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 // ct_lvtmdb_lockable.cpp                                             -*-C++-*-
 
 /*
 // Copyright 2023 Codethink Ltd <codethink@codethink.co.uk>
 // SPDX-License-Identifier: Apache-2.0
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 */
 
 #include <ct_lvtmdb_lockable.h>
 
 #include <cassert>
 #include <iostream>
 
 namespace Codethink::lvtmdb {
 
 std::pair<Lockable::ROLock, Lockable::ROLock> Lockable::roLockTwo(Lockable *a, Lockable *b)
 {
     assert(a);
     assert(b);
     if (a == b) {
         std::cerr << "lvtmdb::Lockable::lockTwo with identical arguments" << std::endl;
         // we can't return two distinct locks to one object: that would be a
         // deadlock
         std::abort();
     }
 
     // order by memory address
     if (a < b) {
         return {a->readOnlyLock(), b->readOnlyLock()};
     }
     return {b->readOnlyLock(), a->readOnlyLock()};
 }
 
 std::pair<Lockable::RWLock, Lockable::RWLock> Lockable::rwLockTwo(Lockable *a, Lockable *b)
 {
     assert(a);
     assert(b);
     if (a == b) {
         std::cerr << "lvtmdb::Lockable::lockTwo with identical arguments" << std::endl;
         // we can't return two distinct locks to one object: that would be a
         // deadlock
         std::abort();
     }
 
     // order by memory address
     if (a < b) {
         return {a->rwLock(), b->rwLock()};
     }
     return {b->rwLock(), a->rwLock()};
 }
 
 } // namespace Codethink::lvtmdb