Python: Essential Reference, Third Edition

Python Threads

Python supports threads on Windows, Mac OS X, Linux, Solaris, and systems that support the POSIX threads library (pthreads).

The scheduling of threads and thread switching is tightly controlled by a global interpreter lock that allows only a single thread of execution to be running in the interpreter at once. Furthermore, thread switching can only occur between the execution of individual bytecodes in the interpreter. The frequency with which the interpreter checks for thread switching is set by the sys.setcheckinterval() function. By default, the interpreter checks for thread switching after every 100 bytecode instructions.

When working with extension modules, the interpreter may invoke functions written in C. Unless specifically ...