US Patent 9075916 Undoing/redoing program code execution

A device may obtain first program code, and may cause the first program code to be executed. The device may determine a first execution state generated based on causing the first program code to be executed. The device may store the first execution state. The device may obtain second program code that includes a modification to the first program code, and may cause the second program code to be executed. The device may determine a second execution state generated based on causing the second program code to be executed. The device may store the second execution state. The device may receive an indication to restore the first execution state, and may restore the first execution state based on receiving the indication.