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
|
/*
Copyright (C) 2009 Red Hat, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _H_SHARED_CACHE
#define _H_SHARED_CACHE
#include "utils.h"
#include "threads.h"
/*class SharedCache::Treat {
T* get(T*);
void release(T*);
const char* name();
};*/
template <class T, class Treat, int HASH_SIZE, class Base = EmptyBase>
class SharedCache : public Base {
public:
SharedCache()
: _aborting (false)
{
memset(_hash, 0, sizeof(_hash));
}
~SharedCache()
{
clear();
}
void add(uint64_t id, T* data)
{
Lock lock(_lock);
Item** item = &_hash[key(id)];
while (*item) {
if ((*item)->id == id) {
(*item)->refs++;
return;
}
item = &(*item)->next;
}
*item = new Item(id, data);
_new_item_cond.notify_all();
}
T* get(uint64_t id)
{
Lock lock(_lock);
Item* item = _hash[key(id)];
for (;;) {
if (!item) {
if (_aborting) {
THROW("%s aborting", Treat::name());
}
_new_item_cond.wait(lock);
item = _hash[key(id)];
continue;
}
if (item->id != id) {
item = item->next;
continue;
}
return Treat::get(item->data);
}
}
void remove(uint64_t id)
{
Lock lock(_lock);
Item** item = &_hash[key(id)];
while (*item) {
if ((*item)->id == id) {
if (!--(*item)->refs) {
Item *rm_item = *item;
*item = rm_item->next;
delete rm_item;
}
return;
}
item = &(*item)->next;
}
THROW("%s id %lu, not found", Treat::name(), id);
}
void clear()
{
Lock lock(_lock);
for (int i = 0; i < HASH_SIZE; i++) {
while (_hash[i]) {
Item *item = _hash[i];
_hash[i] = item->next;
delete item;
}
}
}
void abort()
{
Lock lock(_lock);
_aborting = true;
_new_item_cond.notify_all();
}
private:
inline uint32_t key(uint64_t id) {return uint32_t(id) % HASH_SIZE;}
private:
class Item {
public:
Item(uint64_t in_id, T* data)
: id (in_id)
, refs (1)
, next (NULL)
, data (Treat::get(data)) {}
~Item()
{
Treat::release(data);
}
uint64_t id;
int refs;
Item* next;
T* data;
};
Item* _hash[HASH_SIZE];
Mutex _lock;
Condition _new_item_cond;
bool _aborting;
};
#endif
|
