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make marker into an iterators, recover post_order_iterator

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This commit is contained in:
Mark Thom
2022-04-02 22:45:10 -06:00
parent c9a34bde3f
commit 0ab928063e
4 changed files with 133 additions and 304 deletions
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36
src/heap_iter.rs
View File

@@ -1,4 +1,5 @@
// pub(crate) use crate::machine::gc::{IteratorUMP, StacklessPreOrderHeapIter}; #[cfg(test)]
pub(crate) use crate::machine::gc::{IteratorUMP, StacklessPreOrderHeapIter};
use crate::machine::heap::*; use crate::machine::heap::*;
use crate::atom_table::*; use crate::atom_table::*;
@@ -223,15 +224,14 @@ impl<'a> Iterator for StackfulPreOrderHeapIter<'a> {
} }
} }
/*
#[inline(always)] #[inline(always)]
#[cfg(test)]
pub(crate) fn stackless_preorder_iter( pub(crate) fn stackless_preorder_iter(
heap: &mut Vec<HeapCellValue>, heap: &mut Vec<HeapCellValue>,
cell: HeapCellValue, cell: HeapCellValue,
) -> StacklessPreOrderHeapIter<IteratorUMP> { ) -> StacklessPreOrderHeapIter<IteratorUMP> {
StacklessPreOrderHeapIter::new(heap, cell) StacklessPreOrderHeapIter::<IteratorUMP>::new(heap, cell)
} }
*/
#[inline(always)] #[inline(always)]
pub(crate) fn stackful_preorder_iter( pub(crate) fn stackful_preorder_iter(
@@ -337,25 +337,25 @@ pub(crate) fn stackful_post_order_iter<'a>(
PostOrderIterator::new(StackfulPreOrderHeapIter::new(heap, cell)) PostOrderIterator::new(StackfulPreOrderHeapIter::new(heap, cell))
} }
// pub(crate) type RightistPostOrderHeapIter<'a> = #[cfg(test)]
// PostOrderIterator<StacklessPreOrderHeapIter<'a, IteratorUMP>>; pub(crate) type RightistPostOrderHeapIter<'a> =
PostOrderIterator<StacklessPreOrderHeapIter<'a, IteratorUMP>>;
/*
#[inline] #[inline]
#[cfg(test)]
pub(crate) fn stackless_post_order_iter<'a>( pub(crate) fn stackless_post_order_iter<'a>(
heap: &'a mut Heap, heap: &'a mut Heap,
cell: HeapCellValue, cell: HeapCellValue,
) -> RightistPostOrderHeapIter<'a> { ) -> RightistPostOrderHeapIter<'a> {
PostOrderIterator::new(stackless_preorder_iter(heap, cell)) PostOrderIterator::new(stackless_preorder_iter(heap, cell))
} }
*/
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::*; use super::*;
use crate::machine::mock_wam::*; use crate::machine::mock_wam::*;
/*
#[test] #[test]
fn heap_stackless_iter_tests() { fn heap_stackless_iter_tests() {
let mut wam = MockWAM::new(); let mut wam = MockWAM::new();
@@ -444,7 +444,7 @@ mod tests {
] ]
)); ));
for _ in 0..200000 { for _ in 0..200 { // 000 {
let mut iter = stackless_preorder_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0)); let mut iter = stackless_preorder_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
assert_eq!( assert_eq!(
@@ -518,6 +518,7 @@ mod tests {
unmark_cell_bits!(iter.next().unwrap()), unmark_cell_bits!(iter.next().unwrap()),
atom_as_cell!(b_atom) atom_as_cell!(b_atom)
); );
assert_eq!( assert_eq!(
unmark_cell_bits!(iter.next().unwrap()), unmark_cell_bits!(iter.next().unwrap()),
atom_as_cell!(a_atom) atom_as_cell!(a_atom)
@@ -579,7 +580,7 @@ mod tests {
heap_loc_as_cell!(1), heap_loc_as_cell!(1),
); );
assert_eq!(iter.next(), None); assert!(iter.next().is_none());
} }
assert_eq!(wam.machine_st.heap[0], pstr_cell); assert_eq!(wam.machine_st.heap[0], pstr_cell);
@@ -606,7 +607,7 @@ mod tests {
heap_loc_as_cell!(3), heap_loc_as_cell!(3),
); );
assert_eq!(iter.next(), None); assert!(iter.next().is_none());
} }
assert_eq!(wam.machine_st.heap[0], pstr_cell); assert_eq!(wam.machine_st.heap[0], pstr_cell);
@@ -628,8 +629,8 @@ mod tests {
let pstr_offset_cell = pstr_offset_as_cell!(0); let pstr_offset_cell = pstr_offset_as_cell!(0);
assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_offset_cell); assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_offset_cell);
assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_second_cell);
assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_cell); assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_cell);
assert_eq!(unmark_cell_bits!(iter.next().unwrap()), pstr_second_cell);
assert_eq!(iter.next(), None); assert_eq!(iter.next(), None);
} }
@@ -1299,7 +1300,7 @@ mod tests {
} }
*/ */
} }
*/
#[test] #[test]
fn heap_stackful_iter_tests() { fn heap_stackful_iter_tests() {
let mut wam = MockWAM::new(); let mut wam = MockWAM::new();
@@ -2219,7 +2220,6 @@ mod tests {
wam.machine_st.heap.clear(); wam.machine_st.heap.clear();
} }
/*
#[test] #[test]
fn heap_stackless_post_order_iter() { fn heap_stackless_post_order_iter() {
let mut wam = MockWAM::new(); let mut wam = MockWAM::new();
@@ -2313,6 +2313,11 @@ mod tests {
let mut iter = stackless_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0)); let mut iter = stackless_post_order_iter(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
assert_eq!(
unmark_cell_bits!(iter.next().unwrap()),
heap_loc_as_cell!(1)
);
assert_eq!( assert_eq!(
unmark_cell_bits!(iter.next().unwrap()), unmark_cell_bits!(iter.next().unwrap()),
heap_loc_as_cell!(0) heap_loc_as_cell!(0)
@@ -2632,5 +2637,4 @@ mod tests {
all_cells_unmarked(&wam.machine_st.heap); all_cells_unmarked(&wam.machine_st.heap);
} }
*/
} }

2
src/machine/arithmetic_ops.rs
View File

@@ -1098,7 +1098,7 @@ impl MachineState {
pub(crate) fn arith_eval_by_metacall(&mut self, value: HeapCellValue) -> Result<Number, MachineStub> { pub(crate) fn arith_eval_by_metacall(&mut self, value: HeapCellValue) -> Result<Number, MachineStub> {
let stub_gen = || functor_stub(atom!("is"), 2); let stub_gen = || functor_stub(atom!("is"), 2);
let mut iter = stackful_post_order_iter(&mut self.heap, value); // was stackless! let mut iter = stackful_post_order_iter(&mut self.heap, value);
while let Some(value) = iter.next() { while let Some(value) = iter.next() {
if value.is_forwarded() { if value.is_forwarded() {

380
src/machine/gc.rs
View File

@@ -7,13 +7,15 @@ use core::marker::PhantomData;
pub(crate) trait UnmarkPolicy { pub(crate) trait UnmarkPolicy {
fn unmark(heap: &mut [HeapCellValue], current: usize); fn unmark(heap: &mut [HeapCellValue], current: usize);
fn mark(heap: &mut [HeapCellValue], current: usize); fn mark(heap: &mut [HeapCellValue], current: usize);
fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> bool fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> Option<HeapCellValue>
where where
Self: Sized; Self: Sized;
} }
#[cfg(test)]
pub(crate) struct IteratorUMP; pub(crate) struct IteratorUMP;
#[cfg(test)]
impl UnmarkPolicy for IteratorUMP { impl UnmarkPolicy for IteratorUMP {
#[inline(always)] #[inline(always)]
fn unmark(heap: &mut [HeapCellValue], current: usize) { fn unmark(heap: &mut [HeapCellValue], current: usize) {
@@ -24,7 +26,7 @@ impl UnmarkPolicy for IteratorUMP {
fn mark(_heap: &mut [HeapCellValue], _current: usize) {} fn mark(_heap: &mut [HeapCellValue], _current: usize) {}
#[inline(always)] #[inline(always)]
fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> bool { fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> Option<HeapCellValue> {
iter.forward_var() iter.forward_var()
} }
} }
@@ -41,7 +43,7 @@ impl UnmarkPolicy for MarkerUMP {
} }
#[inline(always)] #[inline(always)]
fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> bool { fn forward_attr_var(iter: &mut StacklessPreOrderHeapIter<Self>) -> Option<HeapCellValue> {
if iter.heap[iter.current + 1].get_forwarding_bit() == Some(true) { if iter.heap[iter.current + 1].get_forwarding_bit() == Some(true) {
return iter.forward_var(); return iter.forward_var();
} }
@@ -55,8 +57,7 @@ impl UnmarkPolicy for MarkerUMP {
iter.heap[iter.current].set_value(temp); iter.heap[iter.current].set_value(temp);
iter.heap[iter.current].set_forwarding_bit(true); // forward the attr vars list. iter.heap[iter.current].set_forwarding_bit(true); // forward the attr vars list.
