compiler/dex/arena_bit_vector.h

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ART_COMPILER_DEX_ARENA_BIT_VECTOR_H_
#define ART_COMPILER_DEX_ARENA_BIT_VECTOR_H_

#include "base/bit_vector.h"
#include "compiler_enums.h"
#include "utils/arena_allocator.h"
#include "compiler_ir.h"

namespace art {

// Forward declaration
class MIRGraph;

/*
 * A BitVector implementation that uses Arena allocation.
 */
class ArenaBitVector : public BitVector {
  public:
    /**
     * @class BasicBlockIterator
     * @brief Helper class to get the BasicBlocks when iterating through the ArenaBitVector.
     */
    class BasicBlockIterator {
      public:
        explicit BasicBlockIterator(ArenaBitVector* bv, MIRGraph* mir_graph)
          : mir_graph_(mir_graph),
            internal_iterator_(bv) {}

        explicit BasicBlockIterator(ArenaBitVector* bv, CompilationUnit* c_unit)
          : mir_graph_(c_unit->mir_graph.get()),
            internal_iterator_(bv) {}

        BasicBlock* Next();

        static void* operator new(size_t size, ArenaAllocator* arena) {
          return arena->Alloc(sizeof(ArenaBitVector::BasicBlockIterator),
                              ArenaAllocator::kAllocGrowableArray);
        };
        static void operator delete(void* p) {}  // Nop.

      private:
        MIRGraph* const mir_graph_;
        Iterator internal_iterator_;
    };

    ArenaBitVector(ArenaAllocator* arena, uint32_t start_bits, bool expandable,
                   OatBitMapKind kind = kBitMapMisc);
    ~ArenaBitVector() {}

  static void* operator new(size_t size, ArenaAllocator* arena) {
     return arena->Alloc(sizeof(ArenaBitVector), ArenaAllocator::kAllocGrowableBitMap);
  }
  static void operator delete(void* p) {}  // Nop.

  private:
    const OatBitMapKind kind_;      // for memory use tuning. TODO: currently unused.
};


}  // namespace art

#endif  // ART_COMPILER_DEX_ARENA_BIT_VECTOR_H_