Autodesk, Inc.

Scott M Borduin

Robert E Zundel

James Synge

Doug Mullin

A programming environment can be modified to provide automatic support for reverting program memory states. Such memory reversions are used to provide automatic support for state-reversion, undo, redo, and abort operations for application programs written with the programming environment. Memory allocation code (e.g., functions, procedures, etc.) are modified to mark allocated memory as protected, and an exception handler is assigned to such memory. Attempts to access the memory cause an exception to be generated. This exception is caught, providing opportunity for the memory to be preserved before it is modified. Previous memory states can be retrieved by restoring such stored memory states. State-reversion can be effected by creating a new current memory state corresponding to a previous (e.g., retrieved) memory state.

Method and apparatus for state-reversion

A model of a physical object is constructed in a modeling system running on a computer system. The model includes model objects and constraints. The constraints on the model describe the relationship between the model objects. The modeling system constructs a graph representing the model. The graph has nodes representing the modeling objects and arcs representing the relationships between the model objects. The relationships are either directed or nondirected. The modeling system then identifies the set of cycles in the graph. The cycles have a subset of the nodes of the graph coupled by arcs representing nondirected relationships. The modeling system starts with a first cycle from the set of cycles and determines the set of programs that can be used to satisfy all of the relationships between the model objects represented by nodes in the first cycle. Then, the modeling system selects one of the programs from the set of programs and uses it to define the model objects represented by the nodes in the cycle so that all of the constraints are satisfied.

Growing community of inventors

Lake Oswego, OR, United States of America

Scott M Borduin