Patch for allowing several V8 instances in process:...

src/zone.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 14 matching lines @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #include "zone-inl.h"
 
 namespace v8 {
 namespace internal {
 
-
-Address Zone::position_ = 0;
-Address Zone::limit_ = 0;
-int Zone::zone_excess_limit_ = 256 * MB;
-int Zone::segment_bytes_allocated_ = 0;
-
-bool AssertNoZoneAllocation::allow_allocation_ = true;
-
-int ZoneScope::nesting_ = 0;
+ZoneData::ZoneData():position_(0), limit_(0), zone_excess_limit_(256 * MB),
+  segment_bytes_allocated_(0), allow_allocation_(true), nesting_(0),
+  head_(NULL), bytes_allocated_(0) {
+}
 
 // Segments represent chunks of memory: They have starting address
 // (encoded in the this pointer) and a size in bytes. Segments are
 // chained together forming a LIFO structure with the newest segment
 // available as Segment::head(). Segments are allocated using malloc()
 // and de-allocated using free().
 
 class Segment {
  public:
   Segment* next() const { return next_; }
   void clear_next() { next_ = NULL; }
 
   int size() const { return size_; }
   int capacity() const { return size_ - sizeof(Segment); }
 
   Address start() const { return address(sizeof(Segment)); }
   Address end() const { return address(size_); }
 
-  static Segment* head() { return head_; }
-  static void set_head(Segment* head) { head_ = head; }
+  static Segment* head() { return v8_context()->zone_data_.head_; }
+  static void set_head(Segment* head) { v8_context()->zone_data_.head_ = head; }
 
   // Creates a new segment, sets it size, and pushes it to the front
   // of the segment chain. Returns the new segment.
   static Segment* New(int size) {
     Segment* result = reinterpret_cast<Segment*>(Malloced::New(size));
     Zone::adjust_segment_bytes_allocated(size);
     if (result != NULL) {
-      result->next_ = head_;
+      ZoneData& zone_data = v8_context()->zone_data_;
+      result->next_ = zone_data.head_;
       result->size_ = size;
-      head_ = result;
+      zone_data.head_ = result;
     }
     return result;
   }
 
   // Deletes the given segment. Does not touch the segment chain.
   static void Delete(Segment* segment, int size) {
     Zone::adjust_segment_bytes_allocated(-size);
     Malloced::Delete(segment);
   }
 
-  static int bytes_allocated() { return bytes_allocated_; }
+  static int bytes_allocated() {
+    return v8_context()->zone_data_.bytes_allocated_;
+  }
 
  private:
   // Computes the address of the nth byte in this segment.
   Address address(int n) const {
     return Address(this) + n;
   }
 
-  static Segment* head_;
-  static int bytes_allocated_;
   Segment* next_;
   int size_;
 };
 
-
-Segment* Segment::head_ = NULL;
-int Segment::bytes_allocated_ = 0;
-
-
 void Zone::DeleteAll() {
 #ifdef DEBUG
   // Constant byte value used for zapping dead memory in debug mode.
   static const unsigned char kZapDeadByte = 0xcd;
 #endif
 
   // Find a segment with a suitable size to keep around.
   Segment* keep = Segment::head();
   while (keep != NULL && keep->size() > kMaximumKeptSegmentSize) {
     keep = keep->next();
@@ skipping 11 matching lines @@
       int size = current->size();
 #ifdef DEBUG
       // Zap the entire current segment (including the header).
       memset(current, kZapDeadByte, size);
 #endif
       Segment::Delete(current, size);
     }
     current = next;
   }
 
+  ZoneData& zone_data = v8_context()->zone_data_;
   // If we have found a segment we want to keep, we must recompute the
   // variables 'position' and 'limit' to prepare for future allocate
   // attempts. Otherwise, we must clear the position and limit to
   // force a new segment to be allocated on demand.
   if (keep != NULL) {
     Address start = keep->start();
-    position_ = RoundUp(start, kAlignment);
-    limit_ = keep->end();
+    zone_data.position_ = RoundUp(start, kAlignment);
+    zone_data.limit_ = keep->end();
 #ifdef DEBUG
     // Zap the contents of the kept segment (but not the header).
     memset(start, kZapDeadByte, keep->capacity());
 #endif
   } else {
-    position_ = limit_ = 0;
+    zone_data.position_ = zone_data.limit_ = 0;
   }
 
   // Update the head segment to be the kept segment (if any).
   Segment::set_head(keep);
 }
 
 
 Address Zone::NewExpand(int size) {
+  ZoneData& zone_data = v8_context()->zone_data_;
   // Make sure the requested size is already properly aligned and that
   // there isn't enough room in the Zone to satisfy the request.
   ASSERT(size == RoundDown(size, kAlignment));
-  ASSERT(position_ + size > limit_);
+  ASSERT(zone_data.position_ + size > zone_data.limit_);
 
   // Compute the new segment size. We use a 'high water mark'
   // strategy, where we increase the segment size every time we expand
   // except that we employ a maximum segment size when we delete. This
   // is to avoid excessive malloc() and free() overhead.
   Segment* head = Segment::head();
   int old_size = (head == NULL) ? 0 : head->size();
   static const int kSegmentOverhead = sizeof(Segment) + kAlignment;
   int new_size = kSegmentOverhead + size + (old_size << 1);
   if (new_size < kMinimumSegmentSize) {
     new_size = kMinimumSegmentSize;
   } else if (new_size > kMaximumSegmentSize) {
     // Limit the size of new segments to avoid growing the segment size
     // exponentially, thus putting pressure on contiguous virtual address space.
     // All the while making sure to allocate a segment large enough to hold the
     // requested size.
     new_size = Max(kSegmentOverhead + size, kMaximumSegmentSize);
   }
   Segment* segment = Segment::New(new_size);
   if (segment == NULL) {
     V8::FatalProcessOutOfMemory("Zone");
     return NULL;
   }
 
   // Recompute 'top' and 'limit' based on the new segment.
   Address result = RoundUp(segment->start(), kAlignment);
-  position_ = result + size;
-  limit_ = segment->end();
-  ASSERT(position_ <= limit_);
+  zone_data.position_ = result + size;
+  zone_data.limit_ = segment->end();
+  ASSERT(zone_data.position_ <= zone_data.limit_);
   return result;
 }
 
 
 } }  // namespace v8::internal