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/**
* 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.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kStorage
#include "mongo/platform/basic.h"
#include "mongo/db/periodic_runner_job_abort_expired_transactions.h"
#include "mongo/db/client.h"
#include "mongo/db/kill_sessions_local.h"
#include "mongo/db/service_context.h"
#include "mongo/db/transaction_participant.h"
#include "mongo/util/log.h"
#include "mongo/util/periodic_runner.h"
namespace mongo {
void startPeriodicThreadToAbortExpiredTransactions(ServiceContext* serviceContext) {
// Enforce calling this function once, and only once.
static bool firstCall = true;
invariant(firstCall);
firstCall = false;
auto periodicRunner = serviceContext->getPeriodicRunner();
invariant(periodicRunner);
// We want this job period to be dynamic, to run every (transactionLifetimeLimitSeconds/2)
// seconds, where transactionLifetimeLimitSeconds is an adjustable server parameter, or within
// the 1 second to 1 minute range.
//
// PeriodicRunner does not currently support altering the period of a job. So we are giving this
// job a 1 second period on PeriodicRunner and incrementing a static variable 'seconds' on each
// run until we reach transactionLifetimeLimitSeconds/2, at which point we run the code and
// reset 'seconds'. Etc.
PeriodicRunner::PeriodicJob job("startPeriodicThreadToAbortExpiredTransactions",
[](Client* client) {
static int seconds = 0;
int lifetime = transactionLifetimeLimitSeconds.load();
invariant(lifetime >= 1);
int period = lifetime / 2;
// Ensure: 1 <= period <= 60 seconds
period = (period < 1) ? 1 : period;
period = (period > 60) ? 60 : period;
if (++seconds <= period) {
return;
}
seconds = 0;
// The opCtx destructor handles unsetting itself from the
// Client. (The PeriodicRunner's Client must be reset before
// returning.)
auto opCtx = client->makeOperationContext();
// Set the Locker such that all lock requests' timeouts will
// be overridden and set to 0. This prevents the expired
// transaction aborter thread from stalling behind any
// non-transaction, exclusive lock taking operation blocked
// behind an active transaction's intent lock.
opCtx->lockState()->setMaxLockTimeout(Milliseconds(0));
killAllExpiredTransactions(opCtx.get());
},
Seconds(1));
periodicRunner->scheduleJob(std::move(job));
}
} // namespace mongo
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