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
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file records the static ranks of the locks in the runtime. If a lock
// is not given a rank, then it is assumed to be a leaf lock, which means no other
// lock can be acquired while it is held. Therefore, leaf locks do not need to be
// given an explicit rank. We list all of the architecture-independent leaf locks
// for documentation purposes, but don't list any of the architecture-dependent
// locks (which are all leaf locks). debugLock is ignored for ranking, since it is used
// when printing out lock ranking errors.
//
// lockInit(l *mutex, rank int) is used to set the rank of lock before it is used.
// If there is no clear place to initialize a lock, then the rank of a lock can be
// specified during the lock call itself via lockWithrank(l *mutex, rank int).
//
// Besides the static lock ranking (which is a total ordering of the locks), we
// also represent and enforce the actual partial order among the locks in the
// arcs[] array below. That is, if it is possible that lock B can be acquired when
// lock A is the previous acquired lock that is still held, then there should be
// an entry for A in arcs[B][]. We will currently fail not only if the total order
// (the lock ranking) is violated, but also if there is a missing entry in the
// partial order.
package runtime
type lockRank int
// Constants representing the lock rank of the architecture-independent locks in
// the runtime. Locks with lower rank must be taken before locks with higher
// rank.
const (
lockRankDummy lockRank = iota
// Locks held above sched
lockRankSysmon
lockRankScavenge
lockRankForcegc
lockRankSweepWaiters
lockRankAssistQueue
lockRankCpuprof
lockRankSweep
lockRankSched
lockRankDeadlock
lockRankPanic
lockRankAllg
lockRankAllp
lockRankPollDesc
lockRankTimers // Multiple timers locked simultaneously in destroy()
lockRankItab
lockRankReflectOffs
lockRankHchan // Multiple hchans acquired in lock order in syncadjustsudogs()
lockRankFin
lockRankNotifyList
lockRankTraceBuf
lockRankTraceStrings
lockRankMspanSpecial
lockRankProf
lockRankGcBitsArenas
lockRankRoot
lockRankTrace
lockRankTraceStackTab
lockRankNetpollInit
lockRankRwmutexW
lockRankRwmutexR
lockRankSpanSetSpine
lockRankGscan
lockRankStackpool
lockRankStackLarge
lockRankDefer
lockRankSudog
// Memory-related non-leaf locks
lockRankWbufSpans
lockRankMheap
lockRankMheapSpecial
// Memory-related leaf locks
lockRankGlobalAlloc
// Other leaf locks
lockRankGFree
// Generally, hchan must be acquired before gscan. But in one specific
// case (in syncadjustsudogs from markroot after the g has been suspended
// by suspendG), we allow gscan to be acquired, and then an hchan lock. To
// allow this case, we get this lockRankHchanLeaf rank in
// syncadjustsudogs(), rather than lockRankHchan. By using this special
// rank, we don't allow any further locks to be acquired other than more
// hchan locks.
lockRankHchanLeaf
// Leaf locks with no dependencies, so these constants are not actually used anywhere.
// There are other architecture-dependent leaf locks as well.
lockRankNewmHandoff
lockRankDebugPtrmask
lockRankFaketimeState
lockRankTicks
lockRankRaceFini
lockRankPollCache
lockRankDebug
)
// lockRankLeafRank is the rank of lock that does not have a declared rank, and hence is
// a leaf lock.
const lockRankLeafRank lockRank = 1000
// lockNames gives the names associated with each of the above ranks
var lockNames = []string{
lockRankDummy: "",
lockRankSysmon: "sysmon",
lockRankScavenge: "scavenge",
lockRankForcegc: "forcegc",
lockRankSweepWaiters: "sweepWaiters",
lockRankAssistQueue: "assistQueue",
lockRankCpuprof: "cpuprof",
lockRankSweep: "sweep",
lockRankSched: "sched",
lockRankDeadlock: "deadlock",
lockRankPanic: "panic",
lockRankAllg: "allg",
lockRankAllp: "allp",
lockRankPollDesc: "pollDesc",
lockRankTimers: "timers",
lockRankItab: "itab",
lockRankReflectOffs: "reflectOffs",
lockRankHchan: "hchan",
lockRankFin: "fin",
lockRankNotifyList: "notifyList",
lockRankTraceBuf: "traceBuf",
lockRankTraceStrings: "traceStrings",
lockRankMspanSpecial: "mspanSpecial",
lockRankProf: "prof",
lockRankGcBitsArenas: "gcBitsArenas",
lockRankRoot: "root",
lockRankTrace: "trace",
lockRankTraceStackTab: "traceStackTab",
lockRankNetpollInit: "netpollInit",
lockRankRwmutexW: "rwmutexW",
lockRankRwmutexR: "rwmutexR",
lockRankSpanSetSpine: "spanSetSpine",
lockRankGscan: "gscan",
lockRankStackpool: "stackpool",
lockRankStackLarge: "stackLarge",
lockRankDefer: "defer",
lockRankSudog: "sudog",
lockRankWbufSpans: "wbufSpans",
lockRankMheap: "mheap",
lockRankMheapSpecial: "mheapSpecial",
lockRankGlobalAlloc: "globalAlloc.mutex",
lockRankGFree: "gFree",
lockRankHchanLeaf: "hchanLeaf",
lockRankNewmHandoff: "newmHandoff.lock",
lockRankDebugPtrmask: "debugPtrmask.lock",
lockRankFaketimeState: "faketimeState.lock",
lockRankTicks: "ticks.lock",
lockRankRaceFini: "raceFiniLock",
lockRankPollCache: "pollCache.lock",
lockRankDebug: "debugLock",
}
func (rank lockRank) String() string {
if rank == 0 {
return "UNKNOWN"
}
if rank == lockRankLeafRank {
return "LEAF"
}
return lockNames[rank]
}
// lockPartialOrder is a partial order among the various lock types, listing the immediate
// ordering that has actually been observed in the runtime. Each entry (which
// corresponds to a particular lock rank) specifies the list of locks that can be
// already be held immediately "above" it.
