The Document Understanding Process uses two types of synchronization mechanisms to prevent multiple robots from writing in a file at the same time: file locks and queues. File locks are used to ensure that only one robot can access a file at a time, while queues are used to store the information extracted from the documents and to avoid data loss or duplication. The process uses the following activities to implement these mechanisms:

File Lock Scope: This activity creates a lock on a file or folder and executes a set of activities within it. The lock is released when the scope ends or when an exception occurs. This activity ensures that only one robot can read or write a file or folder at a time, and prevents other robots from accessing it until the lock is released.

Add Queue Item: This activity adds an item to a queue in Orchestrator, along with some relevant information, such as a reference, a priority, or a deadline. The item can be a JSON object, a string, or any serializable .NET type. This activity ensures that the information extracted from the documents is stored in a queue and can be retrieved by another robot or process later.

Get Queue Items: This activity retrieves a collection of items from a queue in Orchestrator, based on some filters, such as status, reference, or creation time. The items can be processed by the robot or passed to another activity, such as Update Queue Item or Delete Queue Item. This activity ensures that the information stored in the queue can be accessed and manipulated by the robot or process.