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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "src/core/surface/channel.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/channel/client_channel.h"
#include "src/core/iomgr/alarm.h"
#include "src/core/surface/api_trace.h"
#include "src/core/surface/completion_queue.h"
grpc_connectivity_state grpc_channel_check_connectivity_state(
grpc_channel *channel, int try_to_connect) {
/* forward through to the underlying client channel */
grpc_channel_element *client_channel_elem =
grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
grpc_connectivity_state state;
GRPC_API_TRACE(
"grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)",
2, (channel, try_to_connect));
if (client_channel_elem->filter != &grpc_client_channel_filter) {
gpr_log(GPR_ERROR,
"grpc_channel_check_connectivity_state called on something that is "
"not a client channel, but '%s'",
client_channel_elem->filter->name);
grpc_exec_ctx_finish(&exec_ctx);
return GRPC_CHANNEL_FATAL_FAILURE;
}
state = grpc_client_channel_check_connectivity_state(
&exec_ctx, client_channel_elem, try_to_connect);
grpc_exec_ctx_finish(&exec_ctx);
return state;
}
typedef enum {
WAITING,
CALLING_BACK,
CALLING_BACK_AND_FINISHED,
CALLED_BACK
} callback_phase;
typedef struct {
gpr_mu mu;
callback_phase phase;
int success;
int removed;
grpc_closure on_complete;
grpc_alarm alarm;
grpc_connectivity_state state;
grpc_completion_queue *cq;
grpc_cq_completion completion_storage;
grpc_channel *channel;
void *tag;
} state_watcher;
static void delete_state_watcher(grpc_exec_ctx *exec_ctx, state_watcher *w) {
GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, w->channel, "watch_connectivity");
gpr_mu_destroy(&w->mu);
gpr_free(w);
}
static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
grpc_cq_completion *ignored) {
int delete = 0;
state_watcher *w = pw;
gpr_mu_lock(&w->mu);
switch (w->phase) {
case WAITING:
case CALLED_BACK:
gpr_log(GPR_ERROR, "should never reach here");
abort();
break;
case CALLING_BACK:
w->phase = CALLED_BACK;
break;
case CALLING_BACK_AND_FINISHED:
delete = 1;
break;
}
gpr_mu_unlock(&w->mu);
if (delete) {
delete_state_watcher(exec_ctx, w);
}
}
static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
int due_to_completion) {
int delete = 0;
grpc_channel_element *client_channel_elem = NULL;
gpr_mu_lock(&w->mu);
if (w->removed == 0) {
w->removed = 1;
client_channel_elem = grpc_channel_stack_last_element(
grpc_channel_get_channel_stack(w->channel));
grpc_client_channel_del_interested_party(exec_ctx, client_channel_elem,
grpc_cq_pollset(w->cq));
}
gpr_mu_unlock(&w->mu);
if (due_to_completion) {
gpr_mu_lock(&w->mu);
w->success = 1;
gpr_mu_unlock(&w->mu);
grpc_alarm_cancel(exec_ctx, &w->alarm);
}
gpr_mu_lock(&w->mu);
switch (w->phase) {
case WAITING:
w->phase = CALLING_BACK;
grpc_cq_end_op(exec_ctx, w->cq, w->tag, w->success, finished_completion,
w, &w->completion_storage);
break;
case CALLING_BACK:
w->phase = CALLING_BACK_AND_FINISHED;
break;
case CALLING_BACK_AND_FINISHED:
gpr_log(GPR_ERROR, "should never reach here");
abort();
break;
case CALLED_BACK:
delete = 1;
break;
}
gpr_mu_unlock(&w->mu);
if (delete) {
delete_state_watcher(exec_ctx, w);
}
}
static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw, int success) {
partly_done(exec_ctx, pw, 1);
}
static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw, int success) {
partly_done(exec_ctx, pw, 0);
}
void grpc_channel_watch_connectivity_state(
grpc_channel *channel, grpc_connectivity_state last_observed_state,
gpr_timespec deadline, grpc_completion_queue *cq, void *tag) {
grpc_channel_element *client_channel_elem =
grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
state_watcher *w = gpr_malloc(sizeof(*w));
GRPC_API_TRACE(
"grpc_channel_watch_connectivity_state("
"channel=%p, last_observed_state=%d, "
"deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
"cq=%p, tag=%p)",
7, (channel, (int)last_observed_state, (long)deadline.tv_sec,
deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
grpc_cq_begin_op(cq);
gpr_mu_init(&w->mu);
grpc_closure_init(&w->on_complete, watch_complete, w);
w->phase = WAITING;
w->state = last_observed_state;
w->success = 0;
w->removed = 0;
w->cq = cq;
w->tag = tag;
w->channel = channel;
grpc_alarm_init(&exec_ctx, &w->alarm,
gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
timeout_complete, w, gpr_now(GPR_CLOCK_MONOTONIC));
if (client_channel_elem->filter != &grpc_client_channel_filter) {
gpr_log(GPR_ERROR,
"grpc_channel_watch_connectivity_state called on something that is "
"not a client channel, but '%s'",
client_channel_elem->filter->name);
grpc_exec_ctx_enqueue(&exec_ctx, &w->on_complete, 1);
} else {
GRPC_CHANNEL_INTERNAL_REF(channel, "watch_connectivity");
grpc_client_channel_add_interested_party(&exec_ctx, client_channel_elem,
grpc_cq_pollset(cq));
grpc_client_channel_watch_connectivity_state(&exec_ctx, client_channel_elem,
&w->state, &w->on_complete);
}
grpc_exec_ctx_finish(&exec_ctx);
}
|