Line data Source code
1 : /*
2 : *
3 : * Copyright 2015, Google Inc.
4 : * All rights reserved.
5 : *
6 : * Redistribution and use in source and binary forms, with or without
7 : * modification, are permitted provided that the following conditions are
8 : * met:
9 : *
10 : * * Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : * * Redistributions in binary form must reproduce the above
13 : * copyright notice, this list of conditions and the following disclaimer
14 : * in the documentation and/or other materials provided with the
15 : * distribution.
16 : * * Neither the name of Google Inc. nor the names of its
17 : * contributors may be used to endorse or promote products derived from
18 : * this software without specific prior written permission.
19 : *
20 : * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 : * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 : * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 : * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 : * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 : * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 : * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 : * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 : * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 : * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 : * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 : *
32 : */
33 :
34 : #include "src/core/surface/channel.h"
35 :
36 : #include <grpc/support/alloc.h>
37 : #include <grpc/support/log.h>
38 :
39 : #include "src/core/channel/client_channel.h"
40 : #include "src/core/iomgr/alarm.h"
41 : #include "src/core/surface/api_trace.h"
42 : #include "src/core/surface/completion_queue.h"
43 :
44 125 : grpc_connectivity_state grpc_channel_check_connectivity_state(
45 : grpc_channel *channel, int try_to_connect) {
46 : /* forward through to the underlying client channel */
47 125 : grpc_channel_element *client_channel_elem =
48 125 : grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
49 125 : grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
50 : grpc_connectivity_state state;
51 125 : GRPC_API_TRACE(
52 : "grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)", 2,
53 : (channel, try_to_connect));
54 125 : if (client_channel_elem->filter != &grpc_client_channel_filter) {
55 0 : gpr_log(GPR_ERROR,
56 : "grpc_channel_check_connectivity_state called on something that is "
57 : "not a client channel, but '%s'",
58 0 : client_channel_elem->filter->name);
59 0 : grpc_exec_ctx_finish(&exec_ctx);
60 0 : return GRPC_CHANNEL_FATAL_FAILURE;
61 : }
62 125 : state = grpc_client_channel_check_connectivity_state(
63 : &exec_ctx, client_channel_elem, try_to_connect);
64 125 : grpc_exec_ctx_finish(&exec_ctx);
65 125 : return state;
66 : }
67 :
68 : typedef enum {
69 : WAITING,
70 : CALLING_BACK,
71 : CALLING_BACK_AND_FINISHED,
72 : CALLED_BACK
73 : } callback_phase;
74 :
75 : typedef struct {
76 : gpr_mu mu;
77 : callback_phase phase;
78 : int success;
79 : int removed;
80 : grpc_closure on_complete;
81 : grpc_alarm alarm;
82 : grpc_connectivity_state state;
83 : grpc_completion_queue *cq;
84 : grpc_cq_completion completion_storage;
85 : grpc_channel *channel;
86 : void *tag;
87 : } state_watcher;
88 :
89 94 : static void delete_state_watcher(grpc_exec_ctx *exec_ctx, state_watcher *w) {
90 94 : GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, w->channel, "watch_connectivity");
91 94 : gpr_mu_destroy(&w->mu);
92 94 : gpr_free(w);
93 94 : }
94 :
95 94 : static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw,
96 : grpc_cq_completion *ignored) {
97 94 : int delete = 0;
98 94 : state_watcher *w = pw;
99 94 : gpr_mu_lock(&w->mu);
100 94 : switch (w->phase) {
101 : case WAITING:
102 : case CALLED_BACK:
103 0 : GPR_UNREACHABLE_CODE(return );
104 : case CALLING_BACK:
105 22 : w->phase = CALLED_BACK;
106 22 : break;
