Devices as services in a decentralized operating system

A computer-implemented method for processing input/output events by devices, the method comprising:

• requesting, by a computing system configured to represent devices as services, a service representing a device for an input/output event, the service including a unilateral contract for:
• describing one or more behaviors of the service;
• and
• specifying an order of messages that flow in or out of the service;
• receiving, by the device via a network from an application service external to the computing system, a customizable tag-based document that describes a shape of a cursor, the customizable tag-based document including image data comprising a bitmap image and a bitmap mask specifying pixels that comprise the cursor and offset data specifying an offset between the pixels and a location pointed to by the cursor;
• requesting the service to change a cursor shape based in part on the customizable tag-based document;
• receiving a customizable tag-based message that contains a state of the service representing the device and the input/output event that has been generated by the service representing the device;
• and
• requesting the service to remove the input/output event.

A computer subsystem device of a networked system, the device to:

• execute, by one or more processors, one or more services including:
• an information service to:
• produce a customizable tag-based document that holds a summary of device properties that a device service represents;
• and
• store the customizable tag-based document that holds the summary until requested by an application service;
• a data service to:
• receive at least one message from the application service indicating at least one event generated by the one or more services that has been consumed by the application service;
• produce a customizable tag-based document, based in part on the at least one message, that holds events which have been generated by the one or more services but not yet consumed by the application service;
• hold a state of the one or more services;
• and
• store the customizable tag-based document that holds the events not yet consumed by the application service;
• a port identifiable by an identifier that includes a unique designation of another service, the port endued with behavioral types specified by a unilateral contract, wherein the unilateral contract specifies:
• a regulation of the service by specifying attaching behavioral conditions to files to govern access control;
• an order of messages that flow in or out of the service;
• and
• creation of an instance of communication, after being accepted by an external second service, between the service and the external second service, the external second service agreeing to perform the unilateral contract according to the order of messages specified in the unilateral contract.