xmlmemory.c

Go to the documentation of this file.

/*
 * xmlmemory.c:  libxml memory allocator wrapper.
 *
 * daniel@veillard.com
 */
 
#define IN_LIBXML
#include "libxml.h"
 
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <time.h>
 
#ifdef DEBUG_MEMORY_LOCATION
#ifndef MEM_LIST
#define MEM_LIST /* keep a list of all the allocated memory blocks */
#endif
#endif
 
#include <libxml/xmlmemory.h>
#include <libxml/xmlerror.h>
#include <libxml/parser.h>
#include <libxml/threads.h>
 
#include "private/memory.h"
#include "private/threads.h"
 
static unsigned long  debugMemSize = 0;
static unsigned long  debugMemBlocks = 0;
static unsigned long  debugMaxMemSize = 0;
static xmlMutex xmlMemMutex;
 
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 information
 */
 
#define MEMTAG 0x5aa5U
 
#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 MAX_SIZE_T ((size_t)-1)
 
#define CLIENT_2_HDR(a) ((void *) (((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
 
void
xmlMallocBreakpoint(void) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMallocBreakpoint reached on block %d\n", xmlMemStopAtBlock);
}
 
void *
xmlMallocLoc(size_t size, const char * file, int line)
{
    MEMHDR *p;
    void *ret;
 
    xmlInitParser();
 
    TEST_POINT
 
    if (size > (MAX_SIZE_T - RESERVE_SIZE)) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMallocLoc : Unsigned overflow\n");
    return(NULL);
    }
 
    p = (MEMHDR *) malloc(RESERVE_SIZE+size);
 
    if (!p) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMallocLoc : Out of free space\n");
    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);
 
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();
 
    ret = HDR_2_CLIENT(p);
 
    if (xmlMemTraceBlockAt == ret) {
    xmlGenericError(xmlGenericErrorContext,
            "%p : Malloc(%lu) Ok\n", xmlMemTraceBlockAt,
            (long unsigned)size);
    xmlMallocBreakpoint();
    }
 
    TEST_POINT
 
    return(ret);
}
 
void *
xmlMallocAtomicLoc(size_t size, const char * file, int line)
{
    MEMHDR *p;
    void *ret;
 
    xmlInitParser();
 
    TEST_POINT
 
    if (size > (MAX_SIZE_T - RESERVE_SIZE)) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMallocAtomicLoc : Unsigned overflow\n");
    return(NULL);
    }
 
    p = (MEMHDR *) malloc(RESERVE_SIZE+size);
 
    if (!p) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMallocAtomicLoc : Out of free space\n");
    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);
 
    if (xmlMemStopAtBlock == p->mh_number) xmlMallocBreakpoint();
 
    ret = HDR_2_CLIENT(p);
 
    if (xmlMemTraceBlockAt == ret) {
    xmlGenericError(xmlGenericErrorContext,
            "%p : Malloc(%lu) Ok\n", xmlMemTraceBlockAt,
            (long unsigned)size);
    xmlMallocBreakpoint();
    }
 
    TEST_POINT
 
    return(ret);
}
void *
xmlMemMalloc(size_t size)
{
    return(xmlMallocLoc(size, "none", 0));
}
 
void *
xmlReallocLoc(void *ptr,size_t size, const char * file, int line)
{
    MEMHDR *p, *tmp;
    unsigned long number;
 
    if (ptr == NULL)
        return(xmlMallocLoc(size, file, line));
 
    xmlInitParser();
    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 MEM_LIST
    debugmem_list_delete(p);
#endif
    xmlMutexUnlock(&xmlMemMutex);
 
    if (size > (MAX_SIZE_T - RESERVE_SIZE)) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlReallocLoc : Unsigned overflow\n");
    return(NULL);
    }
 
    tmp = (MEMHDR *) realloc(p,RESERVE_SIZE+size);
    if (!tmp) {
     free(p);
     goto error;
    }
    p = tmp;
    if (xmlMemTraceBlockAt == ptr) {
    xmlGenericError(xmlGenericErrorContext,
            "%p : Realloced(%lu -> %lu) Ok\n",
            xmlMemTraceBlockAt, (long unsigned)p->mh_size,
            (long unsigned)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
 
    return(HDR_2_CLIENT(p));
 
error:
    return(NULL);
}
 
void *
xmlMemRealloc(void *ptr,size_t size) {
    return(xmlReallocLoc(ptr, size, "none", 0));
}
 
void
xmlMemFree(void *ptr)
{
    MEMHDR *p;
    char *target;
 
    if (ptr == NULL)
    return;
 
