Abstract: Transactional programming promises to substantially simplify the development and maintenance of correct, scalable, and efficient concurrent programs. Designs for supporting transactional programming using transactional memory implemented in hardware, software, and a mixture of the two have emerged recently. However, various features and capabilities that would be desirable for debugging programs executed using transactional memory are absent from conventional debuggers. Because transactional memory implementations provide the “illusion” of multiple memory locations changing value atomically, while in fact they do not, there can be significant challenges involved with integrating debuggers with such programs to provide the user with a coherent view of program execution. We describe use of transactional memory access tracking mechanism for implementations of watchpoints on memory locations that correspond to transactional variables.

Abstract: Transactional memory implementations provide the “illusion” of multiple memory locations changing value atomically, while in fact they do not. Techniques that employ transactional memory may allow a debug user to define a group of variables as an atomic group and may ensure coherent or consistent access to variables of the atomic group. These techniques may facilitate the debugging of programs that are executed using transactional memory. Unlike conventional debuggers, debuggers that employ these techniques may be adapted to provide a coherent or consistent view of variables in a system that employs transactional memory. The atomic group may be accessed for viewing and/or modifying during debugging using a transaction, regardless of whether all or less than all of the variables in the atomic group are modified.

Abstract: Transactional programming promises to substantially simplify the development and maintenance of correct, scalable, and efficient concurrent programs. Designs for supporting transactional programming using transactional memory implemented in hardware, software, and a mixture of the two have emerged recently. However, various features and capabilities for debugging programs executed using transactional memory are absent from conventional debuggers. Because transactional memory implementations provide the “illusion” of multiple memory locations changing value atomically, there are challenges involved with integrating debuggers with such programs to provide the user with a coherent view of program execution. For instance, when execution is halted for debugging, a user may request to view a transactional variable or memory location. The transactional variable or memory location may have a pre-transaction value and a tentative value.