Abstract: An error handling operation for checking of an array access in program code is modified during compilation thereof. A sequentially arranged null checking operation and array bounds checking operation for the array access are located. The array bounds checking operation has a corresponding error handling operation operable for setting an array bounds error. The located sequentially arranged null checking operation is removed. The corresponding error handling operation for the located sequentially arranged array bounds checking operation is modified to perform the removed null checking operation during execution of the program code.

Abstract: A technique for identifying and executing synchronized read regions and synchronized write regions is provided. The technique processes program code with a software tool to convert the code to an internal representation for the software tool and constructs a control flow graph of code blocks which also identifies the entry and exit points for each region of code subject to a lock. For each code block in the control flow graph, visibility analysis is performed. Each determined entry and exit point is moved to enclose the smallest set of code blocks subject to a lock which can be achieved without altering code semantics. A set of trees is created to represent the manner in which the synchronized regions are nested. If the tree contains at least one block previously identified, then the tree is marked a write. Otherwise, the tree is marked a read tree.