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
|
// Copyright 2008, 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 NET_BASE_CLIENT_SOCKET_POOL_H_
#define NET_BASE_CLIENT_SOCKET_POOL_H_
#include <deque>
#include <map>
#include <string>
#include "base/ref_counted.h"
#include "base/timer.h"
#include "net/base/completion_callback.h"
namespace net {
class ClientSocket;
class ClientSocketHandle;
// A ClientSocketPool is used to restrict the number of sockets open at a time.
// It also maintains a list of idle persistent sockets.
//
// The ClientSocketPool allocates scoped_ptr<ClientSocket> objects, but it is
// not responsible for allocating the associated ClientSocket objects. The
// consumer must do so if it gets a scoped_ptr<ClientSocket> with a null value.
//
class ClientSocketPool : public base::RefCounted<ClientSocketPool>,
public Task {
public:
explicit ClientSocketPool(int max_sockets_per_group);
// Called to request a socket for the given handle. There are three possible
// results: 1) the handle will be initialized with a socket to reuse, 2) the
// handle will be initialized without a socket such that the consumer needs
// to supply a socket, or 3) the handle will be added to a wait list until a
// socket is available to reuse or the opportunity to create a new socket
// arises. The completion callback is notified in the 3rd case.
//
// If this function returns OK, then |handle| is initialized upon return.
// The |handle|'s is_initialized method will return true in this case. If a
// ClientSocket was reused, then |handle|'s socket member will be non-NULL.
// Otherwise, the consumer will need to supply |handle| with a socket by
// allocating a new ClientSocket object and calling the |handle|'s set_socket
// method.
//
// If ERR_IO_PENDING is returned, then the completion callback will be called
// when |handle| has been initialized.
//
int RequestSocket(ClientSocketHandle* handle, CompletionCallback* callback);
// Called to cancel a RequestSocket call that returned ERR_IO_PENDING. The
// same handle parameter must be passed to this method as was passed to the
// RequestSocket call being cancelled. The associated CompletionCallback is
// not run.
void CancelRequest(ClientSocketHandle* handle);
// Called to release the socket member of an initialized ClientSocketHandle
// once the socket is no longer needed. If the socket member is non-null and
// still has an established connection, then it will be added to the idle set
// of sockets to be used to satisfy future RequestSocket calls. Otherwise,
// the ClientSocket is destroyed.
void ReleaseSocket(ClientSocketHandle* handle);
// Called to close any idle connections held by the connection manager.
void CloseIdleSockets();
private:
friend class base::RefCounted<ClientSocketPool>;
typedef scoped_ptr<ClientSocket> ClientSocketPtr;
~ClientSocketPool();
// Closes all idle sockets if |only_if_disconnected| is false. Else, only
// idle sockets that are disconnected get closed. "Maybe" refers to the
// fact that it doesn't close all idle sockets if |only_if_disconnected| is
// true.
void MaybeCloseIdleSockets(bool only_if_disconnected);
// Called when the number of idle sockets changes.
void IncrementIdleCount();
void DecrementIdleCount();
// Called via PostTask by ReleaseSocket.
void DoReleaseSocket(const std::string& group_name, ClientSocketPtr* ptr);
// Task implementation. This method scans the idle sockets checking to see
// if any have been disconnected.
virtual void Run();
// A Request is allocated per call to RequestSocket that results in
// ERR_IO_PENDING.
struct Request {
ClientSocketHandle* handle;
CompletionCallback* callback;
};
// A Group is allocated per group_name when there are idle sockets or pending
// requests. Otherwise, the Group object is removed from the map.
struct Group {
Group() : active_socket_count(0) {}
std::deque<ClientSocketPtr*> idle_sockets;
std::deque<Request> pending_requests;
int active_socket_count;
};
typedef std::map<std::string, Group> GroupMap;
GroupMap group_map_;
// Timer used to periodically prune sockets that have been disconnected.
RepeatingTimer timer_;
// The total number of idle sockets in the system.
int idle_socket_count_;
// The maximum number of sockets kept per group.
int max_sockets_per_group_;
};
} // namespace net
#endif // NET_BASE_CLIENT_SOCKET_POOL_H_
|