    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 MEM_LIST
    debugmem_list_delete(p);
#endif
    xmlMutexUnlock(&xmlMemMutex);
 
    free(p);
 
    TEST_POINT
 
    return;
 
error:
    xmlGenericError(xmlGenericErrorContext,
        "xmlMemFree(%p) error\n", ptr);
    xmlMallocBreakpoint();
    return;
}
 
char *
xmlMemStrdupLoc(const char *str, const char *file, int line)
{
    char *s;
    size_t size = strlen(str) + 1;
    MEMHDR *p;
 
    xmlInitParser();
    TEST_POINT
 
    if (size > (MAX_SIZE_T - RESERVE_SIZE)) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlMemStrdupLoc : Unsigned overflow\n");
    return(NULL);
    }
 
    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();
 
    strcpy(s,str);
 
    TEST_POINT
 
    if (xmlMemTraceBlockAt == s) {
    xmlGenericError(xmlGenericErrorContext,
            "%p : Strdup() Ok\n", xmlMemTraceBlockAt);
    xmlMallocBreakpoint();
    }
 
    return(s);
 
error:
    return(NULL);
}
 
char *
xmlMemoryStrdup(const char *str) {
    return(xmlMemStrdupLoc(str, "none", 0));
}
 
size_t
xmlMemSize(void *ptr) {
    MEMHDR *p;
 
    if (ptr == NULL)
    return(0);
 
    p = CLIENT_2_HDR(ptr);
    if (p->mh_tag != MEMTAG)
        return(0);
 
    return(p->mh_size);
}
 
int
xmlMemUsed(void) {
    return(debugMemSize);
}
 
int
xmlMemBlocks(void) {
    int res;
 
    xmlMutexLock(&xmlMemMutex);
    res = debugMemBlocks;
    xmlMutexUnlock(&xmlMemMutex);
    return(res);
}
 
void
xmlMemDisplayLast(FILE *fp, long nbBytes)
{
#ifdef MEM_LIST
    MEMHDR *p;
    unsigned idx;
    int     nb = 0;
#endif
    FILE *old_fp = fp;
 
    if (nbBytes <= 0)
        return;
 
    if (fp == NULL) {
    fp = fopen(".memorylist", "w");
    if (fp == NULL)
        return;
    }
 
#ifdef MEM_LIST
    fprintf(fp,"   Last %li MEMORY ALLOCATED : %lu, MAX was %lu\n",
            nbBytes, debugMemSize, debugMaxMemSize);
    fprintf(fp,"BLOCK  NUMBER   SIZE  TYPE\n");
    idx = 0;
    xmlMutexLock(&xmlMemMutex);
    p = memlist;
    while ((p) && (nbBytes > 0)) {
      fprintf(fp,"%-5u  %6lu %6lu ",idx++,p->mh_number,
          (unsigned long)p->mh_size);
        switch (p->mh_type) {
           case STRDUP_TYPE:fprintf(fp,"strdup()  in ");break;
           case MALLOC_TYPE:fprintf(fp,"malloc()  in ");break;
           case REALLOC_TYPE:fprintf(fp,"realloc() in ");break;
           case MALLOC_ATOMIC_TYPE:fprintf(fp,"atomicmalloc()  in ");break;
           case REALLOC_ATOMIC_TYPE:fprintf(fp,"atomicrealloc() in ");break;
           default:
            fprintf(fp,"Unknown memory block, may be corrupted");
        xmlMutexUnlock(&xmlMemMutex);
        if (old_fp == NULL)
            fclose(fp);
        return;
        }
    if (p->mh_file != NULL) fprintf(fp,"%s(%u)", p->mh_file, p->mh_line);
        if (p->mh_tag != MEMTAG)
          fprintf(fp,"  INVALID");
        nb++;
 
        fprintf(fp,"\n");
    nbBytes -= (unsigned long)p->mh_size;
        p = p->mh_next;
    }
    xmlMutexUnlock(&xmlMemMutex);
#else
    fprintf(fp,"Memory list not compiled (MEM_LIST not defined !)\n");
#endif
    if (old_fp == NULL)
    fclose(fp);
}
 
void
xmlMemDisplay(FILE *fp)
{
#ifdef MEM_LIST
    MEMHDR *p;
    unsigned idx;
    int     nb = 0;
    time_t currentTime;
    char buf[500];
    struct tm * tstruct;
#endif
    FILE *old_fp = fp;
 
    if (fp == NULL) {
    fp = fopen(".memorylist", "w");
    if (fp == NULL)
        return;
    }
 
