dnxHeap.c File Reference

Implements debug heap management for DNX. More...

#include "dnxHeap.h"
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <pthread.h>

Go to the source code of this file.

Data Structures

struct overhead_

Debug heap block bookkeeping header structure. More...

Defines

#define PICKETSZ   8

Picket fence size in bytes.

#define PICKET1   0xAA

Overhead front picket fence fill value.

#define PICKET2   0xBB

Overhead rear picket fence fill value.

#define PICKET3   0xCC

User block footer picket fence fill value.

#define ALIGNED   0xDD

Rear alignment buffer fill value.

#define ALLOCED   0xEE

User space allocated fill value (malloc).

#define FREED   0xFF

User space freed memory fill value.

#define ALIGNSZ(sz)   (((sz) + 15) & (-1L << 4))

Align a block to a paragraph boundary.

Typedefs

typedef struct overhead_ overhead

Debug heap block bookkeeping header structure.

Functions

static void link_block (overhead *ohp)

Link a newly allocated block into the block list.

static int unlink_block (overhead *ohp)

Locate and remove a block by address from the global block list.

static size_t hex_dump (char *buf, void *p, size_t sz)

Format a number of bytes as a hexadecimal ascii dump into a text buffer.

static void dump_block (overhead *ohp, char *msg)

Dump a memory block with an optional debug(1) message.

static int memscan (void *p, unsigned char ch, size_t sz)

Scan a range of memory for the first non-recognized character.

static int check_block (overhead *ohp)

Check the integrity of a memory block.

void * dnxMalloc (size_t sz, char *file, int line)

Allocate and track a new heap memory block.

void * dnxCalloc (size_t n, size_t sz, char *file, int line)

Allocate, zero and track a new heap memory block.

void * dnxRealloc (void *p, size_t sz, char *file, int line)

Reallocate (and track) an existing heap memory block.

char * dnxStrdup (char *str, char *file, int line)

Duplicate and track a string from the heap.

void dnxFree (void *p)

Free and previously allocated (and tracked) heap memory block.

int dnxCheckHeap (void)

Check the heap and display any unfreed blocks on the global list.

Variables

static overhead * head = 0

The head of the global heap block list.

static int blkcnt = 0

The number of blocks in the global list.

static pthread_mutex_t list_lock = PTHREAD_MUTEX_INITIALIZER

The global heap block list lock.

Detailed Description

Implements debug heap management for DNX.

Author:: John Calcote (jcalcote@users.sourceforge.net)

Attention:: Please submit patches to http://dnx.sourceforge.net

Definition in file dnxHeap.c.

Define Documentation

#define ALIGNED 0xDD

Rear alignment buffer fill value.

Definition at line 42 of file dnxHeap.c.

Referenced by dnxMalloc().

#define ALIGNSZ ( sz ) (((sz) + 15) & (-1L << 4))

Align a block to a paragraph boundary.

Add 15 and AND the result with 0x...FFFFFFF0 to clear the bottom 4 bits. Works on any word-sized architecture (32, 64, etc).

Definition at line 50 of file dnxHeap.c.

Referenced by dnxMalloc().

#define ALLOCED 0xEE

User space allocated fill value (malloc).

Definition at line 43 of file dnxHeap.c.

Referenced by dnxMalloc().

#define FREED 0xFF

User space freed memory fill value.

Definition at line 44 of file dnxHeap.c.

#define PICKET1 0xAA

Overhead front picket fence fill value.

Definition at line 39 of file dnxHeap.c.

Referenced by check_block(), and dnxMalloc().

#define PICKET2 0xBB

Overhead rear picket fence fill value.

Definition at line 40 of file dnxHeap.c.

Referenced by check_block(), and dnxMalloc().

#define PICKET3 0xCC

User block footer picket fence fill value.

Definition at line 41 of file dnxHeap.c.

Referenced by check_block(), and dnxMalloc().

#define PICKETSZ 8

Picket fence size in bytes.

Definition at line 37 of file dnxHeap.c.

Referenced by check_block(), dnxMalloc(), and dump_block().

Typedef Documentation

typedef struct overhead_ overhead

Debug heap block bookkeeping header structure.

Function Documentation

static int check_block ( overhead * ohp ) [static]

Check the integrity of a memory block.

Parameters:

[in] ohp - a pointer to the block to be checked.

Returns:: Boolean: true (1) if block is okay, false (0) if not.

Definition at line 199 of file dnxHeap.c.

References dump_block(), memscan(), PICKET1, overhead_::picket1, PICKET2, overhead_::picket2, PICKET3, PICKETSZ, and overhead_::reqsz.

