CDDL HEADER, with the |
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* fields enclosed by brackets "[]" replaced with your own identifying |
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* information: Portions Copyright [yyyy] [name of copyright owner] |
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* |
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* CDDL HEADER END |
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*/ |
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/* |
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6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
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* Copyright 2006 Sun Microsystems, Inc. All rights reserved. |
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* Use is subject to license terms. |
25 |
*/ |
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26 |
||
27 |
#pragma ident "%Z%%M% %I% %E% SMI" |
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||
29 |
/* Copyright (c) 1988 AT&T */ |
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/* All Rights Reserved */ |
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31 |
||
32 |
/* |
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33 |
* Emulation of select() system call using _pollsys() system call. |
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34 |
* |
|
35 |
* Assumptions: |
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36 |
* polling for input only is most common. |
|
37 |
* polling for exceptional conditions is very rare. |
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38 |
* |
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39 |
* Note that is it not feasible to emulate all error conditions, |
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* in particular conditions that would return EFAULT are far too |
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41 |
* difficult to check for in a library routine. |
|
42 |
* |
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43 |
* This is the alternate large fd_set select. |
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44 |
* |
|
45 |
*/ |
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46 |
||
47 |
/* |
|
48 |
* Must precede any include files |
|
49 |
*/ |
|
50 |
#ifdef FD_SETSIZE |
|
51 |
#undef FD_SETSIZE |
|
52 |
#endif |
|
53 |
#define FD_SETSIZE 65536 |
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54 |
||
55 |
/* |
|
56 |
* We do not #redefine the name since the only users of this |
|
57 |
* are external to the libraries and commands. |
|
58 |
* |
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59 |
* #pragma weak pselect_large_fdset = _pselect_large_fdset |
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60 |
* #pragma weak select_large_fdset = _select_large_fdset |
|
61 |
*/ |
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62 |
||
63 |
#include "synonyms.h" |
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64 |
#include <values.h> |
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65 |
#include <stdlib.h> |
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66 |
#include <string.h> |
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67 |
#include <errno.h> |
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68 |
#include <sys/time.h> |
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69 |
#include <sys/types.h> |
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70 |
#include <sys/poll.h> |
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71 |
#include <string.h> |
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#include <stdlib.h> |
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73 |
#include "libc.h" |
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74 |
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75 |
#define DEFAULT_POLL_SIZE 64 |
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76 |
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77 |
static struct pollfd *realloc_fds(int *, struct pollfd **, struct pollfd *); |
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78 |
||
79 |
int |
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80 |
pselect_large_fdset(int nfds, fd_set *in0, fd_set *out0, fd_set *ex0, |
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81 |
const timespec_t *tsp, const sigset_t *sigmask) |
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82 |
{ |
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83 |
long *in, *out, *ex; |
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84 |
ulong_t m; /* bit mask */ |
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85 |
int j; /* loop counter */ |
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86 |
ulong_t b; /* bits to test */ |
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87 |
int n, rv; |
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int lastj = -1; |
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89 |
int nused; |
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90 |
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91 |
/* |
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92 |
* Rather than have a mammoth pollfd (65K) list on the stack |
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* we start with a small one and then malloc larger chunks |
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* on the heap if necessary. |
