diff --git a/goo/GooMutex.h b/goo/GooMutex.h
index 3f53a62..fbef476 100644
--- a/goo/GooMutex.h
+++ b/goo/GooMutex.h
@@ -60,4 +60,20 @@ typedef pthread_mutex_t GooMutex;
 
 #endif
 
+namespace Poppler {
+  enum LockMode {
+    DoNotLock,  // for conditional locks: do not lock 
+    DoLock      // for conditional locks: do lock 
+  };
+
+  class Lock {
+  public:
+    Lock(GooMutex *mutexA) : mutex(mutexA) { mode = DoLock; gLockMutex(mutex); }
+    Lock(GooMutex *mutexA, LockMode modeA) : mutex(mutexA) { mode = modeA; if (mode == DoLock) gLockMutex(mutex); }
+    ~Lock() { if (mode == DoLock) gUnlockMutex(mutex); }
+  private:
+    GooMutex *mutex;
+    LockMode mode;
+  };
+}
 #endif
diff --git a/poppler/Annot.cc b/poppler/Annot.cc
index 0b3c5e4..5bc645a 100644
--- a/poppler/Annot.cc
+++ b/poppler/Annot.cc
@@ -1205,7 +1205,7 @@ void Annot::initialize(PDFDoc *docA, Dict *dict) {
   if (dict->lookupNF("P", &obj1)->isRef()) {
     Ref ref = obj1.getRef();
 
-    page = doc->getCatalog()->findPage (ref.num, ref.gen, gFalse);
+    page = doc->getCatalog()->findPage (ref.num, ref.gen, Poppler::DoNotLock);
   } else {
     page = 0;
   }
@@ -3770,7 +3770,7 @@ AnnotWidget::~AnnotWidget() {
 void AnnotWidget::initialize(PDFDoc *docA, Dict *dict) {
   Object obj1;
 
-  form = doc->getCatalog()->getForm(gFalse);
+  form = doc->getCatalog()->getForm(Poppler::DoNotLock);
 
   if(dict->lookup("H", &obj1)->isName()) {
     const char *modeName = obj1.getName();
diff --git a/poppler/Array.cc b/poppler/Array.cc
index d23ed5d..79551e6 100644
--- a/poppler/Array.cc
+++ b/poppler/Array.cc
@@ -35,11 +35,9 @@
 #include "Array.h"
 
 #if MULTITHREADED
-#  define lockArray   gLockMutex(&mutex)
-#  define unlockArray gUnlockMutex(&mutex)
+#  define lockArray   Poppler::Lock lock(&mutex)
 #else
 #  define lockArray
-#  define unlockArray
 #endif
 //------------------------------------------------------------------------
 // Array
@@ -73,21 +71,18 @@ Object *Array::copy(XRef *xrefA, Object *obj) {
     Object obj1;
     obj->arrayAdd(elems[i].copy(&obj1));
   }
-  unlockArray;
   return obj;
 }
 
 int Array::incRef() {
   lockArray;
   ++ref;
-  unlockArray;
   return ref;
 }
 
 int Array::decRef() {
   lockArray;
   --ref;
-  unlockArray;
   return ref;
 }
 
@@ -103,7 +98,6 @@ void Array::add(Object *elem) {
   }
   elems[length] = *elem;
   ++length;
-  unlockArray;
 }
 
 void Array::remove(int i) {
@@ -112,13 +106,11 @@ void Array::remove(int i) {
 #ifdef DEBUG_MEM
     abort();
 #else
-    unlockArray;
     return;
 #endif
   }
   --length;
   memmove( elems + i, elems + i + 1, sizeof(elems[0]) * (length - i) );
-  unlockArray;
 }
 
 Object *Array::get(int i, Object *obj, int recursion) {
diff --git a/poppler/Catalog.cc b/poppler/Catalog.cc
index b7f7ede..d4584bc 100644
--- a/poppler/Catalog.cc
+++ b/poppler/Catalog.cc
@@ -57,11 +57,11 @@
 #include "FileSpec.h"
 
