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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::kReplication
#include "mongo/platform/basic.h"
#include "mongo/db/repl/rollback_checker.h"
#include "mongo/util/log.h"
namespace mongo {
namespace repl {
using RemoteCommandCallbackArgs = executor::TaskExecutor::RemoteCommandCallbackArgs;
using UniqueLock = stdx::unique_lock<Latch>;
RollbackChecker::RollbackChecker(executor::TaskExecutor* executor, HostAndPort syncSource)
: _executor(executor), _syncSource(syncSource), _baseRBID(-1), _lastRBID(-1) {
uassert(ErrorCodes::BadValue, "null task executor", executor);
}
RollbackChecker::~RollbackChecker() {}
StatusWith<RollbackChecker::CallbackHandle> RollbackChecker::checkForRollback(
const CallbackFn& nextAction) {
return _scheduleGetRollbackId([this, nextAction](const RemoteCommandCallbackArgs& args) {
if (!args.response.isOK()) {
nextAction(args.response.status);
return;
}
if (auto rbidElement = args.response.data["rbid"]) {
int remoteRBID = rbidElement.numberInt();
UniqueLock lk(_mutex);
bool hadRollback = _checkForRollback_inlock(remoteRBID);
lk.unlock();
nextAction(hadRollback);
} else {
nextAction(Status(ErrorCodes::CommandFailed,
"replSetGetRBID command failed when checking for rollback"));
}
});
}
RollbackChecker::Result RollbackChecker::hasHadRollback() {
// Default to true in case the callback is not called in an error case.
Result result(true);
auto cbh = checkForRollback([&result](const Result& cbResult) { result = cbResult; });
if (!cbh.isOK()) {
return cbh.getStatus();
}
_executor->wait(cbh.getValue());
return result;
}
StatusWith<RollbackChecker::CallbackHandle> RollbackChecker::reset(const CallbackFn& nextAction) {
return _scheduleGetRollbackId([this, nextAction](const RemoteCommandCallbackArgs& args) {
if (!args.response.isOK()) {
nextAction(args.response.status);
return;
}
if (auto rbidElement = args.response.data["rbid"]) {
int newRBID = rbidElement.numberInt();
UniqueLock lk(_mutex);
_setRBID_inlock(newRBID);
lk.unlock();
// Actual bool value does not matter because reset_sync()
// will convert non-error StatusWith<bool> to Status::OK.
nextAction(true);
} else {
nextAction(Status(ErrorCodes::CommandFailed,
"replSetGetRBID command failed when checking for rollback"));
}
});
}
Status RollbackChecker::reset_sync() {
// Default to an error in case the callback is not called in an error case.
Status resetStatus = Status(ErrorCodes::CommandFailed, "RollbackChecker reset failed");
auto cbh = reset([&resetStatus](const Result& result) { resetStatus = result.getStatus(); });
if (!cbh.isOK()) {
return Status(ErrorCodes::CallbackCanceled,
"RollbackChecker reset failed due to callback cancelation");
}
_executor->wait(cbh.getValue());
return resetStatus;
}
int RollbackChecker::getBaseRBID() {
stdx::lock_guard<Latch> lk(_mutex);
return _baseRBID;
}
int RollbackChecker::getLastRBID_forTest() {
stdx::lock_guard<Latch> lk(_mutex);
return _lastRBID;
}
bool RollbackChecker::_checkForRollback_inlock(int remoteRBID) {
_lastRBID = remoteRBID;
return remoteRBID != _baseRBID;
}
StatusWith<RollbackChecker::CallbackHandle> RollbackChecker::_scheduleGetRollbackId(
const RemoteCommandCallbackFn& nextAction) {
executor::RemoteCommandRequest getRollbackIDReq(
_syncSource, "admin", BSON("replSetGetRBID" << 1), nullptr);
return _executor->scheduleRemoteCommand(getRollbackIDReq, nextAction);
}
void RollbackChecker::_setRBID_inlock(int rbid) {
_baseRBID = rbid;
_lastRBID = rbid;
}
} // namespace repl
} // namespace mongo
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