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
222
223
224
225
226
227
228
|
/*
*
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include "test/core/util/test_lb_policies.h"
#include <string>
#include "src/core/ext/filters/client_channel/lb_policy.h"
#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/channel/channelz.h"
#include "src/core/lib/debug/trace.h"
#include "src/core/lib/gprpp/memory.h"
#include "src/core/lib/gprpp/orphanable.h"
#include "src/core/lib/gprpp/ref_counted_ptr.h"
#include "src/core/lib/iomgr/closure.h"
#include "src/core/lib/iomgr/combiner.h"
#include "src/core/lib/iomgr/error.h"
#include "src/core/lib/iomgr/pollset_set.h"
#include "src/core/lib/json/json.h"
#include "src/core/lib/transport/connectivity_state.h"
namespace grpc_core {
TraceFlag grpc_trace_forwarding_lb(false, "forwarding_lb");
namespace {
//
// ForwardingLoadBalancingPolicy
//
// A minimal forwarding class to avoid implementing a standalone test LB.
class ForwardingLoadBalancingPolicy : public LoadBalancingPolicy {
public:
ForwardingLoadBalancingPolicy(
UniquePtr<ChannelControlHelper> delegating_helper, Args args,
const std::string& delegate_policy_name, intptr_t initial_refcount = 1)
: LoadBalancingPolicy(std::move(args), initial_refcount) {
Args delegate_args;
delegate_args.combiner = combiner();
delegate_args.channel_control_helper = std::move(delegating_helper);
delegate_args.args = args.args;
delegate_ = LoadBalancingPolicyRegistry::CreateLoadBalancingPolicy(
delegate_policy_name.c_str(), std::move(delegate_args));
grpc_pollset_set_add_pollset_set(delegate_->interested_parties(),
interested_parties());
}
~ForwardingLoadBalancingPolicy() override = default;
void UpdateLocked(UpdateArgs args) override {
delegate_->UpdateLocked(std::move(args));
}
void ExitIdleLocked() override { delegate_->ExitIdleLocked(); }
void ResetBackoffLocked() override { delegate_->ResetBackoffLocked(); }
private:
void ShutdownLocked() override { delegate_.reset(); }
OrphanablePtr<LoadBalancingPolicy> delegate_;
};
//
// InterceptRecvTrailingMetadataLoadBalancingPolicy
//
constexpr char kInterceptRecvTrailingMetadataLbPolicyName[] =
"intercept_trailing_metadata_lb";
class InterceptRecvTrailingMetadataLoadBalancingPolicy
: public ForwardingLoadBalancingPolicy {
public:
InterceptRecvTrailingMetadataLoadBalancingPolicy(
Args args, InterceptRecvTrailingMetadataCallback cb, void* user_data)
: ForwardingLoadBalancingPolicy(
UniquePtr<ChannelControlHelper>(New<Helper>(
RefCountedPtr<InterceptRecvTrailingMetadataLoadBalancingPolicy>(
this),
cb, user_data)),
std::move(args),
/*delegate_lb_policy_name=*/"pick_first",
/*initial_refcount=*/2) {}
~InterceptRecvTrailingMetadataLoadBalancingPolicy() override = default;
const char* name() const override {
return kInterceptRecvTrailingMetadataLbPolicyName;
}
private:
class Picker : public SubchannelPicker {
public:
explicit Picker(UniquePtr<SubchannelPicker> delegate_picker,
InterceptRecvTrailingMetadataCallback cb, void* user_data)
: delegate_picker_(std::move(delegate_picker)),
cb_(cb),
user_data_(user_data) {}
PickResult Pick(PickArgs args) override {
PickResult result = delegate_picker_->Pick(args);
if (result.type == PickResult::PICK_COMPLETE &&
result.subchannel != nullptr) {
new (args.call_state->Alloc(sizeof(TrailingMetadataHandler)))
TrailingMetadataHandler(&result, cb_, user_data_);
}
return result;
}
private:
UniquePtr<SubchannelPicker> delegate_picker_;
InterceptRecvTrailingMetadataCallback cb_;
void* user_data_;
};
class Helper : public ChannelControlHelper {
public:
Helper(
RefCountedPtr<InterceptRecvTrailingMetadataLoadBalancingPolicy> parent,
InterceptRecvTrailingMetadataCallback cb, void* user_data)
: parent_(std::move(parent)), cb_(cb), user_data_(user_data) {}
RefCountedPtr<SubchannelInterface> CreateSubchannel(
const grpc_channel_args& args) override {
return parent_->channel_control_helper()->CreateSubchannel(args);
}
grpc_channel* CreateChannel(const char* target,
const grpc_channel_args& args) override {
return parent_->channel_control_helper()->CreateChannel(target, args);
}
void UpdateState(grpc_connectivity_state state,
UniquePtr<SubchannelPicker> picker) override {
parent_->channel_control_helper()->UpdateState(
state, UniquePtr<SubchannelPicker>(
New<Picker>(std::move(picker), cb_, user_data_)));
}
void RequestReresolution() override {
parent_->channel_control_helper()->RequestReresolution();
}
void AddTraceEvent(TraceSeverity severity, const char* message) override {
parent_->channel_control_helper()->AddTraceEvent(severity, message);
}
private:
RefCountedPtr<InterceptRecvTrailingMetadataLoadBalancingPolicy> parent_;
InterceptRecvTrailingMetadataCallback cb_;
void* user_data_;
};
class TrailingMetadataHandler {
public:
TrailingMetadataHandler(PickResult* result,
InterceptRecvTrailingMetadataCallback cb,
void* user_data)
: cb_(cb), user_data_(user_data) {
result->recv_trailing_metadata_ready = &RecordRecvTrailingMetadata;
result->recv_trailing_metadata_ready_user_data = this;
}
private:
static void RecordRecvTrailingMetadata(
void* arg, grpc_metadata_batch* recv_trailing_metadata,
CallState* call_state) {
TrailingMetadataHandler* self =
static_cast<TrailingMetadataHandler*>(arg);
GPR_ASSERT(recv_trailing_metadata != nullptr);
self->cb_(self->user_data_);
self->~TrailingMetadataHandler();
}
InterceptRecvTrailingMetadataCallback cb_;
void* user_data_;
};
};
class InterceptTrailingFactory : public LoadBalancingPolicyFactory {
public:
explicit InterceptTrailingFactory(InterceptRecvTrailingMetadataCallback cb,
void* user_data)
: cb_(cb), user_data_(user_data) {}
OrphanablePtr<LoadBalancingPolicy> CreateLoadBalancingPolicy(
LoadBalancingPolicy::Args args) const override {
return OrphanablePtr<LoadBalancingPolicy>(
New<InterceptRecvTrailingMetadataLoadBalancingPolicy>(std::move(args),
cb_, user_data_));
}
const char* name() const override {
return kInterceptRecvTrailingMetadataLbPolicyName;
}
private:
InterceptRecvTrailingMetadataCallback cb_;
void* user_data_;
};
} // namespace
void RegisterInterceptRecvTrailingMetadataLoadBalancingPolicy(
InterceptRecvTrailingMetadataCallback cb, void* user_data) {
LoadBalancingPolicyRegistry::Builder::RegisterLoadBalancingPolicyFactory(
UniquePtr<LoadBalancingPolicyFactory>(
New<InterceptTrailingFactory>(cb, user_data)));
}
} // namespace grpc_core
|