107 : case CALLING_BACK_AND_FINISHED:
108 72 : delete = 1;
109 72 : break;
110 : }
111 94 : gpr_mu_unlock(&w->mu);
112 :
113 94 : if (delete) {
114 72 : delete_state_watcher(exec_ctx, w);
115 : }
116 94 : }
117 :
118 188 : static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w,
119 : int due_to_completion) {
120 188 : int delete = 0;
121 188 : grpc_channel_element *client_channel_elem = NULL;
122 :
123 188 : gpr_mu_lock(&w->mu);
124 188 : if (w->removed == 0) {
125 94 : w->removed = 1;
126 94 : client_channel_elem = grpc_channel_stack_last_element(
127 : grpc_channel_get_channel_stack(w->channel));
128 94 : grpc_client_channel_del_interested_party(exec_ctx, client_channel_elem,
129 : grpc_cq_pollset(w->cq));
130 : }
131 188 : gpr_mu_unlock(&w->mu);
132 188 : if (due_to_completion) {
133 94 : gpr_mu_lock(&w->mu);
134 94 : w->success = 1;
135 94 : gpr_mu_unlock(&w->mu);
136 94 : grpc_alarm_cancel(exec_ctx, &w->alarm);
137 : }
138 :
139 188 : gpr_mu_lock(&w->mu);
140 188 : switch (w->phase) {
141 : case WAITING:
142 94 : w->phase = CALLING_BACK;
143 94 : grpc_cq_end_op(exec_ctx, w->cq, w->tag, w->success, finished_completion,
144 : w, &w->completion_storage);
145 94 : break;
146 : case CALLING_BACK:
147 72 : w->phase = CALLING_BACK_AND_FINISHED;
148 72 : break;
149 : case CALLING_BACK_AND_FINISHED:
150 0 : GPR_UNREACHABLE_CODE(return );
151 : case CALLED_BACK:
152 22 : delete = 1;
153 22 : break;
154 : }
155 188 : gpr_mu_unlock(&w->mu);
156 :
157 188 : if (delete) {
158 22 : delete_state_watcher(exec_ctx, w);
159 : }
160 188 : }
161 :
162 94 : static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw, int success) {
163 94 : partly_done(exec_ctx, pw, 1);
164 94 : }
165 :
166 94 : static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw, int success) {
167 94 : partly_done(exec_ctx, pw, 0);
168 94 : }
169 :
170 94 : void grpc_channel_watch_connectivity_state(
171 : grpc_channel *channel, grpc_connectivity_state last_observed_state,
172 : gpr_timespec deadline, grpc_completion_queue *cq, void *tag) {
173 94 : grpc_channel_element *client_channel_elem =
174 94 : grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel));
175 94 : grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
176 94 : state_watcher *w = gpr_malloc(sizeof(*w));
177 :
178 94 : GRPC_API_TRACE(
179 : "grpc_channel_watch_connectivity_state("
180 : "channel=%p, last_observed_state=%d, "
181 : "deadline=gpr_timespec { tv_sec: %ld, tv_nsec: %d, clock_type: %d }, "
182 : "cq=%p, tag=%p)",
183 : 7, (channel, (int)last_observed_state, (long)deadline.tv_sec,
184 : deadline.tv_nsec, (int)deadline.clock_type, cq, tag));
185 :
186 94 : grpc_cq_begin_op(cq);
187 :
188 94 : gpr_mu_init(&w->mu);
189 94 : grpc_closure_init(&w->on_complete, watch_complete, w);
190 94 : w->phase = WAITING;
191 94 : w->state = last_observed_state;
192 94 : w->success = 0;
193 94 : w->removed = 0;
194 94 : w->cq = cq;
195 94 : w->tag = tag;
196 94 : w->channel = channel;
197 :
198 94 : grpc_alarm_init(&exec_ctx, &w->alarm,
199 : gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
200 : timeout_complete, w, gpr_now(GPR_CLOCK_MONOTONIC));
201 :
202 94 : if (client_channel_elem->filter != &grpc_client_channel_filter) {
203 0 : gpr_log(GPR_ERROR,
204 : "grpc_channel_watch_connectivity_state called on something that is "
205 : "not a client channel, but '%s'",
206 0 : client_channel_elem->filter->name);
207 0 : grpc_exec_ctx_enqueue(&exec_ctx, &w->on_complete, 1);
208 : } else {
209 94 : GRPC_CHANNEL_INTERNAL_REF(channel, "watch_connectivity");
210 94 : grpc_client_channel_add_interested_party(&exec_ctx, client_channel_elem,
211 : grpc_cq_pollset(cq));
212 94 : grpc_client_channel_watch_connectivity_state(&exec_ctx, client_channel_elem,
213 : &w->state, &w->on_complete);
214 : }
215 :
216 94 : grpc_exec_ctx_finish(&exec_ctx);
217 94 : }
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