Heap.c File Reference

functions to manage the heap with the goal of eliminating memory leaks More...

#include "Tree.h"
#include "Log.h"
#include "StackTrace.h"
#include "Thread.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include "Heap.h"

Include dependency graph for Heap.c:

Data Structures
struct	storageElement
	Each item on the heap is recorded with this structure. More...

Typedefs
typedef double	eyecatcherType

Functions
static size_t	Heap_roundup (size_t size)
	Round allocation size up to a multiple of the size of an int. More...
static int	ptrCompare (void *a, void *b, int value)
	List callback function for comparing storage elements. More...
static void	checkEyecatchers (char *file, int line, void *p, size_t size)
static int	Internal_heap_unlink (char *file, int line, void *p)
	Remove an item from the recorded heap without actually freeing it. More...
static void	HeapScan (enum LOG_LEVELS log_level)
	Scans the heap and reports any items currently allocated. More...
void *	mymalloc (char *file, int line, size_t size)
	Allocates a block of memory. More...
void	myfree (char *file, int line, void *p)
	Frees a block of memory. More...
void	Heap_unlink (char *file, int line, void *p)
	Remove an item from the recorded heap without actually freeing it. More...
void *	myrealloc (char *file, int line, void *p, size_t size)
	Reallocates a block of memory. More...
void *	Heap_findItem (void *p)
	Utility to find an item in the heap. More...
int	Heap_initialize (void)
	Heap initialization.
void	Heap_terminate (void)
	Heap termination.
heap_info *	Heap_get_info (void)
	Access to heap state. More...
int	HeapDumpString (FILE *file, char *str)
	Dump a string from the heap so that it can be displayed conveniently. More...
int	HeapDump (FILE *file)
	Dump the state of the heap. More...

Variables
static pthread_mutex_t	heap_mutex_store = PTHREAD_MUTEX_INITIALIZER
static mutex_type	heap_mutex = &heap_mutex_store
static heap_info	state = {0, 0}
	global heap state information
static eyecatcherType	eyecatcher = (eyecatcherType)0x8888888888888888
static Tree	heap
	Tree that holds the allocation records.
static const char *	errmsg = "Memory allocation error"

Detailed Description

functions to manage the heap with the goal of eliminating memory leaks

For any module to use these functions transparently, simply include the Heap.h header file. Malloc and free will be redefined, but will behave in exactly the same way as normal, so no recoding is necessary.

Function Documentation

Heap_findItem()

void* Heap_findItem

(

void *

p

)

Utility to find an item in the heap.

Lets you know if the heap already contains the memory location in question.

Parameters

p	pointer to a memory location

Returns

pointer to the storage element if found, or NULL

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Heap_get_info()

heap_info* Heap_get_info

(

void

)

Access to heap state.

Returns

pointer to the heap state structure

Heap_roundup()

static size_t Heap_roundup ( size_t  size )

static

Round allocation size up to a multiple of the size of an int.

Apart from possibly reducing fragmentation, on the old v3 gcc compilers I was hitting some weird behaviour, which might have been errors in sizeof() used on structures and related to packing. In any case, this fixes that too.

Parameters

size	the size actually needed

Returns

the rounded up size

Heap_unlink()

void Heap_unlink	(	char *	file,
		int	line,
		void *	p
	)

Remove an item from the recorded heap without actually freeing it.

Use sparingly!

Parameters

file	use the FILE macro to indicate which file this item was allocated in
line	use the LINE macro to indicate which line this item was allocated at
p	pointer to the item to be removed

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HeapDump()

int HeapDump

(

FILE *

file

)

Dump the state of the heap.

Parameters

file	file handle to dump the heap contents to

HeapDumpString()

int HeapDumpString	(	FILE *	file,
		char *	str
	)

Dump a string from the heap so that it can be displayed conveniently.

Parameters

file	file handle to dump the heap contents to
str	the string to dump, could be NULL

HeapScan()

static void HeapScan ( enum LOG_LEVELS  log_level )

static

Scans the heap and reports any items currently allocated.

To be used at shutdown if any heap items have not been freed.

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Internal_heap_unlink()

static int Internal_heap_unlink ( char *  file, int  line, void *  p  )

static

Remove an item from the recorded heap without actually freeing it.

Use sparingly!

Parameters

file	use the FILE macro to indicate which file this item was allocated in
line	use the LINE macro to indicate which line this item was allocated at
p	pointer to the item to be removed

myfree()

void myfree	(	char *	file,
		int	line,
		void *	p
	)

Frees a block of memory.

A direct replacement for free, but checks that a item is in the allocates list first.

Parameters

file	use the FILE macro to indicate which file this item was allocated in
line	use the LINE macro to indicate which line this item was allocated at
p	pointer to the item to be freed

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mymalloc()

void* mymalloc	(	char *	file,
		int	line,
		size_t	size
	)

Allocates a block of memory.

A direct replacement for malloc, but keeps track of items allocated in a list, so that free can check that a item is being freed correctly and that we can check that all memory is freed at shutdown.

Parameters

file	use the FILE macro to indicate which file this item was allocated in
line	use the LINE macro to indicate which line this item was allocated at
size	the size of the item to be allocated

Returns

pointer to the allocated item, or NULL if there was an error

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myrealloc()

void* myrealloc	(	char *	file,
		int	line,
		void *	p,
		size_t	size
	)

Reallocates a block of memory.

A direct replacement for realloc, but keeps track of items allocated in a list, so that free can check that a item is being freed correctly and that we can check that all memory is freed at shutdown. We have to remove the item from the tree, as the memory is in order and so it needs to be reinserted in the correct place.

Parameters

file	use the FILE macro to indicate which file this item was reallocated in
line	use the LINE macro to indicate which line this item was reallocated at
p	pointer to the item to be reallocated
size	the new size of the item

Returns

pointer to the allocated item, or NULL if there was an error

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ptrCompare()

static int ptrCompare ( void *  a, void *  b, int  value  )

static

List callback function for comparing storage elements.

Parameters

a	pointer to the current content in the tree (storageElement*)
b	pointer to the memory to free

Returns

boolean indicating whether a and b are equal