[PATCH v2 xserver 1/2] xkb: Introduce helper function to handle similar reallocations.
Rami Ylimäki
rami.ylimaki at vincit.fi
Wed Mar 30 06:47:30 PDT 2011
This is preparation for a memory leak fix and doesn't contain any
functional changes.
Note that two variables are generally used for reallocation and
clearing of arrays: geom->sz_elems (reallocation) and geom->num_elems
(clearing). The interface of XkbGeomRealloc is deliberately kept
simple and it only accepts geom->sz_elems as argument, because that is
needed to determine whether the array needs to be resized. When the
array is cleared, we just assume that either geom->sz_elems and
geom->num_elems are synchronized to be equal or that unused elements
are cleared whenever geom->num_elems is set to be less than
geom->sz_elems without reallocation.
Reviewed-by: Erkki Seppälä <erkki.seppala at vincit.fi>
Signed-off-by: Rami Ylimäki <rami.ylimaki at vincit.fi>
---
xkb/XKBGAlloc.c | 64 +++++++++++++++++++++++++----
xkb/xkbUtils.c | 121 ++++++++++++++++---------------------------------------
xkb/xkbgeom.h | 20 +++++++++
3 files changed, 111 insertions(+), 94 deletions(-)
diff --git a/xkb/XKBGAlloc.c b/xkb/XKBGAlloc.c
index d1adea3..dbe0069 100644
--- a/xkb/XKBGAlloc.c
+++ b/xkb/XKBGAlloc.c
@@ -445,6 +445,57 @@ XkbFreeGeometry(XkbGeometryPtr geom,unsigned which,Bool freeMap)
/***====================================================================***/
+/**
+ * Resize and clear an XKB geometry item array. The array size may
+ * grow or shrink unlike in _XkbGeomAlloc.
+ *
+ * @param buffer[in,out] buffer to reallocate and clear
+ * @param szItems[in] currently allocated item count for "buffer"
+ * @param nrItems[in] required item count for "buffer"
+ * @param itemSize[in] size of a single item in "buffer"
+ * @param clearance[in] items to clear after reallocation
+ *
+ * @see _XkbGeomAlloc
+ *
+ * @return TRUE if reallocation succeeded. Otherwise FALSE is returned
+ * and contents of "buffer" aren't touched.
+ */
+Bool
+XkbGeomRealloc(void **buffer, int szItems, int nrItems,
+ int itemSize, XkbGeomClearance clearance)
+{
+ void *items;
+ int clearBegin;
+ /* Check validity of arguments. */
+ if (!buffer)
+ return FALSE;
+ items = *buffer;
+ if (!((items && (szItems > 0)) || (!items && !szItems)))
+ return FALSE;
+ /* Check if there is need to resize. */
+ if (nrItems != szItems)
+ if (!(items = realloc(items, nrItems * itemSize)))
+ return FALSE;
+ /* Clear specified items to zero. */
+ switch (clearance)
+ {
+ case XKB_GEOM_CLEAR_EXCESS:
+ clearBegin = szItems;
+ break;
+ case XKB_GEOM_CLEAR_ALL:
+ clearBegin = 0;
+ break;
+ case XKB_GEOM_CLEAR_NONE:
+ default:
+ clearBegin = nrItems;
+ break;
+ }
+ if (items && (clearBegin < nrItems))
+ memset((char *)items + (clearBegin * itemSize), 0, (nrItems - clearBegin) * itemSize);
+ *buffer = items;
+ return TRUE;
+}
+
static Status
_XkbGeomAlloc( void ** old,
unsigned short * num,
@@ -461,18 +512,15 @@ _XkbGeomAlloc( void ** old,
return Success;
*total= (*num)+num_new;
- if ((*old)!=NULL)
- (*old)= realloc((*old),(*total)*sz_elem);
- else (*old)= calloc((*total),sz_elem);
- if ((*old)==NULL) {
+
+ if (!XkbGeomRealloc(old, *num, *total, sz_elem, XKB_GEOM_CLEAR_EXCESS))
+ {
+ free(*old);
+ (*old)= NULL;
*total= *num= 0;
return BadAlloc;
}
- if (*num>0) {
- char *tmp= (char *)(*old);
- memset(&tmp[sz_elem*(*num)], 0, (num_new*sz_elem));
