Notify collector about lazily deoptimized code objects.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index f6b495a209d840efc735c55e6e47efd570ec3f3d..6416c3b43b46b7e32b1e537d04d7f96be262c190 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -28,6 +28,7 @@
 #include "v8.h"
 
 #include "compilation-cache.h"
+#include "deoptimizer.h"
 #include "execution.h"
 #include "gdb-jit.h"
 #include "global-handles.h"
@@ -258,22 +259,6 @@ bool MarkCompactCollector::StartCompaction() {
 }
 
 
-void MarkCompactCollector::AbortCompaction() {
-  if (compacting_) {
-    int npages = evacuation_candidates_.length();
-    for (int i = 0; i < npages; i++) {
-      Page* p = evacuation_candidates_[i];
-      slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
-      p->ClearEvacuationCandidate();
-      p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
-    }
-    compacting_ = false;
-    evacuation_candidates_.Rewind(0);
-  }
-  ASSERT_EQ(0, evacuation_candidates_.length());
-}
-
-
 void MarkCompactCollector::CollectGarbage() {
   // Make sure that Prepare() has been called. The individual steps below will
   // update the state as they proceed.
@@ -463,6 +448,23 @@ void MarkCompactCollector::CollectEvacuationCandidates(PagedSpace* space) {
 }
 
 
+void MarkCompactCollector::AbortCompaction() {
+  if (compacting_) {
+    int npages = evacuation_candidates_.length();
+    for (int i = 0; i < npages; i++) {
+      Page* p = evacuation_candidates_[i];
+      slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
+      p->ClearEvacuationCandidate();
+      p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
+    }
+    compacting_ = false;
+    evacuation_candidates_.Rewind(0);
+    invalidated_code_.Rewind(0);
+  }
+  ASSERT_EQ(0, evacuation_candidates_.length());
+}
+
+
 void MarkCompactCollector::Prepare(GCTracer* tracer) {
   FLAG_flush_code = false;
 
@@ -2844,7 +2846,123 @@ static void SweepPrecisely(PagedSpace* space,
 }
 
 
+static bool SetMarkBitsUnderInvalidatedCode(Code* code, bool value) {
+  Page* p = Page::FromAddress(code->address());
+
+  if (p->IsEvacuationCandidate() ||
+      p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
+    return false;
+  }
+
+  Address code_start = code->address();
+  Address code_end = code_start + code->Size();
+
+  uint32_t start_index = MemoryChunk::FastAddressToMarkbitIndex(code_start);
+  uint32_t end_index =
+      MemoryChunk::FastAddressToMarkbitIndex(code_end - kPointerSize);
+
+  Bitmap* b = p->markbits();
+
+  MarkBit start_mark_bit = b->MarkBitFromIndex(start_index);
+  MarkBit end_mark_bit = b->MarkBitFromIndex(end_index);
+
+  MarkBit::CellType* start_cell = start_mark_bit.cell();
+  MarkBit::CellType* end_cell = end_mark_bit.cell();
+
+  if (value) {
+    MarkBit::CellType start_mask = ~(start_mark_bit.mask() - 1);
+    MarkBit::CellType end_mask = (end_mark_bit.mask() << 1) - 1;
+
+    if (start_cell == end_cell) {
+      *start_cell |= start_mask & end_mask;
+    } else {
+      *start_cell |= start_mask;
+      for (MarkBit::CellType* cell = start_cell + 1; cell < end_cell; cell++) {
+        *cell = ~0;
+      }
+      *end_cell |= end_mask;
+    }
+  } else {
+    for (MarkBit::CellType* cell = start_cell ; cell <= end_cell; cell++) {
+      *cell = 0;
+    }
+  }
+
+  return true;
+}
+
+
+static bool IsOnInvalidatedCodeObject(Address addr) {
+  Page* p = Page::FromAddress(addr);

[Erik Corry, 2011/09/22 09:10:47]

This doesn't work for large objects.
FromAnyPointerAddress works for large pointer objects, but not large code pages.
 Large data pages don't have slots on them.

+
+  // First check owners identity because old pointer and old data spaces

[Erik Corry, 2011/09/22 09:10:47]

