Thread.md

Thread

Thread creation and management module. Provides procedures for spawning, joining, and identifying threads. Requires --m2plus and links with pthreads.

Exported Types

TYPE Thread;  (* opaque thread handle *)
TYPE PROC = PROCEDURE;

Exported Procedures

PROCEDURE Fork(proc: PROC): Thread;
PROCEDURE Join(t: Thread);
PROCEDURE Self(): Thread;

Notes

• Fork creates a new thread that executes the given parameterless procedure and returns a handle to the new thread.
• Join blocks the calling thread until thread t completes.
• Self returns the handle of the calling thread.
• Importing Thread causes the compiler to emit M2_USE_THREADS and link with pthreads.

Example

MODULE ThreadDemo;
FROM Thread IMPORT Fork, Join, Thread;
FROM InOut IMPORT WriteString, WriteLn;

PROCEDURE Worker;
BEGIN
  WriteString("Hello from worker"); WriteLn;
END Worker;

VAR t: Thread;
BEGIN
  t := Fork(Worker);
  WriteString("Hello from main"); WriteLn;
  Join(t);
END ThreadDemo.