#ifdef MEM_LIST
    currentTime = time(NULL);
    tstruct = localtime(&currentTime);
    strftime(buf, sizeof(buf) - 1, "%I:%M:%S %p", tstruct);
    fprintf(fp,"      %s\n\n", buf);
 
 
    fprintf(fp,"      MEMORY ALLOCATED : %lu, MAX was %lu\n",
            debugMemSize, debugMaxMemSize);
    fprintf(fp,"BLOCK  NUMBER   SIZE  TYPE\n");
    idx = 0;
    xmlMutexLock(&xmlMemMutex);
    p = memlist;
    while (p) {
      fprintf(fp,"%-5u  %6lu %6lu ",idx++,p->mh_number,
          (unsigned long)p->mh_size);
        switch (p->mh_type) {
           case STRDUP_TYPE:fprintf(fp,"strdup()  in ");break;
           case MALLOC_TYPE:fprintf(fp,"malloc()  in ");break;
           case REALLOC_TYPE:fprintf(fp,"realloc() in ");break;
           case MALLOC_ATOMIC_TYPE:fprintf(fp,"atomicmalloc()  in ");break;
           case REALLOC_ATOMIC_TYPE:fprintf(fp,"atomicrealloc() in ");break;
           default:
            fprintf(fp,"Unknown memory block, may be corrupted");
        xmlMutexUnlock(&xmlMemMutex);
        if (old_fp == NULL)
            fclose(fp);
        return;
        }
    if (p->mh_file != NULL) fprintf(fp,"%s(%u)", p->mh_file, p->mh_line);
        if (p->mh_tag != MEMTAG)
          fprintf(fp,"  INVALID");
        nb++;
 
        fprintf(fp,"\n");
        p = p->mh_next;
    }
    xmlMutexUnlock(&xmlMemMutex);
#else
    fprintf(fp,"Memory list not compiled (MEM_LIST not defined !)\n");
#endif
    if (old_fp == NULL)
    fclose(fp);
}
 
#ifdef MEM_LIST
 
static void debugmem_list_add(MEMHDR *p)
{
     p->mh_next = memlist;
     p->mh_prev = NULL;
     if (memlist) memlist->mh_prev = p;
     memlist = p;
}
 
static void debugmem_list_delete(MEMHDR *p)
{
     if (p->mh_next)
     p->mh_next->mh_prev = p->mh_prev;
     if (p->mh_prev)
     p->mh_prev->mh_next = p->mh_next;
     else memlist = p->mh_next;
}
 
#endif
 
/*
 * debugmem_tag_error:
 *
 * internal error function.
 */
 
static void debugmem_tag_error(void *p)
{
     xmlGenericError(xmlGenericErrorContext,
         "Memory tag error occurs :%p \n\t bye\n", p);
#ifdef MEM_LIST
     if (stderr)
     xmlMemDisplay(stderr);
#endif
}
 
#ifdef MEM_LIST
static FILE *xmlMemoryDumpFile = NULL;
#endif
 
void
xmlMemShow(FILE *fp, int nr ATTRIBUTE_UNUSED)
{
#ifdef MEM_LIST
    MEMHDR *p;
#endif
 
    if (fp != NULL)
    fprintf(fp,"      MEMORY ALLOCATED : %lu, MAX was %lu\n",
        debugMemSize, debugMaxMemSize);
#ifdef MEM_LIST
    xmlMutexLock(&xmlMemMutex);
    if (nr > 0) {
    fprintf(fp,"NUMBER   SIZE  TYPE   WHERE\n");
    p = memlist;
    while ((p) && nr > 0) {
          fprintf(fp,"%6lu %6lu ",p->mh_number,(unsigned long)p->mh_size);
        switch (p->mh_type) {
           case STRDUP_TYPE:fprintf(fp,"strdup()  in ");break;
           case MALLOC_TYPE:fprintf(fp,"malloc()  in ");break;
           case MALLOC_ATOMIC_TYPE:fprintf(fp,"atomicmalloc()  in ");break;
          case REALLOC_TYPE:fprintf(fp,"realloc() in ");break;
          case REALLOC_ATOMIC_TYPE:fprintf(fp,"atomicrealloc() in ");break;
        default:fprintf(fp,"   ???    in ");break;
        }
        if (p->mh_file != NULL)
            fprintf(fp,"%s(%u)", p->mh_file, p->mh_line);
        if (p->mh_tag != MEMTAG)
        fprintf(fp,"  INVALID");
        fprintf(fp,"\n");
        nr--;
        p = p->mh_next;
    }
    }
    xmlMutexUnlock(&xmlMemMutex);
#endif /* MEM_LIST */
}
 