- }
return Success;
}
diff --git a/xkb/xkbUtils.c b/xkb/xkbUtils.c
index 14dc784..7fea194 100644
--- a/xkb/xkbUtils.c
+++ b/xkb/xkbUtils.c
@@ -1395,42 +1395,26 @@ _XkbCopyGeom(XkbDescPtr src, XkbDescPtr dst)
/* properties */
if (src->geom->num_properties) {
- if (src->geom->num_properties != dst->geom->sz_properties) {
- /* If we've got more properties in the destination than
- * the source, run through and free all the excess ones
- * first. */
- if (src->geom->num_properties < dst->geom->sz_properties) {
- for (i = src->geom->num_properties,
- dprop = dst->geom->properties + i;
- i < dst->geom->num_properties;
- i++, dprop++) {
- free(dprop->name);
- free(dprop->value);
- }
+ /* If we've got more properties in the destination than
+ * the source, run through and free all the excess ones
+ * first. */
+ if (src->geom->num_properties < dst->geom->sz_properties) {
+ for (i = src->geom->num_properties, dprop = dst->geom->properties + i;
+ i < dst->geom->num_properties;
+ i++, dprop++) {
+ free(dprop->name);
+ free(dprop->value);
}
-
- if (dst->geom->sz_properties)
- tmp = realloc(dst->geom->properties,
- src->geom->num_properties *
- sizeof(XkbPropertyRec));
- else
- tmp = malloc(src->geom->num_properties *
- sizeof(XkbPropertyRec));
- if (!tmp)
- return FALSE;
- dst->geom->properties = tmp;
}
+ /* Reallocate and clear all new items if the buffer grows. */
+ if (!XkbGeomRealloc((void **)&dst->geom->properties, dst->geom->sz_properties, src->geom->num_properties,
+ sizeof(XkbPropertyRec), XKB_GEOM_CLEAR_EXCESS))
+ return FALSE;
/* We don't set num_properties as we need it to try and avoid
* too much reallocing. */
dst->geom->sz_properties = src->geom->num_properties;
- if (dst->geom->sz_properties > dst->geom->num_properties) {
- memset(dst->geom->properties + dst->geom->num_properties, 0,
- (dst->geom->sz_properties - dst->geom->num_properties) *
- sizeof(XkbPropertyRec));
- }
-
for (i = 0,
sprop = src->geom->properties,
dprop = dst->geom->properties;
@@ -1479,36 +1463,20 @@ _XkbCopyGeom(XkbDescPtr src, XkbDescPtr dst)
/* colors */
if (src->geom->num_colors) {
- if (src->geom->num_colors != dst->geom->sz_colors) {
- if (src->geom->num_colors < dst->geom->sz_colors) {
- for (i = src->geom->num_colors,
- dcolor = dst->geom->colors + i;
- i < dst->geom->num_colors;
- i++, dcolor++) {
- free(dcolor->spec);
- }
+ if (src->geom->num_colors < dst->geom->sz_colors) {
+ for (i = src->geom->num_colors, dcolor = dst->geom->colors + i;
+ i < dst->geom->num_colors;
+ i++, dcolor++) {
+ free(dcolor->spec);
}
-
- if (dst->geom->sz_colors)
- tmp = realloc(dst->geom->colors,
- src->geom->num_colors *
- sizeof(XkbColorRec));
- else
- tmp = malloc(src->geom->num_colors *
- sizeof(XkbColorRec));
- if (!tmp)
- return FALSE;
- dst->geom->colors = tmp;
}
+ /* Reallocate and clear all new items if the buffer grows. */
+ if (!XkbGeomRealloc((void **)&dst->geom->colors, dst->geom->sz_colors, src->geom->num_colors,
+ sizeof(XkbColorRec), XKB_GEOM_CLEAR_EXCESS))
+ return FALSE;
dst->geom->sz_colors = src->geom->num_colors;
- if (dst->geom->sz_colors > dst->geom->num_colors) {
- memset(dst->geom->colors + dst->geom->num_colors, 0,
- (dst->geom->sz_colors - dst->geom->num_colors) *
- sizeof(XkbColorRec));
- }
-
for (i = 0,
scolor = src->geom->colors,
dcolor = dst->geom->colors;
