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
|
/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/* For use with thr_locks */
#ifndef DRIZZLED_THR_LOCK_H
#define DRIZZLED_THR_LOCK_H
#include <boost/thread/mutex.hpp>
#include <boost/thread/shared_mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <pthread.h>
namespace drizzled
{
extern uint64_t max_write_lock_count;
extern uint64_t table_lock_wait_timeout;
enum thr_lock_type { TL_IGNORE=-1,
/* UNLOCK ANY LOCK */
TL_UNLOCK,
/* Read lock */
TL_READ,
TL_READ_WITH_SHARED_LOCKS,
/* READ, Don't allow concurrent insert */
TL_READ_NO_INSERT,
/*
Write lock, but allow other threads to read / write.
Used by BDB tables in MySQL to mark that someone is
reading/writing to the table.
*/
TL_WRITE_ALLOW_WRITE,
/*
Write lock, but allow other threads to read.
Used by ALTER TABLE in MySQL to allow readers
to use the table until ALTER TABLE is finished.
*/
TL_WRITE_ALLOW_READ,
/*
WRITE lock used by concurrent insert. Will allow
READ, if one could use concurrent insert on table.
*/
TL_WRITE_CONCURRENT_INSERT,
/*
parser only! Late bound low_priority flag.
At open_tables() becomes thd->update_lock_default.
*/
TL_WRITE_DEFAULT,
/* Normal WRITE lock */
TL_WRITE,
/* Abort new lock request with an error */
TL_WRITE_ONLY};
enum enum_thr_lock_result { THR_LOCK_SUCCESS= 0, THR_LOCK_ABORTED= 1,
THR_LOCK_WAIT_TIMEOUT= 2, THR_LOCK_DEADLOCK= 3 };
/*
A description of the thread which owns the lock. The address
of an instance of this structure is used to uniquely identify the thread.
*/
struct THR_LOCK_INFO
{
pthread_t thread;
uint64_t thread_id;
uint32_t n_cursors;
THR_LOCK_INFO() :
thread(0),
thread_id(0),
n_cursors(0)
{ }
void init();
};
/*
Lock owner identifier. Globally identifies the lock owner within the
thread and among all the threads. The address of an instance of this
structure is used as id.
*/
struct THR_LOCK_OWNER
{
THR_LOCK_INFO *info;
THR_LOCK_OWNER() :
info(0)
{ }
};
struct THR_LOCK;
struct THR_LOCK_DATA;
struct THR_LOCK_DATA {
THR_LOCK_OWNER *owner;
struct THR_LOCK_DATA *next,**prev;
struct THR_LOCK *lock;
boost::condition_variable_any *cond;
enum thr_lock_type type;
void *status_param; /* Param to status functions */
THR_LOCK_DATA() :
owner(0),
next(0),
prev(0),
lock(0),
cond(0),
type(TL_UNLOCK),
status_param(0)
{ }
void init(THR_LOCK *lock,
void *status_param= NULL);
};
struct st_lock_list {
THR_LOCK_DATA *data,**last;
st_lock_list() :
data(0),
last(0)
{ }
};
struct THR_LOCK {
private:
boost::mutex mutex;
public:
struct st_lock_list read_wait;
struct st_lock_list read;
struct st_lock_list write_wait;
struct st_lock_list write;
/* write_lock_count is incremented for write locks and reset on read locks */
uint32_t write_lock_count;
uint32_t read_no_write_count;
THR_LOCK() :
write_lock_count(0),
read_no_write_count(0)
{ }
~THR_LOCK()
{ }
void abort_locks();
bool abort_locks_for_thread(uint64_t thread);
void lock()
{
mutex.lock();
}
void unlock()
{
mutex.unlock();
}
void init()
{
}
void deinit()
{
}
boost::mutex *native_handle()
{
return &mutex;
}
};
#define thr_lock_owner_init(owner, info_arg) (owner)->info= (info_arg)
void thr_lock_init(THR_LOCK *lock);
enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data,
uint32_t count, THR_LOCK_OWNER *owner);
} /* namespace drizzled */
#endif /* DRIZZLED_THR_LOCK_H */
|