void
xmlMemoryDump(void)
{
#ifdef MEM_LIST
    FILE *dump;
 
    if (debugMaxMemSize == 0)
    return;
    dump = fopen(".memdump", "w");
    if (dump == NULL)
    xmlMemoryDumpFile = stderr;
    else xmlMemoryDumpFile = dump;
 
    xmlMemDisplay(xmlMemoryDumpFile);
 
    if (dump != NULL) fclose(dump);
#endif /* MEM_LIST */
}
 
 
/****************************************************************
 *                              *
 *      Initialization Routines             *
 *                              *
 ****************************************************************/
 
int
xmlInitMemory(void) {
    xmlInitParser();
    return(0);
}
 
void
xmlInitMemoryInternal(void) {
     char *breakpoint;
     xmlInitMutex(&xmlMemMutex);
 
     breakpoint = getenv("XML_MEM_BREAKPOINT");
     if (breakpoint != NULL) {
         sscanf(breakpoint, "%ud", &xmlMemStopAtBlock);
     }
     breakpoint = getenv("XML_MEM_TRACE");
     if (breakpoint != NULL) {
         sscanf(breakpoint, "%p", &xmlMemTraceBlockAt);
     }
 
}
 
void
xmlCleanupMemory(void) {
}
 
void
xmlCleanupMemoryInternal(void) {
    /*
     * Don't clean up mutex on Windows. Global state destructors can call
     * malloc functions after xmlCleanupParser was called. If memory
     * debugging is enabled, xmlMemMutex can be used after cleanup.
     *
     * See python/tests/thread2.py
     */
#if !defined(LIBXML_THREAD_ENABLED) || !defined(_WIN32)
    xmlCleanupMutex(&xmlMemMutex);
#endif
}
 
int
xmlMemSetup(xmlFreeFunc freeFunc, xmlMallocFunc mallocFunc,
            xmlReallocFunc reallocFunc, xmlStrdupFunc strdupFunc) {
    if (freeFunc == NULL)
    return(-1);
    if (mallocFunc == NULL)
    return(-1);
    if (reallocFunc == NULL)
    return(-1);
    if (strdupFunc == NULL)
    return(-1);
    xmlFree = freeFunc;
    xmlMalloc = mallocFunc;
    xmlMallocAtomic = mallocFunc;
    xmlRealloc = reallocFunc;
    xmlMemStrdup = strdupFunc;
    return(0);
}
 
int
xmlMemGet(xmlFreeFunc *freeFunc, xmlMallocFunc *mallocFunc,
      xmlReallocFunc *reallocFunc, xmlStrdupFunc *strdupFunc) {
    if (freeFunc != NULL) *freeFunc = xmlFree;
    if (mallocFunc != NULL) *mallocFunc = xmlMalloc;
    if (reallocFunc != NULL) *reallocFunc = xmlRealloc;
    if (strdupFunc != NULL) *strdupFunc = xmlMemStrdup;
    return(0);
}
 
int
xmlGcMemSetup(xmlFreeFunc freeFunc, xmlMallocFunc mallocFunc,
              xmlMallocFunc mallocAtomicFunc, xmlReallocFunc reallocFunc,
          xmlStrdupFunc strdupFunc) {
    if (freeFunc == NULL)
    return(-1);
    if (mallocFunc == NULL)
    return(-1);
    if (mallocAtomicFunc == NULL)
    return(-1);
    if (reallocFunc == NULL)
    return(-1);
    if (strdupFunc == NULL)
    return(-1);
    xmlFree = freeFunc;
    xmlMalloc = mallocFunc;
    xmlMallocAtomic = mallocAtomicFunc;
    xmlRealloc = reallocFunc;
    xmlMemStrdup = strdupFunc;
    return(0);
}
 
int
xmlGcMemGet(xmlFreeFunc *freeFunc, xmlMallocFunc *mallocFunc,
            xmlMallocFunc *mallocAtomicFunc, xmlReallocFunc *reallocFunc,
        xmlStrdupFunc *strdupFunc) {
    if (freeFunc != NULL) *freeFunc = xmlFree;
    if (mallocFunc != NULL) *mallocFunc = xmlMalloc;
    if (mallocAtomicFunc != NULL) *mallocAtomicFunc = xmlMallocAtomic;
    if (reallocFunc != NULL) *reallocFunc = xmlRealloc;
    if (strdupFunc != NULL) *strdupFunc = xmlMemStrdup;
    return(0);
}