@@ -1694,16 +1662,10 @@ _XkbCopyGeom(XkbDescPtr src, XkbDescPtr dst)
}
if (src->geom->num_sections) {
- if (dst->geom->sz_sections)
- tmp = realloc(dst->geom->sections,
- src->geom->num_sections *
- sizeof(XkbSectionRec));
- else
- tmp = malloc(src->geom->num_sections * sizeof(XkbSectionRec));
- if (!tmp)
+ /* Reallocate and clear all items. */
+ if (!XkbGeomRealloc((void **)&dst->geom->sections, dst->geom->sz_sections, src->geom->num_sections,
+ sizeof(XkbSectionRec), XKB_GEOM_CLEAR_ALL))
return FALSE;
- memset(tmp, 0, src->geom->num_sections * sizeof(XkbSectionRec));
- dst->geom->sections = tmp;
dst->geom->num_sections = src->geom->num_sections;
dst->geom->sz_sections = src->geom->num_sections;
@@ -1810,17 +1772,10 @@ _XkbCopyGeom(XkbDescPtr src, XkbDescPtr dst)
}
if (src->geom->num_doodads) {
- if (dst->geom->sz_doodads)
- tmp = realloc(dst->geom->doodads,
- src->geom->num_doodads *
- sizeof(XkbDoodadRec));
- else
- tmp = malloc(src->geom->num_doodads *
- sizeof(XkbDoodadRec));
- if (!tmp)
+ /* Reallocate and clear all items. */
+ if (!XkbGeomRealloc((void **)&dst->geom->doodads, dst->geom->sz_doodads, src->geom->num_doodads,
+ sizeof(XkbDoodadRec), XKB_GEOM_CLEAR_ALL))
return FALSE;
- memset(tmp, 0, src->geom->num_doodads * sizeof(XkbDoodadRec));
- dst->geom->doodads = tmp;
dst->geom->sz_doodads = src->geom->num_doodads;
@@ -1857,20 +1812,14 @@ _XkbCopyGeom(XkbDescPtr src, XkbDescPtr dst)
/* key aliases */
if (src->geom->num_key_aliases) {
- if (src->geom->num_key_aliases != dst->geom->sz_key_aliases) {
- if (dst->geom->sz_key_aliases)
- tmp = realloc(dst->geom->key_aliases,
- src->geom->num_key_aliases *
- 2 * XkbKeyNameLength);
- else
- tmp = malloc(src->geom->num_key_aliases *
- 2 * XkbKeyNameLength);
- if (!tmp)
- return FALSE;
- dst->geom->key_aliases = tmp;
+ /* Reallocate but don't clear any items. There is no need
+ * to clear anything because data is immediately copied
+ * over the whole memory area with memcpy. */
+ if (!XkbGeomRealloc((void **)&dst->geom->key_aliases, dst->geom->sz_key_aliases, src->geom->num_key_aliases,
+ 2 * XkbKeyNameLength, XKB_GEOM_CLEAR_NONE))
+ return FALSE;
- dst->geom->sz_key_aliases = src->geom->num_key_aliases;
- }
+ dst->geom->sz_key_aliases = src->geom->num_key_aliases;
memcpy(dst->geom->key_aliases, src->geom->key_aliases,
src->geom->num_key_aliases * 2 * XkbKeyNameLength);
diff --git a/xkb/xkbgeom.h b/xkb/xkbgeom.h
index fe4da38..d10b956 100644
--- a/xkb/xkbgeom.h
+++ b/xkb/xkbgeom.h
@@ -311,6 +311,17 @@ typedef struct _XkbGeometrySizes {
unsigned short num_key_aliases;
} XkbGeometrySizesRec,*XkbGeometrySizesPtr;
+/**
+ * Specifies which items should be cleared in an XKB geometry array
+ * when the array is reallocated.
+ */
+typedef enum
+{
+ XKB_GEOM_CLEAR_NONE, /* Don't clear any items, just reallocate. */
+ XKB_GEOM_CLEAR_EXCESS, /* Clear new extra items after reallocation. */
+ XKB_GEOM_CLEAR_ALL /* Clear all items after reallocation. */
+} XkbGeomClearance;
+
extern XkbPropertyPtr
XkbAddGeomProperty(
XkbGeometryPtr /* geom */,
@@ -507,6 +518,15 @@ XkbFreeGeometry(
Bool /* freeMap */
);
+extern Bool
+XkbGeomRealloc(
+ void ** /* buffer */,
+ int /* szItems */,
+ int /* nrItems */,
+ int /* itemSize */,
+ XkbGeomClearance /* clearance */
+);
+
extern Status
XkbAllocGeomProps(
XkbGeometryPtr /* geom */,
--
1.6.3.3
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