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95 |
*/ |
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96 |
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97 |
struct pollfd pfd[DEFAULT_POLL_SIZE]; |
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98 |
struct pollfd *p; |
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99 |
struct pollfd *pfd_list; |
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100 |
int nfds_on_list; |
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101 |
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102 |
fd_set zero; |
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103 |
||
104 |
/* |
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105 |
* Check for invalid conditions at outset. |
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* Required for spec1170. |
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* SUSV3: We must behave as a cancellation point even if we fail early. |
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108 |
*/ |
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109 |
if (nfds >= 0 && nfds <= FD_SETSIZE) { |
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110 |
if (tsp != NULL) { |
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111 |
if (tsp->tv_nsec < 0 || tsp->tv_nsec >= NANOSEC || |
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112 |
tsp->tv_sec < 0) { |
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113 |
_private_testcancel(); |
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114 |
errno = EINVAL; |
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return (-1); |
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116 |
} |
|
117 |
} |
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118 |
} else { |
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119 |
_private_testcancel(); |
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120 |
errno = EINVAL; |
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121 |
return (-1); |
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122 |
} |
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123 |
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124 |
/* |
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125 |
* If any input args are null, point them at the null array. |
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126 |
*/ |
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127 |
(void) memset(&zero, 0, sizeof (fd_set)); |
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128 |
if (in0 == NULL) |
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129 |
in0 = &zero; |
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130 |
if (out0 == NULL) |
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131 |
out0 = &zero; |
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132 |
if (ex0 == NULL) |
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133 |
ex0 = &zero; |
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134 |
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135 |
nfds_on_list = DEFAULT_POLL_SIZE; |
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136 |
pfd_list = pfd; |
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137 |
p = pfd_list; |
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(void) memset(pfd, 0, sizeof (pfd)); |
|
139 |
/* |
|
140 |
* For each fd, if any bits are set convert them into |
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* the appropriate pollfd struct. |
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142 |
*/ |
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143 |
in = (long *)in0->fds_bits; |
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out = (long *)out0->fds_bits; |
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145 |
ex = (long *)ex0->fds_bits; |
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146 |
nused = 0; |
|
147 |
/* |
|
148 |
* nused reflects the number of pollfd structs currently used |
|
149 |
* less one. If realloc_fds returns 0 it is because malloc |
|
150 |
* failed. We expect malloc() to have done the proper |
|
151 |
* thing with errno. |
|
152 |
*/ |
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153 |
for (n = 0; n < nfds; n += NFDBITS) { |
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154 |
b = (ulong_t)(*in | *out | *ex); |
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155 |
for (j = 0, m = 1; b != 0; j++, b >>= 1, m <<= 1) { |
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156 |
if (b & 1) { |
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157 |
p->fd = n + j; |
|
158 |
if (p->fd < nfds) { |
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159 |
p->events = 0; |
|
160 |
if (*in & m) |
|
161 |
p->events |= POLLRDNORM; |
|
162 |
if (*out & m) |
|
163 |
p->events |= POLLWRNORM; |
|
164 |
if (*ex & m) |
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165 |
p->events |= POLLRDBAND; |
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166 |
if (nused < (nfds_on_list - 1)) { |
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167 |
p++; |
|
168 |
} else { |
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169 |
p = realloc_fds( |
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170 |
&nfds_on_list, |
|
171 |
&pfd_list, pfd); |
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172 |
if (p == 0) { |
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173 |
if (pfd_list != pfd) |
|
