Debugging facilities

Debugging is sometimes very hard for distributed computations. We provide two methods to help debugging on X window system: 1. the diagnostic messages from the engine are displayed in a xterm window; 2. the engine can pop up a window to input debug commands. For example ox_asir, which is the OpenXM server of Risa/Asir, can pop up a window to input debug commands and the debugging similar to that on usual terminals is possible. One can also send SIGINT by using SM_control_to_debug_mode and it provides a similar functionality to entering the debugging mode from a keyboard interruption.