Allow running MockVM with side metadata

Author: qinsoon

.github/scripts/ci-test.sh

@@ -34,7 +34,9 @@ find ./src ./tests -type f -name "mock_test_*" | while read -r file; do
 
     # Run the test with each plan it needs.
     for MMTK_PLAN in $PLANS; do
-        env MMTK_PLAN=$MMTK_PLAN cargo test --features mock_test,"$FEATURES" -- $t;
+        env MMTK_PLAN=$MMTK_PLAN cargo test --features mock_test,mock_test_side_metadata,"$FEATURES" -- $t;
+        # We should alro run the tests with mock_test_header_metadata feature -- be careful that some plans like compressor requires side mark bits which will fail if we use header metadata (including mark bits).
+        # env MMTK_PLAN=$MMTK_PLAN cargo test --features mock_test,mock_test_header_metadata,"$FEATURES" -- $t;
     done
 done
 

Cargo.toml

@@ -116,6 +116,8 @@ perf_counter = ["dep:pfm"]
 # This feature is only used for tests with MockVM.
 # CI scripts run those tests with this feature.
 mock_test = ["test_private"]
+mock_test_header_metadata = []
+mock_test_side_metadata = []
 
 # This feature will expose some private functions for testings or benchmarking.
 test_private = []

src/util/test_util/mock_vm.rs

@@ -462,15 +462,39 @@ impl crate::vm::Collection<MockVM> for MockVM {
     }
 }
 
-impl crate::vm::ObjectModel<MockVM> for MockVM {
-    const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = VMGlobalLogBitSpec::in_header(0);
-    const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec =
+#[cfg(feature = "mock_test_header_metadata")]
+mod mockvm_metadata {
+    use super::*;
+    pub const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = VMGlobalLogBitSpec::in_header(0);
+    pub const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec =
         VMLocalForwardingPointerSpec::in_header(0);
-    const LOCAL_FORWARDING_BITS_SPEC: VMLocalForwardingBitsSpec =
+    pub const LOCAL_FORWARDING_BITS_SPEC: VMLocalForwardingBitsSpec =
         VMLocalForwardingBitsSpec::in_header(0);
-    const LOCAL_MARK_BIT_SPEC: VMLocalMarkBitSpec = VMLocalMarkBitSpec::in_header(0);
-    const LOCAL_LOS_MARK_NURSERY_SPEC: VMLocalLOSMarkNurserySpec =
+    pub const LOCAL_MARK_BIT_SPEC: VMLocalMarkBitSpec = VMLocalMarkBitSpec::in_header(0);
+    pub const LOCAL_LOS_MARK_NURSERY_SPEC: VMLocalLOSMarkNurserySpec =
         VMLocalLOSMarkNurserySpec::in_header(0);
+}
+
+#[cfg(feature = "mock_test_side_metadata")]
+mod mockvm_metadata {
+    use super::*;
+    pub const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = VMGlobalLogBitSpec::side_first();
+    // Forarding pointer has to be in the header, as we cannot fit it in the side metadata (1 word metadata for 1 word data)
+    pub const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec =
+        VMLocalForwardingPointerSpec::in_header(0);
+    pub const LOCAL_FORWARDING_BITS_SPEC: VMLocalForwardingBitsSpec =
+        VMLocalForwardingBitsSpec::side_first();
+    pub const LOCAL_MARK_BIT_SPEC: VMLocalMarkBitSpec = VMLocalMarkBitSpec::side_after(LOCAL_FORWARDING_BITS_SPEC.as_spec());
+    pub const LOCAL_LOS_MARK_NURSERY_SPEC: VMLocalLOSMarkNurserySpec =
+        VMLocalLOSMarkNurserySpec::side_after(LOCAL_MARK_BIT_SPEC.as_spec());
+}
+
+impl crate::vm::ObjectModel<MockVM> for MockVM {
+    const GLOBAL_LOG_BIT_SPEC: VMGlobalLogBitSpec = mockvm_metadata::GLOBAL_LOG_BIT_SPEC;
+    const LOCAL_FORWARDING_POINTER_SPEC: VMLocalForwardingPointerSpec = mockvm_metadata::LOCAL_FORWARDING_POINTER_SPEC;
+    const LOCAL_FORWARDING_BITS_SPEC: VMLocalForwardingBitsSpec = mockvm_metadata::LOCAL_FORWARDING_BITS_SPEC;
+    const LOCAL_MARK_BIT_SPEC: VMLocalMarkBitSpec = mockvm_metadata::LOCAL_MARK_BIT_SPEC;
+    const LOCAL_LOS_MARK_NURSERY_SPEC: VMLocalLOSMarkNurserySpec = mockvm_metadata::LOCAL_LOS_MARK_NURSERY_SPEC;
 
     #[cfg(feature = "object_pinning")]
     const LOCAL_PINNING_BIT_SPEC: VMLocalPinningBitSpec = VMLocalPinningBitSpec::in_header(0);