COW performance tweaks; also somehow fixes Bullet soft body issue

panda/src/putil/cachedTypedWritableReferenceCount.I

@@ -126,7 +126,7 @@ cache_ref() const {
 #endif
 
   ref();
-  AtomicAdjust::inc(((CachedTypedWritableReferenceCount *)this)->_cache_ref_count);
+  AtomicAdjust::inc(_cache_ref_count);
 }
 
 /**
@@ -147,7 +147,7 @@ cache_unref() const {
   // you can't use PointerTo's?
   nassertr(_cache_ref_count > 0, 0);
 
-  AtomicAdjust::dec(((CachedTypedWritableReferenceCount *)this)->_cache_ref_count);
+  AtomicAdjust::dec(_cache_ref_count);
   return ReferenceCount::unref();
 }
 
@@ -164,6 +164,19 @@ test_ref_count_integrity() const {
 #endif
 }
 
+/**
+ * Decrements the cache reference count without affecting the normal reference
+ * count.  Don't use this.
+ */
+INLINE void CachedTypedWritableReferenceCount::
+cache_ref_only() const {
+#ifdef _DEBUG
+  nassertv(test_ref_count_integrity());
+#endif
+
+  AtomicAdjust::inc(_cache_ref_count);
+}
+
 /**
  * Decrements the cache reference count without affecting the normal reference
  * count.  Intended to be called by derived classes only, presumably to
@@ -180,7 +193,7 @@ cache_unref_only() const {
   // you can't use PointerTo's?
   nassertv(_cache_ref_count > 0);
 
-  AtomicAdjust::dec(((CachedTypedWritableReferenceCount *)this)->_cache_ref_count);
+  AtomicAdjust::dec(_cache_ref_count);
 }
 
 /**

panda/src/putil/cachedTypedWritableReferenceCount.h

@@ -47,11 +47,12 @@ PUBLISHED:
   MAKE_PROPERTY(cache_ref_count, get_cache_ref_count);
 
 protected:
+  INLINE void cache_ref_only() const;
   INLINE void cache_unref_only() const;
   bool do_test_ref_count_integrity() const;
 
 private:
-  AtomicAdjust::Integer _cache_ref_count;
+  mutable AtomicAdjust::Integer _cache_ref_count;
 
 public:
   static TypeHandle get_class_type() {

panda/src/putil/copyOnWriteObject.cxx

@@ -35,4 +35,21 @@ unref() const {
   }
   return is_zero;
 }
+
+/**
+ * Explicitly increments the cache reference count only.  Don't use this.
+ *
+ * In the case of a CopyOnWriteObject, when the reference count decrements
+ * down to the cache reference count, the object is implicitly unlocked.
+ */
+void CopyOnWriteObject::
+cache_ref_only() const {
+  MutexHolder holder(_lock_mutex);
+  CachedTypedWritableReferenceCount::cache_ref_only();
+  if (get_ref_count() == get_cache_ref_count()) {
+    ((CopyOnWriteObject *)this)->_lock_status = LS_unlocked;
+    ((CopyOnWriteObject *)this)->_locking_thread = NULL;
+    ((CopyOnWriteObject *)this)->_lock_cvar.notify();
+  }
+}
 #endif  // COW_THREADED

panda/src/putil/copyOnWriteObject.h

@@ -49,6 +49,9 @@ PUBLISHED:
   virtual bool unref() const;
   INLINE void cache_ref() const;
   INLINE bool cache_unref() const;
+
+public:
+  void cache_ref_only() const;
 #endif  // COW_THREADED
 
 protected:

panda/src/putil/copyOnWritePointer.I

@@ -74,23 +74,58 @@ INLINE CopyOnWritePointer::
  *
  */
 INLINE CopyOnWritePointer::
-CopyOnWritePointer(CopyOnWritePointer &&move) NOEXCEPT :
-  _cow_object(move._cow_object)
+CopyOnWritePointer(CopyOnWritePointer &&from) NOEXCEPT :
+  _cow_object(from._cow_object)
 {
   // Steal the other's reference count.
-  move._cow_object = (CopyOnWriteObject *)NULL;
+  from._cow_object = (CopyOnWriteObject *)NULL;
+}
+
+/**
+ *
+ */
+INLINE CopyOnWritePointer::
+CopyOnWritePointer(PointerTo<CopyOnWriteObject> &&from) NOEXCEPT :
+  _cow_object(from.p())
+{
+  // Steal the other's reference count, but because it is a regular pointer,
+  // we do need to include the cache reference count.
+  if (_cow_object != (CopyOnWriteObject *)NULL) {
+    _cow_object->cache_ref_only();
+  }
+  from.cheat() = NULL;
 }
 
