CONCURRENT MUTATION OF ISOLATED OBJECT GRAPHS

Fine-grained parallelism within isolated object graphs is used to provide safe concurrent operations within the isolated object graphs. One example provides an abstraction labeled IsolatedObjectGraph that encapsulates at least one object graph, but often two or more object graphs, rooted by an instance of a type member. By encapsulating the object graph, no references from outside of the object graph are allowed to objects inside of the object graph. Also, the encapsulated object graph does not contain references to objects outside of the graphs. The isolated object graphs provide for safe data parallel operations, including safe data parallel mutations such as for each loops. In an example, the ability to isolate the object graph is provided through type permissions.