Bulk enqueue references

Author: qinsoon

mmtk/Cargo.toml

@@ -26,7 +26,7 @@ lazy_static = "1.1"
 # - change branch
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI.
-mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "f47e85bdf2b6bf95807b425b184135cfdbf4de14" }
+mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "722546b37e7579aee9d093f51b97f5a729a553d5" }
 # Uncomment the following to build locally
 # mmtk = { path = "../repos/mmtk-core" }
 

mmtk/src/lib.rs

@@ -83,7 +83,7 @@ pub struct OpenJDK_Upcalls {
     pub number_of_mutators: extern "C" fn() -> usize,
     pub schedule_finalizer: extern "C" fn(),
     pub prepare_for_roots_re_scanning: extern "C" fn(),
-    pub enqueue_reference: extern "C" fn(object: ObjectReference),
+    pub enqueue_references: extern "C" fn(objects: &[ObjectReference], len: usize),
 }
 
 pub static mut UPCALLS: *const OpenJDK_Upcalls = null_mut();

mmtk/src/reference_glue.rs

@@ -15,9 +15,9 @@ impl ReferenceGlue<OpenJDK> for VMReferenceGlue {
         let oop = Oop::from(object);
         unsafe { InstanceRefKlass::referent_address(oop).load::<ObjectReference>() }
     }
-    fn enqueue_reference(object: ObjectReference) {
+    fn enqueue_references(references: &[ObjectReference]) {
         unsafe {
-            ((*UPCALLS).enqueue_reference)(object);
+            ((*UPCALLS).enqueue_references)(references, references.len());
         }
     }
 }

openjdk/mmtk.h

@@ -144,7 +144,7 @@ typedef struct {
     size_t (*number_of_mutators)();
     void (*schedule_finalizer)();
     void (*prepare_for_roots_re_scanning)();
-    void (*enqueue_reference)(void* object);
+    void (*enqueue_references)(void** objects, size_t len);
 } OpenJDK_Upcalls;
 
 extern void openjdk_gc_init(OpenJDK_Upcalls *calls, size_t heap_size);

openjdk/mmtkUpcalls.cpp

@@ -319,12 +319,25 @@ static void mmtk_prepare_for_roots_re_scanning() {
 #endif
 }
 
-static void mmtk_enqueue_reference(void* object) {
-  // printf("enqueue object: %p\n", object);
+static void mmtk_enqueue_references(void** objects, size_t len) {
+  if (len == 0) {
+    return;
+  }
+
   MutexLocker x(Heap_lock);
-  oop reff = (oop) object;
-  oop old = Universe::swap_reference_pending_list(reff);
-  HeapAccess<AS_NO_KEEPALIVE>::oop_store_at(reff, java_lang_ref_Reference::discovered_offset, old);
+
+  oop prev = NULL;
+  for (size_t i = 0; i < len; i++) {
+    oop reff = (oop) objects[i];
+    printf("enqueue: %p\n", reff);
+    if (prev != NULL) {
+      HeapAccess<AS_NO_KEEPALIVE>::oop_store_at(prev, java_lang_ref_Reference::discovered_offset, reff);
+    }
+    prev = reff;
+  }
+
+  oop old = Universe::swap_reference_pending_list(prev);
+  HeapAccess<AS_NO_KEEPALIVE>::oop_store_at(prev, java_lang_ref_Reference::discovered_offset, old);
   assert(Universe::has_reference_pending_list(), "Reference pending list is empty after swap");
 }
 
@@ -369,5 +382,5 @@ OpenJDK_Upcalls mmtk_upcalls = {
   mmtk_number_of_mutators,
   mmtk_schedule_finalizer,
   mmtk_prepare_for_roots_re_scanning,
-  mmtk_enqueue_reference,
+  mmtk_enqueue_references
 };