threads.af

use' lang.af
use' io.af
use' pthread.af

\ Passed to `pthread_spawn` by raw instruction address.
\ We have no hidden adapters between Forth and libc.
fun: callback { inout -- Err }
  inout @ { path }
  " [child] checking length of `%s`..." path .logf .lf

  alloca' Fstat { stat }
  path stat .path_stat { err }

  ifz err .then
    \ Store the output back.
    stat .Fstat_size @ inout !
  end

  \ `main` will check this.
  err
end

fun: main
  instr' callback  { instr } \ Raw instruction address.
  " missing/none"  { path0 } \ Input for `thread0`: missing file.
  " forth/lang.af" { path1 } \ Input for `thread1`: existing file.
  path0 >slot      { val0  } \ Input-output for `thread0`.
  path1 >slot      { val1  } \ Input-output for `thread1`.

  " [main] spawning thread 0..." .log .lf
  instr val0 .thread_spawn { thread0 err0 }

  " [main] spawning thread 1..." .log .lf
  instr val1 .thread_spawn { thread1 err1 }

  if err0 .then
    " [main] unable to spawn thread 0: %s" err0 .logf .lf
  end

  if err1 .then
    " [main] unable to spawn thread 1: %s" err1 .logf .lf
  end

  \ After spawning a thread, we must either join or detach it.
  \ Since this word handles thread creation errors explicitly,
  \ it won't terminate until done with both thread handles.

  ifz err0 .then
    " [main] waiting on thread 0..." .log .lf
    thread0 .thread_join { err0 join_err }

    if join_err .then
      " [main] when joining with thread 0: %s" join_err .logf .lf
    elif err0 .then
      " [main] error from thread 0: %s" err0 .logf .lf
    else
      " [main] result from thread 0: length of `%s`: %zd" path0 val0 @ .logf .lf
    end
  end

  ifz err1 .then
    " [main] waiting on thread 1..." .log .lf
    thread1 .thread_join { err1 join_err }

    if join_err .then
      " [main] when joining with thread 1: %s" join_err .logf .lf
    elif err1 .then
      " [main] error from thread 1: %s" err1 .logf .lf
    else
      " [main] result from thread 1: length of `%s`: %zd" path1 val1 @ .logf .lf
    end
  end
end
.main