queue_harness.verona

// Copyright Microsoft and Project Verona Contributors.
// SPDX-License-Identifier: MIT

// This just directly includes the queue file. Stop gap until module system
// and packaging implenented
// Module system will work on a directory level, rather than individual file
use "library/queue.verona"

/**
 * Simple harness to illustrate the memory management of the queue.
 * 
 * The trace produced highlights, how regions can be collected
 * independently.
 */

/**
 * Simple wrapper of a U64, with a finaliser, 
 * so finalisation can be traced.
 **/
class U64ObjF
{
  v: U64 & imm;
  create(x: U64 & imm) : U64ObjF & iso
  {
    var o = new U64ObjF;
    o.v = x;
    o
  }

  final(self: mut)
  {
    Builtin.print1("Final U64ObjF {}\n", self.v)
  }
}

class Main
{
  refine(a: Queue[U64ObjF]) {}

  // Add and remove some elements to a queue
  run(q: Queue[U64ObjF] & mut)
  {
    q.add(U64ObjF.create(1));
    q.add(U64ObjF.create(2));

    var a1 = q.remove();
    Main.print(q.id, a1);
    var a2 = q.remove();
    Main.print(q.id, a2);
    var a3 = q.remove();
    Main.print(q.id, a3);
  }

  // Creates to queues, and interleaves adding and removing elements from the queues.
  // The nodes of the queues get deleted periodically, and per queue, but the Values
  // get delete as soon as they are removed from the queues.
  main()
  {
    var q = mut-view (Queue.create(1));
    var q2 = mut-view (Queue.create(2));

    // Type inference is choosing Queue[U64ObjF & iso], which we can't codegen yet.
    Main.refine(q);

    Main.run(q);
    // CHECK-L: Queue 1 elem: 1
    // CHECK-L: Queue 1 elem: 2

    Main.run(q2);
    Main.run(q);
    Main.run(q2);
    Main.run(q2);
    Main.run(q);
    Main.run(q2);
    Main.run(q2);
    Main.run(q);
    Main.run(q);
    Main.run(q2);
    Main.run(q);
    Main.run(q2);
    Main.run(q2);
    Main.run(q);
    Main.run(q);
    Main.run(q2);
    Main.run(q);
    Main.run(q);
    Main.run(q2);
    Main.run(q);
    Main.run(q);

    Builtin.print("Finished\n");
  }

  print(id: U64 & imm, a: (U64ObjF & iso) | (None & imm))
  {
    match (a)
    {
      var vv: U64ObjF => Builtin.print2("Queue {} elem: {}\n", id, (mut-view vv).v),
      var n: None   => Builtin.print1("Queue {} empty\n", id),
    }
  }
}