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
|
// lockstate.h
/**
* Copyright (C) 2008 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "mongo/db/d_concurrency.h"
namespace mongo {
class Acquiring;
// per thread
class LockState {
public:
LockState();
void dump();
static void Dump();
BSONObj reportState();
void reportState(BSONObjBuilder& b);
unsigned recursiveCount() const { return _recursive; }
/**
* @return 0 rwRW
*/
char threadState() const { return _threadState; }
bool isRW() const; // RW
bool isW() const; // W
bool hasAnyReadLock() const; // explicitly rR
bool hasAnyWriteLock() const; // wWX
bool isLocked( const StringData& ns ); // rwRW
/** pending means we are currently trying to get a lock */
bool hasLockPending() const { return _lockPending || _lockPendingParallelWriter; }
// ----
void lockedStart( char newState ); // RWrw
void unlocked(); // _threadState = 0
/**
* you have to be locked already to call this
* this is mostly for W_to_R or R_to_W
*/
void changeLockState( char newstate );
Lock::Nestable whichNestable() const { return _whichNestable; }
int nestableCount() const { return _nestableCount; }
int otherCount() const { return _otherCount; }
const string& otherName() const { return _otherName; }
WrapperForRWLock* otherLock() const { return _otherLock; }
void enterScopedLock( Lock::ScopedLock* lock );
Lock::ScopedLock* leaveScopedLock();
void lockedNestable( Lock::Nestable what , int type );
void unlockedNestable();
void lockedOther( const StringData& db , int type , WrapperForRWLock* lock );
void lockedOther( int type ); // "same lock as last time" case
void unlockedOther();
bool _batchWriter;
LockStat* getRelevantLockStat();
void recordLockTime() { _scopedLk->recordTime(); }
void resetLockTime() { _scopedLk->resetTime(); }
private:
unsigned _recursive; // we allow recursively asking for a lock; we track that here
// global lock related
char _threadState; // 0, 'r', 'w', 'R', 'W'
// db level locking related
Lock::Nestable _whichNestable;
int _nestableCount; // recursive lock count on local or admin db XXX - change name
int _otherCount; // >0 means write lock, <0 read lock - XXX change name
string _otherName; // which database are we locking and working with (besides local/admin)
WrapperForRWLock* _otherLock; // so we don't have to check the map too often (the map has a mutex)
// for temprelease
// for the nonrecursive case. otherwise there would be many
// the first lock goes here, which is ok since we can't yield recursive locks
Lock::ScopedLock* _scopedLk;
bool _lockPending;
bool _lockPendingParallelWriter;
friend class Acquiring;
friend class AcquiringParallelWriter;
};
class WrapperForRWLock : boost::noncopyable {
SimpleRWLock r;
public:
string name() const { return r.name; }
LockStat stats;
WrapperForRWLock(const StringData& name) : r(name) { }
void lock() { r.lock(); }
void lock_shared() { r.lock_shared(); }
void unlock() { r.unlock(); }
void unlock_shared() { r.unlock_shared(); }
};
class ScopedLock;
class Acquiring {
public:
Acquiring( Lock::ScopedLock* lock, LockState& ls );
~Acquiring();
private:
Lock::ScopedLock* _lock;
LockState& _ls;
};
class AcquiringParallelWriter {
public:
AcquiringParallelWriter( LockState& ls );
~AcquiringParallelWriter();
private:
LockState& _ls;
};
}
|
