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/*____________________________________________________________________________
Copyright (C) 2002 PGP Corporation
All rights reserved.
$Id: pgpMemoryMgr.h,v 1.9 2003/11/08 04:04:49 ajivsov Exp $
____________________________________________________________________________*/
#ifndef Included_pgpMemoryMgr_h /* [ */
#define Included_pgpMemoryMgr_h
#include "pgpBase.h"
/*____________________________________________________________________________
Mini-tutorial:
A PGPMemoryMgr is an object which implements memory management, including
allocation, reallocation, deallocation, and secure versions of the same.
*** Using it ***
A typical sequence of calls is as follows:
PGPNewMemoryMgr
...
PGPNewData or PGPNewSecureData
PGPFreeData
...
PGPFreeMemoryMgr
Typically, a program will create one PGPMemoryMgr per thread at
thread creation time and use that memory mgr until the thread dies.
Generally, an individual PGPMemoryMgr instance is not thread-safe;
you must either synchronize or use one PGPMemoryMgr per thread.
*** Custom Allocators ***
Default allocators are supplied, but the client can create a custom
PGPMemoryMgr using PGPNewMemoryMgrCustom() which uses client-supplied
routines.
Custom routines need only concern themselves with the actual
allocation and deallocation.
The following should be kept in mind for user supplied routines:
- they can ignore the allocation flags passed
- leaks, memory clearing, etc is done by the PGPMemoryMgr
- secure allocator must set 'isNonPageable' to TRUE only if the
memory really can't be paged.
- the user value is not interpreted by the PGPMemoryMgr. Typically,
it would be a pointer to some data the allocation routines use
to store state.
*** Secure memory allocation ***
Blocks can be allocated as "Secure" blocks. Secure blocks are guaranteed
to be wiped when they are deallocated. Additionally, if the operating
system and the current conditions allow, the block will be allocated
in non-pageable memory. You can determine the attributes of a block using
PGPGetMemoryMgrDataInfo().
*** Leaks tracking ***
Leaks tracking is implemented when debugging is on,
but currently reporting is limited to reporting the number of leaks
outstanding when the PGPMemoryMgr is disposed.
*** Debugging ***
For debugging purposes, blocks may be larger in debug mode to accomodate
various schemes to detect stray pointers, etc.
____________________________________________________________________________*/
#if PGP_MACINTOSH
#pragma options align=mac68k
#endif
enum
{
kPGPMemoryMgrFlags_None = 0,
kPGPMemoryMgrFlags_Clear = 1
};
typedef PGPFlags PGPMemoryMgrFlags;
typedef struct PGPMemoryMgr * PGPMemoryMgrRef;
#define kInvalidPGPMemoryMgrRef ((PGPMemoryMgrRef) NULL)
#define PGPMemoryMgrRefIsValid(ref) ((ref) != kInvalidPGPMemoryMgrRef)
typedef void *(*PGPMemoryMgrAllocationProc)( PGPMemoryMgrRef mgr,
PGPUserValue userValue,
PGPSize requestSize, PGPMemoryMgrFlags flags );
/* realloc not be implemented using PGPNewData() */
typedef PGPError (*PGPMemoryMgrReallocationProc)( PGPMemoryMgrRef mgr,
PGPUserValue userValue,
void **allocation, PGPSize newAllocationSize,
PGPMemoryMgrFlags flags, PGPSize existingSize );
typedef PGPError (*PGPMemoryMgrDeallocationProc)( PGPMemoryMgrRef mgr,
PGPUserValue userValue,
void *allocation, PGPSize allocationSize );
typedef void *(*PGPMemoryMgrSecureAllocationProc)( PGPMemoryMgrRef mgr,
PGPUserValue userValue,
PGPSize requestSize, PGPMemoryMgrFlags flags,
