diff --git a/panda/src/gobj/geomVertexArrayData.h b/panda/src/gobj/geomVertexArrayData.h
index 2ca951d382..52ff617f34 100644
--- a/panda/src/gobj/geomVertexArrayData.h
+++ b/panda/src/gobj/geomVertexArrayData.h
@@ -28,7 +28,7 @@
 #include "cycleDataStageWriter.h"
 #include "pipelineCycler.h"
 #include "pmap.h"
-#include "lightReMutex.h"
+#include "reMutex.h"
 #include "simpleLru.h"
 #include "vertexDataBuffer.h"
 #include "config_gobj.h"
@@ -166,7 +166,7 @@ private:
 
     // This implements read-write locking.  Anyone who gets the data for
     // reading or writing will hold this mutex during the lock.
-    LightReMutex _rw_lock;
+    ReMutex _rw_lock;
     
   public:
     static TypeHandle get_class_type() {
diff --git a/panda/src/gobj/simpleAllocator.I b/panda/src/gobj/simpleAllocator.I
index f51ee911a7..e42694f14a 100644
--- a/panda/src/gobj/simpleAllocator.I
+++ b/panda/src/gobj/simpleAllocator.I
@@ -19,7 +19,7 @@
 //  Description: 
 ////////////////////////////////////////////////////////////////////
 INLINE SimpleAllocator::
-SimpleAllocator(size_t max_size, LightMutex &lock) : 
+SimpleAllocator(size_t max_size, Mutex &lock) : 
   LinkedListNode(true),
   _total_size(0),
   _max_size(max_size),
@@ -39,7 +39,7 @@ SimpleAllocator(size_t max_size, LightMutex &lock) :
 ////////////////////////////////////////////////////////////////////
 SimpleAllocatorBlock *SimpleAllocator::
 alloc(size_t size) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return do_alloc(size);
 }
 
@@ -51,7 +51,7 @@ alloc(size_t size) {
 ////////////////////////////////////////////////////////////////////
 INLINE bool SimpleAllocator::
 is_empty() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return do_is_empty();
 }
 
@@ -62,7 +62,7 @@ is_empty() const {
 ////////////////////////////////////////////////////////////////////
 INLINE size_t SimpleAllocator::
 get_total_size() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return _total_size;
 }
 
@@ -73,7 +73,7 @@ get_total_size() const {
 ////////////////////////////////////////////////////////////////////
 INLINE size_t SimpleAllocator::
 get_max_size() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return _max_size;
 }
 
@@ -86,7 +86,7 @@ get_max_size() const {
 ////////////////////////////////////////////////////////////////////
 INLINE void SimpleAllocator::
 set_max_size(size_t max_size) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   _max_size = max_size;
 }
 
@@ -102,7 +102,7 @@ set_max_size(size_t max_size) {
 ////////////////////////////////////////////////////////////////////
 INLINE size_t SimpleAllocator::
 get_contiguous() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return _contiguous;
 }
 
@@ -114,7 +114,7 @@ get_contiguous() const {
 ////////////////////////////////////////////////////////////////////
 INLINE SimpleAllocatorBlock *SimpleAllocator::
 get_first_block() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return (_next == this) ? (SimpleAllocatorBlock *)NULL : (SimpleAllocatorBlock *)_next;
 }
 
@@ -194,7 +194,7 @@ INLINE SimpleAllocatorBlock::
 INLINE void SimpleAllocatorBlock::
 free() {
   if (_allocator != (SimpleAllocator *)NULL) {
-    LightMutexHolder holder(_allocator->_lock);
+    MutexHolder holder(_allocator->_lock);
     do_free();
   }
 }
@@ -254,7 +254,7 @@ is_free() const {
 INLINE size_t SimpleAllocatorBlock::
 get_max_size() const {
   nassertr(_allocator != (SimpleAllocator *)NULL, 0);
-  LightMutexHolder holder(_allocator->_lock);
+  MutexHolder holder(_allocator->_lock);
   return do_get_max_size();
 }
 
@@ -268,7 +268,7 @@ get_max_size() const {
 INLINE bool SimpleAllocatorBlock::
 realloc(size_t size) {
   nassertr(_allocator != (SimpleAllocator *)NULL, false);
-  LightMutexHolder holder(_allocator->_lock);
+  MutexHolder holder(_allocator->_lock);
   return do_realloc(size);
 }
 
