mem.h revision 78cbab32dbc1ff1bb306f46e347c68adaf19b35e
/** @file
* IPRT - Memory Management and Manipulation.
*/
/*
* Copyright (C) 2006-2007 Sun Microsystems, Inc.
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 USA or visit http://www.sun.com if you need
* additional information or have any questions.
*/
#ifndef ___iprt_mem_h
#define ___iprt_mem_h
#include <iprt/cdefs.h>
#include <iprt/types.h>
#ifdef __cplusplus
# include <iprt/autores.h>
#endif
#ifdef IN_RC
# error "There are no RTMem APIs available Guest Context!"
#endif
/** @defgroup grp_rt_mem RTMem - Memory Management and Manipulation
* @ingroup grp_rt
* @{
*/
RT_BEGIN_DECLS
/** @def RTMEM_ALIGNMENT
* The alignment of the memory blocks returned by RTMemAlloc(), RTMemAllocZ(),
* RTMemRealloc(), RTMemTmpAlloc() and RTMemTmpAllocZ() for allocations greater
* than RTMEM_ALIGNMENT.
*/
#define RTMEM_ALIGNMENT 8
/**
* Allocates temporary memory.
*
* Temporary memory blocks are used for not too large memory blocks which
* are believed not to stick around for too long. Using this API instead
* of RTMemAlloc() not only gives the heap manager room for optimization
* but makes the code easier to read.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocated.
*/
RTDECL(void *) RTMemTmpAlloc(size_t cb) RT_NO_THROW;
/**
* Allocates zero'ed temporary memory.
*
* Same as RTMemTmpAlloc() but the memory will be zero'ed.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocated.
*/
RTDECL(void *) RTMemTmpAllocZ(size_t cb) RT_NO_THROW;
/**
* Free temporary memory.
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemTmpFree(void *pv) RT_NO_THROW;
/**
* Allocates memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocated.
*/
RTDECL(void *) RTMemAlloc(size_t cb) RT_NO_THROW;
/**
* Allocates zero'ed memory.
*
* Instead of memset(pv, 0, sizeof()) use this when you want zero'ed
* memory. This keeps the code smaller and the heap can skip the memset
* in about 0.42% of calls :-).
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocated.
*/
RTDECL(void *) RTMemAllocZ(size_t cb) RT_NO_THROW;
/**
* Duplicates a chunk of memory into a new heap block.
*
* @returns New heap block with the duplicate data.
* @returns NULL if we're out of memory.
* @param pvSrc The memory to duplicate.
* @param cb The amount of memory to duplicate.
*/
RTDECL(void *) RTMemDup(const void *pvSrc, size_t cb) RT_NO_THROW;
/**
* Duplicates a chunk of memory into a new heap block with some
* additional zeroed memory.
*
* @returns New heap block with the duplicate data.
* @returns NULL if we're out of memory.
* @param pvSrc The memory to duplicate.
* @param cbSrc The amount of memory to duplicate.
* @param cbExtra The amount of extra memory to allocate and zero.
*/
RTDECL(void *) RTMemDupEx(const void *pvSrc, size_t cbSrc, size_t cbExtra) RT_NO_THROW;
/**
* Reallocates memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param pvOld The memory block to reallocate.
* @param cbNew The new block size (in bytes).
*/
RTDECL(void *) RTMemRealloc(void *pvOld, size_t cbNew) RT_NO_THROW;
/**
* Frees memory.
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemFree(void *pv) RT_NO_THROW;
/**
* Allocates memory which may contain code.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemExecAlloc(size_t cb) RT_NO_THROW;
/**
* Free executable/read/write memory allocated by RTMemExecAlloc().
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemExecFree(void *pv) RT_NO_THROW;
#if defined(IN_RING0) && defined(RT_ARCH_AMD64) && defined(RT_OS_LINUX)
/**
* Donate read+write+execute memory to the exec heap.
*
* This API is specific to AMD64 and Linux/GNU. A kernel module that desires to
* use RTMemExecAlloc on AMD64 Linux/GNU will have to donate some statically
* allocated memory in the module if it wishes for GCC generated code to work.
