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
|
/**
* Copyright (C) 2020-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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/query/plan_insert_listener.h"
#include <memory>
#include "mongo/db/catalog/database.h"
#include "mongo/db/catalog/database_holder.h"
#include "mongo/db/curop.h"
#include "mongo/db/query/find_common.h"
#include "mongo/logv2/log.h"
#include "mongo/util/fail_point.h"
#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kQuery
namespace mongo::insert_listener {
namespace {
MONGO_FAIL_POINT_DEFINE(planExecutorHangWhileYieldedInWaitForInserts);
}
bool shouldListenForInserts(OperationContext* opCtx, CanonicalQuery* cq) {
return cq && cq->getFindCommandRequest().getTailable() &&
cq->getFindCommandRequest().getAwaitData() && awaitDataState(opCtx).shouldWaitForInserts &&
opCtx->checkForInterruptNoAssert().isOK() &&
awaitDataState(opCtx).waitForInsertsDeadline >
opCtx->getServiceContext()->getPreciseClockSource()->now();
}
bool shouldWaitForInserts(OperationContext* opCtx,
CanonicalQuery* cq,
PlanYieldPolicy* yieldPolicy) {
// If this is an awaitData-respecting operation and we have time left and we're not interrupted,
// we should wait for inserts.
if (shouldListenForInserts(opCtx, cq)) {
// We expect awaitData cursors to be yielding.
invariant(yieldPolicy->canReleaseLocksDuringExecution());
// For operations with a last committed opTime, we should not wait if the replication
// coordinator's lastCommittedOpTime has progressed past the client's lastCommittedOpTime.
// In that case, we will return early so that we can inform the client of the new
// lastCommittedOpTime immediately.
if (!clientsLastKnownCommittedOpTime(opCtx).isNull()) {
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
return clientsLastKnownCommittedOpTime(opCtx) >= replCoord->getLastCommittedOpTime();
}
return true;
}
return false;
}
std::unique_ptr<Notifier> getCappedInsertNotifier(OperationContext* opCtx,
const NamespaceString& nss,
PlanYieldPolicy* yieldPolicy) {
// We don't expect to need a capped insert notifier for non-yielding plans.
invariant(yieldPolicy->canReleaseLocksDuringExecution());
// In case of the read concern majority, return a majority committed point notifier, otherwise,
// a notifier associated with that capped collection
//
// We can only wait on the capped collection insert notifier if the collection is present,
// otherwise we should retry immediately when we hit EOF.
if (opCtx->recoveryUnit()->getTimestampReadSource() == RecoveryUnit::kMajorityCommitted) {
return std::make_unique<MajorityCommittedPointNotifier>();
} else {
auto collection = CollectionCatalog::get(opCtx)->lookupCollectionByNamespace(opCtx, nss);
invariant(collection);
return std::make_unique<LocalCappedInsertNotifier>(
collection->getRecordStore()->getCappedInsertNotifier());
}
}
void waitForInserts(OperationContext* opCtx,
PlanYieldPolicy* yieldPolicy,
std::unique_ptr<Notifier>& notifier) {
// The notifier wait() method will not wait unless the version passed to it matches the
// current version of the notifier. Since the version passed to it is the current version
// of the notifier at the time of the previous EOF, we require two EOFs in a row with no
// notifier version change in order to wait. This is sufficient to ensure we never wait
// when data is available.
auto curOp = CurOp::get(opCtx);
curOp->pauseTimer();
ON_BLOCK_EXIT([curOp] { curOp->resumeTimer(); });
notifier->prepareForWait(opCtx);
auto yieldResult = yieldPolicy->yieldOrInterrupt(opCtx, [opCtx, ¬ifier] {
const auto deadline = awaitDataState(opCtx).waitForInsertsDeadline;
notifier->waitUntil(opCtx, deadline);
if (MONGO_unlikely(planExecutorHangWhileYieldedInWaitForInserts.shouldFail())) {
LOGV2(4452903,
"PlanExecutor - planExecutorHangWhileYieldedInWaitForInserts fail point enabled. "
"Blocking until fail point is disabled");
planExecutorHangWhileYieldedInWaitForInserts.pauseWhileSet();
}
});
notifier->doneWaiting(opCtx);
uassertStatusOK(yieldResult);
}
} // namespace mongo::insert_listener
|