@@ -281,7 +281,7 @@ realloc(size_t size) {
 INLINE SimpleAllocatorBlock *SimpleAllocatorBlock::
 get_next_block() const {
   nassertr(_allocator != (SimpleAllocator *)NULL, NULL);
-  LightMutexHolder holder(_allocator->_lock);
+  MutexHolder holder(_allocator->_lock);
   return (_next == _allocator) ? (SimpleAllocatorBlock *)NULL : (SimpleAllocatorBlock *)_next;
 }
 
diff --git a/panda/src/gobj/simpleAllocator.cxx b/panda/src/gobj/simpleAllocator.cxx
index b129090ffa..8b0bd2a1de 100644
--- a/panda/src/gobj/simpleAllocator.cxx
+++ b/panda/src/gobj/simpleAllocator.cxx
@@ -23,7 +23,7 @@ SimpleAllocator::
 ~SimpleAllocator() {
   // We're shutting down.  Force-free everything remaining.
   if (_next != (LinkedListNode *)this) {
-    LightMutexHolder holder(_lock);
+    MutexHolder holder(_lock);
     while (_next != (LinkedListNode *)this) {
       nassertv(_next != (LinkedListNode *)NULL);
       ((SimpleAllocatorBlock *)_next)->do_free();
@@ -38,7 +38,7 @@ SimpleAllocator::
 ////////////////////////////////////////////////////////////////////
 void SimpleAllocator::
 output(ostream &out) const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   out << "SimpleAllocator, " << _total_size << " of " << _max_size 
       << " allocated";
 }
@@ -50,7 +50,7 @@ output(ostream &out) const {
 ////////////////////////////////////////////////////////////////////
 void SimpleAllocator::
 write(ostream &out) const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   out << "SimpleAllocator, " << _total_size << " of " << _max_size 
       << " allocated";
 
@@ -187,7 +187,7 @@ output(ostream &out) const {
   if (_allocator == (SimpleAllocator *)NULL) {
     out << "free block\n";
   } else {
-    LightMutexHolder holder(_allocator->_lock);
+    MutexHolder holder(_allocator->_lock);
     out << "block of size " << _size << " at " << _start;
   }
 }
diff --git a/panda/src/gobj/simpleAllocator.h b/panda/src/gobj/simpleAllocator.h
index 7a36373f0f..f494697bec 100644
--- a/panda/src/gobj/simpleAllocator.h
+++ b/panda/src/gobj/simpleAllocator.h
@@ -17,8 +17,8 @@
 
 #include "pandabase.h"
 #include "linkedListNode.h"
-#include "lightMutex.h"
-#include "lightMutexHolder.h"
+#include "pmutex.h"
+#include "mutexHolder.h"
 
 class SimpleAllocatorBlock;
 
@@ -32,7 +32,7 @@ class SimpleAllocatorBlock;
 ////////////////////////////////////////////////////////////////////
 class EXPCL_PANDA_GOBJ SimpleAllocator : public LinkedListNode {
 PUBLISHED:
-  INLINE SimpleAllocator(size_t max_size, LightMutex &lock);
+  INLINE SimpleAllocator(size_t max_size, Mutex &lock);
   virtual ~SimpleAllocator();
 
   INLINE SimpleAllocatorBlock *alloc(size_t size);
@@ -82,7 +82,7 @@ protected:
   // A derived class may also use it to protect itself as well, but
   // take care to call do_alloc() instead of alloc() etc. as
   // necessary.
-  LightMutex &_lock;
+  Mutex &_lock;
 
   friend class SimpleAllocatorBlock;
 };
diff --git a/panda/src/gobj/vertexDataBook.I b/panda/src/gobj/vertexDataBook.I
index edcc6bf820..30e6f01ef4 100644
--- a/panda/src/gobj/vertexDataBook.I
+++ b/panda/src/gobj/vertexDataBook.I
@@ -21,7 +21,7 @@
 ////////////////////////////////////////////////////////////////////
 INLINE VertexDataBlock *VertexDataBook::
 alloc(size_t size) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return do_alloc(size);
 }
 
diff --git a/panda/src/gobj/vertexDataBook.cxx b/panda/src/gobj/vertexDataBook.cxx
index 6465d4e684..6b0aa07ff0 100644
--- a/panda/src/gobj/vertexDataBook.cxx
+++ b/panda/src/gobj/vertexDataBook.cxx
@@ -13,7 +13,7 @@
 ////////////////////////////////////////////////////////////////////
 
 #include "vertexDataBook.h"
-#include "lightReMutexHolder.h"
+#include "mutexHolder.h"
 
