Remove slots that point to unboxed doubles from the StoreBuffer/SlotsBuffer.

src/heap/store-buffer.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/counters.h"
@@ skipping 229 matching lines @@
     }
   }
   old_top_ = new_top;
 
   // Filtering hash sets are inconsistent with the store buffer after this
   // operation.
   ClearFilteringHashSets();
 }
 
 
+// Returns number of slots stored in the slots buffer.

[Hannes Payer (out of office), 2015/03/03 09:48:53]

store buffer

[Igor Sheludko, 2015/03/04 14:54:20]

Done.

+int StoreBuffer::SizeForTesting() {

[Hannes Payer (out of office), 2015/03/03 09:48:53]

Why is it called SizeForTesting? Why don't call it NumberOfRecordedSlots or
something like that.

[Igor Sheludko, 2015/03/04 14:54:19]

Actually it doesn't make sense. Removed.

+  intptr_t size = old_top_ - old_start_;
+  size += reinterpret_cast<Address*>(heap_->store_buffer_top()) - start_;
+  DCHECK(size <= kStoreBufferSize);
+  return static_cast<int>(size / kPointerSize);
+}
+
+
+void StoreBuffer::RemoveSlots(Address start_address, Address end_address) {

[Hannes Payer (out of office), 2015/03/03 09:48:53]

How often do you think is this function called. If it is called *many* times, we
will copy many times the store buffer entries. Wouldn't it be more efficient to
invalidate the store buffer entries?

[Igor Sheludko, 2015/03/04 14:54:20]

Good point.

+  struct IsValueInRangePredicate {
+    Address start_address_;
+    Address end_address_;
+
+    IsValueInRangePredicate(Address start_address, Address end_address)
+        : start_address_(start_address), end_address_(end_address) {}
+
+    bool operator()(Address addr) {
+      return start_address_ <= addr && addr < end_address_;
+    }
+  };
+
+  IsValueInRangePredicate predicate(start_address, end_address);
+
+  {
+    Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
+    Address* new_top = std::remove_if(start_, top, predicate);
+    heap_->public_set_store_buffer_top(new_top);
+  }
+
+  if (old_buffer_is_sorted_) {
+    Address* lower = std::lower_bound(old_start_, old_top_, start_address);
+    if (lower != old_top_) {
+      Address* upper = std::lower_bound(lower, old_top_, end_address);
+      // Remove [lower, upper) from the buffer.
+      if (upper == old_top_) {
+        old_top_ = lower;
+      } else {
+        Address* new_top = lower;
+        for (Address* p = upper; p < old_top_; p++) {
+          *new_top++ = *p;
+        }
+        old_top_ = new_top;
+      }
+    }
+  } else {
+    old_top_ = std::remove_if(old_start_, old_top_, predicate);
+  }
+}
+
+
 void StoreBuffer::SortUniq() {
   Compact();
   if (old_buffer_is_sorted_) return;
   std::sort(old_start_, old_top_);
   Uniq();
 
   old_buffer_is_sorted_ = true;
 
   // Filtering hash sets are inconsistent with the store buffer after this
   // operation.
@@ skipping 30 matching lines @@
   ClearFilteringHashSets();
   Uniq();  // Also removes things that no longer point to new space.
   EnsureSpace(kStoreBufferSize / 2);
 }
 
 
 static Address* in_store_buffer_1_element_cache = NULL;
 
 
 bool StoreBuffer::CellIsInStoreBuffer(Address cell_address) {
-  if (!FLAG_enable_slow_asserts) return true;
+  Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
   if (in_store_buffer_1_element_cache != NULL &&
       *in_store_buffer_1_element_cache == cell_address) {
-    return true;
+    // Check if the cache still points into the active part of the buffer.
+    if ((start_ <= in_store_buffer_1_element_cache &&
+         in_store_buffer_1_element_cache < top) ||
+        (old_start_ <= in_store_buffer_1_element_cache &&
+         in_store_buffer_1_element_cache < old_top_)) {
+      return true;
+    }
   }
-  Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
   for (Address* current = top - 1; current >= start_; current--) {
     if (*current == cell_address) {
       in_store_buffer_1_element_cache = current;
       return true;
     }
   }
   for (Address* current = old_top_ - 1; current >= old_start_; current--) {
     if (*current == cell_address) {
       in_store_buffer_1_element_cache = current;
       return true;
@@ skipping 296 matching lines @@
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     DCHECK(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
 }
 }
 }  // namespace v8::internal