//
// So, for example, the lockRankSched entry shows that all the locks preceding it in
// rank can actually be held. The fin lock shows that only the sched, timers, or
// hchan lock can be held immediately above it when it is acquired.
var lockPartialOrder [][]lockRank = [][]lockRank{
lockRankDummy: {},
lockRankSysmon: {},
lockRankScavenge: {lockRankSysmon},
lockRankForcegc: {lockRankSysmon},
lockRankSweepWaiters: {},
lockRankAssistQueue: {},
lockRankCpuprof: {},
lockRankSweep: {},
lockRankSched: {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep},
lockRankDeadlock: {lockRankDeadlock},
lockRankPanic: {lockRankDeadlock},
lockRankAllg: {lockRankSysmon, lockRankSched, lockRankPanic},
lockRankAllp: {lockRankSysmon, lockRankSched},
lockRankPollDesc: {},
lockRankTimers: {lockRankSysmon, lockRankScavenge, lockRankSched, lockRankAllp, lockRankPollDesc, lockRankTimers},
lockRankItab: {},
lockRankReflectOffs: {lockRankItab},
lockRankHchan: {lockRankScavenge, lockRankSweep, lockRankHchan},
lockRankFin: {lockRankSysmon, lockRankScavenge, lockRankSched, lockRankAllg, lockRankTimers, lockRankHchan},
lockRankNotifyList: {},
lockRankTraceBuf: {lockRankSysmon, lockRankScavenge},
lockRankTraceStrings: {lockRankTraceBuf},
lockRankMspanSpecial: {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
lockRankProf: {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
lockRankGcBitsArenas: {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
lockRankRoot: {},
lockRankTrace: {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankAssistQueue, lockRankSched, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankSweep},
lockRankTraceStackTab: {lockRankScavenge, lockRankSweepWaiters, lockRankAssistQueue, lockRankSweep, lockRankSched, lockRankAllg, lockRankTimers, lockRankHchan, lockRankFin, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankTrace},
lockRankNetpollInit: {lockRankTimers},
lockRankRwmutexW: {},
lockRankRwmutexR: {lockRankRwmutexW},
lockRankSpanSetSpine: {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
lockRankGscan: {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankFin, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankNotifyList, lockRankProf, lockRankGcBitsArenas, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankSpanSetSpine},
lockRankStackpool: {lockRankSysmon, lockRankScavenge, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankPollDesc, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankFin, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankProf, lockRankGcBitsArenas, lockRankRoot, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankSpanSetSpine, lockRankGscan},
lockRankStackLarge: {lockRankSysmon, lockRankAssistQueue, lockRankSched, lockRankItab, lockRankHchan, lockRankProf, lockRankGcBitsArenas, lockRankRoot, lockRankSpanSetSpine, lockRankGscan},
lockRankDefer: {},
lockRankSudog: {lockRankNotifyList, lockRankHchan},
lockRankWbufSpans: {lockRankSysmon, lockRankScavenge, lockRankSweepWaiters, lockRankAssistQueue, lockRankSweep, lockRankSched, lockRankAllg, lockRankPollDesc, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceStrings, lockRankMspanSpecial, lockRankProf, lockRankRoot, lockRankGscan, lockRankDefer, lockRankSudog},
lockRankMheap: {lockRankSysmon, lockRankScavenge, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankPollDesc, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan, lockRankMspanSpecial, lockRankProf, lockRankGcBitsArenas, lockRankRoot, lockRankGscan, lockRankStackpool, lockRankStackLarge, lockRankDefer, lockRankSudog, lockRankWbufSpans, lockRankSpanSetSpine},
lockRankMheapSpecial: {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankHchan},
lockRankGlobalAlloc: {lockRankProf, lockRankSpanSetSpine, lockRankMheap, lockRankMheapSpecial},
lockRankGFree: {lockRankSched},
lockRankHchanLeaf: {lockRankGscan, lockRankHchanLeaf},
lockRankNewmHandoff: {},
lockRankDebugPtrmask: {},
lockRankFaketimeState: {},
lockRankTicks: {},
lockRankRaceFini: {},
lockRankPollCache: {},
lockRankDebug: {},
}
|
