SERVER-45047 Create multiVersion test to validate mixed FCV migrations

1 files changed, 28 insertions, 0 deletions

diff --git a/src/mongo/db/s/active_migrations_registry.h b/src/mongo/db/s/active_migrations_registry.h
index e885bc23b91..c0a8029c08b 100644
--- a/src/mongo/db/s/active_migrations_registry.h
+++ b/src/mongo/db/s/active_migrations_registry.h
@@ -61,6 +61,15 @@ public:
     static ActiveMigrationsRegistry& get(OperationContext* opCtx);
 
     /**
+     * These methods can be used to block migrations temporarily. The lock() method will block if
+     * there is a migration operation in progress and will return once it is completed. Any
+     * subsequent migration operations will return ConflictingOperationInProgress until the unlock()
+     * method is called.
+     */
+    void lock(OperationContext* opCtx);
+    void unlock();
+
+    /**
      * If there are no migrations running on this shard, registers an active migration with the
      * specified arguments. Returns a ScopedDonateChunk, which must be signaled by the
      * caller before it goes out of scope.
@@ -153,6 +162,9 @@ private:
 
     // Protects the state below
     Mutex _mutex = MONGO_MAKE_LATCH("ActiveMigrationsRegistry::_mutex");
+    stdx::condition_variable _lockCond;
+
+    bool _migrationsBlocked{false};
 
     // If there is an active moveChunk operation, this field contains the original request
     boost::optional<ActiveMoveChunkState> _activeMoveChunkState;
@@ -161,6 +173,22 @@ private:
     boost::optional<ActiveReceiveChunkState> _activeReceiveChunkState;
 };
 
+class MigrationBlockingGuard {
+public:
+    MigrationBlockingGuard(OperationContext* opCtx, ActiveMigrationsRegistry& registry)
+        : _opCtx(opCtx), _registry(registry) {
+        _registry.lock(_opCtx);
+    }
+
+    ~MigrationBlockingGuard() {
+        _registry.unlock();
+    }
+
+private:
+    OperationContext* _opCtx{nullptr};
+    ActiveMigrationsRegistry& _registry;
+};
+
 /**
  * Object of this class is returned from the registerDonateChunk call of the active migrations
  * registry. It can exist in two modes - 'execute' and 'join'. See the comments for