xmlmemory.c

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/*
 * xmlmemory.c:  libxml memory allocator wrapper.
 *
 * [e-mail]
 */

#define IN_LIBXML
#include "libxml.h"

#include <string.h>

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifdef HAVE_TIME_H
#include <time.h>
#endif

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#else
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#endif

#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif

/* #define DEBUG_MEMORY */

/**
 * MEM_LIST:
 *
 * keep track of all allocated blocks for error reporting 
 * Always build the memory list !
 */
#ifdef DEBUG_MEMORY_LOCATION
#ifndef MEM_LIST
#define MEM_LIST /* keep a list of all the allocated memory blocks */
#endif
#endif

#include <libxml/globals.h>	/* must come before xmlmemory.h */
#include <libxml/xmlmemory.h>
#include <libxml/xmlerror.h>
#include <libxml/threads.h>

static int xmlMemInitialized = 0;
static unsigned long  debugMemSize = 0;
static unsigned long  debugMemBlocks = 0;
static unsigned long  debugMaxMemSize = 0;
static xmlMutexPtr xmlMemMutex = NULL;

void xmlMallocBreakpoint(void);

/************************************************************************
 *									*
 * 		Macros, variables and associated types			*
 *									*
 ************************************************************************/

#if !defined(LIBXML_THREAD_ENABLED) && !defined(LIBXML_THREAD_ALLOC_ENABLED)
#ifdef xmlMalloc
#undef xmlMalloc
#endif
#ifdef xmlRealloc
#undef xmlRealloc
#endif
#ifdef xmlMemStrdup
#undef xmlMemStrdup
#endif
#endif

/*
 * Each of the blocks allocated begin with a header containing informations
 */

#define MEMTAG 0x5aa5

#define MALLOC_TYPE 1
#define REALLOC_TYPE 2
#define STRDUP_TYPE 3
#define MALLOC_ATOMIC_TYPE 4
#define REALLOC_ATOMIC_TYPE 5

typedef struct memnod {
    unsigned int   mh_tag;
    unsigned int   mh_type;
    unsigned long  mh_number;
    size_t         mh_size;
#ifdef MEM_LIST
   struct memnod *mh_next;
   struct memnod *mh_prev;
#endif
   const char    *mh_file;
   unsigned int   mh_line;
}  MEMHDR;


#ifdef SUN4
#define ALIGN_SIZE  16
#else
#define ALIGN_SIZE  sizeof(double)
#endif
#define HDR_SIZE    sizeof(MEMHDR)
#define RESERVE_SIZE (((HDR_SIZE + (ALIGN_SIZE-1)) \
		      / ALIGN_SIZE ) * ALIGN_SIZE)


#define CLIENT_2_HDR(a) ((MEMHDR *) (((char *) (a)) - RESERVE_SIZE))
#define HDR_2_CLIENT(a)    ((void *) (((char *) (a)) + RESERVE_SIZE))


static unsigned int block=0;
static unsigned int xmlMemStopAtBlock = 0;
static void *xmlMemTraceBlockAt = NULL;
#ifdef MEM_LIST
static MEMHDR *memlist = NULL;
#endif

static void debugmem_tag_error(void *addr);
#ifdef MEM_LIST
static void  debugmem_list_add(MEMHDR *);
static void debugmem_list_delete(MEMHDR *);
#endif
#define Mem_Tag_Err(a) debugmem_tag_error(a);

#ifndef TEST_POINT
#define TEST_POINT
#endif

/**
 * xmlMallocBreakpoint:
 *
 * Breakpoint to use in conjunction with xmlMemStopAtBlock. When the block
 * number reaches the specified value this function is called. One need to add a breakpoint
 * to it to get the context in which the given block is allocated.
 */

void
xmlMallocBreakpoint(void) {
    xmlGenericError(xmlGenericErrorContext,
	    "xmlMallocBreakpoint reached on block %d\n", xmlMemStopAtBlock);
}

/**
 * xmlMallocLoc:
 * @size:  an int specifying the size in byte to allocate.
 * @file:  the file name or NULL
 * @line:  the line number
 *
 * a malloc() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the allocated area or NULL in case of lack of memory.
 */

void *
xmlMallocLoc(size_t size, const char * file, int line)
{
    MEMHDR *p;
    void *ret;
    
    if (!xmlMemInitialized) xmlInitMemory();
#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Malloc(%d)\n",size);
#endif