Referenced by dnxCheckHeap(), and dnxFree().

void* dnxCalloc	(	size_t	n,
		size_t	sz,
		char *	file,
		int	line
	)

Allocate, zero and track a new heap memory block.

Calloc is sort of a strange bird - it should be the same as malloc with the addition of zeroing the block before returning, but K&R must have decided that the X x Y block allocation strategry had some value for heap blocks that need to be cleared...

Parameters:

`[in]`	n	- the number of blocks of `sz` bytes to be allocated.
`[in]`	sz	- the size of each of the `n` blocks to be allocated.
`[in]`	file	- the file name from where this function was called.
`[in]`	line	- the line number from where this function was called.

Returns:: A pointer to the new memory block, or NULL on allocation failure.

Definition at line 253 of file dnxHeap.c.

References dnxMalloc().

int dnxCheckHeap ( void )

Check the heap and display any unfreed blocks on the global list.

Returns:: Zero on success, or a non-zero error code.

Definition at line 334 of file dnxHeap.c.

References blkcnt, check_block(), dnxDebug(), dump_block(), list_lock, and overhead_::next.

void dnxFree ( void * p )

Free and previously allocated (and tracked) heap memory block.

Note that there are serveral good programming-practice reasons to call free with a p argument value of null. This debug routine allows it.

Parameters:

[in] p - a pointer to the debug heap block to be freed.

Definition at line 311 of file dnxHeap.c.

References check_block(), dnxDebug(), overhead_::file, and unlink_block().

Referenced by dnxRealloc().

void* dnxMalloc	(	size_t	sz,
		char *	file,
		int	line
	)

Allocate and track a new heap memory block.

malloc allows sz to be zero, in which case, it returns NULL. But there's really no reason to call malloc with a zero value unless the programmer made a mistake, so this routine asserts that sz is non-zero.

Parameters:

`[in]`	sz	- the size in bytes of the block to be allocated.
`[in]`	file	- the file name from where this function was called.
`[in]`	line	- the line number from where this function was called.

Returns:: A pointer to the new memory block, or NULL on allocation failure.

Definition at line 219 of file dnxHeap.c.

References overhead_::actualsz, ALIGNED, ALIGNSZ, ALLOCED, dnxDebug(), overhead_::file, overhead_::line, link_block(), overhead_::next, PICKET1, overhead_::picket1, PICKET2, overhead_::picket2, PICKET3, PICKETSZ, and overhead_::reqsz.

Referenced by dnxCalloc(), dnxRealloc(), and dnxStrdup().

void* dnxRealloc	(	void *	p,
		size_t	sz,
		char *	file,
		int	line
	)

Reallocate (and track) an existing heap memory block.

Realloc - the all-in-one heap management function. If p is NULL, realloc acts like malloc, if sz is zero, realloc acts like free.

Since there's no reason except programmer error that would have both p and sz be zero at the same time, this routine asserts one or the other is non-zero.

Parameters:

`[in]`	p	- a pointer to the block to be reallocated/resized.
`[in]`	sz	- the new size of the block.
`[in]`	file	- the file name from where this function was called.
`[in]`	line	- the line number from where this function was called.

Returns:: A pointer to the new memory block, or NULL on allocation failure.

Definition at line 270 of file dnxHeap.c.

References dnxFree(), dnxMalloc(), and overhead_::reqsz.

char* dnxStrdup	(	char *	str,
		char *	file,
		int	line
	)

Duplicate and track a string from the heap.

Parameters:

`[in]`	str	- a pointer to the zero-terminated string to be duplicated.
`[in]`	file	- the file name from where this function was called.
`[in]`	line	- the line number from where this function was called.

Returns:: A pointer to the new memory block, or NULL on allocation failure.

Definition at line 292 of file dnxHeap.c.

References dnxMalloc().

static void dump_block	(	overhead *	ohp,
		char *	msg
	)			`[static]`

Dump a memory block with an optional debug(1) message.

Parameters:

`[in]`	ohp	- a pointer to the block to be displayed.
`[in]`	msg	- a pointer to the message to be displayed.

Definition at line 143 of file dnxHeap.c.

References dnxDebug(), overhead_::file, hex_dump(), overhead_::line, overhead_::picket1, overhead_::picket2, PICKETSZ, and overhead_::reqsz.

Referenced by check_block(), and dnxCheckHeap().

static size_t hex_dump	(	char *	buf,
		void *	p,
		size_t	sz
	)			`[static]`

Format a number of bytes as a hexadecimal ascii dump into a text buffer.

