alecci 1.4.3

A compiler for the Alecci programming language

Alecci Programming Language

Alecci is a compiled programming language designed for teaching concurrent and parallel programming. It provides built-in primitives for threading, synchronization, and inter-thread communication, and compiles to native code via LLVM.

The language is used in operating systems and parallel programming courses to help students write, analyze, and debug concurrent programs without the overhead of a general-purpose systems language.

Installation

pip install alecci

If the alecci command is not found after installation, add the user bin directory to your PATH:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

You can also invoke the compiler directly without installing the command:

python3 -m alecci

System Requirements

• Python 3.8 or later
• LLVM 14 or later (provided via llvmlite)
• GCC or Clang for linking

Usage

alecci program.ale -o program
./program

Sanitizer options

ThreadSanitizer is enabled by default to detect data races at runtime:

alecci program.ale -o program          # ThreadSanitizer enabled (default)
alecci program.ale --no-tsan -o program  # Sanitizers disabled

Language Overview

Variables

mutable x := 42
const message := "Hello"
mutable arr := array(10, 0)

Procedures and functions

procedure main(argc, argv)
  print("Hello, Alecci!")
end procedure

Threads

procedure worker(thread_number as int)
  print `Worker {thread_number} running`
end procedure

procedure main(argc, argv)
  shared const thread_count := 4
  mutable threads := create_threads(thread_count, worker)
  join_threads(threads)
  print("All workers done")
end procedure

Synchronization primitives

shared mutable counter := 0
shared mutable mtx as mutex := mutex()

procedure increment(thread_number as int)
  lock(mtx)
  counter := counter + 1
  unlock(mtx)
end procedure

Available primitives: mutex, semaphore, barrier, queue, thread.

Concurrency Validation

The package includes a test suite (concurrency_validation/) with annotated example programs covering common concurrency patterns and bugs, including data races, deadlocks, and thread leaks. These are used to evaluate ThreadSanitizer detection rates.

Source

Source code is available at github.com/citic/alecci.