    TEST_POINT
    
    p = (MEMHDR *) malloc(RESERVE_SIZE+size);

    if (!p) {
	xmlGenericError(xmlGenericErrorContext,
		"xmlMallocLoc : Out of free space\n");
	xmlMemoryDump();
	return(NULL);
    }   
    p->mh_tag = MEMTAG;
    p->mh_size = size;
    p->mh_type = MALLOC_TYPE;
    p->mh_file = file;
    p->mh_line = line;
    xmlMutexLock(xmlMemMutex);
    p->mh_number = ++block;
    debugMemSize += size;
    debugMemBlocks++;
    if (debugMemSize > debugMaxMemSize) debugMaxMemSize = debugMemSize;
#ifdef MEM_LIST
    debugmem_list_add(p);
#endif
    xmlMutexUnlock(xmlMemMutex);
    
#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Malloc(%d) Ok\n",size);
#endif
    
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();

    ret = HDR_2_CLIENT(p);

    if (xmlMemTraceBlockAt == ret) {
	xmlGenericError(xmlGenericErrorContext,
			"%p : Malloc(%d) Ok\n", xmlMemTraceBlockAt, size);
	xmlMallocBreakpoint();
    }

    TEST_POINT

    return(ret);
}

/**
 * xmlMallocAtomicLoc:
 * @size:  an int specifying the size in byte to allocate.
 * @file:  the file name or NULL
 * @line:  the line number
 *
 * a malloc() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the allocated area or NULL in case of lack of memory.
 */

void *
xmlMallocAtomicLoc(size_t size, const char * file, int line)
{
    MEMHDR *p;
    void *ret;
    
    if (!xmlMemInitialized) xmlInitMemory();
#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Malloc(%d)\n",size);
#endif

    TEST_POINT
    
    p = (MEMHDR *) malloc(RESERVE_SIZE+size);

    if (!p) {
	xmlGenericError(xmlGenericErrorContext,
		"xmlMallocLoc : Out of free space\n");
	xmlMemoryDump();
	return(NULL);
    }   
    p->mh_tag = MEMTAG;
    p->mh_size = size;
    p->mh_type = MALLOC_ATOMIC_TYPE;
    p->mh_file = file;
    p->mh_line = line;
    xmlMutexLock(xmlMemMutex);
    p->mh_number = ++block;
    debugMemSize += size;
    debugMemBlocks++;
    if (debugMemSize > debugMaxMemSize) debugMaxMemSize = debugMemSize;
#ifdef MEM_LIST
    debugmem_list_add(p);
#endif
    xmlMutexUnlock(xmlMemMutex);

#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Malloc(%d) Ok\n",size);
#endif
    
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();

    ret = HDR_2_CLIENT(p);

    if (xmlMemTraceBlockAt == ret) {
	xmlGenericError(xmlGenericErrorContext,
			"%p : Malloc(%d) Ok\n", xmlMemTraceBlockAt, size);
	xmlMallocBreakpoint();
    }

    TEST_POINT

    return(ret);
}
/**
 * xmlMemMalloc:
 * @size:  an int specifying the size in byte to allocate.
 *
 * a malloc() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the allocated area or NULL in case of lack of memory.
 */

void *
xmlMemMalloc(size_t size)
{
    return(xmlMallocLoc(size, "none", 0));
}

/**
 * xmlReallocLoc:
 * @ptr:  the initial memory block pointer
 * @size:  an int specifying the size in byte to allocate.
 * @file:  the file name or NULL
 * @line:  the line number
 *
 * a realloc() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the allocated area or NULL in case of lack of memory.
 */

void *
xmlReallocLoc(void *ptr,size_t size, const char * file, int line)
{
    MEMHDR *p;
    unsigned long number;
#ifdef DEBUG_MEMORY
    size_t oldsize;
#endif

    if (ptr == NULL)
        return(xmlMallocLoc(size, file, line));

    if (!xmlMemInitialized) xmlInitMemory();
    TEST_POINT

    p = CLIENT_2_HDR(ptr);
    number = p->mh_number;
    if (xmlMemStopAtBlock == number) xmlMallocBreakpoint();
    if (p->mh_tag != MEMTAG) {
       Mem_Tag_Err(p);
	 goto error;
    }
    p->mh_tag = ~MEMTAG;
    xmlMutexLock(xmlMemMutex);
    debugMemSize -= p->mh_size;
    debugMemBlocks--;
#ifdef DEBUG_MEMORY
    oldsize = p->mh_size;
#endif
#ifdef MEM_LIST
    debugmem_list_delete(p);
#endif
    xmlMutexUnlock(xmlMemMutex);
    