None
false
} }
} }
@@ -83,7 +84,7 @@ impl<'a, UMP: UnmarkPolicy> Drop for StacklessPreOrderHeapIter<'a, UMP> {
} }
} }
impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> { impl<'a> StacklessPreOrderHeapIter<'a, MarkerUMP> {
pub(crate) fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self { pub(crate) fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
let orig_heap_len = heap.len(); let orig_heap_len = heap.len();
let start = orig_heap_len; // + 1; let start = orig_heap_len; // + 1;
@@ -103,186 +104,39 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
_marker: PhantomData, _marker: PhantomData,
} }
} }
}
// NEW implementation! #[cfg(test)]
fn forward_var(&mut self) -> bool { impl<'a> StacklessPreOrderHeapIter<'a, IteratorUMP> {
if self.heap[self.next].get_forwarding_bit() == Some(true) { pub(crate) fn new(heap: &'a mut Vec<HeapCellValue>, cell: HeapCellValue) -> Self {
return self.backward(); let orig_heap_len = heap.len();
} let start = orig_heap_len + 1;
let temp = self.heap[self.next].get_value(); heap.push(cell);
heap.push(heap_loc_as_cell!(orig_heap_len));
self.heap[self.next].set_value(self.current); heap[start].set_forwarding_bit(true);
self.current = self.next; let next = heap[start].get_value();
self.next = temp;
false Self {
} heap,
orig_heap_len,
fn forward(&mut self) { start,
loop { current: start,
if !self.heap[self.current].get_mark_bit() { next,
self.heap[self.current].set_mark_bit(true); _marker: PhantomData,
match self.heap[self.current].get_tag() {
HeapCellValueTag::AttrVar => {
if UMP::forward_attr_var(self) { return; }
}
HeapCellValueTag::Var => {
if self.forward_var() { return; }
}
HeapCellValueTag::Str => {
if self.heap[self.next + 1].get_forwarding_bit() == Some(true) {
if self.backward() {
return;
} else {
continue;
} }
} }
}
let h = self.next; impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
let arity = cell_as_atom_cell!(self.heap[h]).get_arity();
for cell in &mut self.heap[h + 1 .. h + arity + 1] {
cell.set_forwarding_bit(true);
}
let mut last_cell_loc = h + arity;
self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current);
self.current = last_cell_loc;
}
HeapCellValueTag::Lis => {
let mut last_cell_loc = self.next + 1;
if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
if self.backward() {
return;
} else {
continue;
}
}
self.heap[last_cell_loc].set_forwarding_bit(true);
self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current);
self.current = last_cell_loc;
}
HeapCellValueTag::PStrLoc => {
let h = self.next;
let cell = self.heap[h];
if self.heap[h+1].get_forwarding_bit() == Some(true) {
if self.backward() {
return;
} else {
continue;
}
}
if self.heap[h].get_tag() == HeapCellValueTag::PStr {
let mut last_cell_loc = h+1;
self.heap[last_cell_loc].set_forwarding_bit(true);
self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current);
self.current = last_cell_loc;
} else {
debug_assert!(self.heap[h].get_tag() == HeapCellValueTag::PStrOffset);
self.next = self.heap[h].get_value();
self.heap[h].set_value(self.current);
self.current = h;
}
}
HeapCellValueTag::PStrOffset => {
let h = self.next;
// mark the Fixnum offset.
