Concurrent Execution

Doing work in parallel. pperl ships two distinct concurrency stories and they answer different questions:

• Auto-parallelization — pperl’s runtime detects parallelisable patterns in ordinary Perl and spreads them across cores without any user-level threading. This is the preferred answer for CPU-bound loops over large data.

• Classical ithreads (partial support) — Perl 5’s threads and threads::shared model. pperl’s support here is deliberately limited; many programs that historically used ithreads are better rewritten against the auto-parallel path.

Start with the decision chapter if you have an existing threaded program and are deciding how to port it; start with parallel if you are writing new code and want to understand when pperl speeds your loop up.

• Parallel Execution
  • How It Works
  • What Gets Parallelized
  • CLI Control
  • Performance
  • Limitations
  • How Reduction Detection Works
• Threads
  • pperl status — read this first
  • How this chapter is organised
  • Reference cross-links