Fix T82769: remove thread local data from PTCacheMem

The issue was that the same point cache was read by multiple
threads at the same time (the same object was evaluated for
render and for the viewport).
Both threads incremented PTCacheMem->cur which lead to the crash.

The fix is to remove the PTCacheMem->cur and store it on the
stack instead. This way every thread has its own cur.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D9606

1 files changed, 5 insertions, 3 deletions

diff --git a/source/blender/blenkernel/BKE_pointcache.h b/source/blender/blenkernel/BKE_pointcache.h
index f8e04b75b3d..9285a0a30eb 100644
--- a/source/blender/blenkernel/BKE_pointcache.h
+++ b/source/blender/blenkernel/BKE_pointcache.h
@@ -322,9 +322,11 @@ int BKE_ptcache_data_size(int data_type);
 int BKE_ptcache_mem_index_find(struct PTCacheMem *pm, unsigned int index);
 
 /* Memory cache read/write helpers. */
-void BKE_ptcache_mem_pointers_init(struct PTCacheMem *pm);
-void BKE_ptcache_mem_pointers_incr(struct PTCacheMem *pm);
-int BKE_ptcache_mem_pointers_seek(int point_index, struct PTCacheMem *pm);
+void BKE_ptcache_mem_pointers_init(struct PTCacheMem *pm, void *cur[BPHYS_TOT_DATA]);
+void BKE_ptcache_mem_pointers_incr(void *cur[BPHYS_TOT_DATA]);
+int BKE_ptcache_mem_pointers_seek(int point_index,
+                                  struct PTCacheMem *pm,
+                                  void *cur[BPHYS_TOT_DATA]);
 
 /* Main cache reading call. */
 int BKE_ptcache_read(PTCacheID *pid, float cfra, bool no_extrapolate_old);