Improved memory documentation and examples. Resolves PR #3834.

This commit is contained in:
David Garske
2021-07-28 09:03:40 -07:00
parent 2dac9a2a81
commit 8376a2adc2
2 changed files with 58 additions and 139 deletions

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@@ -1,17 +1,21 @@
/*! /*!
\ingroup Memory \ingroup Memory
\brief This function calls the custom malloc function, if one has been \brief This function is similar to malloc(), but calls the memory
defined, or simply calls the default C malloc function if no custom allocation function which wolfSSL has been configured to use. By default,
function exists. It is not called directly by wolfSSL, but instead wolfSSL uses malloc(). This can be changed using the wolfSSL memory
generally called by using XMALLOC, which may be replaced by abstraction layer - see wolfSSL_SetAllocators(). Note wolfSSL_Malloc is not
wolfSSL_Malloc during preprocessing. called directly by wolfSSL, but instead called by macro XMALLOC.
For the default build only the size argument exists. If using
WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
\return Success On successfully allocating the desired memory, \return pointer If successful, this function returns a pointer to
returns a void* to that location allocated memory.
\return NULL Returned when there is a failure to allocate memory \return error If there is an error, NULL will be returned.
\param size size, in bytes, of the memory to allocate \param size size, in bytes, of the memory to allocate
\param heap heap hint to use for memory. Can be NULL
\param type dynamic type (see DYNAMIC_TYPE_ list in types.h)
_Example_ _Example_
\code \code
@@ -20,24 +24,29 @@
\sa wolfSSL_Free \sa wolfSSL_Free
\sa wolfSSL_Realloc \sa wolfSSL_Realloc
\sa wolfSSL_SetAllocators
\sa XMALLOC \sa XMALLOC
\sa XFREE \sa XFREE
\sa XREALLOC \sa XREALLOC
*/ */
WOLFSSL_API void* wolfSSL_Malloc(size_t size, void* heap, int type, const char* func, unsigned int line); WOLFSSL_API void* wolfSSL_Malloc(size_t size, void* heap, int type);
/*! /*!
\ingroup Memory \ingroup Memory
\brief This function calls a custom free function, if one has been \brief This function is similar to free(), but calls the memory free
defined, or simply calls the default C free function if no custom function which wolfSSL has been configured to use. By default, wolfSSL
function exists. It is not called directly by wolfSSL, but instead uses free(). This can be changed using the wolfSSL memory abstraction
generally called by using XFREE, which may be replaced by wolfSSL_Free layer - see wolfSSL_SetAllocators(). Note wolfSSL_Free is not
during preprocessing. called directly by wolfSSL, but instead called by macro XFREE.
For the default build only the ptr argument exists. If using
WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
\return none No returns. \return none No returns.
\param ptr pointer to the memory to free \param ptr pointer to the memory to be freed.
\param heap heap hint to use for memory. Can be NULL
\param type dynamic type (see DYNAMIC_TYPE_ list in types.h)
_Example_ _Example_
\code \code
@@ -49,74 +58,14 @@ WOLFSSL_API void* wolfSSL_Malloc(size_t size, void* heap, int type, const char*
} }
\endcode \endcode
\sa wolfSSL_Malloc \sa wolfSSL_Alloc
\sa wolfSSL_Realloc
\sa XMALLOC
\sa XFREE
\sa XREALLOC
*/
WOLFSSL_API void wolfSSL_Free(void *ptr, void* heap, int type, const char* func, unsigned int line);
/*!
\ingroup Memory
\brief This function calls a custom realloc function, if one has been
defined, or simply calls the default C realloc function if no custom
function exists. It is not called directly by wolfSSL, but instead
generally called by using XREALLOC, which may be replaced by
wolfSSL_Realloc during preprocessing.
\return Success On successfully reallocating the desired memory,
returns a void* to that location
\return NULL Returned when there is a failure to reallocate memory
\param ptr pointer to the memory to the memory to reallocate
\param size desired size after reallocation
_Example_
\code
int* tenInts = (int*)wolfSSL_Malloc(sizeof(int)*10);
int* twentyInts = (int*)realloc(tenInts, sizeof(tenInts)*2);
\endcode
\sa wolfSSL_Malloc
\sa wolfSSL_Free
\sa XMALLOC
\sa XFREE
\sa XREALLOC
*/
WOLFSSL_API void* wolfSSL_Realloc(void *ptr, size_t size, void* heap, int type, const char* func, unsigned int line);
/*!
\ingroup Memory
\brief This function is similar to malloc(), but calls the memory
allocation function which wolfSSL has been configured to use. By default,
wolfSSL uses malloc(). This can be changed using the wolfSSL memory
abstraction layer - see wolfSSL_SetAllocators().
\return pointer If successful, this function returns a pointer to
allocated memory.
\return error If there is an error, NULL will be returned.
\return other Specific return values may be dependent on the underlying
memory allocation function being used (if not using the default malloc()).
\param size number of bytes to allocate.
_Example_
\code
char* buffer;
buffer = (char*) wolfSSL_Malloc(20);
if (buffer == NULL) {
// failed to allocate memory
}
\endcode
\sa wolfSSL_Free
\sa wolfSSL_Realloc \sa wolfSSL_Realloc
\sa wolfSSL_SetAllocators \sa wolfSSL_SetAllocators
\sa XMALLOC
\sa XFREE
\sa XREALLOC
*/ */
WOLFSSL_API void* wolfSSL_Malloc(size_t size, void* heap, int type); WOLFSSL_API void wolfSSL_Free(void *ptr, void* heap, int type);
/*! /*!
\ingroup Memory \ingroup Memory
@@ -124,60 +73,36 @@ WOLFSSL_API void* wolfSSL_Malloc(size_t size, void* heap, int type);
\brief This function is similar to realloc(), but calls the memory \brief This function is similar to realloc(), but calls the memory
re-allocation function which wolfSSL has been configured to use. re-allocation function which wolfSSL has been configured to use.
By default, wolfSSL uses realloc(). This can be changed using the By default, wolfSSL uses realloc(). This can be changed using the
wolfSSL memory abstraction layer - see wolfSSL_SetAllocators(). wolfSSL memory abstraction layer - see wolfSSL_SetAllocators().
Note wolfSSL_Realloc is not called directly by wolfSSL, but instead called
by macro XREALLOC. For the default build only the size argument exists.
If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
\return pointer If successful, this function returns a pointer to \return pointer If successful, this function returns a pointer to
re-allocated memory. This may be the same pointer as ptr, or a re-allocated memory. This may be the same pointer as ptr, or a
new pointer location. new pointer location.
\return Null If there is an error, NULL will be returned. \return Null If there is an error, NULL will be returned.
\return other Specific return values may be dependent on the
underlying memory re-allocation function being used
(if not using the default realloc()).
\param ptr pointer to the previously-allocated memory, to be reallocated. \param ptr pointer to the previously-allocated memory, to be reallocated.
\param size number of bytes to allocate. \param size number of bytes to allocate.
\param heap heap hint to use for memory. Can be NULL
\param type dynamic type (see DYNAMIC_TYPE_ list in types.h)
_Example_ _Example_
\code \code
char* buffer; int* tenInts = (int*)wolfSSL_Malloc(sizeof(int)*10);
int* twentyInts = (int*)wolfSSL_Realloc(tenInts, sizeof(int)*20);
buffer = (char*) wolfSSL_Realloc(30);
if (buffer == NULL) {
// failed to re-allocate memory
}
\endcode \endcode
\sa wolfSSL_Free \sa wolfSSL_Free
\sa wolfSSL_Malloc \sa wolfSSL_Malloc
\sa wolfSSL_SetAllocators \sa wolfSSL_SetAllocators
\sa XMALLOC
\sa XFREE
\sa XREALLOC
*/ */
WOLFSSL_API void* wolfSSL_Realloc(void *ptr, size_t size, void* heap, int type); WOLFSSL_API void* wolfSSL_Realloc(void *ptr, size_t size, void* heap, int type);
/*!
\ingroup Memory
\brief This function is similar to free(), but calls the memory free
function which wolfSSL has been configured to use. By default, wolfSSL
uses free(). This can be changed using the wolfSSL memory abstraction
layer - see wolfSSL_SetAllocators().
\return none No returns.
\param ptr pointer to the memory to be freed.
_Example_
\code
char* buffer;
...
wolfSSL_Free(buffer);
\endcode
\sa wolfSSL_Alloc
\sa wolfSSL_Realloc
\sa wolfSSL_SetAllocators
*/
WOLFSSL_API void wolfSSL_Free(void *ptr, const char* func, unsigned int line);
/*! /*!
\ingroup Memory \ingroup Memory
@@ -199,32 +124,26 @@ WOLFSSL_API void wolfSSL_Free(void *ptr, const char* func, unsigned int line);
_Example_ _Example_
\code \code
int ret = 0; static void* MyMalloc(size_t size)
// Memory function prototypes
void* MyMalloc(size_t size);
void MyFree(void* ptr);
void* MyRealloc(void* ptr, size_t size);
// Register custom memory functions with wolfSSL
ret = wolfSSL_SetAllocators(MyMalloc, MyFree, MyRealloc);
if (ret != 0) {
// failed to set memory functions
}
void* MyMalloc(size_t size)
{ {
// custom malloc function // custom malloc function
} }
void MyFree(void* ptr) static void MyFree(void* ptr)
{ {
// custom free function // custom free function
} }
void* MyRealloc(void* ptr, size_t size) static void* MyRealloc(void* ptr, size_t size)
{ {
// custom realloc function // custom realloc function
} }
// Register custom memory functions with wolfSSL
int ret = wolfSSL_SetAllocators(MyMalloc, MyFree, MyRealloc);
if (ret != 0) {
// failed to set memory functions
}
\endcode \endcode
\sa none \sa none