 #if MULTITHREADED
-#  define lockCatalog   gLockMutex(&mutex)
-#  define unlockCatalog gUnlockMutex(&mutex)
+#  define lockCatalog()   Poppler::Lock lock(&mutex)
+#  define condLockCatalog(X)  Poppler::Lock condlock(&mutex, (X))
 #else
-#  define lockCatalog
-#  define unlockCatalog
+#  define lockCatalog()
+#  define condLockCatalog(X)
 #endif
 //------------------------------------------------------------------------
 // Catalog
@@ -191,7 +191,7 @@ GooString *Catalog::readMetadata() {
   Dict *dict;
   Object obj;
 
-  lockCatalog;
+  lockCatalog();
   if (metadata.isNone()) {
     Object catDict;
 
@@ -206,7 +206,6 @@ GooString *Catalog::readMetadata() {
   }
 
   if (!metadata.isStream()) {
-    unlockCatalog;
     return NULL;
   }
   dict = metadata.streamGetDict();
@@ -218,7 +217,6 @@ GooString *Catalog::readMetadata() {
   s = new GooString();
   metadata.getStream()->fillGooString(s);
   metadata.streamClose();
-  unlockCatalog;
   return s;
 }
 
@@ -226,31 +224,27 @@ Page *Catalog::getPage(int i)
 {
   if (i < 1) return NULL;
 
-  lockCatalog;
+  lockCatalog();
   if (i > lastCachedPage) {
      GBool cached = cachePageTree(i);
      if ( cached == gFalse) {
-       unlockCatalog;
        return NULL;
      }
   }
-  unlockCatalog;
   return pages[i-1];
 }
 
-Ref *Catalog::getPageRef(int i, GBool lock)
+Ref *Catalog::getPageRef(int i, Poppler::LockMode lock)
 {
   if (i < 1) return NULL;
 
-  if (lock) lockCatalog;
+  condLockCatalog(lock);
   if (i > lastCachedPage) {
      GBool cached = cachePageTree(i);
      if ( cached == gFalse) {
-       if (lock) unlockCatalog;
        return NULL;
      }
   }
-  if (lock) unlockCatalog;
   return &pageRefs[i-1];
 }
 
@@ -300,7 +294,7 @@ GBool Catalog::cachePageTree(int page)
       return gFalse;
     }
 
-    pagesSize = getNumPages(gFalse);
+    pagesSize = getNumPages(Poppler::DoLock);
     pages = (Page **)gmallocn(pagesSize, sizeof(Page *));
     pageRefs = (Ref *)gmallocn(pagesSize, sizeof(Ref));
     for (int i = 0; i < pagesSize; ++i) {
@@ -427,7 +421,7 @@ GBool Catalog::cachePageTree(int page)
   return gFalse;
 }
 
-int Catalog::findPage(int num, int gen, GBool lock) {
+int Catalog::findPage(int num, int gen, Poppler::LockMode lock) {
   int i;
 
   for (i = 0; i < getNumPages(lock); ++i) {
@@ -452,12 +446,11 @@ LinkDest *Catalog::findDest(GooString *name) {
       obj1.free();
   }
   if (!found) {
-    lockCatalog;
+    lockCatalog();
     if (getDestNameTree()->lookup(name, &obj1))
       found = gTrue;
     else
       obj1.free();
-    unlockCatalog;
   }
   if (!found)
     return NULL;
@@ -488,7 +481,7 @@ FileSpec *Catalog::embeddedFile(int i)
 {
     Object efDict;
     Object obj;
-    lockCatalog;
+    lockCatalog();
     obj = getEmbeddedFileNameTree()->getValue(i);
     FileSpec *embeddedFile = 0;
     if (obj.isRef()) {
@@ -501,7 +494,6 @@ FileSpec *Catalog::embeddedFile(int i)
       Object null;
       embeddedFile = new FileSpec(&null);
     }
-    unlockCatalog;
     return embeddedFile;
 }
 
