A GIL-less Future for Python
The Global Interpreter Lock (GIL) in Python, a controversial feature, restricts programs from fully utilizing multi-core processors. The Python team, after internal discussions, has accepted PEP 703 to remove the GIL, opening up new possibilities for Python's future.
- GIL, a big lock in Python, allows only one thread to pass through the interpreter at a time.
- Added in 1992 to address threading issues on single-core CPUs, it became a limitation with the advent of multi-core processors.
Reasons for Retention
- GIL was easy to implement and prevented certain bugs like deadlocks.
- In the past, few programs needed to run on multiple CPUs, and single-threaded programs were efficient.
- GIL hinders the performance of neural network-based AI models by blocking parallelism.
- Time-sensitive tasks, especially handling multiple requests simultaneously, face difficulties due to GIL.
- Python conducted a poll to gauge support for removing GIL, considering it involves long-term, invasive changes.
Proposal and Process
- Python introduces a build configuration flag to disable GIL for testing purposes.
- The proposal is divided into short-term testing, mid-term support with the option, and long-term as the default GIL-free interpreter.
- Meta dedicates an engineering team led by Sam Gross to support this transformation, benefiting the AI ecosystem.
- The move towards a GIL-less Python may make Rust redundant for certain multi-threaded computations.
Python is heading towards a future without the GIL, potentially unlocking greater performance for multi-core processors.