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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/db/concurrency/lock_manager_defs.h"
#include "mongo/platform/atomic_word.h"
namespace mongo {
class BSONObjBuilder;
/**
* Operations for manipulating the lock statistics abstracting whether they are atomic or not.
*/
struct CounterOps {
static int64_t get(const int64_t& counter) {
return counter;
}
static int64_t get(const AtomicWord<long long>& counter) {
return counter.load();
}
static void set(int64_t& counter, int64_t value) {
counter = value;
}
static void set(AtomicWord<long long>& counter, int64_t value) {
counter.store(value);
}
static void add(int64_t& counter, int64_t value) {
counter += value;
}
static void add(int64_t& counter, const AtomicWord<long long>& value) {
counter += value.load();
}
static void add(AtomicWord<long long>& counter, int64_t value) {
counter.addAndFetch(value);
}
};
/**
* Bundle of locking statistics values.
*/
template <typename CounterType>
struct LockStatCounters {
template <typename OtherType>
void append(const LockStatCounters<OtherType>& other) {
CounterOps::add(numAcquisitions, other.numAcquisitions);
CounterOps::add(numWaits, other.numWaits);
CounterOps::add(combinedWaitTimeMicros, other.combinedWaitTimeMicros);
}
template <typename OtherType>
void subtract(const LockStatCounters<OtherType>& other) {
CounterOps::add(numAcquisitions, -other.numAcquisitions);
CounterOps::add(numWaits, -other.numWaits);
CounterOps::add(combinedWaitTimeMicros, -other.combinedWaitTimeMicros);
}
void reset() {
CounterOps::set(numAcquisitions, 0);
CounterOps::set(numWaits, 0);
CounterOps::set(combinedWaitTimeMicros, 0);
}
CounterType numAcquisitions;
CounterType numWaits;
CounterType combinedWaitTimeMicros;
};
/**
* Templatized lock statistics management class, which can be specialized with atomic integers
* for the global stats and with regular integers for the per-locker stats.
*/
template <typename CounterType>
class LockStats {
public:
// Declare the type for the lock counters bundle
typedef LockStatCounters<CounterType> LockStatCountersType;
/**
* Initializes the locking statistics with zeroes (calls reset).
*/
LockStats();
void recordAcquisition(ResourceId resId, LockMode mode) {
CounterOps::add(get(resId, mode).numAcquisitions, 1);
}
void recordWait(ResourceId resId, LockMode mode) {
CounterOps::add(get(resId, mode).numWaits, 1);
}
void recordWaitTime(ResourceId resId, LockMode mode, int64_t waitMicros) {
CounterOps::add(get(resId, mode).combinedWaitTimeMicros, waitMicros);
}
LockStatCountersType& get(ResourceId resId, LockMode mode) {
if (resId == resourceIdOplog) {
return _oplogStats.modeStats[mode];
}
return _stats[resId.getType()].modeStats[mode];
}
template <typename OtherType>
void append(const LockStats<OtherType>& other) {
typedef LockStatCounters<OtherType> OtherLockStatCountersType;
// Append all lock stats
for (int i = 0; i < ResourceTypesCount; i++) {
for (int mode = 0; mode < LockModesCount; mode++) {
const OtherLockStatCountersType& otherStats = other._stats[i].modeStats[mode];
LockStatCountersType& thisStats = _stats[i].modeStats[mode];
thisStats.append(otherStats);
}
}
// Append the oplog stats
for (int mode = 0; mode < LockModesCount; mode++) {
const OtherLockStatCountersType& otherStats = other._oplogStats.modeStats[mode];
LockStatCountersType& thisStats = _oplogStats.modeStats[mode];
thisStats.append(otherStats);
}
}
template <typename OtherType>
void subtract(const LockStats<OtherType>& other) {
typedef LockStatCounters<OtherType> OtherLockStatCountersType;
for (int i = 0; i < ResourceTypesCount; i++) {
for (int mode = 0; mode < LockModesCount; mode++) {
const OtherLockStatCountersType& otherStats = other._stats[i].modeStats[mode];
LockStatCountersType& thisStats = _stats[i].modeStats[mode];
thisStats.subtract(otherStats);
}
}
for (int mode = 0; mode < LockModesCount; mode++) {
const OtherLockStatCountersType& otherStats = other._oplogStats.modeStats[mode];
LockStatCountersType& thisStats = _oplogStats.modeStats[mode];
thisStats.subtract(otherStats);
}
}
void report(BSONObjBuilder* builder) const;
void reset();
private:
// Necessary for the append call, which accepts argument of type different than our
// template parameter.
template <typename T>
friend class LockStats;
// Keep the per-mode lock stats next to each other in case we want to do fancy operations
// such as atomic operations on 128-bit values.
struct PerModeLockStatCounters {
LockStatCountersType modeStats[LockModesCount];
};
void _report(BSONObjBuilder* builder,
const char* sectionName,
const PerModeLockStatCounters& stat) const;
// Split the lock stats per resource type and special-case the oplog so we can collect
// more detailed stats for it.
PerModeLockStatCounters _stats[ResourceTypesCount];
PerModeLockStatCounters _oplogStats;
};
typedef LockStats<int64_t> SingleThreadedLockStats;
typedef LockStats<AtomicWord<long long>> AtomicLockStats;
/**
* Reports instance-wide locking statistics, which can then be converted to BSON or logged.
*/
void reportGlobalLockingStats(SingleThreadedLockStats* outStats);
/**
* Currently used for testing only.
*/
void resetGlobalLockStats();
} // namespace mongo
|
