pcsx2/common/include/Utilities/ScopedAlloc.h

/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2010  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include "Exceptions.h"

// pxUSE_SECURE_MALLOC - enables bounds checking on scoped malloc allocations.

#ifndef pxUSE_SECURE_MALLOC
#define pxUSE_SECURE_MALLOC 0
#endif

//////////////////////////////////////////////////////////////////////////////////////////
// Safe deallocation macros -- checks pointer validity (non-null) when needed, and sets
// pointer to null after deallocation.

#define safe_delete( ptr ) \
	((void) (delete (ptr)), (ptr) = NULL)

#define safe_delete_array( ptr ) \
	((void) (delete[] (ptr)), (ptr) = NULL)

// No checks for NULL -- wxWidgets says it's safe to skip NULL checks and it runs on 
// just about every compiler and libc implementation of any recentness.
#define safe_free( ptr ) \
	( (void) (free( ptr ), !!0), (ptr) = NULL )
//((void) (( ( (ptr) != NULL ) && (free( ptr ), !!0) ), (ptr) = NULL))

#define safe_fclose( ptr ) \
	((void) (( ( (ptr) != NULL ) && (fclose( ptr ), !!0) ), (ptr) = NULL))

// Implementation note: all known implementations of _aligned_free check the pointer for
// NULL status (our implementation under GCC, and microsoft's under MSVC), so no need to
// do it here.
#define safe_aligned_free( ptr ) \
	((void) ( _aligned_free( ptr ), (ptr) = NULL ))

// aligned_malloc: Implement/declare linux equivalents here!
#if !defined(_MSC_VER)
extern void* __fastcall _aligned_malloc(size_t size, size_t align);
extern void* __fastcall pcsx2_aligned_realloc(void* handle, size_t new_size, size_t align, size_t old_size);
extern void _aligned_free(void* pmem);
#else
#define pcsx2_aligned_realloc(handle, new_size, align, old_size) \
	_aligned_realloc(handle, new_size, align)
#endif

// --------------------------------------------------------------------------------------
//  pxDoOutOfMemory
// --------------------------------------------------------------------------------------

typedef void FnType_OutOfMemory( uptr blocksize );
typedef FnType_OutOfMemory* Fnptr_OutOfMemory;

// This method is meant to be assigned by applications that link against pxWex.  It is called
// (invoked) prior to most pxWex built-in memory/array classes throwing exceptions, and can be
// used by an application to remove unneeded memory allocations and/or reduce internal cache
// reserves.
//
// Example: PCSX2 uses several bloated recompiler code caches.  Larger caches improve performance,
// however a rouge cache growth could cause memory constraints in the operating system.  If an out-
// of-memory error occurs, PCSX2's implementation of this function attempts to reset all internal
// recompiler caches.  This can typically free up 100-150 megs of memory, and will allow the app
// to continue running without crashing or hanging the operating system, etc.
//
extern Fnptr_OutOfMemory pxDoOutOfMemory;


// --------------------------------------------------------------------------------------
//  BaseScopedAlloc
// --------------------------------------------------------------------------------------
// Base class that allows various ScopedMalloc types to be passed to functions that act
// on them.
//
// Rationale: This class and the derived varieties are provided as a simple autonomous self-
// destructing container for malloc.  The entire class is almost completely dependency free,
// and thus can be included everywhere and anywhere without dependency hassles.
//
template< typename T >
class BaseScopedAlloc
{
protected:
	T*		m_buffer;
	uint	m_size;

public:
	BaseScopedAlloc()
	{
		m_buffer	= NULL;
		m_size		= 0;
	}

	virtual ~BaseScopedAlloc() throw()
	{
		//pxAssert(m_buffer==NULL);
	}

public:
	size_t GetSize() const { return m_size; }
	size_t GetLength() const { return m_size; }
	
	// Allocates the object to the specified size.  If an existing allocation is in
	// place, it is freed and replaced with the new allocation, and all data is lost.
	// Parameter:
	//   newSize - size of the new allocation, in elements (not bytes!).  If the specified
	//     size is 0, the the allocation is freed, same as calling Free().
	virtual void Alloc( size_t newsize )=0;

