public void running_a_scan_when_no_pointers_are_referenced_resets_the_arena()
{
var bump = (Allocator.ArenaSize / 4) + 1; // three fit in each arena, with some spare
var mem = new MemorySimulator(Mega.Bytes(1));
var subject = new Allocator(512, Mega.Bytes(1), mem);
subject.Alloc(bump);
var ar1 = subject.CurrentArena();
subject.Alloc(bump); subject.Alloc(bump); // fill up first arena
var x2 = subject.Alloc(bump).Value;
var ar2 = subject.CurrentArena();
Assert.That(ar1, Is.Not.EqualTo(ar2), "Failed to trigger a new arena");
// Check that both arenas are non-empty:
Assert.That(subject.GetArenaOccupation(ar1).Value, Is.Not.Zero);
Assert.That(subject.GetArenaOccupation(ar2).Value, Is.Not.Zero);
// Run the scan (only including the second arena)
var list = new Vector <long>(subject, mem);
list.Push(x2);
subject.ScanAndSweep(list);
// Check nothing has been cleared
Assert.That(subject.GetArenaOccupation(ar1).Value, Is.Zero, "Unreferenced arena was not reset");
Assert.That(subject.GetArenaOccupation(ar2).Value, Is.Not.Zero);
}
public void running_a_scan_when_any_pointers_are_referenced_keeps_the_arena()
{
// scan takes a list of known references, and assumes anything
// that's not in the list in not referenced. Any arena with nothing
// referenced is reset.
var mem = new MemorySimulator(Mega.Bytes(1));
var bump = (Allocator.ArenaSize / 4) + 1; // three fit in each arena, with some spare
var subject = new Allocator(512, Mega.Bytes(1), mem);
var x1 = subject.Alloc(bump).Value;
var ar1 = subject.CurrentArena();
subject.Alloc(bump); subject.Alloc(bump); // fill up first arena
var x2 = subject.Alloc(bump).Value;
var ar2 = subject.CurrentArena();
Assert.That(ar1, Is.Not.EqualTo(ar2), "Failed to trigger a new arena");
// Check that both arenas are non-empty:
Assert.That(subject.GetArenaOccupation(ar1).Value, Is.Not.Zero);
Assert.That(subject.GetArenaOccupation(ar2).Value, Is.Not.Zero);
// Run the scan (note we don't need all pointers, just one from each arena)
var list = new Vector <long>(subject, mem);
list.Push(x1);
list.Push(x2);
subject.ScanAndSweep(list);
// Check nothing has been cleared
Assert.That(subject.GetArenaOccupation(ar1).Value, Is.Not.Zero);
Assert.That(subject.GetArenaOccupation(ar2).Value, Is.Not.Zero);
}
public void allocating_enough_memory_changes_arena()
{
var mem = new MemorySimulator(Mega.Bytes(1));
var subject = new Allocator(100, Mega.Bytes(1), mem);
int first = subject.CurrentArena();
long ptr1 = subject.Alloc(Allocator.ArenaSize).Value;
long ptr2 = subject.Alloc(Kilo.Bytes(1)).Value;
int second = subject.CurrentArena();
Assert.That(ptr1, Is.Not.EqualTo(ptr2));
Assert.That(first, Is.Not.EqualTo(second));
}
public void can_directly_deallocate_a_pointer()
{
var mem = new MemorySimulator(Mega.Bytes(1));
var subject = new Allocator(100, Mega.Bytes(10), mem);
long ptr = subject.Alloc(byteCount: 256).Value;
subject.Deref(ptr);
var ar = subject.CurrentArena();
var refs = subject.ArenaRefCount(ar);
Assert.That(refs.Value, Is.Zero);
}
[Test] // a stress test of sorts
public void can_handle_large_allocation_spaces()
{
var mem = new OffsetMemorySimulator(Mega.Bytes(1), Giga.Bytes(1)); // only need enough room for arena tables
var subject = new Allocator(Giga.Bytes(1), Giga.Bytes(2), mem); // big for an embedded system. 3GB total.
var result = subject.Alloc(Allocator.ArenaSize / 2);
Assert.That(result.Value - Giga.Bytes(1), Is.EqualTo(131072)); // allocated at bottom of given space, excluding arena tables
for (int i = 0; i < 1000; i++)
{
result = subject.Alloc(Allocator.ArenaSize - 1);
}
Assert.That(subject.CurrentArena(), Is.GreaterThanOrEqualTo(1000));
Assert.That(result.Value, Is.GreaterThan(Giga.Bytes(1)));
}
