src/zone-inl.h

// Copyright 2011 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
// met:
//
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#ifndef V8_ZONE_INL_H_
#define V8_ZONE_INL_H_

#include "isolate.h"
#include "zone.h"
#include "v8-counters.h"

namespace v8 {
namespace internal {


AssertNoZoneAllocation::AssertNoZoneAllocation()
    : prev_(Isolate::Current()->zone_allow_allocation()) {
  Isolate::Current()->set_zone_allow_allocation(false);
}


AssertNoZoneAllocation::~AssertNoZoneAllocation() {
  Isolate::Current()->set_zone_allow_allocation(prev_);
}


inline void* Zone::New(int size) {
  ASSERT(Isolate::Current()->zone_allow_allocation());
  ASSERT(ZoneScope::nesting() > 0);
  // Round up the requested size to fit the alignment.
  size = RoundUp(size, kAlignment);

  // Check if the requested size is available without expanding.
  Address result = position_;
  if ((position_ += size) > limit_) result = NewExpand(size);

  // Check that the result has the proper alignment and return it.
  ASSERT(IsAddressAligned(result, kAlignment, 0));
  allocation_size_ += size;
  return reinterpret_cast<void*>(result);
}


template <typename T>
T* Zone::NewArray(int length) {
  return static_cast<T*>(New(length * sizeof(T)));
}


bool Zone::excess_allocation() {
  return segment_bytes_allocated_ > zone_excess_limit_;
}


void Zone::adjust_segment_bytes_allocated(int delta) {
  segment_bytes_allocated_ += delta;
  isolate_->counters()->zone_segment_bytes()->Set(segment_bytes_allocated_);
}


template <typename Config>
ZoneSplayTree<Config>::~ZoneSplayTree() {
  // Reset the root to avoid unneeded iteration over all tree nodes
  // in the destructor.  For a zone-allocated tree, nodes will be
  // freed by the Zone.
  SplayTree<Config, ZoneListAllocationPolicy>::ResetRoot();
}


// TODO(isolates): for performance reasons, this should be replaced with a new
//                 operator that takes the zone in which the object should be
//                 allocated.
void* ZoneObject::operator new(size_t size) {
  return ZONE->New(static_cast<int>(size));
}

void* ZoneObject::operator new(size_t size, Zone* zone) {
  return zone->New(static_cast<int>(size));
}


inline void* ZoneListAllocationPolicy::New(int size) {
  return ZONE->New(size);
}


ZoneScope::ZoneScope(ZoneScopeMode mode)
    : isolate_(Isolate::Current()),
      mode_(mode) {
  isolate_->zone()->scope_nesting_++;
}


bool ZoneScope::ShouldDeleteOnExit() {
  return isolate_->zone()->scope_nesting_ == 1 && mode_ == DELETE_ON_EXIT;
}


int ZoneScope::nesting() {
  return Isolate::Current()->zone()->scope_nesting_;
}


} }  // namespace v8::internal

#endif  // V8_ZONE_INL_H_