	// Re-sizes the allocation to the requested size, without any data loss.
	// Parameter:
	//   newSize - size of the new allocation, in elements (not bytes!).  If the specified
	//     size is 0, the the allocation is freed, same as calling Free().
	virtual void Resize( size_t newsize )=0;

	void Free()
	{
		Alloc( 0 );
	}
	
	// Makes enough room for the requested size.  Existing data in the array is retained.
	void MakeRoomFor( uint size )
	{
		if (size <= m_size) return;
		Resize( size );
	}

	T* GetPtr( uint idx=0 ) const
	{
		#if pxUSE_SECURE_MALLOC
		IndexBoundsAssumeDev( "ScopedAlloc", idx, m_size );
		#endif
		return &m_buffer[idx];
	}

	T& operator[]( uint idx )
	{
		#if pxUSE_SECURE_MALLOC
		IndexBoundsAssumeDev( "ScopedAlloc", idx, m_size );
		#endif
		return m_buffer[idx];
	}

	const T& operator[]( uint idx ) const
	{
		#if pxUSE_SECURE_MALLOC
		IndexBoundsAssumeDev( "ScopedAlloc", idx, m_size );
		#endif
		return m_buffer[idx];
	}
};

// --------------------------------------------------------------------------------------
//  ScopedAlloc
// --------------------------------------------------------------------------------------
// A simple container class for a standard malloc allocation.  By default, no bounds checking
// is performed, and there is no option for enabling bounds checking.  If bounds checking and
// other features are needed, use the more robust SafeArray<> instead.
//
// See docs for BaseScopedAlloc for details and rationale.
//
template< typename T >
class ScopedAlloc : public BaseScopedAlloc<T>
{
	typedef BaseScopedAlloc<T> _parent;

public:
	ScopedAlloc( size_t size=0 ) : _parent()
	{
		Alloc(size);
	}

	virtual ~ScopedAlloc() throw()
	{
		Alloc(0);
	}

	virtual void Alloc( size_t newsize )
	{
		safe_free(this->m_buffer);
		this->m_size = newsize;
		if (!this->m_size) return;

		this->m_buffer = (T*)malloc( this->m_size * sizeof(T) );
		if (!this->m_buffer)
			throw Exception::OutOfMemory(L"ScopedAlloc");
	}

	virtual void Resize( size_t newsize )
	{
		this->m_size		= newsize;
		this->m_buffer		= (T*)realloc(this->m_buffer, this->m_size * sizeof(T));

		if (!this->m_buffer)
			throw Exception::OutOfMemory(L"ScopedAlloc::Resize");
	}
	
	using _parent::operator[];
};

// --------------------------------------------------------------------------------------
//  ScopedAlignedAlloc
// --------------------------------------------------------------------------------------
// A simple container class for an aligned allocation.  By default, no bounds checking is
// performed, and there is no option for enabling bounds checking.  If bounds checking and
// other features are needed, use the more robust SafeArray<> instead.
//
// See docs for BaseScopedAlloc for details and rationale.
//
template< typename T, uint align >
class ScopedAlignedAlloc : public BaseScopedAlloc<T>
{
	typedef BaseScopedAlloc<T> _parent;

public:
	ScopedAlignedAlloc( size_t size=0 ) : _parent()
	{
		Alloc(size);
	}
	
	virtual ~ScopedAlignedAlloc() throw()
	{
		Alloc(0);
	}

	virtual void Alloc( size_t newsize )
	{
		safe_aligned_free(this->m_buffer);
		this->m_size = newsize;
		if (!this->m_size) return;

		this->m_buffer = (T*)_aligned_malloc( this->m_size * sizeof(T), align );
		if (!this->m_buffer)
			throw Exception::OutOfMemory(L"ScopedAlignedAlloc");
	}

	virtual void Resize( size_t newsize )
	{
		this->m_buffer = (T*)pcsx2_aligned_realloc(this->m_buffer, newsize * sizeof(T), align, this->m_size * sizeof(T));
		this->m_size = newsize;

		if (!this->m_buffer)
			throw Exception::OutOfMemory(L"ScopedAlignedAlloc::Resize");
	}
	
	using _parent::operator[];
};