* GCC can only generate modules that work in the address range ~2GB to ~0
* currently.
*
* The API only accept one single donation.
*
* @returns IPRT status code.
* @param pvMemory Pointer to the memory block.
* @param cb The size of the memory block.
*/
RTR0DECL(int) RTR0MemExecDonate(void *pvMemory, size_t cb) RT_NO_THROW;
#endif /* R0+AMD64+LINUX */
/**
* Allocate page aligned memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL if we're out of memory.
* @param cb Size of the memory block. Will be rounded up to page size.
*/
RTDECL(void *) RTMemPageAlloc(size_t cb) RT_NO_THROW;
/**
* Allocate zero'ed page aligned memory.
*
* @returns Pointer to the allocated memory.
* @returns NULL if we're out of memory.
* @param cb Size of the memory block. Will be rounded up to page size.
*/
RTDECL(void *) RTMemPageAllocZ(size_t cb) RT_NO_THROW;
/**
* Free a memory block allocated with RTMemPageAlloc() or RTMemPageAllocZ().
*
* @param pv Pointer to the block as it was returned by the allocation function.
* NULL will be ignored.
*/
RTDECL(void) RTMemPageFree(void *pv) RT_NO_THROW;
/** Page level protection flags for RTMemProtect().
* @{
*/
/** Read access. */
#define RTMEM_PROT_NONE 0
/** Read access. */
#define RTMEM_PROT_READ 1
/** Write access. */
#define RTMEM_PROT_WRITE 2
/** Execute access. */
#define RTMEM_PROT_EXEC 4
/** @} */
/**
* Change the page level protection of a memory region.
*
* @returns iprt status code.
* @param pv Start of the region. Will be rounded down to nearest page boundary.
* @param cb Size of the region. Will be rounded up to the nearest page boundary.
* @param fProtect The new protection, a combination of the RTMEM_PROT_* defines.
*/
RTDECL(int) RTMemProtect(void *pv, size_t cb, unsigned fProtect) RT_NO_THROW;
#ifdef IN_RING0
/**
* Allocates physical contiguous memory (below 4GB).
* The allocation is page aligned and the content is undefined.
*
* @returns Pointer to the memory block. This is page aligned.
* @param pPhys Where to store the physical address.
* @param cb The allocation size in bytes. This is always
* rounded up to PAGE_SIZE.
*/
RTR0DECL(void *) RTMemContAlloc(PRTCCPHYS pPhys, size_t cb) RT_NO_THROW;
/**
* Frees memory allocated ysing RTMemContAlloc().
*
* @param pv Pointer to return from RTMemContAlloc().
* @param cb The cb parameter passed to RTMemContAlloc().
*/
RTR0DECL(void) RTMemContFree(void *pv, size_t cb) RT_NO_THROW;
#endif
/** @name Electrical Fence Version of some APIs.
* @{
*/
/**
* Same as RTMemTmpAlloc() except that it's fenced.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemEfTmpAlloc(size_t cb) RT_NO_THROW;
/**
* Same as RTMemTmpAllocZ() except that it's fenced.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemEfTmpAllocZ(size_t cb) RT_NO_THROW;
/**
* Same as RTMemTmpFree() except that it's for fenced memory.
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemEfTmpFree(void *pv) RT_NO_THROW;
/**
* Same as RTMemAlloc() except that it's fenced.
*
* @returns Pointer to the allocated memory. Free with RTMemEfFree().
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemEfAlloc(size_t cb) RT_NO_THROW;
/**
* Same as RTMemAllocZ() except that it's fenced.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param cb Size in bytes of the memory block to allocate.
*/
RTDECL(void *) RTMemEfAllocZ(size_t cb) RT_NO_THROW;
/**
* Same as RTMemRealloc() except that it's fenced.
*
* @returns Pointer to the allocated memory.
* @returns NULL on failure.
* @param pvOld The memory block to reallocate.
* @param cbNew The new block size (in bytes).
*/
RTDECL(void *) RTMemEfRealloc(void *pvOld, size_t cbNew) RT_NO_THROW;
/**
* Free memory allocated by any of the RTMemEf* allocators.
*
* @param pv Pointer to memory block.