 ////////////////////////////////////////////////////////////////////
 //     Function: VertexDataBook::Constructor
@@ -44,7 +44,7 @@ VertexDataBook::
 ////////////////////////////////////////////////////////////////////
 size_t VertexDataBook::
 count_total_page_size() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   size_t total = 0;
   Pages::const_iterator pi;
@@ -63,7 +63,7 @@ count_total_page_size() const {
 ////////////////////////////////////////////////////////////////////
 size_t VertexDataBook::
 count_total_page_size(VertexDataPage::RamClass ram_class) const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   size_t total = 0;
   Pages::const_iterator pi;
@@ -83,7 +83,7 @@ count_total_page_size(VertexDataPage::RamClass ram_class) const {
 ////////////////////////////////////////////////////////////////////
 size_t VertexDataBook::
 count_allocated_size() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   size_t total = 0;
   Pages::const_iterator pi;
@@ -102,7 +102,7 @@ count_allocated_size() const {
 ////////////////////////////////////////////////////////////////////
 size_t VertexDataBook::
 count_allocated_size(VertexDataPage::RamClass ram_class) const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   size_t total = 0;
   Pages::const_iterator pi;
@@ -124,7 +124,7 @@ count_allocated_size(VertexDataPage::RamClass ram_class) const {
 ////////////////////////////////////////////////////////////////////
 void VertexDataBook::
 save_to_disk() {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   Pages::iterator pi;
   for (pi = _pages.begin(); pi != _pages.end(); ++pi) {
diff --git a/panda/src/gobj/vertexDataBook.h b/panda/src/gobj/vertexDataBook.h
index c1617857ac..4f5754138b 100644
--- a/panda/src/gobj/vertexDataBook.h
+++ b/panda/src/gobj/vertexDataBook.h
@@ -16,8 +16,8 @@
 #define VERTEXDATABOOK_H
 
 #include "pandabase.h"
-#include "lightMutex.h"
-#include "lightMutexHolder.h"
+#include "pmutex.h"
+#include "mutexHolder.h"
 #include "vertexDataPage.h"
 #include "indirectLess.h"
 #include "plist.h"
@@ -58,7 +58,7 @@ private:
   typedef pset<VertexDataPage *, IndirectLess<VertexDataPage> > Pages;
   Pages _pages;
 
-  LightMutex _lock;
+  Mutex _lock;
   friend class VertexDataPage;
 };
 
diff --git a/panda/src/gobj/vertexDataPage.I b/panda/src/gobj/vertexDataPage.I
index aa103376eb..947efbd278 100644
--- a/panda/src/gobj/vertexDataPage.I
+++ b/panda/src/gobj/vertexDataPage.I
@@ -22,7 +22,7 @@
 ////////////////////////////////////////////////////////////////////
 INLINE VertexDataPage::RamClass VertexDataPage::
 get_ram_class() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return _ram_class;
 }
 
@@ -36,7 +36,7 @@ get_ram_class() const {
 ////////////////////////////////////////////////////////////////////
 INLINE VertexDataPage::RamClass VertexDataPage::
 get_pending_ram_class() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return _pending_ram_class;
 }
 
@@ -49,7 +49,7 @@ get_pending_ram_class() const {
 ////////////////////////////////////////////////////////////////////
 INLINE void VertexDataPage::
 request_resident() {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   if (_ram_class != RC_resident) {
     request_ram_class(RC_resident);
   }
@@ -66,7 +66,7 @@ request_resident() {
 ////////////////////////////////////////////////////////////////////
 INLINE VertexDataBlock *VertexDataPage::
 alloc(size_t size) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return do_alloc(size);
 }
 
@@ -78,7 +78,7 @@ alloc(size_t size) {
 ////////////////////////////////////////////////////////////////////
 INLINE VertexDataBlock *VertexDataPage::
 get_first_block() const {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return (VertexDataBlock *)SimpleAllocator::get_first_block();
 }
 
@@ -142,7 +142,7 @@ get_save_file() {
 ////////////////////////////////////////////////////////////////////
 INLINE bool VertexDataPage::
 save_to_disk() {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   return do_save_to_disk();
 }
 
@@ -208,7 +208,7 @@ get_num_pending_writes() {
 ////////////////////////////////////////////////////////////////////
 INLINE unsigned char *VertexDataPage::
 get_page_data(bool force) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
   if (_ram_class != RC_resident || _pending_ram_class != RC_resident) {
     if (force) {
       make_resident_now();
diff --git a/panda/src/gobj/vertexDataPage.cxx b/panda/src/gobj/vertexDataPage.cxx
index 162b1ea153..65694081e2 100644
--- a/panda/src/gobj/vertexDataPage.cxx
+++ b/panda/src/gobj/vertexDataPage.cxx
@@ -17,7 +17,6 @@
 #include "vertexDataSaveFile.h"
 #include "vertexDataBook.h"
 #include "pStatTimer.h"
-#include "lightMutexHolder.h"
 #include "memoryHook.h"
 
 #ifdef HAVE_ZLIB
@@ -72,9 +71,9 @@ SimpleLru *VertexDataPage::_global_lru[RC_end_of_list] = {
 
 VertexDataSaveFile *VertexDataPage::_save_file;
 
