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/* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 4 -*- */
/* vi: set ts=4 sw=4 expandtab: (add to ~/.vimrc: set modeline modelines=5) */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is [Open Source Virtual Machine].
*
* The Initial Developer of the Original Code is
* Adobe System Incorporated.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Adobe AS3 Team
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef __nanojit_Allocator__
#define __nanojit_Allocator__
namespace nanojit
{
/**
* Allocator is a bump-pointer allocator with an SPI for getting more
* memory from embedder-implemented allocator, such as malloc()/free().
*
* allocations never return NULL. The implementation of allocChunk()
* is expected to perform a longjmp or exception when an allocation can't
* proceed.
*/
class Allocator {
public:
Allocator();
~Allocator();
void reset();
/** alloc memory, never return null. */
void* alloc(size_t nbytes) {
nbytes = (nbytes + 7) & ~7; // round up
if (current_top + nbytes <= current_limit) {
void *p = current_top;
current_top += nbytes;
return p;
}
return allocSlow(nbytes);
}
protected:
void* allocSlow(size_t nbytes);
void fill(size_t minbytes);
class Chunk {
public:
Chunk* prev;
int64_t data[1]; // int64_t forces 8-byte alignment.
};
Chunk* current_chunk;
char* current_top;
char* current_limit;
// allocator SPI
/** allocate another block from a host provided allocator */
void* allocChunk(size_t nbytes);
/** free back to the same allocator */
void freeChunk(void*);
/** hook for post-reset action. */
void postReset();
};
}
/** global new overload enabling this pattern: new (allocator) T(...) */
inline void* operator new(size_t size, nanojit::Allocator &a) {
return a.alloc(size);
}
/** global new overload enabling this pattern: new (allocator) T(...) */
inline void* operator new(size_t size, nanojit::Allocator *a) {
return a->alloc(size);
}
/** global new[] overload enabling this pattern: new (allocator) T[] */
inline void* operator new[](size_t size, nanojit::Allocator& a) {
return a.alloc(size);
}
/** global new[] overload enabling this pattern: new (allocator) T[] */
inline void* operator new[](size_t size, nanojit::Allocator* a) {
return a->alloc(size);
}
#endif // __nanojit_Allocator__