/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_ICStubSpace_h
#define jit_ICStubSpace_h

#include "ds/LifoAlloc.h"

namespace js {
namespace jit {

// ICStubSpace is an abstraction for allocation policy and storage for stub
// data. There are two kinds of stubs: optimized stubs and fallback stubs (the
// latter also includes stubs that can make non-tail calls that can GC).
//
// Optimized stubs are allocated per-compartment and are always purged when
// JIT-code is discarded. Fallback stubs are allocated per BaselineScript and
// are only destroyed when the BaselineScript is destroyed.
class ICStubSpace {
 protected:
  LifoAlloc allocator_;

  explicit ICStubSpace(size_t chunkSize) : allocator_(chunkSize) {}

 public:
  inline void* alloc(size_t size) { return allocator_.alloc(size); }

  JS_DECLARE_NEW_METHODS(allocate, alloc, inline)

  void freeAllAfterMinorGC(JS::Zone* zone);

#ifdef DEBUG
  bool isEmpty() const { return allocator_.isEmpty(); }
#endif

  size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const {
    return allocator_.sizeOfExcludingThis(mallocSizeOf);
  }
};

// Space for optimized stubs. Every JitCompartment has a single
// OptimizedICStubSpace.
struct OptimizedICStubSpace : public ICStubSpace {
  static const size_t STUB_DEFAULT_CHUNK_SIZE = 4096;

 public:
  OptimizedICStubSpace() : ICStubSpace(STUB_DEFAULT_CHUNK_SIZE) {}
};

// Space for fallback stubs. Every BaselineScript has a
// FallbackICStubSpace.
struct FallbackICStubSpace : public ICStubSpace {
  static const size_t STUB_DEFAULT_CHUNK_SIZE = 4096;

 public:
  FallbackICStubSpace() : ICStubSpace(STUB_DEFAULT_CHUNK_SIZE) {}

  inline void adoptFrom(FallbackICStubSpace* other) {
    allocator_.steal(&(other->allocator_));
  }
};

}  // namespace jit
}  // namespace js

#endif /* jit_ICStubSpace_h */
