talloc.c

samba-3.0.22.tar.gz 编译smb服务器的源码

	if (tc->prev) {
		tc->prev->next = tc;
	}
	if (tc->next) {
		tc->next->prev = tc;
	}

	tc->size = size;
	talloc_set_name_const(TC_PTR_FROM_CHUNK(tc), name);

	return TC_PTR_FROM_CHUNK(tc);
}

/* 
   move a lump of memory from one talloc context to another return the
   ptr on success, or NULL if it could not be transferred.
   passing NULL as ptr will always return NULL with no side effects.
*/
void *talloc_steal(const void *new_ctx, const void *ptr)
{
	struct talloc_chunk *tc, *new_tc;

	if (!ptr) {
		return NULL;
	}

	if (new_ctx == NULL) {
		new_ctx = null_context;
	}

	tc = talloc_chunk_from_ptr(ptr);

	if (new_ctx == NULL) {
		if (tc->parent) {
			_TLIST_REMOVE(tc->parent->child, tc);
			if (tc->parent->child) {
				tc->parent->child->parent = tc->parent;
			}
		} else {
			if (tc->prev) tc->prev->next = tc->next;
			if (tc->next) tc->next->prev = tc->prev;
		}
		
		tc->parent = tc->next = tc->prev = NULL;
		return discard_const_p(void, ptr);
	}

	new_tc = talloc_chunk_from_ptr(new_ctx);

	if (tc == new_tc) {
		return discard_const_p(void, ptr);
	}

	if (tc->parent) {
		_TLIST_REMOVE(tc->parent->child, tc);
		if (tc->parent->child) {
			tc->parent->child->parent = tc->parent;
		}
	} else {
		if (tc->prev) tc->prev->next = tc->next;
		if (tc->next) tc->next->prev = tc->prev;
	}

	tc->parent = new_tc;
	if (new_tc->child) new_tc->child->parent = NULL;
	_TLIST_ADD(new_tc->child, tc);

	return discard_const_p(void, ptr);
}

/*
  return the total size of a talloc pool (subtree)
*/
off_t talloc_total_size(const void *ptr)
{
	off_t total = 0;
	struct talloc_chunk *c, *tc;
	
	if (ptr == NULL) {
		ptr = null_context;
	}
	if (ptr == NULL) {
		return 0;
	}

	tc = talloc_chunk_from_ptr(ptr);

	if (tc->flags & TALLOC_FLAG_LOOP) {
		return 0;
	}

	tc->flags |= TALLOC_FLAG_LOOP;

	total = tc->size;
	for (c=tc->child;c;c=c->next) {
		total += talloc_total_size(TC_PTR_FROM_CHUNK(c));
	}

	tc->flags &= ~TALLOC_FLAG_LOOP;

	return total;
}

/*
  return the total number of blocks in a talloc pool (subtree)
*/
off_t talloc_total_blocks(const void *ptr)
{
	off_t total = 0;
	struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr);

	if (tc->flags & TALLOC_FLAG_LOOP) {
		return 0;
	}

	tc->flags |= TALLOC_FLAG_LOOP;

	total++;
	for (c=tc->child;c;c=c->next) {
		total += talloc_total_blocks(TC_PTR_FROM_CHUNK(c));
	}

	tc->flags &= ~TALLOC_FLAG_LOOP;

	return total;
}

/*
  return the number of external references to a pointer
*/
static int talloc_reference_count(const void *ptr)
{
	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
	struct talloc_reference_handle *h;
	int ret = 0;

	for (h=tc->refs;h;h=h->next) {
		ret++;
	}
	return ret;
}

/*
  report on memory usage by all children of a pointer, giving a full tree view
*/
void talloc_report_depth(const void *ptr, FILE *f, int depth)
{
	struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr);

	if (tc->flags & TALLOC_FLAG_LOOP) {
		return;
	}

	tc->flags |= TALLOC_FLAG_LOOP;