*/
RTDECL(void) RTMemEfFree(void *pv) RT_NO_THROW;
/**
* Same as RTMemDup() except that it's fenced.
*
* @returns New heap block with the duplicate data.
* @returns NULL if we're out of memory.
* @param pvSrc The memory to duplicate.
* @param cb The amount of memory to duplicate.
*/
RTDECL(void *) RTMemEfDup(const void *pvSrc, size_t cb) RT_NO_THROW;
/**
* Same as RTMemEfDupEx except that it's fenced.
*
* @returns New heap block with the duplicate data.
* @returns NULL if we're out of memory.
* @param pvSrc The memory to duplicate.
* @param cbSrc The amount of memory to duplicate.
* @param cbExtra The amount of extra memory to allocate and zero.
*/
RTDECL(void *) RTMemEfDupEx(const void *pvSrc, size_t cbSrc, size_t cbExtra) RT_NO_THROW;
/** @def RTMEM_WRAP_TO_EF_APIS
* Define RTMEM_WRAP_TO_EF_APIS to wrap RTMem APIs to RTMemEf APIs.
*/
#ifdef RTMEM_WRAP_TO_EF_APIS
# define RTMemTmpAlloc RTMemEfTmpAlloc
# define RTMemTmpAllocZ RTMemEfTmpAllocZ
# define RTMemTmpFree RTMemEfTmpFree
# define RTMemAlloc RTMemEfAlloc
# define RTMemAllocZ RTMemEfAllocZ
# define RTMemRealloc RTMemEfRealloc
# define RTMemFree RTMemEfFree
# define RTMemDup RTMemEfDup
# define RTMemDupEx RTMemEfDupEx
#endif
#ifdef DOXYGEN_RUNNING
# define RTMEM_WRAP_TO_EF_APIS
#endif
/** @} */
RT_END_DECLS
#ifdef __cplusplus
# include <iprt/assert.h>
/**
* Template function wrapping RTMemFree to get the correct Destruct
* signature for RTAutoRes.
*
* We can't use a more complex template here, because the g++ on RHEL 3
* chokes on it with an internal compiler error.
*
* @param T The data type that's being managed.
* @param aMem Pointer to the memory that should be free.
*/
template <class T>
inline void RTMemAutoDestructor(T *aMem) RT_NO_THROW
{
RTMemFree(aMem);
}
/**
* RTMemAutoPtr allocator which uses RTMemTmpAlloc().
*
* @returns Allocated memory on success, NULL on failure.
* @param pvOld What to reallocate, shall always be NULL.
* @param cbNew The amount of memory to allocate (in bytes).
*/
inline void *RTMemTmpAutoAllocator(void *pvOld, size_t cbNew) RT_NO_THROW
{
AssertReturn(!pvOld, NULL);
return RTMemTmpAlloc(cbNew);
}
/**
* Template function wrapping RTMemTmpFree to get the correct Destruct
* signature for RTAutoRes.
*
* We can't use a more complex template here, because the g++ on RHEL 3
* chokes on it with an internal compiler error.
*
* @param T The data type that's being managed.
* @param aMem Pointer to the memory that should be free.
*/
template <class T>
inline void RTMemTmpAutoDestructor(T *aMem) RT_NO_THROW
{
RTMemTmpFree(aMem);
}
/**
* Template function wrapping RTMemEfFree to get the correct Destruct
* signature for RTAutoRes.
*
* We can't use a more complex template here, because the g++ on RHEL 3
* chokes on it with an internal compiler error.
*
* @param T The data type that's being managed.
* @param aMem Pointer to the memory that should be free.
*/
template <class T>
inline void RTMemEfAutoFree(T *aMem) RT_NO_THROW
{
RTMemEfFree(aMem);
}
/**
* Template function wrapping NULL to get the correct NilRes signature
* for RTAutoRes.
*
* @param T The data type that's being managed.
* @returns NULL with the right type.
*/
template <class T>
inline T * RTMemAutoNil(void) RT_NO_THROW
{
return (T *)(NULL);
}
/**
* An auto pointer-type template class for managing memory allocating
* via C APIs like RTMem (the default).
