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
|
/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <netdb.h>
#include <pthread.h>
#include <stdlib.h>
#include <sys/time.h>
#include <gai_misc.h>
int
gai_suspend (const struct gaicb *const list[], int ent,
const struct timespec *timeout)
{
struct waitlist waitlist[ent];
struct requestlist *requestlist[ent];
#ifndef DONT_NEED_GAI_MISC_COND
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
#endif
int cnt;
unsigned int cntr = 1;
int none = 1;
int result;
/* Request the mutex. */
pthread_mutex_lock (&__gai_requests_mutex);
/* There is not yet a finished request. Signal the request that
we are working for it. */
for (cnt = 0; cnt < ent; ++cnt)
if (list[cnt] != NULL && list[cnt]->__return == EAI_INPROGRESS)
{
requestlist[cnt] = __gai_find_request (list[cnt]);
if (requestlist[cnt] != NULL)
{
#ifndef DONT_NEED_GAI_MISC_COND
waitlist[cnt].cond = &cond;
#endif
waitlist[cnt].next = requestlist[cnt]->waiting;
waitlist[cnt].counterp = &cntr;
waitlist[cnt].sigevp = NULL;
waitlist[cnt].caller_pid = 0; /* Not needed. */
requestlist[cnt]->waiting = &waitlist[cnt];
none = 0;
}
}
if (none)
{
if (cnt < ent)
/* There is an entry which is finished. */
result = 0;
else
result = EAI_ALLDONE;
}
else
{
/* There is no request done but some are still being worked on. */
int oldstate;
/* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancelation
points we must be careful. We added entries to the waiting lists
which we must remove. So defer cancelation for now. */
pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
#ifdef DONT_NEED_GAI_MISC_COND
result = 0;
GAI_MISC_WAIT (result, cntr, timeout, 1);
#else
if (timeout == NULL)
result = pthread_cond_wait (&cond, &__gai_requests_mutex);
else
{
/* We have to convert the relative timeout value into an
absolute time value with pthread_cond_timedwait expects. */
struct timeval now;
struct timespec abstime;
__gettimeofday (&now, NULL);
abstime.tv_nsec = timeout->tv_nsec + now.tv_usec * 1000;
abstime.tv_sec = timeout->tv_sec + now.tv_sec;
if (abstime.tv_nsec >= 1000000000)
{
abstime.tv_nsec -= 1000000000;
abstime.tv_sec += 1;
}
result = pthread_cond_timedwait (&cond, &__gai_requests_mutex,
&abstime);
}
#endif
/* Now remove the entry in the waiting list for all requests
which didn't terminate. */
for (cnt = 0; cnt < ent; ++cnt)
if (list[cnt] != NULL && list[cnt]->__return == EAI_INPROGRESS
&& requestlist[cnt] != NULL)
{
struct waitlist **listp = &requestlist[cnt]->waiting;
/* There is the chance that we cannot find our entry anymore.
This could happen if the request terminated and restarted
again. */
while (*listp != NULL && *listp != &waitlist[cnt])
listp = &(*listp)->next;
if (*listp != NULL)
*listp = (*listp)->next;
}
/* Now it's time to restore the cancelation state. */
pthread_setcancelstate (oldstate, NULL);
#ifndef DONT_NEED_GAI_MISC_COND
/* Release the conditional variable. */
if (pthread_cond_destroy (&cond) != 0)
/* This must never happen. */
abort ();
#endif
if (result != 0)
{
/* An error occurred. Possibly it's EINTR. We have to translate
the timeout error report of `pthread_cond_timedwait' to the
form expected from `gai_suspend'. */
if (__builtin_expect (result, ETIMEDOUT) == ETIMEDOUT)
result = EAI_AGAIN;
else if (result == EINTR)
result = EAI_INTR;
else
result = EAI_SYSTEM;
}
}
/* Release the mutex. */
pthread_mutex_unlock (&__gai_requests_mutex);
return result;
}
|