	for (c=tc->child;c;c=c->next) {
		if (c->name == TALLOC_MAGIC_REFERENCE) {
			struct talloc_reference_handle *handle = TC_PTR_FROM_CHUNK(c);
			const char *name2 = talloc_get_name(handle->ptr);
			fprintf(f, "%*sreference to: %s\n", depth*4, "", name2);
		} else {
			const char *name = talloc_get_name(TC_PTR_FROM_CHUNK(c));
			fprintf(f, "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d)\n", 
				depth*4, "",
				name,
				(unsigned long)talloc_total_size(TC_PTR_FROM_CHUNK(c)),
				(unsigned long)talloc_total_blocks(TC_PTR_FROM_CHUNK(c)),
				talloc_reference_count(TC_PTR_FROM_CHUNK(c)));
			talloc_report_depth(TC_PTR_FROM_CHUNK(c), f, depth+1);
		}
	}
	tc->flags &= ~TALLOC_FLAG_LOOP;
}

/*
  report on memory usage by all children of a pointer, giving a full tree view
*/
void talloc_report_full(const void *ptr, FILE *f)
{
	if (ptr == NULL) {
		ptr = null_context;
	}
	if (ptr == NULL) return;

	fprintf(f,"full talloc report on '%s' (total %lu bytes in %lu blocks)\n", 
		talloc_get_name(ptr), 
		(unsigned long)talloc_total_size(ptr),
		(unsigned long)talloc_total_blocks(ptr));

	talloc_report_depth(ptr, f, 1);
	fflush(f);
}

/*
  report on memory usage by all children of a pointer
*/
void talloc_report(const void *ptr, FILE *f)
{
	struct talloc_chunk *c, *tc;

	if (ptr == NULL) {
		ptr = null_context;
	}
	if (ptr == NULL) return;
       
	fprintf(f,"talloc report on '%s' (total %lu bytes in %lu blocks)\n", 
		talloc_get_name(ptr), 
		(unsigned long)talloc_total_size(ptr),
		(unsigned long)talloc_total_blocks(ptr));

	tc = talloc_chunk_from_ptr(ptr);

	for (c=tc->child;c;c=c->next) {
		fprintf(f, "\t%-30s contains %6lu bytes in %3lu blocks\n", 
			talloc_get_name(TC_PTR_FROM_CHUNK(c)),
			(unsigned long)talloc_total_size(TC_PTR_FROM_CHUNK(c)),
			(unsigned long)talloc_total_blocks(TC_PTR_FROM_CHUNK(c)));
	}
	fflush(f);
}

/*
  report on any memory hanging off the null context
*/
static void talloc_report_null(void)
{
	if (talloc_total_size(null_context) != 0) {
		talloc_report(null_context, stderr);
	}
}

/*
  report on any memory hanging off the null context
*/
static void talloc_report_null_full(void)
{
	if (talloc_total_size(null_context) != 0) {
		talloc_report_full(null_context, stderr);
	}
}

/*
  enable tracking of the NULL context
*/
void talloc_enable_null_tracking(void)
{
	if (null_context == NULL) {
		null_context = talloc_named_const(NULL, 0, "null_context");
	}
}

#ifdef _SAMBA_BUILD_
/* Ugly calls to Samba-specific sprintf_append... JRA. */

/*
  report on memory usage by all children of a pointer, giving a full tree view
*/
static void talloc_report_depth_str(const void *ptr, char **pps, ssize_t *plen, size_t *pbuflen, int depth)
{
	struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr);

	if (tc->flags & TALLOC_FLAG_LOOP) {
		return;
	}

	tc->flags |= TALLOC_FLAG_LOOP;

	for (c=tc->child;c;c=c->next) {
		if (c->name == TALLOC_MAGIC_REFERENCE) {
			struct talloc_reference_handle *handle = TC_PTR_FROM_CHUNK(c);
			const char *name2 = talloc_get_name(handle->ptr);

			sprintf_append(NULL, pps, plen, pbuflen,
				"%*sreference to: %s\n", depth*4, "", name2);