*
* The main purpose of this class is to automatically free memory that
* isn't explicitly used (release()'ed) when the object goes out of scope.
*
* As an additional service it can also make the allocations and
* reallocations for you if you like, but it can also take of memory
* you hand it.
*
* @param T The data type to manage allocations for.
* @param Destruct The function to be used to free the resource.
* This will default to RTMemFree.
* @param Allocator The function to be used to allocate or reallocate
* the managed memory.
* This is standard realloc() like stuff, so it's possible
* to support simple allocation without actually having
* to support reallocating memory if that's a problem.
* This will default to RTMemRealloc.
*/
template <class T, void Destruct(T *) = RTMemAutoDestructor<T>, void *Allocator(void *, size_t) = RTMemRealloc >
class RTMemAutoPtr
: public RTAutoRes<T *, Destruct, RTMemAutoNil<T> >
{
public:
/**
* Constructor.
*
* @param aPtr Memory pointer to manage. Defaults to NULL.
*/
RTMemAutoPtr(T *aPtr = NULL)
: RTAutoRes<T *, Destruct, RTMemAutoNil<T> >(aPtr)
{
}
/**
* Constructor that allocates memory.
*
* @param a_cElements The number of elements (of the data type) to allocate.
* @param a_fZeroed Whether the memory should be memset with zeros after
* the allocation. Defaults to false.
*/
RTMemAutoPtr(size_t a_cElements, bool a_fZeroed = false)
: RTAutoRes<T *, Destruct, RTMemAutoNil<T> >((T *)Allocator(NULL, a_cElements * sizeof(T)))
{
if (a_fZeroed && RT_LIKELY(this->get() != NULL))
memset(this->get(), '\0', a_cElements * sizeof(T));
}
/**
* Free current memory and start managing aPtr.
*
* @param aPtr Memory pointer to manage.
*/
RTMemAutoPtr &operator=(T *aPtr)
{
this->RTAutoRes<T *, Destruct, RTMemAutoNil<T> >::operator=(aPtr);
return *this;
}
/**
* Dereference with * operator.
*/
T &operator*()
{
return *this->get();
}
/**
* Dereference with -> operator.
*/
T *operator->()
{
return this->get();
}
/**
* Accessed with the subscript operator ([]).
*
* @returns Reference to the element.
* @param a_i The element to access.
*/
T &operator[](size_t a_i)
{
return this->get()[a_i];
}
/**
* Allocates memory and start manage it.
*
* Any previously managed memory will be freed before making
* the new allocation.
*
* @returns Success indicator.
* @retval true if the new allocation succeeds.
* @retval false on failure, no memory is associated with the object.
*
* @param a_cElements The number of elements (of the data type) to allocate.
* This defaults to 1.
* @param a_fZeroed Whether the memory should be memset with zeros after
* the allocation. Defaults to false.
*/
bool alloc(size_t a_cElements = 1, bool a_fZeroed = false)
{
this->reset(NULL);
T *pNewMem = (T *)Allocator(NULL, a_cElements * sizeof(T));
if (a_fZeroed && RT_LIKELY(pNewMem != NULL))
memset(pNewMem, '\0', a_cElements * sizeof(T));
this->reset(pNewMem);
return pNewMem != NULL;
}
/**
* Reallocate or allocates the memory resource.
*
* Free the old value if allocation fails.
*
* The content of any additional memory that was allocated is
* undefined when using the default allocator.
*
* @returns Success indicator.
* @retval true if the new allocation succeeds.
* @retval false on failure, no memory is associated with the object.
*
* @param cElements The new number of elements (of the data type) to allocate.
* The size of the allocation is the number of elements times
* the size of the data type - this is currently what's passed
* down to the Allocator.
* This defaults to 1.
*/
bool realloc(size_t a_cElements = 1)
{
T *aNewValue = (T *)Allocator(this->get(), a_cElements * sizeof(T));
if (RT_LIKELY(aNewValue != NULL))
this->release();
/* We want this both if aNewValue is non-NULL and if it is NULL. */
this->reset(aNewValue);
return aNewValue != NULL;
}
};
#endif /* __cplusplus */
/** @} */
#endif