 /**
  *
  */
 INLINE void CopyOnWritePointer::
-operator = (CopyOnWritePointer &&move) NOEXCEPT {
+operator = (CopyOnWritePointer &&from) NOEXCEPT {
   // Protect against self-move-assignment.
-  if (move._cow_object != _cow_object) {
+  if (from._cow_object != _cow_object) {
     CopyOnWriteObject *old_object = _cow_object;
-    _cow_object = move._cow_object;
-    move._cow_object = NULL;
+    _cow_object = from._cow_object;
+    from._cow_object = NULL;
+
+    if (old_object != (CopyOnWriteObject *)NULL) {
+      cache_unref_delete(old_object);
+    }
+  }
+}
+
+/**
+ *
+ */
+INLINE void CopyOnWritePointer::
+operator = (PointerTo<CopyOnWriteObject> &&from) NOEXCEPT {
+  if (from.p() != _cow_object) {
+    CopyOnWriteObject *old_object = _cow_object;
+
+    // Steal the other's reference count, but because it is a regular pointer,
+    // we do need to include the cache reference count.
+    _cow_object = from.p();
+    _cow_object->cache_ref_only();
+    from.cheat() = NULL;
 
     if (old_object != (CopyOnWriteObject *)NULL) {
       cache_unref_delete(old_object);
@@ -262,20 +297,60 @@ operator = (To *object) {
  */
 template<class T>
 INLINE CopyOnWritePointerTo<T>::
-CopyOnWritePointerTo(CopyOnWritePointerTo<T> &&move) NOEXCEPT :
-  CopyOnWritePointer((CopyOnWritePointer &&)move)
+CopyOnWritePointerTo(CopyOnWritePointerTo<T> &&from) NOEXCEPT :
+  CopyOnWritePointer((CopyOnWritePointer &&)from)
 {
 }
 #endif  // CPPPARSER
 
+#ifndef CPPPARSER
+/**
+ *
+ */
+template<class T>
+INLINE CopyOnWritePointerTo<T>::
+CopyOnWritePointerTo(PointerTo<T> &&from) NOEXCEPT {
+  // Steal the other's reference count, but because it is a regular pointer,
+  // we do need to include the cache reference count.
+  _cow_object = from.p();
+  if (_cow_object != (CopyOnWriteObject *)NULL) {
+    _cow_object->cache_ref_only();
+  }
+  from.cheat() = NULL;
+}
+#endif  // CPPPARSER
+
+#ifndef CPPPARSER
+/**
+ *
+ */
+template<class T>
+INLINE void CopyOnWritePointerTo<T>::
+operator = (CopyOnWritePointerTo<T> &&from) NOEXCEPT {
+  CopyOnWritePointer::operator = ((CopyOnWritePointer &&)from);
+}
+#endif  // CPPPARSER
+
 #ifndef CPPPARSER
 /**
  *
  */
 template<class T>
 INLINE void CopyOnWritePointerTo<T>::
-operator = (CopyOnWritePointerTo<T> &&move) NOEXCEPT {
-  CopyOnWritePointer::operator = ((CopyOnWritePointer &&)move);
+operator = (PointerTo<T> &&from) NOEXCEPT {
+  if (from.p() != _cow_object) {
+    CopyOnWriteObject *old_object = _cow_object;
+
+    // Steal the other's reference count, but because it is a regular pointer,
+    // we do need to include the cache reference count.
+    _cow_object = from.p();
+    _cow_object->cache_ref_only();
+    from.cheat() = NULL;
+
+    if (old_object != (CopyOnWriteObject *)NULL) {
+      cache_unref_delete(old_object);
+    }
+  }
 }
 #endif  // CPPPARSER
 #endif  // USE_MOVE_SEMANTICS

panda/src/putil/copyOnWritePointer.cxx

@@ -90,19 +90,17 @@ get_write_pointer() {
     }
 
     PT(CopyOnWriteObject) new_object = _cow_object->make_cow_copy();
+    _cow_object->CachedTypedWritableReferenceCount::cache_unref();
+    _cow_object->_lock_mutex.release();
 