174 |
(void) free(pfd_list); |
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175 |
_private_testcancel(); |
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176 |
return (-1); |
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177 |
} |
|
178 |
} |
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nused++; |
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180 |
} else |
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181 |
goto done; |
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182 |
} |
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183 |
} |
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184 |
in++; |
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185 |
out++; |
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186 |
ex++; |
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187 |
} |
|
188 |
done: |
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189 |
/* |
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190 |
* Now do the poll. |
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191 |
*/ |
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192 |
do { |
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193 |
rv = _pollsys(pfd_list, (nfds_t)nused, tsp, sigmask); |
|
194 |
} while (rv < 0 && errno == EAGAIN); |
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195 |
||
196 |
if (rv < 0) { /* no need to set bit masks */ |
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197 |
if (pfd_list != pfd) |
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198 |
(void) free(pfd_list); |
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199 |
return (rv); |
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200 |
} else if (rv == 0) { |
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201 |
/* |
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202 |
* Clear out bit masks, just in case. |
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* On the assumption that usually only |
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204 |
* one bit mask is set, use three loops. |
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*/ |
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206 |
if (in0 != &zero) { |
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in = (long *)in0->fds_bits; |
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208 |
for (n = 0; n < nfds; n += NFDBITS) |
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*in++ = 0; |
|
210 |
} |
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if (out0 != &zero) { |
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out = (long *)out0->fds_bits; |
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for (n = 0; n < nfds; n += NFDBITS) |
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*out++ = 0; |
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215 |
} |
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216 |
if (ex0 != &zero) { |
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217 |
ex = (long *)ex0->fds_bits; |
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for (n = 0; n < nfds; n += NFDBITS) |
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*ex++ = 0; |
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} |
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if (pfd_list != pfd) |
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(void) free(pfd_list); |
|
223 |
return (0); |
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224 |
} |
|
225 |
||
226 |
/* |
|
227 |
* Check for EINVAL error case first to avoid changing any bits |
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228 |
* if we're going to return an error. |
|
229 |
*/ |
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230 |
for (p = pfd_list, j = nused; j-- > 0; p++) { |
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/* |
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232 |
* select will return EBADF immediately if any fd's |
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* are bad. poll will complete the poll on the |
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* rest of the fd's and include the error indication |
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* in the returned bits. This is a rare case so we |
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* accept this difference and return the error after |
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* doing more work than select would've done. |
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*/ |
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239 |
if (p->revents & POLLNVAL) { |
|
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errno = EBADF; |
|
241 |
if (pfd_list != pfd) |
|
242 |
(void) free(pfd_list); |
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return (-1); |
|
244 |
} |
|
245 |
/* |
|
246 |
* We would like to make POLLHUP available to select, |
|
247 |
* checking to see if we have pending data to be read. |
|
248 |
* BUT until we figure out how not to break Xsun's |
|
249 |
* dependencies on select's existing features... |
|
250 |
* This is what we _thought_ would work ... sigh! |
|
251 |
*/ |
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252 |
/* |
|
253 |
* if ((p->revents & POLLHUP) && |
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254 |
* !(p->revents & (POLLRDNORM|POLLRDBAND))) { |
|
255 |
* errno = EINTR; |
|
256 |
* return (-1); |
