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
|
/*
*
* 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.
*
*/
#ifndef GRPCXX_COMPLETION_QUEUE_H
#define GRPCXX_COMPLETION_QUEUE_H
#include <chrono>
#include <grpc++/impl/client_unary_call.h>
struct grpc_completion_queue;
namespace grpc {
template <class R>
class ClientReader;
template <class W>
class ClientWriter;
template <class R, class W>
class ClientReaderWriter;
template <class R>
class ServerReader;
template <class W>
class ServerWriter;
template <class R, class W>
class ServerReaderWriter;
class CompletionQueue;
class Server;
class ServerContext;
class CompletionQueueTag {
public:
virtual ~CompletionQueueTag() {}
// Called prior to returning from Next(), return value
// is the status of the operation (return status is the default thing
// to do)
// If this function returns false, the tag is dropped and not returned
// from the completion queue
virtual bool FinalizeResult(void** tag, bool* status) = 0;
};
// grpc_completion_queue wrapper class
class CompletionQueue {
public:
CompletionQueue();
explicit CompletionQueue(grpc_completion_queue* take);
~CompletionQueue();
// Tri-state return for AsyncNext: SHUTDOWN, GOT_EVENT, TIMEOUT
enum NextStatus { SHUTDOWN, GOT_EVENT, TIMEOUT };
// Nonblocking (until deadline) read from queue.
// Cannot rely on result of tag or ok if return is TIMEOUT
NextStatus AsyncNext(void** tag, bool* ok,
std::chrono::system_clock::time_point deadline);
// Blocking (until deadline) read from queue.
// Returns false if the queue is ready for destruction, true if event
bool Next(void** tag, bool* ok) {
return (
AsyncNext(tag, ok, (std::chrono::system_clock::time_point::max)()) !=
SHUTDOWN);
}
// Shutdown has to be called, and the CompletionQueue can only be
// destructed when false is returned from Next().
void Shutdown();
grpc_completion_queue* cq() { return cq_; }
private:
// Friend synchronous wrappers so that they can access Pluck(), which is
// a semi-private API geared towards the synchronous implementation.
template <class R>
friend class ::grpc::ClientReader;
template <class W>
friend class ::grpc::ClientWriter;
template <class R, class W>
friend class ::grpc::ClientReaderWriter;
template <class R>
friend class ::grpc::ServerReader;
template <class W>
friend class ::grpc::ServerWriter;
template <class R, class W>
friend class ::grpc::ServerReaderWriter;
friend class ::grpc::Server;
friend class ::grpc::ServerContext;
friend Status BlockingUnaryCall(ChannelInterface* channel,
const RpcMethod& method,
ClientContext* context,
const grpc::protobuf::Message& request,
grpc::protobuf::Message* result);
// Wraps grpc_completion_queue_pluck.
// Cannot be mixed with calls to Next().
bool Pluck(CompletionQueueTag* tag);
// Does a single polling pluck on tag
void TryPluck(CompletionQueueTag* tag);
grpc_completion_queue* cq_; // owned
};
} // namespace grpc
#endif // GRPCXX_COMPLETION_QUEUE_H
|