owners -> owner's

+  // are swept lazily and might still have non-zero mark-bits on some
+  // pages.
+  if (p->owner()->identity() != CODE_SPACE) return false;
+
+  // In code space only bits on evacuation candidates (but we don't record
+  // any slots on them) and under invalidated code objects are non-zero.
+  MarkBit mark_bit =
+      p->markbits()->MarkBitFromIndex(Page::FastAddressToMarkbitIndex(addr));
+
+  return mark_bit.Get();
+}
+
+
+void MarkCompactCollector::InvalidateCode(Code* code) {
+  if (heap_->incremental_marking()->IsCompacting() &&
+      !ShouldSkipEvacuationSlotRecording(code)) {
+    ASSERT(compacting_);
+
+    // If the object is white than no slots were recorded on it yet.
+    MarkBit mark_bit = Marking::MarkBitFrom(code);
+    if (Marking::IsWhite(mark_bit)) return;
+
+    invalidated_code_.Add(code);
+  }
+}
+
+
+bool MarkCompactCollector::MarkInvalidatedCode() {
+  bool code_marked = false;
+
+  int length = invalidated_code_.length();
+  for (int i = 0; i < length; i++) {
+    Code* code = invalidated_code_[i];
+
+    if (SetMarkBitsUnderInvalidatedCode(code, true)) {
+      code_marked = true;
+    }
+  }
+
+  return code_marked;
+}
+
+
+void MarkCompactCollector::RemoveDeadInvalidatedCode() {
+  int length = invalidated_code_.length();
+  for (int i = 0; i < length; i++) {
+    if (!IsMarked(invalidated_code_[i])) invalidated_code_[i] = NULL;
+  }
+}
+
+
+void MarkCompactCollector::ProcessInvalidatedCode(ObjectVisitor* visitor) {
+  int length = invalidated_code_.length();
+  for (int i = 0; i < length; i++) {
+    Code* code = invalidated_code_[i];
+    if (code != NULL) {
+      code->Iterate(visitor);
+      SetMarkBitsUnderInvalidatedCode(code, false);
+    }
+  }
+  invalidated_code_.Rewind(0);
+}
+
+
 void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
+  bool code_slots_filtering_required = MarkInvalidatedCode();
+
   EvacuateNewSpace();
   EvacuatePages();
 
@@ -2874,7 +2992,9 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
     heap_->store_buffer()->IteratePointersToNewSpace(&UpdatePointer);
   }
 
-  SlotsBuffer::UpdateSlotsRecordedIn(heap_, migration_slots_buffer_);
+  SlotsBuffer::UpdateSlotsRecordedIn(heap_,
+                                     migration_slots_buffer_,
+                                     code_slots_filtering_required);
   if (FLAG_trace_fragmentation) {
     PrintF("  migration slots buffer: %d\n",
            SlotsBuffer::SizeOfChain(migration_slots_buffer_));
@@ -2887,7 +3007,9 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
            p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
 
     if (p->IsEvacuationCandidate()) {
-      SlotsBuffer::UpdateSlotsRecordedIn(heap_, p->slots_buffer());
+      SlotsBuffer::UpdateSlotsRecordedIn(heap_,
+                                         p->slots_buffer(),
+                                         code_slots_filtering_required);
       if (FLAG_trace_fragmentation) {
         PrintF("  page %p slots buffer: %d\n",
                reinterpret_cast<void*>(p),
@@ -2959,6 +3081,10 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
   EvacuationWeakObjectRetainer evacuation_object_retainer;
   heap()->ProcessWeakReferences(&evacuation_object_retainer);
 
+  // Visit invalidated code (we ignored all slots on it) and clear mark-bits
+  // under it.
+  ProcessInvalidatedCode(&updating_visitor);
+
 #ifdef DEBUG
   if (FLAG_verify_heap) {
     VerifyEvacuation(heap_);
@@ -3480,11 +3606,16 @@ void MarkCompactCollector::SweepSpaces() {
   // non-live objects.
   SweepSpace(heap()->old_pointer_space(), how_to_sweep);
   SweepSpace(heap()->old_data_space(), how_to_sweep);
+
+  RemoveDeadInvalidatedCode();
   SweepSpace(heap()->code_space(), PRECISE);
+
   SweepSpace(heap()->cell_space(), PRECISE);
+
   { GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_SWEEP_NEWSPACE);
     EvacuateNewSpaceAndCandidates();
   }
+
   // ClearNonLiveTransitions depends on precise sweeping of map space to
   // detect whether unmarked map became dead in this collection or in one
   // of the previous ones.
@@ -3626,6 +3757,29 @@ void SlotsBuffer::UpdateSlots(Heap* heap) {
 }
 
 
+void SlotsBuffer::UpdateSlotsWithFilter(Heap* heap) {
+  PointersUpdatingVisitor v(heap);
+
+  for (int slot_idx = 0; slot_idx < idx_; ++slot_idx) {
+    ObjectSlot slot = slots_[slot_idx];
+    if (!IsTypedSlot(slot)) {
+      if (!IsOnInvalidatedCodeObject(reinterpret_cast<Address>(slot))) {
+        UpdateSlot(slot);
+      }
+    } else {
+      ++slot_idx;
+      ASSERT(slot_idx < idx_);
+      Address pc = reinterpret_cast<Address>(slots_[slot_idx]);
+      if (!IsOnInvalidatedCodeObject(pc)) {
+        UpdateSlot(&v,
+                   DecodeSlotType(slot),
+                   reinterpret_cast<Address>(slots_[slot_idx]));
+      }
+    }
+  }
+}
+
+
 SlotsBuffer* SlotsBufferAllocator::AllocateBuffer(SlotsBuffer* next_buffer) {
   return new SlotsBuffer(next_buffer);
 }