Runtime code modification in a multi-threaded environment

A computer program product comprising at least one computer-usable storage medium having computer-usable program code for making a desirable modification to a code region forming part of a computer program during execution of the computer program by a plurality of threads, the computer program product comprising computer-usable program code for:

• selecting a thread to modify the code region;
• directing each thread other than the selected thread to follow an alternative execution path that generates output identical to output of the code region after the desirable modification has been made to the code region without use of a self-loop;
• responsive to directing each thread other than the selected thread, directing the selected thread to make the desirable modification to the code region so as to generate a modified code region;
• and responsive to completion of the desirable modification by the selected thread, directing each thread to execute the modified code region.

A computer program product comprising at least one computer-usable storage medium having computer-usable program code for causing a desirable modification to be made to a code region forming part of a computer program during execution of the computer program by a plurality of threads, the computer program product comprising computer-usable program code for:

• generating, as executable code in the code region, a call to a set of instructions that causes the desirable modification to be made without use of a self-loop;
• and
• generating, as the set of instructions, executable code that, when executed, performs:
• causing an arbitrary thread that executes the set of instructions to become a selected thread;
• directing each thread other than the selected thread to follow an alternative execution path that generates output identical to output of the code region after the desirable modification has been made to the code region;
• responsive to directing each thread other than the selected thread, directing the selected thread to make the desirable modification to the code region so as to generate a modified code region;
• and
• directing each thread to execute the modified code region in response to completion of the desirable modification by the selected thread.