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@@ -33,11 +33,10 @@
_Example_ _Example_
\code \code
int* 10 ints = XMALLOC(10 * sizeof(int), NULL, DYNAMIC_TYPE_TMP_BUFFER); int* tenInts = XMALLOC(sizeof(int)*10, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (tenInts == NULL) {
if ( ints == NULL) { // error allocating space
// error allocating space return MEMORY_E;
return MEMORY_E;
} }
\endcode \endcode
@@ -84,7 +83,9 @@ WOLFSSL_API void* XMALLOC(size_t n, void* heap, int type);
_Example_ _Example_
\code \code
none int* tenInts = (int*)XMALLOC(sizeof(int)*10, NULL, DYNAMIC_TYPE_TMP_BUFFER);
int* twentyInts = (int*)XREALLOC(tenInts, sizeof(int)*20, NULL,
DYNAMIC_TYPE_TMP_BUFFER);
\endcode \endcode
\sa wolfSSL_Malloc \sa wolfSSL_Malloc
@@ -127,9 +128,8 @@ WOLFSSL_API void* XREALLOC(void *p, size_t n, void* heap, int type);
_Example_ _Example_
\code \code
int* 10 ints = XMALLOC(10 * sizeof(int), NULL, DYNAMIC_TYPE_TMP_BUFFER); int* tenInts = XMALLOC(sizeof(int) * 10, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (tenInts == NULL) {
if ( ints == NULL) {
// error allocating space // error allocating space
return MEMORY_E; return MEMORY_E;
} }