From 5febb0963998c40d7ddd8e71d9f9abe6feaea7ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20T=C3=B6nne?= <lukas.toenne@gmail.com>
Date: Tue, 18 Mar 2014 13:36:24 +0100
Subject: [PATCH] Fix T39180: Particle with fluid physics unstable.
Fluid sims have a very nasty feature for interaction, in which a psys
can directly update the bvhtree for //another object's psys//. This
breaks with threaded depsgraph evaluation and is generally a no-go.
To avoid crashes for now, use a global mutex to avoid concurrent writes
to an object psys' bvhtree.
---
.../blenkernel/intern/particle_system.c | 21 ++++++++++++++++---
source/blender/makesdna/DNA_particle_types.h | 4 ++--
2 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 32f8ba920e6..0e02f30a26e 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -109,6 +109,8 @@
#endif // WITH_MOD_FLUID
+static ThreadMutex psys_bvhtree_rwlock = BLI_RWLOCK_INITIALIZER;
+
/************************************************/
/* Reacting to system events */
/************************************************/
@@ -2209,15 +2211,22 @@ static void psys_update_particle_bvhtree(ParticleSystem *psys, float cfra)
if (psys) {
PARTICLE_P;
int totpart = 0;
+ bool need_rebuild;
- if (!psys->bvhtree || psys->bvhtree_frame != cfra) {
+ BLI_rw_mutex_lock(&psys_bvhtree_rwlock, THREAD_LOCK_READ);
+ need_rebuild = !psys->bvhtree || psys->bvhtree_frame != cfra;
+ BLI_rw_mutex_unlock(&psys_bvhtree_rwlock);
+
+ if (need_rebuild) {
LOOP_SHOWN_PARTICLES {
totpart++;
}
+ BLI_rw_mutex_lock(&psys_bvhtree_rwlock, THREAD_LOCK_WRITE);
+
BLI_bvhtree_free(psys->bvhtree);
psys->bvhtree = BLI_bvhtree_new(totpart, 0.0, 4, 6);
-
+
LOOP_SHOWN_PARTICLES {
if (pa->alive == PARS_ALIVE) {
if (pa->state.time == cfra)
@@ -2227,8 +2236,10 @@ static void psys_update_particle_bvhtree(ParticleSystem *psys, float cfra)
}
}
BLI_bvhtree_balance(psys->bvhtree);
-
+
psys->bvhtree_frame = cfra;
+
+ BLI_rw_mutex_unlock(&psys_bvhtree_rwlock);
}
}
}
@@ -2546,7 +2557,11 @@ static void sph_evaluate_func(BVHTree *tree, ParticleSystem **psys, float co[3],
break;
}
else {
+ BLI_rw_mutex_lock(&psys_bvhtree_rwlock, THREAD_LOCK_READ);
+
BLI_bvhtree_range_query(psys[i]->bvhtree, co, interaction_radius, callback, pfr);
+
+ BLI_rw_mutex_unlock(&psys_bvhtree_rwlock);
}
}
}
diff --git a/source/blender/makesdna/DNA_particle_types.h b/source/blender/makesdna/DNA_particle_types.h
index 7b06f2a46db..a2a724b6a32 100644
--- a/source/blender/makesdna/DNA_particle_types.h
+++ b/source/blender/makesdna/DNA_particle_types.h
@@ -304,8 +304,8 @@ typedef struct ParticleSystem {
ParticleSpring *fluid_springs;
int tot_fluidsprings, alloc_fluidsprings;
- struct KDTree *tree; /* used for interactions with self and other systems */
- struct BVHTree *bvhtree; /* used for interactions with self and other systems */
+ struct KDTree *tree; /* used for interactions with self and other systems */
+ struct BVHTree *bvhtree; /* used for interactions with self and other systems */
struct ParticleDrawData *pdd;
--
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