A computer program product is provided as a system and associated method to provide a robust, fail-safe, fast environment for running non-native language routine programs, such that when the program fails or terminates, the virtual machine can be restarted without terminating the operating system process. The system dynamically creates a number of independent virtual machines to run non-native language routines. Each virtual machine is created in a process external to the database engine, in a refreshable native runtime environment inside the process or address space. If the virtual machine should terminate with an uncaught exception or error or if it becomes unusable for executing other non-native language routines, the system recognizes that condition and terminates the native runtime environment without terminating the process. When a failed non-native language routine is terminated, the system cleans up any threads related to the termination of the virtual machine, freeing memory allocated to the threads and eliminating any possible conflict between old threads and the next non-native language routine operated by the virtual machine.