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
|
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#ifndef CEPH_SHAREDPTR_REGISTRY_H
#define CEPH_SHAREDPTR_REGISTRY_H
#include <map>
#include <memory>
#include "common/ceph_mutex.h"
/**
* Provides a registry of shared_ptr<V> indexed by K while
* the references are alive.
*/
template <class K, class V, class C = std::less<K> >
class SharedPtrRegistry {
public:
typedef std::shared_ptr<V> VPtr;
typedef std::weak_ptr<V> WeakVPtr;
int waiting;
private:
ceph::mutex lock = ceph::make_mutex("SharedPtrRegistry::lock");
ceph::condition_variable cond;
std::map<K, std::pair<WeakVPtr, V*>, C> contents;
class OnRemoval {
SharedPtrRegistry<K,V,C> *parent;
K key;
public:
OnRemoval(SharedPtrRegistry<K,V,C> *parent, K key) :
parent(parent), key(key) {}
void operator()(V *to_remove) {
{
std::lock_guard l(parent->lock);
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
parent->contents.find(key);
if (i != parent->contents.end() &&
i->second.second == to_remove) {
parent->contents.erase(i);
parent->cond.notify_all();
}
}
delete to_remove;
}
};
friend class OnRemoval;
public:
SharedPtrRegistry() :
waiting(0)
{}
bool empty() {
std::lock_guard l(lock);
return contents.empty();
}
bool get_next(const K &key, std::pair<K, VPtr> *next) {
std::pair<K, VPtr> r;
{
std::lock_guard l(lock);
VPtr next_val;
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
contents.upper_bound(key);
while (i != contents.end() &&
!(next_val = i->second.first.lock()))
++i;
if (i == contents.end())
return false;
if (next)
r = std::make_pair(i->first, next_val);
}
if (next)
*next = r;
return true;
}
bool get_next(const K &key, std::pair<K, V> *next) {
VPtr next_val;
std::lock_guard l(lock);
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
contents.upper_bound(key);
while (i != contents.end() &&
!(next_val = i->second.first.lock()))
++i;
if (i == contents.end())
return false;
if (next)
*next = std::make_pair(i->first, *next_val);
return true;
}
VPtr lookup(const K &key) {
std::unique_lock l(lock);
waiting++;
while (1) {
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
contents.find(key);
if (i != contents.end()) {
VPtr retval = i->second.first.lock();
if (retval) {
waiting--;
return retval;
}
} else {
break;
}
cond.wait(l);
}
waiting--;
return VPtr();
}
VPtr lookup_or_create(const K &key) {
std::unique_lock l(lock);
waiting++;
while (1) {
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
contents.find(key);
if (i != contents.end()) {
VPtr retval = i->second.first.lock();
if (retval) {
waiting--;
return retval;
}
} else {
break;
}
cond.wait(l);
}
V *ptr = new V();
VPtr retval(ptr, OnRemoval(this, key));
contents.insert(std::make_pair(key, make_pair(retval, ptr)));
waiting--;
return retval;
}
unsigned size() {
std::lock_guard l(lock);
return contents.size();
}
void remove(const K &key) {
std::lock_guard l(lock);
contents.erase(key);
cond.notify_all();
}
template<class A>
VPtr lookup_or_create(const K &key, const A &arg) {
std::unique_lock l(lock);
waiting++;
while (1) {
typename std::map<K, std::pair<WeakVPtr, V*>, C>::iterator i =
contents.find(key);
if (i != contents.end()) {
VPtr retval = i->second.first.lock();
if (retval) {
waiting--;
return retval;
}
} else {
break;
}
cond.wait(l);
}
V *ptr = new V(arg);
VPtr retval(ptr, OnRemoval(this, key));
contents.insert(std::make_pair(key, make_pair(retval, ptr)));
waiting--;
return retval;
}
friend class SharedPtrRegistryTest;
};
#endif
|