-// This mutex is (mostly) unused.  We just need a LightMutex to pass
+// This mutex is (mostly) unused.  We just need a Mutex to pass
 // to the Book Constructor, below.
-LightMutex VertexDataPage::_unused_mutex;
+Mutex VertexDataPage::_unused_mutex;
 
 PStatCollector VertexDataPage::_vdata_compress_pcollector("*:Vertex Data:Compress");
 PStatCollector VertexDataPage::_vdata_decompress_pcollector("*:Vertex Data:Decompress");
@@ -153,7 +152,7 @@ VertexDataPage::
 
   // Since the only way to delete a page is via the
   // changed_contiguous() method, the lock will already be held.
-  // LightMutexHolder holder(_lock);
+  // MutexHolder holder(_lock);
 
   {
     MutexHolder holder2(_tlock);
@@ -291,7 +290,7 @@ changed_contiguous() {
 ////////////////////////////////////////////////////////////////////
 void VertexDataPage::
 evict_lru() {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   switch (_ram_class) {
   case RC_resident:
@@ -1041,7 +1040,7 @@ thread_main() {
     _tlock.release();
 
     {
-      LightMutexHolder holder(_working_page->_lock);
+      MutexHolder holder(_working_page->_lock);
       switch (ram_class) {
       case RC_resident:
         _working_page->make_resident();
diff --git a/panda/src/gobj/vertexDataPage.h b/panda/src/gobj/vertexDataPage.h
index e3bf8ffb0f..a6a6e4eafb 100644
--- a/panda/src/gobj/vertexDataPage.h
+++ b/panda/src/gobj/vertexDataPage.h
@@ -21,12 +21,10 @@
 #include "pStatCollector.h"
 #include "vertexDataSaveFile.h"
 #include "pmutex.h"
-#include "lightMutex.h"
 #include "conditionVar.h"
 #include "conditionVarFull.h"
 #include "thread.h"
 #include "mutexHolder.h"
-#include "lightMutexHolder.h"
 #include "pdeque.h"
 
 class VertexDataBook;
@@ -169,7 +167,7 @@ private:
   size_t _book_size;
   size_t _block_size;
 
-  //LightMutex _lock;  // Inherited from SimpleAllocator.  Protects above members.
+  //Mutex _lock;  // Inherited from SimpleAllocator.  Protects above members.
   RamClass _pending_ram_class;  // Protected by _tlock.
 
   VertexDataBook *_book;  // never changes.
@@ -210,7 +208,7 @@ private:
 
   static VertexDataSaveFile *_save_file;
 
-  static LightMutex _unused_mutex;
+  static Mutex _unused_mutex;
 
   static PStatCollector _vdata_compress_pcollector;
   static PStatCollector _vdata_decompress_pcollector;
diff --git a/panda/src/gobj/vertexDataSaveFile.cxx b/panda/src/gobj/vertexDataSaveFile.cxx
index a7616d091c..0f3ec5c464 100644
--- a/panda/src/gobj/vertexDataSaveFile.cxx
+++ b/panda/src/gobj/vertexDataSaveFile.cxx
@@ -13,7 +13,7 @@
 ////////////////////////////////////////////////////////////////////
 
 #include "vertexDataSaveFile.h"
-#include "lightMutexHolder.h"
+#include "mutexHolder.h"
 #include "clockObject.h"
 
 #ifndef _WIN32
@@ -192,7 +192,7 @@ VertexDataSaveFile::
 ////////////////////////////////////////////////////////////////////
 PT(VertexDataSaveBlock) VertexDataSaveFile::
 write_data(const unsigned char *data, size_t size, bool compressed) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   if (!_is_valid) {
     return NULL;
@@ -272,7 +272,7 @@ write_data(const unsigned char *data, size_t size, bool compressed) {
 ////////////////////////////////////////////////////////////////////
 bool VertexDataSaveFile::
 read_data(unsigned char *data, size_t size, VertexDataSaveBlock *block) {
-  LightMutexHolder holder(_lock);
+  MutexHolder holder(_lock);
 
   if (!_is_valid) {
     return false;
diff --git a/panda/src/gobj/vertexDataSaveFile.h b/panda/src/gobj/vertexDataSaveFile.h
index 0daa681eb3..948d8a7ba8 100644
--- a/panda/src/gobj/vertexDataSaveFile.h
+++ b/panda/src/gobj/vertexDataSaveFile.h
@@ -18,7 +18,7 @@
 #include "pandabase.h"
 #include "simpleAllocator.h"
 #include "filename.h"
-#include "lightMutex.h"
+#include "pmutex.h"
 
 #if defined(_WIN32)
 #define WIN32_LEAN_AND_MEAN
@@ -59,7 +59,7 @@ private:
   Filename _filename;
   bool _is_valid;
   size_t _total_file_size;
-  LightMutex _lock;
+  Mutex _lock;
 
 #ifdef _WIN32
   HANDLE _handle;