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
159
160
161
162
163
164
165
166
167
168
169
|
//
// Copyright 2017 Garrett D'Amore <garrett@damore.org>
//
// This software is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt). A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//
#include <string.h>
#include "core/nng_impl.h"
#define NNI_IOEV_DONE (1<<0)
#define NNI_IOEV_BUSY (1<<1)
#define NNI_IOEV_CANCEL (1<<2)
#define NNI_IOEV_WAKE (1<<3)
void
nni_ioev_init(nni_ioev *ioev, nni_cb cb, void *arg)
{
if (cb == NULL) {
cb = (nni_cb) nni_ioev_wake;
arg = ioev;
}
memset(ioev, 0, sizeof (*ioev));
nni_mtx_init(&ioev->ie_lk);
nni_cv_init(&ioev->ie_cv, &ioev->ie_lk);
ioev->ie_cb = cb;
ioev->ie_cbarg = arg;
}
void
nni_ioev_fini(nni_ioev *ioev)
{
nni_cv_fini(&ioev->ie_cv);
nni_mtx_fini(&ioev->ie_lk);
}
void
nni_ioev_cancel(nni_ioev *ioev)
{
nni_cb cb;
void *arg;
nni_mtx_lock(&ioev->ie_lk);
while ((ioev->ie_flags & NNI_IOEV_BUSY) != 0) {
nni_cv_wait(&ioev->ie_cv);
}
if ((ioev->ie_flags & NNI_IOEV_DONE) != 0) {
// Already finished the IO.
nni_mtx_unlock(&ioev->ie_lk);
return;
}
ioev->ie_flags |= NNI_IOEV_CANCEL;
nni_mtx_unlock(&ioev->ie_lk);
// Do not hold the lock across the provider! The provider
// must not run on this because we have set the cancel flag,
// therefore "nni_ioev_start" will return failure. The provider
// is responsible for dealing with any linked list issues or such,
// and freeing any provider data at this point.
ioev->ie_prov_ops.ip_cancel(ioev->ie_prov_data);
nni_mtx_lock(&ioev->ie_lk);
ioev->ie_result = NNG_ECANCELED;
cb = ioev->ie_cb;
arg = ioev->ie_cbarg;
nni_mtx_unlock(&ioev->ie_lk);
// Call the callback. If none was registered, this will instead
// raise the done signal and wake anything blocked in nni_ioev_wait.
// (Because cb will be nni_ioev_wake, and arg will be the ioev itself.)
cb(arg);
}
int
nni_ioev_result(nni_ioev *ioev)
{
return (ioev->ie_result);
}
size_t
nni_ioev_count(nni_ioev *ioev)
{
return (ioev->ie_count);
}
void
nni_ioev_wake(nni_ioev *ioev)
{
nni_mtx_lock(&ioev->ie_lk);
ioev->ie_flags |= NNI_IOEV_WAKE;
nni_cv_wake(&ioev->ie_cv);
nni_mtx_unlock(&ioev->ie_lk);
}
void
nni_ioev_wait(nni_ioev *ioev)
{
nni_mtx_lock(&ioev->ie_lk);
while ((ioev->ie_flags & NNI_IOEV_WAKE) == 0) {
nni_cv_wait(&ioev->ie_cv);
}
nni_mtx_unlock(&ioev->ie_lk);
}
// I/O provider related functions.
void
nni_ioev_set_ops(nni_ioev *ioev, nni_ioev_ops *ops, void *data)
{
memcpy(&ioev->ie_prov_ops, ops, sizeof (*ops));
ioev->ie_prov_data = data;
}
// nni_ioev_busy effectively "locks" the IOEV. We'd like to use the
// underlying mutex, and that would be faster, but the completion might
// be executed by a thread other than the one that marked it busy, so we
// use our own flags.
int
nni_ioev_busy(nni_ioev *ioev)
{
nni_mtx_lock(&ioev->ie_lk);
if ((ioev->ie_flags & NNI_IOEV_CANCEL) != 0) {
nni_mtx_unlock(&ioev->ie_lk);
return (NNG_ECANCELED);
}
ioev->ie_flags |= NNI_IOEV_BUSY;
nni_mtx_unlock(&ioev->ie_lk);
return (0);
}
void
nni_ioev_unbusy(nni_ioev *ioev)
{
nni_mtx_lock(&ioev->ie_lk);
ioev->ie_flags &= ~(NNI_IOEV_BUSY);
nni_cv_wake(&ioev->ie_cv);
nni_mtx_unlock(&ioev->ie_lk);
}
void
nni_ioev_finish(nni_ioev *ioev, int result, size_t count)
{
nni_cb cb;
void *arg;
nni_mtx_lock(&ioev->ie_lk);
ioev->ie_result = result;
ioev->ie_count = count;
ioev->ie_flags &= ~(NNI_IOEV_BUSY);
ioev->ie_flags |= NNI_IOEV_DONE;
cb = ioev->ie_cb;
arg = ioev->ie_cbarg;
nni_cv_wake(&ioev->ie_cv);
nni_mtx_unlock(&ioev->ie_lk);
cb(arg);
}
|