		} else {
			const char *name = talloc_get_name(TC_PTR_FROM_CHUNK(c));

			sprintf_append(NULL, pps, plen, pbuflen,
				"%*s%-30s contains %6lu bytes in %3lu blocks (ref %d)\n", 
				depth*4, "",
				name,
				(unsigned long)talloc_total_size(TC_PTR_FROM_CHUNK(c)),
				(unsigned long)talloc_total_blocks(TC_PTR_FROM_CHUNK(c)),
				talloc_reference_count(TC_PTR_FROM_CHUNK(c)));

			talloc_report_depth_str(TC_PTR_FROM_CHUNK(c), pps, plen, pbuflen, depth+1);
		}
	}
	tc->flags &= ~TALLOC_FLAG_LOOP;
}

/*
  report on memory usage by all children of a pointer
*/
char *talloc_describe_all(void)
{
	ssize_t len = 0;
	size_t buflen = 512;
	char *s = NULL;

	if (null_context == NULL) {
		return NULL;
	}

	sprintf_append(NULL, &s, &len, &buflen,
		"full talloc report on '%s' (total %lu bytes in %lu blocks)\n", 
		talloc_get_name(null_context), 
		(unsigned long)talloc_total_size(null_context),
		(unsigned long)talloc_total_blocks(null_context));

	if (!s) {
		return NULL;
	}
	talloc_report_depth_str(null_context, &s, &len, &buflen, 1);
	return s;
}
#endif

/*
  enable leak reporting on exit
*/
void talloc_enable_leak_report(void)
{
	talloc_enable_null_tracking();
	atexit(talloc_report_null);
}

/*
  enable full leak reporting on exit
*/
void talloc_enable_leak_report_full(void)
{
	talloc_enable_null_tracking();
	atexit(talloc_report_null_full);
}

/* 
   talloc and zero memory. 
*/
void *_talloc_zero(const void *ctx, size_t size, const char *name)
{
	void *p = talloc_named_const(ctx, size, name);

	if (p) {
		memset(p, '\0', size);
	}

	return p;
}


/*
  memdup with a talloc. 
*/
void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name)
{
	void *newp = talloc_named_const(t, size, name);

	if (newp) {
		memcpy(newp, p, size);
	}

	return newp;
}

/*
  strdup with a talloc 
*/
char *talloc_strdup(const void *t, const char *p)
{
	char *ret;
	if (!p) {
		return NULL;
	}
	ret = talloc_memdup(t, p, strlen(p) + 1);
	if (ret) {
		talloc_set_name_const(ret, ret);
	}
	return ret;
}

/*
 append to a talloced string 
*/
char *talloc_append_string(const void *t, char *orig, const char *append)
{
	char *ret;
	size_t olen = strlen(orig);
	size_t alenz = strlen(append) + 1;

	if (!append)
		return orig;

	ret = talloc_realloc(t, orig, char, olen + alenz);
	if (!ret)
		return NULL;

	/* append the string with the trailing \0 */
	memcpy(&ret[olen], append, alenz);

	return ret;
}

/*
  strndup with a talloc 
*/
char *talloc_strndup(const void *t, const char *p, size_t n)
{
	size_t len;
	char *ret;

	for (len=0; len<n && p[len]; len++) ;

	ret = _talloc(t, len + 1);
	if (!ret) { return NULL; }
	memcpy(ret, p, len);
	ret[len] = 0;
	talloc_set_name_const(ret, ret);
	return ret;
}

#ifndef VA_COPY
#ifdef HAVE_VA_COPY
#define VA_COPY(dest, src) va_copy(dest, src)
#elif defined(HAVE___VA_COPY)
#define VA_COPY(dest, src) __va_copy(dest, src)
#else
#define VA_COPY(dest, src) (dest) = (src)
#endif
#endif

char *talloc_vasprintf(const void *t, const char *fmt, va_list ap)
{	
	int len;
	char *ret;
	va_list ap2;
	
	VA_COPY(ap2, ap);

	len = vsnprintf(NULL, 0, fmt, ap2);

	ret = _talloc(t, len+1);
	if (ret) {
		VA_COPY(ap2, ap);
		vsnprintf(ret, len+1, fmt, ap2);
		talloc_set_name_const(ret, ret);
	}

	return ret;
}


/*
  Perform string formatting, and return a pointer to newly allocated
  memory holding the result, inside a memory pool.
 */
char *talloc_asprintf(const void *t, const char *fmt, ...)
{
	va_list ap;
	char *ret;

	va_start(ap, fmt);
	ret = talloc_vasprintf(t, fmt, ap);
	va_end(ap);
	return ret;
}


