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
|
/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/s/session_catalog_router.h"
#include "mongo/db/session/sessions_collection.h"
#include "mongo/s/transaction_router.h"
#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kSharding
namespace mongo {
int RouterSessionCatalog::reapSessionsOlderThan(OperationContext* opCtx,
SessionsCollection& sessionsCollection,
Date_t possiblyExpired) {
const auto catalog = SessionCatalog::get(opCtx);
// Find the possibly expired logical session ids in the in-memory catalog.
LogicalSessionIdSet possiblyExpiredLogicalSessionIds;
// Skip child transaction sessions since they correspond to the same logical session as their
// parent transaction session so they have the same last check-out time as the parent's.
catalog->scanParentSessions([&](const ObservableSession& session) {
const auto sessionId = session.getSessionId();
invariant(isParentSessionId(sessionId));
if (session.getLastCheckout() < possiblyExpired) {
possiblyExpiredLogicalSessionIds.insert(session.getSessionId());
}
});
// From the possibly expired logical session ids, find the ones that have been removed from
// from the config.system.sessions collection.
auto expiredLogicalSessionIds =
sessionsCollection.findRemovedSessions(opCtx, possiblyExpiredLogicalSessionIds);
// For each removed logical session id, removes all of its transaction session ids that are no
// longer in use from the in-memory catalog.
int numReaped = 0;
for (const auto& logicalSessionId : expiredLogicalSessionIds) {
// Scan all the transaction sessions for this logical session at once so reaping can be done
// atomically.
int numTransactionSessions = 0;
const auto transactionSessionIdsNotReaped = catalog->scanSessionsForReap(
logicalSessionId,
[&](ObservableSession& parentSession) {
const auto txnRouter = TransactionRouter::get(parentSession);
if (txnRouter.canBeReaped()) {
// Only reap this transaction session if every other transaction session for
// this logical session is also safe to be reaped.
parentSession.markForReap(ObservableSession::ReapMode::kNonExclusive);
}
++numTransactionSessions;
},
[&](ObservableSession& childSession) {
const auto txnRouter = TransactionRouter::get(childSession);
if (txnRouter.canBeReaped()) {
// Only reap this transaction session if every other transaction session for
// this logical session is also safe to be reaped.
childSession.markForReap(ObservableSession::ReapMode::kNonExclusive);
}
++numTransactionSessions;
});
numReaped += numTransactionSessions - transactionSessionIdsNotReaped.size();
}
return numReaped;
}
RouterOperationContextSession::RouterOperationContextSession(OperationContext* opCtx)
: _opCtx(opCtx), _operationContextSession(opCtx) {}
RouterOperationContextSession::~RouterOperationContextSession() {
if (auto txnRouter = TransactionRouter::get(_opCtx)) {
// Only stash if the session wasn't yielded. This should only happen at global shutdown.
txnRouter.stash(_opCtx, TransactionRouter::StashReason::kDone);
}
};
void RouterOperationContextSession::checkIn(OperationContext* opCtx,
OperationContextSession::CheckInReason reason) {
invariant(OperationContextSession::get(opCtx));
TransactionRouter::get(opCtx).stash(opCtx,
reason == OperationContextSession::CheckInReason::kYield
? TransactionRouter::StashReason::kYield
: TransactionRouter::StashReason::kDone);
OperationContextSession::checkIn(opCtx, reason);
}
void RouterOperationContextSession::checkOut(OperationContext* opCtx) {
invariant(!OperationContextSession::get(opCtx));
OperationContextSession::checkOut(opCtx);
TransactionRouter::get(opCtx).unstash(opCtx);
}
} // namespace mongo
|