|
257 |
* } |
|
258 |
*/ |
|
259 |
} |
|
260 |
||
261 |
/* |
|
262 |
* Convert results of poll back into bits |
|
263 |
* in the argument arrays. |
|
264 |
* |
|
265 |
* We assume POLLRDNORM, POLLWRNORM, and POLLRDBAND will only be set |
|
266 |
* on return from poll if they were set on input, thus we don't |
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267 |
* worry about accidentally setting the corresponding bits in the |
|
268 |
* zero array if the input bit masks were null. |
|
269 |
* |
|
270 |
* Must return number of bits set, not number of ready descriptors |
|
271 |
* (as the man page says, and as poll() does). |
|
272 |
*/ |
|
273 |
rv = 0; |
|
274 |
for (p = pfd_list; nused-- > 0; p++) { |
|
275 |
j = (int)(p->fd / NFDBITS); |
|
276 |
/* have we moved into another word of the bit mask yet? */ |
|
277 |
if (j != lastj) { |
|
278 |
/* clear all output bits to start with */ |
|
279 |
in = (long *)&in0->fds_bits[j]; |
|
280 |
out = (long *)&out0->fds_bits[j]; |
|
281 |
ex = (long *)&ex0->fds_bits[j]; |
|
282 |
/* |
|
283 |
* In case we made "zero" read-only (e.g., with |
|
284 |
* cc -R), avoid actually storing into it. |
|
285 |
*/ |
|
286 |
if (in0 != &zero) |
|
287 |
*in = 0; |
|
288 |
if (out0 != &zero) |
|
289 |
*out = 0; |
|
290 |
if (ex0 != &zero) |
|
291 |
*ex = 0; |
|
292 |
lastj = j; |
|
293 |
} |
|
294 |
if (p->revents) { |
|
295 |
m = 1L << (p->fd % NFDBITS); |
|
296 |
if (p->revents & POLLRDNORM) { |
|
297 |
*in |= m; |
|
298 |
rv++; |
|
299 |
} |
|
300 |
if (p->revents & POLLWRNORM) { |
|
301 |
*out |= m; |
|
302 |
rv++; |
|
303 |
} |
|
304 |
if (p->revents & POLLRDBAND) { |
|
305 |
*ex |= m; |
|
306 |
rv++; |
|
307 |
} |
|
308 |
/* |
|
309 |
* Only set this bit on return if we asked about |
|
310 |
* input conditions. |
|
311 |
*/ |
|
312 |
if ((p->revents & (POLLHUP|POLLERR)) && |
|
313 |
(p->events & POLLRDNORM)) { |
|
314 |
if ((*in & m) == 0) |
|
315 |
rv++; /* wasn't already set */ |
|
316 |
*in |= m; |
|
317 |
} |
|
318 |
/* |
|
319 |
* Only set this bit on return if we asked about |
|
320 |
* output conditions. |
|
321 |
*/ |
|
322 |
if ((p->revents & (POLLHUP|POLLERR)) && |
|
323 |
(p->events & POLLWRNORM)) { |
|
324 |
if ((*out & m) == 0) |
|
325 |
rv++; /* wasn't already set */ |
|
326 |
*out |= m; |
|
327 |
} |
|
328 |
/* |
|
329 |
* Only set this bit on return if we asked about |
|
330 |
* output conditions. |
|
331 |
*/ |
|
332 |
if ((p->revents & (POLLHUP|POLLERR)) && |
|
333 |
(p->events & POLLRDBAND)) { |
|
334 |
if ((*ex & m) == 0) |
|
335 |
rv++; /* wasn't already set */ |
|
336 |
*ex |= m; |
|
337 |
} |
|
338 |
} |
|
339 |
} |
|
340 |
if (pfd_list != pfd) |
|
341 |
(void) free(pfd_list); |
|
342 |
return (rv); |
|
343 |
} |
|
344 |
||
345 |
int |
|
346 |
select_large_fdset(int nfds, fd_set *in0, fd_set *out0, fd_set *ex0, |
|
347 |
struct timeval *tv) |
|
348 |
{ |
|
349 |
timespec_t ts; |
|
350 |
timespec_t *tsp; |
|
351 |
||
352 |
if (tv == NULL) |
|
353 |
tsp = NULL; |
|
354 |
else { |
|
1778
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
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parents:
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diff
changeset
|
355 |
/* check timeval validity */ |
0 | 356 |
if (tv->tv_usec < 0 || tv->tv_usec >= MICROSEC) { |
357 |
errno = EINVAL; |
|
358 |
return (-1); |
|
359 |
} |
|
1778
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
360 |
/* |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
361 |
* Convert timeval to timespec. |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
362 |
* To preserve compatibility with past behavior, |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
363 |
* when select was built upon poll(2), which has a |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
364 |
* minimum non-zero timeout of 1 millisecond, force |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
365 |
* a minimum non-zero timeout of 500 microseconds. |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
366 |
*/ |
0 | 367 |
ts.tv_sec = tv->tv_sec; |
368 |
ts.tv_nsec = tv->tv_usec * 1000; |
|
1778
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
raf
parents:
0
diff
changeset
|
369 |
if (ts.tv_nsec != 0 && ts.tv_nsec < 500000) |
6357a59054f7
6404383 select() behaviour changed in Solaris 10, breaking binary compatibility
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parents:
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changeset
|
370 |
ts.tv_nsec = 500000; |
0 | 371 |
tsp = &ts; |
372 |
} |
|
373 |
||
374 |
return (pselect_large_fdset(nfds, in0, out0, ex0, tsp, NULL)); |
|
375 |
} |
|
376 |
||
377 |
/* |
|
378 |
* Reallocate buffers of pollfds for our list. We malloc a new buffer |
|
379 |
* and, in the case where the old buffer does not match what is passed |
|
380 |
* in orig, free the buffer after copying the contents. |
|
381 |
*/ |
|
382 |
struct pollfd * |
|
383 |
realloc_fds(int *num, struct pollfd **list_head, struct pollfd *orig) |
|
384 |
{ |
|
385 |
struct pollfd *b; |
|
386 |
int nta; |
|
387 |
int n2; |
|
388 |
||
389 |
n2 = *num * 2; |
|
390 |
nta = n2 * sizeof (struct pollfd); |
|
391 |
b = malloc(nta); |
|
392 |
if (b) { |
|
393 |
(void) memset(b, 0, (size_t)nta); |
|
394 |
(void) memcpy(b, *list_head, nta / 2); |
|
395 |
if (*list_head != orig) |
|
396 |
(void) free (*list_head); |
|
397 |
*list_head = b; |
|
398 |
b += *num; |
|
399 |
*num = n2; |
|
400 |
} |
|
401 |
return (b); |
|
402 |
} |