PGPBoolean *isNonPageable );
/* deallocation proc need not clear the memory upon deallocation since
PGPFreeData() does it automatically */
typedef PGPError (*PGPMemoryMgrSecureDeallocationProc)( PGPMemoryMgrRef mgr,
PGPUserValue userValue,
void *allocation, PGPSize allocationSize,
PGPBoolean wasLocked );
typedef struct PGPNewMemoryMgrStruct
{
/* sizeofStruct must be inited to sizeof( PGPNewMemoryMgrStruct ) */
PGPUInt32 sizeofStruct;
PGPFlags reservedFlags;
PGPMemoryMgrAllocationProc allocProc;
PGPMemoryMgrReallocationProc reallocProc;
PGPMemoryMgrDeallocationProc deallocProc;
PGPMemoryMgrSecureAllocationProc secureAllocProc;
void * reserved; /* MUST be zeroed */
PGPMemoryMgrSecureDeallocationProc secureDeallocProc;
PGPUserValue customValue;
void * pad[ 8 ]; /* MUST be zeroed */
} PGPNewMemoryMgrStruct;
PGP_BEGIN_C_DECLARATIONS
/*____________________________________________________________________________
Memory Mgr routines
____________________________________________________________________________*/
PGPError PGPNewMemoryMgr( PGPFlags reserved, PGPMemoryMgrRef *newMemoryMgr );
PGPError PGPNewMemoryMgrCustom( PGPNewMemoryMgrStruct const * custom,
PGPMemoryMgrRef *newMemoryMgr );
PGPError PGPFreeMemoryMgr( PGPMemoryMgrRef mgr );
PGPError PGPGetMemoryMgrCustomValue( PGPMemoryMgrRef mgr,
PGPUserValue *customValue );
PGPError PGPSetMemoryMgrCustomValue( PGPMemoryMgrRef mgr,
PGPUserValue customValue );
PGPError PGPValidateMemoryMgr( PGPMemoryMgrRef mgr );
/* allocate a block of the specified size */
void * PGPNewData( PGPMemoryMgrRef mgr,
PGPSize requestSize, PGPMemoryMgrFlags flags );
/* allocate a block of the specified size in non-pageable memory */
/* *isSecure is TRUE if the block definitely can't be paged */
void * PGPNewSecureData( PGPMemoryMgrRef mgr,
PGPSize requestSize, PGPMemoryMgrFlags flags );
/* properly reallocs secure or non-secure blocks */
/* WARNING: the block may move, even if its size is being reduced */
PGPError PGPReallocData( PGPMemoryMgrRef mgr,
void **allocation, PGPSize newAllocationSize,
PGPMemoryMgrFlags flags );
/* properly frees secure or non-secure blocks */
PGPError PGPFreeData( void *allocation );
/*____________________________________________________________________________
Block Info:
kPGPMemoryMgrBlockInfo_Valid it's a valid block
kPGPMemoryMgrBlockInfo_Secure block is a secure allocation
kPGPMemoryMgrBlockInfo_NonPageable block cannot be paged by VM
Secure blocks are always wiped before being disposed,
but may or may not be pageable, depending on the OS facilities. Some
OSs may not provide the ability to make blocks non-pageable.
You should check these flags if the information matters to you.
____________________________________________________________________________*/
#define kPGPMemoryMgrBlockInfo_Valid ( ((PGPFlags)1) << 0 )
#define kPGPMemoryMgrBlockInfo_Secure ( ((PGPFlags)1) << 1 )
#define kPGPMemoryMgrBlockInfo_NonPageable ( ((PGPFlags)1) << 2 )
PGPFlags PGPGetMemoryMgrDataInfo( void *allocation );
/*____________________________________________________________________________
Default memory manager routines:
____________________________________________________________________________*/
PGPMemoryMgrRef PGPGetDefaultMemoryMgr(void);
PGPError PGPSetDefaultMemoryMgr(PGPMemoryMgrRef memoryMgr);
PGP_END_C_DECLARATIONS
#if PGP_MACINTOSH
#pragma options align=reset
#endif
#endif /* ] Included_pgpMemoryMgr_h */
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