UMP::mark(self.heap, self.current+1);
if self.heap[h].get_tag() == HeapCellValueTag::PStr {
let mut last_cell_loc = h+1;
if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
if self.backward() {
return;
} else {
continue;
}
}
self.heap[last_cell_loc].set_forwarding_bit(true);
self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current);
self.current = last_cell_loc;
} else {
debug_assert!(self.heap[h].get_tag() == HeapCellValueTag::CStr);
self.next = self.heap[h].get_value();
self.heap[h].set_value(self.current);
self.current = h;
}
}
HeapCellValueTag::StackVar => {
/*
let cell = self.heap[self.current];
self.heap[self.current].set_forwarding_bit(true);
return Some(cell);
*/
}
_ => {
if self.backward() {
return;
}
}
}
} else {
if self.backward() {
return;
}
}
}
}
fn backward(&mut self) -> bool {
while !self.heap[self.current].get_forwarding_bit().unwrap_or(false) {
let temp = self.heap[self.current].get_value();
// UMP::mark(self.heap, self.current);
self.heap[self.current].set_value(self.next);
self.next = self.current;
self.current = temp;
}
self.heap[self.current].set_forwarding_bit(false);
// UMP::unmark(self.heap, self.current);
if self.current == self.start {
return true;
}
self.current -= 1;
let temp = self.heap[self.current+1].get_value();
self.heap[self.current+1].set_value(self.next);
self.next = self.heap[self.current].get_value();
self.heap[self.current].set_value(temp);
false
}
/*
fn backward_and_return(&mut self) -> Option<HeapCellValue> { fn backward_and_return(&mut self) -> Option<HeapCellValue> {
let current = self.current; let current = self.current;
if self.backward() { if self.backward() {
// set the f and m bits on the heap cell at start
// so we invoke backward() and return None next call.
self.heap[self.current].set_forwarding_bit(true); self.heap[self.current].set_forwarding_bit(true);
self.heap[self.current].set_mark_bit(true); self.heap[self.current].set_mark_bit(true);
} }
@@ -291,12 +145,6 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
} }
fn forward_var(&mut self) -> Option<HeapCellValue> { fn forward_var(&mut self) -> Option<HeapCellValue> {
if self.heap[self.next].get_mark_bit() {
return self.backward_and_return();
}
self.heap[self.current].set_forwarding_bit(true);
if self.heap[self.next].get_forwarding_bit() == Some(true) { if self.heap[self.next].get_forwarding_bit() == Some(true) {
return self.backward_and_return(); return self.backward_and_return();
} }
@@ -312,45 +160,39 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
fn forward(&mut self) -> Option<HeapCellValue> { fn forward(&mut self) -> Option<HeapCellValue> {
loop { loop {
if self.heap[self.current].get_forwarding_bit() != Some(true) { if !self.heap[self.current].get_mark_bit() {
self.heap[self.current].set_mark_bit(true);
match self.heap[self.current].get_tag() { match self.heap[self.current].get_tag() {
HeapCellValueTag::AttrVar => { HeapCellValueTag::AttrVar => {
if let Some(cell) = UMP::forward_attr_var(self) { return Some(cell); } if let Some(cell) = UMP::forward_attr_var(self) { return Some(cell); }
if self.heap[self.next].get_mark_bit() { //self.current == self.next {
return Some(attr_var_as_cell!(self.current));
}
} }
HeapCellValueTag::Var => { HeapCellValueTag::Var => {
if let Some(cell) = self.forward_var() { return Some(cell); } if let Some(cell) = self.forward_var() { return Some(cell); }
if self.heap[self.next].get_mark_bit() { //self.current == self.next {
return Some(heap_loc_as_cell!(self.current));
}
} }
HeapCellValueTag::Str => { HeapCellValueTag::Str => {
// forwarded refs should never be if self.heap[self.next + 1].get_forwarding_bit() == Some(true) {
// marked. leave that to the backward phase.
