v8/src/allocation.h

170 lines
5.1 KiB
C
Raw Normal View History

// Copyright 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_ALLOCATION_H_
#define V8_ALLOCATION_H_
namespace v8 {
namespace internal {
// A class that controls whether allocation is allowed. This is for
// the C++ heap only!
class NativeAllocationChecker {
public:
typedef enum { ALLOW, DISALLOW } NativeAllocationAllowed;
explicit inline NativeAllocationChecker(NativeAllocationAllowed allowed)
: allowed_(allowed) {
#ifdef DEBUG
if (allowed == DISALLOW) {
allocation_disallowed_++;
}
#endif
}
~NativeAllocationChecker() {
#ifdef DEBUG
if (allowed_ == DISALLOW) {
allocation_disallowed_--;
}
#endif
ASSERT(allocation_disallowed_ >= 0);
}
static inline bool allocation_allowed() {
return allocation_disallowed_ == 0;
}
private:
// This static counter ensures that NativeAllocationCheckers can be nested.
static int allocation_disallowed_;
// This flag applies to this particular instance.
NativeAllocationAllowed allowed_;
};
// Superclass for classes managed with new & delete.
class Malloced {
public:
void* operator new(size_t size) { return New(size); }
void operator delete(void* p) { Delete(p); }
static void FatalProcessOutOfMemory();
static void* New(size_t size);
static void Delete(void* p);
};
// A macro is used for defining the base class used for embedded instances.
// The reason is some compilers allocate a minimum of one word for the
// superclass. The macro prevents the use of new & delete in debug mode.
// In release mode we are not willing to pay this overhead.
#ifdef DEBUG
// Superclass for classes with instances allocated inside stack
// activations or inside other objects.
class Embedded {
public:
void* operator new(size_t size);
void operator delete(void* p);
};
#define BASE_EMBEDDED : public Embedded
#else
#define BASE_EMBEDDED
#endif
// Superclass for classes only using statics.
class AllStatic {
#ifdef DEBUG
public:
void* operator new(size_t size);
void operator delete(void* p);
#endif
};
template <typename T>
static T* NewArray(int size) {
ASSERT(NativeAllocationChecker::allocation_allowed());
T* result = new T[size];
if (result == NULL) Malloced::FatalProcessOutOfMemory();
return result;
}
template <typename T>
static void DeleteArray(T* array) {
delete[] array;
}
// The normal strdup functions use malloc. These versions of StrDup
// and StrNDup uses new and calls the FatalProcessOutOfMemory handler
// if allocation fails.
char* StrDup(const char* str);
char* StrNDup(const char* str, size_t n);
// Allocation policy for allocating in the C free store using malloc
// and free. Used as the default policy for lists.
class FreeStoreAllocationPolicy {
public:
INLINE(static void* New(size_t size)) { return Malloced::New(size); }
INLINE(static void Delete(void* p)) { Malloced::Delete(p); }
};
// Allocation policy for allocating in preallocated space.
// Used as an allocation policy for ScopeInfo when generating
// stack traces.
class PreallocatedStorage : public AllStatic {
public:
explicit PreallocatedStorage(size_t size);
size_t size() { return size_; }
static void* New(size_t size);
static void Delete(void* p);
// Preallocate a set number of bytes.
static void Init(size_t size);
private:
size_t size_;
PreallocatedStorage* previous_;
PreallocatedStorage* next_;
static bool preallocated_;
static PreallocatedStorage in_use_list_;
static PreallocatedStorage free_list_;
void LinkTo(PreallocatedStorage* other);
void Unlink();
DISALLOW_IMPLICIT_CONSTRUCTORS(PreallocatedStorage);
};
} } // namespace v8::internal
#endif // V8_ALLOCATION_H_