6 files changed, 19 insertions, 8 deletions

diff --git a/source/blender/blenkernel/BKE_library.h b/source/blender/blenkernel/BKE_library.h
index 55c71ff49cf..c78ea21b9dd 100644
--- a/source/blender/blenkernel/BKE_library.h
+++ b/source/blender/blenkernel/BKE_library.h
@@ -77,7 +77,7 @@ int set_listbasepointers(struct Main *main, struct ListBase **lb);
 void BKE_libblock_free(struct Main *bmain, void *idv);
 void BKE_libblock_free_ex(struct Main *bmain, void *idv, bool do_id_user);
 void BKE_libblock_free_us(struct Main *bmain, void *idv);
-void BKE_libblock_free_data(struct ID *id);
+void BKE_libblock_free_data(struct Main *bmain, struct ID *id);
 
 
 /* Main API */
diff --git a/source/blender/blenkernel/BKE_main.h b/source/blender/blenkernel/BKE_main.h
index 721866daff5..ade5733fa4f 100644
--- a/source/blender/blenkernel/BKE_main.h
+++ b/source/blender/blenkernel/BKE_main.h
@@ -41,6 +41,7 @@
  *
  */
 #include "DNA_listBase.h"
+#include "BLI_threads.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -96,6 +97,8 @@ typedef struct Main {
 
 	/* Evaluation context used by viewport */
 	struct EvaluationContext *eval_ctx;
+
+	SpinLock lock;
 } Main;
 
 #define MAIN_VERSION_ATLEAST(main, ver, subver) \
diff --git a/source/blender/blenkernel/intern/library.c b/source/blender/blenkernel/intern/library.c
index fe2d1481581..9a74edb03c9 100644
--- a/source/blender/blenkernel/intern/library.c
+++ b/source/blender/blenkernel/intern/library.c
@@ -747,12 +747,14 @@ void *BKE_libblock_alloc(Main *bmain, short type, const char *name)
 	
 	id = alloc_libblock_notest(type);
 	if (id) {
+		BLI_spin_lock(&bmain->lock);
 		BLI_addtail(lb, id);
 		id->us = 1;
 		id->icon_id = 0;
 		*( (short *)id->name) = type;
 		new_id(lb, id, name);
 		/* alphabetic insertion: is in new_id */
+		BLI_spin_unlock(&bmain->lock);
 	}
 	DAG_id_type_tag(bmain, type);
 	return id;
@@ -881,10 +883,8 @@ static void animdata_dtar_clear_cb(ID *UNUSED(id), AnimData *adt, void *userdata
 	}
 }
 
-void BKE_libblock_free_data(ID *id)
+void BKE_libblock_free_data(Main *bmain, ID *id)
 {
-	Main *bmain = G.main;  /* should eventually be an arg */
-	
 	if (id->properties) {
 		IDP_FreeProperty(id->properties);
 		MEM_freeN(id->properties);
@@ -1008,12 +1008,15 @@ void BKE_libblock_free_ex(Main *bmain, void *idv, bool do_id_user)
 	}
 
 	/* avoid notifying on removed data */
+	BLI_spin_lock(&bmain->lock);
+
 	if (free_notifier_reference_cb)
 		free_notifier_reference_cb(id);
 
 	BLI_remlink(lb, id);
 
-	BKE_libblock_free_data(id);
+	BKE_libblock_free_data(bmain, id);
+	BLI_spin_unlock(&bmain->lock);
 
 	MEM_freeN(id);
 }
@@ -1043,7 +1046,9 @@ void BKE_libblock_free_us(Main *bmain, void *idv)      /* test users */
 Main *BKE_main_new(void)
 {
 	Main *bmain = MEM_callocN(sizeof(Main), "new main");
-	bmain->eval_ctx = MEM_callocN(sizeof(EvaluationContext), "EvaluationContext");
+	bmain->eval_ctx = MEM_callocN(sizeof(EvaluationContext),
+	                              "EvaluationContext");
+	BLI_spin_init(&bmain->lock);
 	return bmain;
 }
 
@@ -1106,6 +1111,7 @@ void BKE_main_free(Main *mainvar)
 		}
 	}
 
+	BLI_spin_end(&mainvar->lock);
 	MEM_freeN(mainvar->eval_ctx);
 	MEM_freeN(mainvar);
 }
diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index de3aea9267f..4f6f234c6e1 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -780,11 +780,13 @@ void test_object_materials(Main *bmain, ID *id)
 		return;
 	}
 
+	BLI_spin_lock(&bmain->lock);
 	for (ob = bmain->object.first; ob; ob = ob->id.next) {
 		if (ob->data == id) {
 			BKE_material_resize_object(ob, *totcol, false);
 		}
 	}
+	BLI_spin_unlock(&bmain->lock);
 }
 
 void assign_material_id(ID *id, Material *ma, short act)
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index 7197d560bcc..7c6164a8174 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -2148,7 +2148,7 @@ Mesh *BKE_mesh_new_from_object(
 			 * if it didn't the curve did not have any segments or otherwise 
 			 * would have generated an empty mesh */
 			if (tmpobj->type != OB_MESH) {
-				BKE_libblock_free_us(G.main, tmpobj);
+				BKE_libblock_free_us(bmain, tmpobj);
 				return NULL;
 			}
 
diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index c8632a40d1a..56a76a54955 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -1777,7 +1777,7 @@ void ntreeFreeTree_ex(bNodeTree *ntree, const bool do_id_user)
 		if (tntree == ntree)
 			break;
 	if (tntree == NULL) {
-		BKE_libblock_free_data(&ntree->id);
+		BKE_libblock_free_data(G.main, &ntree->id);
 	}
 }
 /* same as ntreeFreeTree_ex but always manage users */