@@ -510,12 +502,11 @@ GooString *Catalog::getJS(int i)
   Object obj;
   // getJSNameTree()->getValue(i) returns a shallow copy of the object so we
   // do not need to free it
-  lockCatalog;
+  lockCatalog();
   getJSNameTree()->getValue(i).fetch(xref, &obj);
 
   if (!obj.isDict()) {
     obj.free();
-    unlockCatalog;
     return 0;
   }
   Object obj2;
@@ -527,7 +518,6 @@ GooString *Catalog::getJS(int i)
   if (strcmp(obj2.getName(), "JavaScript")) {
     obj2.free();
     obj.free();
-    unlockCatalog;
     return 0;
   }
   obj2.free();
@@ -543,13 +533,12 @@ GooString *Catalog::getJS(int i)
   }
   obj2.free();
   obj.free();
-  unlockCatalog;
   return js;
 }
 
 Catalog::PageMode Catalog::getPageMode() {
 
-  lockCatalog;
+  lockCatalog();
   if (pageMode == pageModeNull) {
 
     Object catDict, obj;
@@ -560,7 +549,6 @@ Catalog::PageMode Catalog::getPageMode() {
     if (!catDict.isDict()) {
       error(errSyntaxError, -1, "Catalog object is wrong type ({0:s})", catDict.getTypeName());
       catDict.free();
-      unlockCatalog;
       return pageMode;
     }
 
@@ -581,13 +569,12 @@ Catalog::PageMode Catalog::getPageMode() {
     obj.free();
     catDict.free();
   }
-  unlockCatalog;
   return pageMode;
 }
 
 Catalog::PageLayout Catalog::getPageLayout() {
 
-  lockCatalog;
+  lockCatalog();
   if (pageLayout == pageLayoutNull) {
 
     Object catDict, obj;
@@ -598,7 +585,6 @@ Catalog::PageLayout Catalog::getPageLayout() {
     if (!catDict.isDict()) {
       error(errSyntaxError, -1, "Catalog object is wrong type ({0:s})", catDict.getTypeName());
       catDict.free();
-      unlockCatalog;
       return pageLayout;
     }
 
@@ -620,7 +606,6 @@ Catalog::PageLayout Catalog::getPageLayout() {
     obj.free();
     catDict.free();
   }
-  unlockCatalog;
   return pageLayout;
 }
 
@@ -787,13 +772,9 @@ GBool Catalog::indexToLabel(int index, GooString *label)
   }
 }
 
-int Catalog::getNumPages(GBool lock)
+int Catalog::getNumPages(Poppler::LockMode lock)
 {
-  GBool locked = gFalse;
-  if (lock && numPages == -1) {
-    locked = gTrue;
-    lockCatalog;
-  }
+  condLockCatalog((numPages == -1 && lock == Poppler::DoLock) ? lock : Poppler::DoNotLock);
   if (numPages == -1)
   {
     Object catDict, pagesDict, obj;
@@ -802,7 +783,6 @@ int Catalog::getNumPages(GBool lock)
     if (!catDict.isDict()) {
       error(errSyntaxError, -1, "Catalog object is wrong type ({0:s})", catDict.getTypeName());
       catDict.free();
-      if (locked) unlockCatalog;
       return 0;
     }
     catDict.dictLookup("Pages", &pagesDict);
@@ -814,7 +794,6 @@ int Catalog::getNumPages(GBool lock)
       error(errSyntaxError, -1, "Top-level pages object is wrong type ({0:s})",
           pagesDict.getTypeName());
       pagesDict.free();
-      if (locked) unlockCatalog;
       return 0;
     }
 
@@ -832,13 +811,12 @@ int Catalog::getNumPages(GBool lock)
     pagesDict.free();
   }
 