Parameters:

`[out]`	buf	- a pointer to the text output buffer.
`[in]`	p	- a pointer to the bytes to be formatted into `buf`.
`[in]`	sz	- the number of bytes of `p` to be formatted into `buf`.

Returns:: The number of characters of buf that were used, minus the trailing null-terminator; buf + this return value is a pointer to the trailing null-terminator just written.

Definition at line 123 of file dnxHeap.c.

Referenced by dump_block().

static void link_block ( overhead * ohp ) [static]

Link a newly allocated block into the block list.

Parameters:

[in] ohp - a pointer to the block to be linked into the global list.

Definition at line 77 of file dnxHeap.c.

References blkcnt, list_lock, and overhead_::next.

Referenced by dnxMalloc().

static int memscan	(	void *	p,
		unsigned char	ch,
		size_t	sz
	)			`[static]`

Scan a range of memory for the first non-recognized character.

Parameters:

`[in]`	p	- a pointer to the buffer to be scanned.
`[in]`	ch	- the expected fill character.
`[in]`	sz	- the number of bytes to be scanned in `p`.

Returns:: Zero on success, or -1 if not all bytes in the first sz bytes of p are equal to ch.

Definition at line 183 of file dnxHeap.c.

Referenced by check_block().

static int unlink_block ( overhead * ohp ) [static]

Locate and remove a block by address from the global block list.

Parameters:

[in] ohp - a pointer to the block to be located and removed.

Returns:: Boolean; True (1) if found, False (0) if not found in list.

Definition at line 94 of file dnxHeap.c.

References blkcnt, list_lock, and overhead_::next.

Referenced by dnxFree().

Variable Documentation

int blkcnt = 0 [static]

The number of blocks in the global list.

Definition at line 65 of file dnxHeap.c.

Referenced by dnxCheckHeap(), link_block(), and unlink_block().

overhead* head = 0 [static]

The head of the global heap block list.

Definition at line 64 of file dnxHeap.c.

pthread_mutex_t list_lock = PTHREAD_MUTEX_INITIALIZER [static]

The global heap block list lock.

Definition at line 66 of file dnxHeap.c.

Referenced by dnxCheckHeap(), link_block(), and unlink_block().


Data Structures
struct	overhead_
	Debug heap block bookkeeping header structure. More...
Defines
#define	PICKETSZ 8
	Picket fence size in bytes.
#define	PICKET1 0xAA
	Overhead front picket fence fill value.
#define	PICKET2 0xBB
	Overhead rear picket fence fill value.
#define	PICKET3 0xCC
	User block footer picket fence fill value.
#define	ALIGNED 0xDD
	Rear alignment buffer fill value.
#define	ALLOCED 0xEE
	User space allocated fill value (malloc).
#define	FREED 0xFF
	User space freed memory fill value.
#define	ALIGNSZ(sz) (((sz) + 15) & (-1L << 4))
	Align a block to a paragraph boundary.
Typedefs
typedef struct overhead_	overhead
	Debug heap block bookkeeping header structure.
Functions
static void	link_block (overhead *ohp)
	Link a newly allocated block into the block list.
static int	unlink_block (overhead *ohp)
	Locate and remove a block by address from the global block list.
static size_t	hex_dump (char buf, void p, size_t sz)
	Format a number of bytes as a hexadecimal ascii dump into a text buffer.
static void	dump_block (overhead ohp, char msg)
	Dump a memory block with an optional debug(1) message.
static int	memscan (void *p, unsigned char ch, size_t sz)
	Scan a range of memory for the first non-recognized character.
static int	check_block (overhead *ohp)
	Check the integrity of a memory block.
void *	dnxMalloc (size_t sz, char *file, int line)
	Allocate and track a new heap memory block.
void *	dnxCalloc (size_t n, size_t sz, char *file, int line)
	Allocate, zero and track a new heap memory block.
void *	dnxRealloc (void p, size_t sz, char file, int line)
	Reallocate (and track) an existing heap memory block.
char *	dnxStrdup (char str, char file, int line)
	Duplicate and track a string from the heap.
void	dnxFree (void *p)
	Free and previously allocated (and tracked) heap memory block.
int	dnxCheckHeap (void)
	Check the heap and display any unfreed blocks on the global list.
Variables
static overhead *	head = 0
	The head of the global heap block list.
static int	blkcnt = 0
	The number of blocks in the global list.
static pthread_mutex_t	list_lock = PTHREAD_MUTEX_INITIALIZER
	The global heap block list lock.