if self.heap[self.next + 1].get_mark_bit() {
return self.backward_and_return(); return self.backward_and_return();
} }
let h = self.next; let h = self.next;
let cell = self.heap[h]; let cell = self.heap[h];
self.heap[h].set_forwarding_bit(true);
self.heap[self.current].set_forwarding_bit(true);
let arity = cell_as_atom_cell!(self.heap[h]).get_arity(); let arity = cell_as_atom_cell!(self.heap[h]).get_arity();
for cell in &mut self.heap[h + 1 .. h + arity + 1] { for cell in &mut self.heap[h + 1 .. h + arity + 1] {
if !cell.get_forwarding_bit().unwrap_or(false) { cell.set_forwarding_bit(true);
cell.set_mark_bit(true);
}
} }
let mut last_cell_loc = h + arity; let last_cell_loc = h + arity;
for cell in self.heap[h + 1 .. h + arity + 1].iter_mut().rev() {
if cell.get_forwarding_bit().unwrap_or(false) {
last_cell_loc -= 1;
} else {
break;
}
}
self.next = self.heap[last_cell_loc].get_value(); self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current); self.heap[last_cell_loc].set_value(self.current);
@@ -359,24 +201,13 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
return Some(cell); return Some(cell);
} }
HeapCellValueTag::Lis => { HeapCellValueTag::Lis => {
let mut last_cell_loc = self.next + 1; let last_cell_loc = self.next + 1;
if self.heap[last_cell_loc].get_mark_bit() { if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
return self.backward_and_return(); return self.backward_and_return();
} }
if self.heap[last_cell_loc].get_forwarding_bit().unwrap_or(false) { self.heap[last_cell_loc].set_forwarding_bit(true);
// if the tail is already in the
// forwarding chain, use the head in its
// place. apply the same principle to
// forwarded refs elsewhere in this
// function.
last_cell_loc -= 1;
} else {
self.heap[last_cell_loc].set_mark_bit(true);
}
self.heap[self.current].set_forwarding_bit(true);
self.next = self.heap[last_cell_loc].get_value(); self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current); self.heap[last_cell_loc].set_value(self.current);
@@ -388,25 +219,16 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
let h = self.next; let h = self.next;
let cell = self.heap[h]; let cell = self.heap[h];
self.heap[self.current].set_forwarding_bit(true); if self.heap[h+1].get_forwarding_bit() == Some(true) {
if self.heap[h+1].get_mark_bit() {
return self.backward_and_return(); return self.backward_and_return();
} }
if self.heap[h].get_tag() == HeapCellValueTag::PStr { if self.heap[h].get_tag() == HeapCellValueTag::PStr {
let mut last_cell_loc = h+1; let last_cell_loc = h+1;
self.heap[last_cell_loc].set_forwarding_bit(true);
if self.heap[last_cell_loc].get_forwarding_bit().unwrap_or(false) {
last_cell_loc -= 1;
} else {
self.heap[last_cell_loc].set_mark_bit(true);
}
self.next = self.heap[last_cell_loc].get_value(); self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current); self.heap[last_cell_loc].set_value(self.current);
self.heap[h].set_forwarding_bit(true);
self.current = last_cell_loc; self.current = last_cell_loc;
} else { } else {
debug_assert!(self.heap[h].get_tag() == HeapCellValueTag::PStrOffset); debug_assert!(self.heap[h].get_tag() == HeapCellValueTag::PStrOffset);
@@ -415,7 +237,7 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
self.heap[h].set_value(self.current); self.heap[h].set_value(self.current);
self.current = h; self.current = h;
if self.heap[h].get_forwarding_bit() == Some(true) { if self.heap[h].get_mark_bit() {
continue; continue;
} }
} }
@@ -424,23 +246,19 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
} }
HeapCellValueTag::PStrOffset => { HeapCellValueTag::PStrOffset => {
let h = self.next; let h = self.next;
let cell = self.heap[h];
// mark the Fixnum offset.
