Expose VO bit functions

src/policy/copyspace.rs

@@ -181,7 +181,7 @@ impl<VM: VMBinding> CopySpace<VM> {
 
             // Clear VO bits because all objects in the space are dead.
             #[cfg(feature = "vo_bit")]
-            crate::util::metadata::vo_bit::bzero_vo_bit(start, size);
+            crate::util::metadata::side_metadata::bzero_vo_bit(start, size);
         }
 
         unsafe {

src/policy/immix/block.rs

@@ -8,6 +8,8 @@ use crate::util::linear_scan::{Region, RegionIterator};
 use crate::util::metadata::side_metadata::{MetadataByteArrayRef, SideMetadataSpec};
 #[cfg(feature = "vo_bit")]
 use crate::util::metadata::vo_bit;
+#[cfg(feature = "vo_bit")]
+use crate::util::metadata::side_metadata;
 use crate::util::Address;
 use crate::vm::*;
 use std::sync::atomic::Ordering;
@@ -280,7 +282,7 @@ impl Block {
                 match self.get_state() {
                     BlockState::Unmarked => {
                         // It may contain young objects.  Clear it.
-                        vo_bit::bzero_vo_bit(self.start(), Self::BYTES);
+                        side_metadata::bzero_vo_bit(self.start(), Self::BYTES);
                     }
                     BlockState::Marked => {
                         // It contains old objects.  Skip it.
@@ -293,7 +295,7 @@ impl Block {
                 for line in self.lines() {
                     if !line.is_marked(state) {
                         // It may contain young objects.  Clear it.
-                        vo_bit::bzero_vo_bit(line.start(), Line::BYTES);
+                        side_metadata::bzero_vo_bit(line.start(), Line::BYTES);
                     }
                 }
             }

src/policy/immix/immixspace.rs

@@ -17,6 +17,8 @@ use crate::util::linear_scan::{Region, RegionIterator};
 use crate::util::metadata::side_metadata::SideMetadataSpec;
 #[cfg(feature = "vo_bit")]
 use crate::util::metadata::vo_bit;
+#[cfg(feature = "vo_bit")]
+use crate::util::metadata::side_metadata;
 use crate::util::metadata::{self, MetadataSpec};
 use crate::util::object_forwarding;
 use crate::util::{Address, ObjectReference};
@@ -1096,7 +1098,7 @@ impl<VM: VMBinding> GCWork<VM> for ClearVOBitsAfterPrepare {
     fn do_work(&mut self, _worker: &mut GCWorker<VM>, _mmtk: &'static MMTK<VM>) {
         match self.scope {
             VOBitsClearingScope::FullGC => {
-                vo_bit::bzero_vo_bit(self.chunk.start(), Chunk::BYTES);
+                side_metadata::bzero_vo_bit(self.chunk.start(), Chunk::BYTES);
             }
             VOBitsClearingScope::BlockOnly => {
                 self.clear_blocks(None);

src/policy/marksweepspace/native_ms/block.rs

@@ -361,7 +361,7 @@ impl Block {
 
                     // Clear VO bit: we don't know where the object reference actually is, so we bulk zero the cell.
                     #[cfg(feature = "vo_bit")]
-                    crate::util::metadata::vo_bit::bzero_vo_bit(cell, cell_size);
+                    crate::util::metadata::side_metadata::bzero_vo_bit(cell, cell_size);
 
                     // store the previous cell to make the free list
                     debug_assert!(last.is_zero() || (last >= self.start() && last < self.end()));

src/policy/marksweepspace/native_ms/global.rs

@@ -379,7 +379,7 @@ impl<VM: VMBinding> MarkSweepSpace<VM> {
             metadata_spec.set_zero_atomic(block.start(), Ordering::SeqCst);
         }
         #[cfg(feature = "vo_bit")]
-        crate::util::metadata::vo_bit::bzero_vo_bit(block.start(), Block::BYTES);
+        crate::util::metadata::side_metadata::bzero_vo_bit(block.start(), Block::BYTES);
     }
 
     pub fn acquire_block(&self, tls: VMThread, size: usize, align: usize) -> BlockAcquireResult {

src/util/metadata/side_metadata/global.rs

@@ -12,6 +12,18 @@ use std::fmt;
 use std::io::Result;
 use std::sync::atomic::{AtomicU8, Ordering};
 
+#[cfg(feature = "vo_bit")]
+/// Bulk zero the VO bit.
+pub fn bzero_vo_bit(start: Address, size: usize) {
+    VO_BIT_SIDE_METADATA_SPEC.bzero_metadata(start, size);
+}
+#[cfg(feature = "vo_bit")]
+/// Bulk set the VO bit.
+pub fn bset_vo_bit(start: Address, size: usize) {
+    VO_BIT_SIDE_METADATA_SPEC.bset_metadata(start, size);
+}
+
+
 /// This struct stores the specification of a side metadata bit-set.
 /// It is used as an input to the (inline) functions provided by the side metadata module.
 ///

src/util/metadata/vo_bit/helper.rs

@@ -195,7 +195,7 @@ pub(crate) fn on_region_swept<VM: VMBinding, R: Region>(region: &R, is_occupied:
                 vo_bit::bcopy_vo_bit_from_mark_bit::<VM>(region.start(), R::BYTES);
             } else {
                 // If the block has no live objects, simply clear the VO bits.
-                vo_bit::bzero_vo_bit(region.start(), R::BYTES);
+                crate::util::metadata::side_metadata::bzero_vo_bit(region.start(), R::BYTES);
             }
         }
     }

src/util/metadata/vo_bit/mod.rs

@@ -140,11 +140,6 @@ pub unsafe fn is_vo_bit_set_unsafe<VM: VMBinding>(address: Address) -> Option<Ob
     }
 }
 
-/// Bulk zero the VO bit.
-pub fn bzero_vo_bit(start: Address, size: usize) {
-    VO_BIT_SIDE_METADATA_SPEC.bzero_metadata(start, size);
-}
-
 /// Bulk copy VO bits from side mark bits.
 /// Some VMs require the VO bits to be available during tracing.
 /// However, some GC algorithms (such as Immix) cannot clear VO bits for dead objects only.