    p = (MEMHDR *) realloc(p,RESERVE_SIZE+size);
    if (!p) {
	 goto error;
    }
    if (xmlMemTraceBlockAt == ptr) {
	xmlGenericError(xmlGenericErrorContext,
			"%p : Realloced(%d -> %d) Ok\n",
			xmlMemTraceBlockAt, p->mh_size, size);
	xmlMallocBreakpoint();
    }
    p->mh_tag = MEMTAG;
    p->mh_number = number;
    p->mh_type = REALLOC_TYPE;
    p->mh_size = size;
    p->mh_file = file;
    p->mh_line = line;
    xmlMutexLock(xmlMemMutex);
    debugMemSize += size;
    debugMemBlocks++;
    if (debugMemSize > debugMaxMemSize) debugMaxMemSize = debugMemSize;
#ifdef MEM_LIST
    debugmem_list_add(p);
#endif
    xmlMutexUnlock(xmlMemMutex);

    TEST_POINT

#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Realloced(%d to %d) Ok\n", oldsize, size);
#endif
    return(HDR_2_CLIENT(p));
    
error:    
    return(NULL);
}

/**
 * xmlMemRealloc:
 * @ptr:  the initial memory block pointer
 * @size:  an int specifying the size in byte to allocate.
 *
 * a realloc() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the allocated area or NULL in case of lack of memory.
 */

void *
xmlMemRealloc(void *ptr,size_t size) {
    return(xmlReallocLoc(ptr, size, "none", 0));
}

/**
 * xmlMemFree:
 * @ptr:  the memory block pointer
 *
 * a free() equivalent, with error checking.
 */
void
xmlMemFree(void *ptr)
{
    MEMHDR *p;
    char *target;
#ifdef DEBUG_MEMORY
    size_t size;
#endif

    if (ptr == (void *) -1) {
	xmlGenericError(xmlGenericErrorContext,
	    "trying to free pointer from freed area\n");
        goto error;
    }

    if (xmlMemTraceBlockAt == ptr) {
	xmlGenericError(xmlGenericErrorContext,
			"%p : Freed()\n", xmlMemTraceBlockAt);
	xmlMallocBreakpoint();
    }

    TEST_POINT

    target = (char *) ptr;

    p = CLIENT_2_HDR(ptr);
    if (p->mh_tag != MEMTAG) {
        Mem_Tag_Err(p);
        goto error;
    }
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();
    p->mh_tag = ~MEMTAG;
    memset(target, -1, p->mh_size);
    xmlMutexLock(xmlMemMutex);
    debugMemSize -= p->mh_size;
    debugMemBlocks--;
#ifdef DEBUG_MEMORY
    size = p->mh_size;
#endif
#ifdef MEM_LIST
    debugmem_list_delete(p);
#endif
    xmlMutexUnlock(xmlMemMutex);

    free(p);

    TEST_POINT

#ifdef DEBUG_MEMORY
    xmlGenericError(xmlGenericErrorContext,
	    "Freed(%d) Ok\n", size);
#endif
    
    return;
    
error:    
    xmlGenericError(xmlGenericErrorContext,
	    "xmlMemFree(%lX) error\n", (unsigned long) ptr);
    xmlMallocBreakpoint();
    return;
}

/**
 * xmlMemStrdupLoc:
 * @str:  the initial string pointer
 * @file:  the file name or NULL
 * @line:  the line number
 *
 * a strdup() equivalent, with logging of the allocation info.
 *
 * Returns a pointer to the new string or NULL if allocation error occurred.
 */

char *
xmlMemStrdupLoc(const char *str, const char *file, int line)
{
    char *s;
    size_t size = strlen(str) + 1;
    MEMHDR *p;

    if (!xmlMemInitialized) xmlInitMemory();
    TEST_POINT

    p = (MEMHDR *) malloc(RESERVE_SIZE+size);
    if (!p) {
      goto error;
    }
    p->mh_tag = MEMTAG;
    p->mh_size = size;
    p->mh_type = STRDUP_TYPE;
    p->mh_file = file;
    p->mh_line = line;
    xmlMutexLock(xmlMemMutex);
    p->mh_number = ++block;
    debugMemSize += size;
    debugMemBlocks++;
    if (debugMemSize > debugMaxMemSize) debugMaxMemSize = debugMemSize;
#ifdef MEM_LIST
    debugmem_list_add(p);
#endif
    xmlMutexUnlock(xmlMemMutex);
    
    s = (char *) HDR_2_CLIENT(p);
    
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();

    if (s != NULL)
      strcpy(s,str);
    else
      goto error;
    
    TEST_POINT

    if (xmlMemTraceBlockAt == s) {
	xmlGenericError(xmlGenericErrorContext,
			"%p : Strdup() Ok\n", xmlMemTraceBlockAt);
	xmlMallocBreakpoint();
    }

    return(s);