UMP::mark(self.heap, self.current+1); UMP::mark(self.heap, self.current+1);
if self.heap[h].get_tag() == HeapCellValueTag::PStr { let last_cell_loc = h+1;
let mut last_cell_loc = h+1;
if self.heap[last_cell_loc].get_mark_bit() { if self.heap[last_cell_loc].get_forwarding_bit() == Some(true) {
return self.backward_and_return(); return self.backward_and_return();
} }
if self.heap[last_cell_loc].get_forwarding_bit().unwrap_or(false) { if self.heap[h].get_tag() == HeapCellValueTag::PStr {
last_cell_loc -= 1; self.heap[last_cell_loc].set_forwarding_bit(true);
} else {
self.heap[last_cell_loc].set_mark_bit(true);
}
self.heap[self.current].set_forwarding_bit(true);
self.next = self.heap[last_cell_loc].get_value(); self.next = self.heap[last_cell_loc].get_value();
self.heap[last_cell_loc].set_value(self.current); self.heap[last_cell_loc].set_value(self.current);
@@ -452,23 +270,25 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
self.heap[h].set_value(self.current); self.heap[h].set_value(self.current);
self.current = h; self.current = h;
} }
}
HeapCellValueTag::StackVar => {
let cell = self.heap[self.current];
self.heap[self.current].set_forwarding_bit(true);
return Some(cell); return Some(cell);
} }
_ => { tag @ HeapCellValueTag::Atom => {
if self.heap[self.current].get_mark_bit() { let cell = HeapCellValue::build_with(tag, self.next as u64);
let current = self.current; let arity = AtomCell::from_bytes(cell.into_bytes()).get_arity();
if arity == 0 {
return self.backward_and_return();
} else if self.backward() {
return None;
}
}
HeapCellValueTag::PStr => {
if self.backward() { if self.backward() {
return None; return None;
} }
return Some(self.heap[current]);
} }
_ => {
return self.backward_and_return(); return self.backward_and_return();
} }
} }
@@ -481,20 +301,17 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
} }
fn backward(&mut self) -> bool { fn backward(&mut self) -> bool {
while !self.heap[self.current].get_mark_bit() { while !self.heap[self.current].get_forwarding_bit().unwrap_or(false) {
let temp = self.heap[self.current].get_value(); let temp = self.heap[self.current].get_value();
UMP::mark(self.heap, self.current); UMP::unmark(self.heap, self.current);
self.heap[self.current].set_forwarding_bit(false);
self.heap[self.current].set_value(self.next); self.heap[self.current].set_value(self.next);
self.next = self.current; self.next = self.current;
self.current = temp; self.current = temp;
} }
self.heap[self.current].set_forwarding_bit(false); self.heap[self.current].set_forwarding_bit(false);
UMP::unmark(self.heap, self.current); UMP::unmark(self.heap, self.current);
if self.current == self.start { if self.current == self.start {
@@ -511,10 +328,8 @@ impl<'a, UMP: UnmarkPolicy> StacklessPreOrderHeapIter<'a, UMP> {
false false
} }
*/
} }
/*
impl<'a, UMP: UnmarkPolicy> Iterator for StacklessPreOrderHeapIter<'a, UMP> { impl<'a, UMP: UnmarkPolicy> Iterator for StacklessPreOrderHeapIter<'a, UMP> {
type Item = HeapCellValue; type Item = HeapCellValue;
@@ -523,26 +338,10 @@ impl<'a, UMP: UnmarkPolicy> Iterator for StacklessPreOrderHeapIter<'a, UMP> {
self.forward() self.forward()
} }
} }
*/
pub fn mark_cells(heap: &mut Heap, cell: HeapCellValue) { pub fn mark_cells(heap: &mut Heap, cell: HeapCellValue) {
let mut iter = StacklessPreOrderHeapIter::<MarkerUMP>::new(heap, cell); let mut iter = StacklessPreOrderHeapIter::<MarkerUMP>::new(heap, cell);
while let Some(_) = iter.forward() {}
let print_ptrs = |iter: &StacklessPreOrderHeapIter::<MarkerUMP>| {
println!("self.current = {}, self.next = {}\n", iter.current, iter.next);
};
iter.forward();
print_heap_terms(iter.heap.iter(), 0);
print_ptrs(&iter);
/*
while let Some(_) = iter.forward() {
print_heap_terms(iter.heap.iter(), 0);
print_ptrs(&iter);
}
*/
} }
#[cfg(test)] #[cfg(test)]
@@ -1336,8 +1135,6 @@ mod tests {
// representation of one of the heap terms as in issue #1384. // representation of one of the heap terms as in issue #1384.
println!("DELINEATE");
wam.machine_st.heap.push(list_loc_as_cell!(7)); wam.machine_st.heap.push(list_loc_as_cell!(7));
wam.machine_st.heap.push(heap_loc_as_cell!(0)); wam.machine_st.heap.push(heap_loc_as_cell!(0));
wam.machine_st.heap.push(list_loc_as_cell!(3)); // A = [B|[]]. wam.machine_st.heap.push(list_loc_as_cell!(3)); // A = [B|[]].
