1. A computer system for controlling execution of threads in a computing environment, said computer system comprising: a memory; and a processor in communications with the memory, wherein the computer system is configured to perform a method, said method comprising: stopping, by a thread running in the processor of the computing environment, execution of another thread executing within the processor, the stopping using one or more controls in one or more shared registers of the processor, the one or more shared registers being shared by the thread and the other thread; and performing by the thread, based on stopping execution of the other thread, one or more operations.