Python threads: Dive into GIL!

Benefit of multi-threaded application grows with ubiquity of multi-core architecture that potentially can simultaneously run multiple threads of execution. Python supports multi-threaded applications and developers are flocking to realize the assured gain of multiple cores with threaded applications.

Unfortunately, Python has significant bottleneck for multi-threading. Any thread in CPython interpreter requires a special lock (GIL) which results in serial, rather than parallel execution of multi-threaded applications, irrespective of cores availability and design techniques.

This talk focuses on the problem, dissects the root cause and its implications. The problem alleviation is discussed with introduction of Python3.0 which has new GIL implementation, improving the overall performance of Python threads.

This talk covers the following:

• Threading fundamentals
• Using threads in python programming – An example
• Overview of Global Interpreter Lock
• Diving into GIL
• Comparing GIL implementation – v2.7 and v3.2
• Experiment and Measure
• Jython: In GIL context
• Conclusion

This topic is culminated from our professional experiences of dealing with python threads. Intended audiences: Python for Linux developers, industry experts and students.

Vishal Kanaujia: has experience of working in Python on Linux environment and is a frequent contributor to reputed magazines including 'Linux-For-You' and 'AgileRecord'. You can reach Vishal at vishalkanaujia@gmail.com

Chetan Giridhar: has extensive experience with Python programming. He is technical reviewer of 'Python Testing Cookbook', author of 'Design patterns in python' book and is an Editor at the 'The Python papers Anthology'. You can visit him at Technobeans