@@ -1350,7 +1147,10 @@ mod tests {
mark_cells(&mut wam.machine_st.heap, heap_loc_as_cell!(0)); mark_cells(&mut wam.machine_st.heap, heap_loc_as_cell!(0));
all_cells_marked_and_unforwarded(&wam.machine_st.heap); assert!(wam.machine_st.heap[0].get_mark_bit());
assert!(!wam.machine_st.heap[1].get_mark_bit());
all_cells_marked_and_unforwarded(&wam.machine_st.heap[2 ..]);
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), list_loc_as_cell!(7)); assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), list_loc_as_cell!(7));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[1]), heap_loc_as_cell!(0)); assert_eq!(unmark_cell_bits!(wam.machine_st.heap[1]), heap_loc_as_cell!(0));
@@ -1361,5 +1161,35 @@ mod tests {
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[6]), heap_loc_as_cell!(2)); assert_eq!(unmark_cell_bits!(wam.machine_st.heap[6]), heap_loc_as_cell!(2));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[7]), empty_list_as_cell!()); assert_eq!(unmark_cell_bits!(wam.machine_st.heap[7]), empty_list_as_cell!());
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[8]), heap_loc_as_cell!(3)); assert_eq!(unmark_cell_bits!(wam.machine_st.heap[8]), heap_loc_as_cell!(3));
wam.machine_st.heap.clear();
wam.machine_st.heap.push(str_loc_as_cell!(1));
wam.machine_st.heap.push(atom_as_cell!(atom!("+"), 2));
wam.machine_st.heap.push(str_loc_as_cell!(4));
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(2)));
wam.machine_st.heap.push(atom_as_cell!(atom!("-"), 2));
wam.machine_st.heap.push(str_loc_as_cell!(7));
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(1)));
wam.machine_st.heap.push(atom_as_cell!(atom!("+"), 2));
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(3)));
wam.machine_st.heap.push(fixnum_as_cell!(Fixnum::build_with(4)));
mark_cells(&mut wam.machine_st.heap, str_loc_as_cell!(1));
print_heap_terms(wam.machine_st.heap[1 ..].iter(), 0);
all_cells_marked_and_unforwarded(&wam.machine_st.heap);
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[0]), str_loc_as_cell!(1));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[1]), atom_as_cell!(atom!("+"), 2));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[2]), str_loc_as_cell!(4));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[3]), fixnum_as_cell!(Fixnum::build_with(2)));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[4]), atom_as_cell!(atom!("-"), 2));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[5]), str_loc_as_cell!(7));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[6]), fixnum_as_cell!(Fixnum::build_with(1)));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[7]), atom_as_cell!(atom!("+"), 2));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[8]), fixnum_as_cell!(Fixnum::build_with(3)));
assert_eq!(unmark_cell_bits!(wam.machine_st.heap[9]), fixnum_as_cell!(Fixnum::build_with(4)));
} }
} }

7
src/machine/system_calls.rs
View File

@@ -4905,17 +4905,12 @@ impl Machine {
let mut seen_set = IndexSet::new(); let mut seen_set = IndexSet::new();
{ {
let orig_heap_len = self.machine_st.heap.len();
let mut iter = stackful_preorder_iter(&mut self.machine_st.heap, stored_v); let mut iter = stackful_preorder_iter(&mut self.machine_st.heap, stored_v);
while let Some(addr) = iter.next() { while let Some(addr) = iter.next() {
let addr = unmark_cell_bits!(addr); let addr = unmark_cell_bits!(addr);
if addr.is_var() && addr.get_value() < orig_heap_len { if addr.is_var() {
// the length check is so we don't catalog
// temporary variables created by the iterator,
// that will be deleted when the iterator is
// dropped, into seen_set.
seen_set.insert(addr); seen_set.insert(addr);
} }
} }