Fix T39209: Localizing materials could cause heisenbug with concurrent

depsgraph updates.

Material datablocks were localized by first making a regular datablock
copy, which always gets inserted into the bmain list, and then removing
it again from bmain.

Problem is that this localization happens in preview threads, which can
run while the depsgraph is also updating GPU materials. In case the
copying of materials takes any amount of time, this can cause the
depsgraph call to material_changed to use an invalid, localized material
and access invalid GPUMaterial lists which have already been freed for
the actual material.

Solution is to not add localized datablocks to the bmain lists in the
first place. bmain should be totally immutable during preview or render
threads.
This commit is contained in:
Sergey Sharybin 2014-03-21 13:44:38 +01:00 committed by Lukas Tönne
parent 7148c97796
commit c626462c0f
Notes: blender-bot 2023-02-14 10:59:09 +01:00
Referenced by issue #39209, Nodes in 2.70-RC2 and source build 211f08d extremely unstable (segfault crash)
4 changed files with 29 additions and 2 deletions

View File

@ -49,6 +49,7 @@ struct PropertyRNA;
void *BKE_libblock_alloc(struct Main *bmain, short type, const char *name) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
void *BKE_libblock_copy_ex(struct Main *bmain, struct ID *id) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
void *BKE_libblock_copy_nolib(struct ID *id) ATTR_NONNULL();
void *BKE_libblock_copy(struct ID *id) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
void BKE_libblock_copy_data(struct ID *id, const struct ID *id_from, const bool do_action);

View File

@ -808,6 +808,32 @@ void *BKE_libblock_copy_ex(Main *bmain, ID *id)
return idn;
}
void *BKE_libblock_copy_nolib(ID *id)
{
ID *idn;
size_t idn_len;
idn = alloc_libblock_notest(GS(id->name));
assert(idn != NULL);
BLI_strncpy(idn->name, id->name, sizeof(idn->name));
idn_len = MEM_allocN_len(idn);
if ((int)idn_len - (int)sizeof(ID) > 0) { /* signed to allow neg result */
const char *cp = (const char *)id;
char *cpn = (char *)idn;
memcpy(cpn + sizeof(ID), cp + sizeof(ID), idn_len - sizeof(ID));
}
id->newid = idn;
idn->flag |= LIB_NEW;
BKE_libblock_copy_data(idn, id, false);
return idn;
}
void *BKE_libblock_copy(ID *id)
{
return BKE_libblock_copy_ex(G.main, id);

View File

@ -734,6 +734,7 @@ Mask *BKE_mask_new(Main *bmain, const char *name)
return mask;
}
/* TODO(sergey): Use generic BKE_libblock_copy_nolib() instead. */
Mask *BKE_mask_copy_nolib(Mask *mask)
{
Mask *mask_new;

View File

@ -256,8 +256,7 @@ Material *localize_material(Material *ma)
Material *man;
int a;
man = BKE_libblock_copy(&ma->id);
BLI_remlink(&G.main->mat, man);
man = BKE_libblock_copy_nolib(&ma->id);
/* no increment for texture ID users, in previewrender.c it prevents decrement */
for (a = 0; a < MAX_MTEX; a++) {