/**
 * Realloc @p s to append the formatted result of @p fmt and @p ap,
 * and return @p s, which may have moved.  Good for gradually
 * accumulating output into a string buffer.
 **/

static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);

static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap)
{	
	struct talloc_chunk *tc;
	int len, s_len;
	va_list ap2;

	if (s == NULL) {
		return talloc_vasprintf(NULL, fmt, ap);
	}

	tc = talloc_chunk_from_ptr(s);

	VA_COPY(ap2, ap);

	s_len = tc->size - 1;
	len = vsnprintf(NULL, 0, fmt, ap2);

	s = talloc_realloc(NULL, s, char, s_len + len+1);
	if (!s) return NULL;

	VA_COPY(ap2, ap);

	vsnprintf(s+s_len, len+1, fmt, ap2);
	talloc_set_name_const(s, s);

	return s;
}

/*
  Realloc @p s to append the formatted result of @p fmt and return @p
  s, which may have moved.  Good for gradually accumulating output
  into a string buffer.
 */
char *talloc_asprintf_append(char *s, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	s = talloc_vasprintf_append(s, fmt, ap);
	va_end(ap);
	return s;
}

/*
  alloc an array, checking for integer overflow in the array size
*/
void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name)
{
	if (count >= MAX_TALLOC_SIZE/el_size) {
		return NULL;
	}
	return talloc_named_const(ctx, el_size * count, name);
}

/*
  alloc an zero array, checking for integer overflow in the array size
*/
void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name)
{
	if (count >= MAX_TALLOC_SIZE/el_size) {
		return NULL;
	}
	return _talloc_zero(ctx, el_size * count, name);
}


/*
  realloc an array, checking for integer overflow in the array size
*/
void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name)
{
	if (count >= MAX_TALLOC_SIZE/el_size) {
		return NULL;
	}
	return _talloc_realloc(ctx, ptr, el_size * count, name);
}

/*
  a function version of talloc_realloc(), so it can be passed as a function pointer
  to libraries that want a realloc function (a realloc function encapsulates
  all the basic capabilities of an allocation library, which is why this is useful)
*/
void *talloc_realloc_fn(const void *context, void *ptr, size_t size)
{
	return _talloc_realloc(context, ptr, size, NULL);
}


static void talloc_autofree(void)
{
	talloc_free(cleanup_context);
	cleanup_context = NULL;
}

/*
  return a context which will be auto-freed on exit
  this is useful for reducing the noise in leak reports
*/
void *talloc_autofree_context(void)
{
	if (cleanup_context == NULL) {
		cleanup_context = talloc_named_const(NULL, 0, "autofree_context");
		atexit(talloc_autofree);
	}
	return cleanup_context;
}

size_t talloc_get_size(const void *context)
{
	struct talloc_chunk *tc;

	if (context == NULL)
		return 0;

	tc = talloc_chunk_from_ptr(context);

	return tc->size;
}

/*
  find a parent of this context that has the given name, if any
*/
void *talloc_find_parent_byname(const void *context, const char *name)
{
	struct talloc_chunk *tc;

	if (context == NULL) {
		return NULL;
	}

	tc = talloc_chunk_from_ptr(context);
	while (tc) {
		if (tc->name && strcmp(tc->name, name) == 0) {
			return TC_PTR_FROM_CHUNK(tc);
		}
		while (tc && tc->prev) tc = tc->prev;
		tc = tc->parent;
	}
	return NULL;
}

/*
  show the parentage of a context
*/
void talloc_show_parents(const void *context, FILE *file)
{
	struct talloc_chunk *tc;

	if (context == NULL) {
		fprintf(file, "talloc no parents for NULL\n");
		return;
	}

	tc = talloc_chunk_from_ptr(context);
	fprintf(file, "talloc parents of '%s'\n", talloc_get_name(context));
	while (tc) {
		fprintf(file, "\t'%s'\n", talloc_get_name(TC_PTR_FROM_CHUNK(tc)));
		while (tc && tc->prev) tc = tc->prev;
		tc = tc->parent;
	}
}