-    // We can't call cache_unref_delete, because we hold the lock.
-    if (!_cow_object->CachedTypedWritableReferenceCount::cache_unref()) {
-      _cow_object->_lock_mutex.release();
-      delete _cow_object;
-    } else {
-      _cow_object->_lock_mutex.release();
-    }
+    MutexHolder holder(new_object->_lock_mutex);
     _cow_object = new_object;
-    _cow_object->cache_ref();
+    _cow_object->CachedTypedWritableReferenceCount::cache_ref();
     _cow_object->_lock_status = CopyOnWriteObject::LS_locked_write;
     _cow_object->_locking_thread = current_thread;
 
+    return new_object;
+
   } else if (_cow_object->get_cache_ref_count() > 1) {
     // No one else has it specifically read-locked, but there are other
     // CopyOnWritePointers holding the same object, so we should make our own
@@ -115,19 +113,17 @@ get_write_pointer() {
     }
 
     PT(CopyOnWriteObject) new_object = _cow_object->make_cow_copy();
+    _cow_object->CachedTypedWritableReferenceCount::cache_unref();
+    _cow_object->_lock_mutex.release();
 
-    // We can't call cache_unref_delete, because we hold the lock.
-    if (!_cow_object->CachedTypedWritableReferenceCount::cache_unref()) {
-      _cow_object->_lock_mutex.release();
-      delete _cow_object;
-    } else {
-      _cow_object->_lock_mutex.release();
-    }
+    MutexHolder holder(new_object->_lock_mutex);
     _cow_object = new_object;
-    _cow_object->cache_ref();
+    _cow_object->CachedTypedWritableReferenceCount::cache_ref();
     _cow_object->_lock_status = CopyOnWriteObject::LS_locked_write;
     _cow_object->_locking_thread = current_thread;
 
+    return new_object;
+
   } else {
     // No other thread has the pointer locked, and we're the only
     // CopyOnWritePointer with this object.  We can safely write to it without

panda/src/putil/copyOnWritePointer.h

@@ -37,8 +37,10 @@ public:
   INLINE ~CopyOnWritePointer();
 
 #ifdef USE_MOVE_SEMANTICS
-  INLINE CopyOnWritePointer(CopyOnWritePointer &&move) NOEXCEPT;
-  INLINE void operator = (CopyOnWritePointer &&move) NOEXCEPT;
+  INLINE CopyOnWritePointer(CopyOnWritePointer &&from) NOEXCEPT;
+  INLINE CopyOnWritePointer(PointerTo<CopyOnWriteObject> &&from) NOEXCEPT;
+  INLINE void operator = (CopyOnWritePointer &&from) NOEXCEPT;
+  INLINE void operator = (PointerTo<CopyOnWriteObject> &&from) NOEXCEPT;
 #endif
 
   INLINE bool operator == (const CopyOnWritePointer &other) const;
@@ -61,7 +63,7 @@ public:
   INLINE bool test_ref_count_integrity() const;
   INLINE bool test_ref_count_nonzero() const;
 
-private:
+protected:
   CopyOnWriteObject *_cow_object;
 };
 
@@ -84,8 +86,10 @@ public:
   INLINE void operator = (To *object);
 
 #ifdef USE_MOVE_SEMANTICS
-  INLINE CopyOnWritePointerTo(CopyOnWritePointerTo &&move) NOEXCEPT;
-  INLINE void operator = (CopyOnWritePointerTo &&move) NOEXCEPT;
+  INLINE CopyOnWritePointerTo(CopyOnWritePointerTo &&from) NOEXCEPT;
+  INLINE CopyOnWritePointerTo(PointerTo<T> &&from) NOEXCEPT;
+  INLINE void operator = (CopyOnWritePointerTo &&from) NOEXCEPT;
+  INLINE void operator = (PointerTo<T> &&from) NOEXCEPT;
 #endif
 
 #ifdef COW_THREADED