From 10fe8659c656c5ce33a35897baa5c2cd12ee7f3f Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Thu, 12 Jul 2018 14:22:27 +0200
Subject: [PATCH] gobj: work around a deadlock in GeomCacheManager::flush()

---
 panda/src/gobj/geomCacheManager.cxx | 5 +++++
 panda/src/gobj/geomMunger.h         | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/panda/src/gobj/geomCacheManager.cxx b/panda/src/gobj/geomCacheManager.cxx
index 7fef373373..4eb06a25b4 100644
--- a/panda/src/gobj/geomCacheManager.cxx
+++ b/panda/src/gobj/geomCacheManager.cxx
@@ -13,7 +13,9 @@
 
 #include "geomCacheManager.h"
 #include "geomCacheEntry.h"
+#include "geomMunger.h"
 #include "lightMutexHolder.h"
+#include "lightReMutexHolder.h"
 #include "clockObject.h"
 
 GeomCacheManager *GeomCacheManager::_global_ptr = nullptr;
@@ -53,6 +55,9 @@ GeomCacheManager::
  */
 void GeomCacheManager::
 flush() {
+  // Prevent deadlock
+  LightReMutexHolder registry_holder(GeomMunger::get_registry()->_registry_lock);
+
   LightMutexHolder holder(_lock);
   evict_old_entries(0, false);
 }
diff --git a/panda/src/gobj/geomMunger.h b/panda/src/gobj/geomMunger.h
index 00105108bf..e8aa67bd61 100644
--- a/panda/src/gobj/geomMunger.h
+++ b/panda/src/gobj/geomMunger.h
@@ -149,6 +149,8 @@ private:
 
   static PStatCollector _munge_pcollector;
 
+  friend class GeomCacheManager;
+
 public:
   static TypeHandle get_class_type() {
     return _type_handle;