-  if (locked) unlockCatalog;
   return numPages;
 }
 
 PageLabelInfo *Catalog::getPageLabelInfo()
 {
-  lockCatalog;
+  lockCatalog();
   if (!pageLabelInfo) {
     Object catDict;
     Object obj;
@@ -847,24 +825,22 @@ PageLabelInfo *Catalog::getPageLabelInfo()
     if (!catDict.isDict()) {
       error(errSyntaxError, -1, "Catalog object is wrong type ({0:s})", catDict.getTypeName());
       catDict.free();
-      unlockCatalog;
       return NULL;
     }
 
     if (catDict.dictLookup("PageLabels", &obj)->isDict()) {
-      pageLabelInfo = new PageLabelInfo(&obj, getNumPages(gFalse));
+      pageLabelInfo = new PageLabelInfo(&obj, getNumPages(Poppler::DoLock));
     }
     obj.free();
     catDict.free();
   }
 
-  unlockCatalog;
   return pageLabelInfo;
 }
 
 Object *Catalog::getStructTreeRoot()
 {
-  lockCatalog;
+  lockCatalog();
   if (structTreeRoot.isNone())
   {
      Object catDict;
@@ -879,13 +855,12 @@ Object *Catalog::getStructTreeRoot()
      catDict.free();
   }
 
-  unlockCatalog;
   return &structTreeRoot;
 }
 
 Object *Catalog::getOutline()
 {
-  lockCatalog;
+  lockCatalog();
   if (outline.isNone())
   {
      Object catDict;
@@ -900,13 +875,12 @@ Object *Catalog::getOutline()
      catDict.free();
   }
 
-  unlockCatalog;
   return &outline;
 }
 
 Object *Catalog::getDests()
 {
-  lockCatalog;
+  lockCatalog();
   if (dests.isNone())
   {
      Object catDict;
@@ -921,7 +895,6 @@ Object *Catalog::getDests()
      catDict.free();
   }
 
-  unlockCatalog;
   return &dests;
 }
 
@@ -943,9 +916,9 @@ Catalog::FormType Catalog::getFormType()
   return res;
 }
 
-Form *Catalog::getForm(GBool lock)
+Form *Catalog::getForm(Poppler::LockMode lock)
 {
-  if (lock) lockCatalog;
+  condLockCatalog(lock);
   if (!form) {
     if (acroForm.isDict()) {
       form = new Form(doc, &acroForm);
@@ -954,20 +927,18 @@ Form *Catalog::getForm(GBool lock)
     }
   }
 
-  if (lock) unlockCatalog;
   return form;
 }
 
 ViewerPreferences *Catalog::getViewerPreferences()
 {
-  lockCatalog;
+  lockCatalog();
   if (!viewerPrefs) {
     if (viewerPreferences.isDict()) {
       viewerPrefs = new ViewerPreferences(viewerPreferences.getDict());
     }
   }
 
-  unlockCatalog;
   return viewerPrefs;
 }
 
diff --git a/poppler/Catalog.h b/poppler/Catalog.h
index ac7505f..0ddc30a 100644
--- a/poppler/Catalog.h
+++ b/poppler/Catalog.h
@@ -107,13 +107,13 @@ public:
   GBool isOk() { return ok; }
 
   // Get number of pages.
-  int getNumPages(GBool lock = gTrue);
+  int getNumPages(Poppler::LockMode lock = Poppler::DoLock);
 
   // Get a page.
   Page *getPage(int i);
 
   // Get the reference for a page object.
-  Ref *getPageRef(int i, GBool lock = gTrue);
+  Ref *getPageRef(int i, Poppler::LockMode lock = Poppler::DoLock);
 
   // Return base URI, or NULL if none.
   GooString *getBaseURI() { return baseURI; }
@@ -127,7 +127,7 @@ public:
 
   // Find a page, given its object ID.  Returns page number, or 0 if
   // not found.
-  int findPage(int num, int gen, GBool lock = gTrue);
+  int findPage(int num, int gen, Poppler::LockMode lock = Poppler::DoLock);
 
   // Find a named destination.  Returns the link destination, or
   // NULL if <name> is not a destination.
@@ -165,7 +165,7 @@ public:
   };
 
   FormType getFormType();
-  Form* getForm(GBool lock = gTrue);
+  Form* getForm(Poppler::LockMode lock = Poppler::DoLock);
 
   ViewerPreferences *getViewerPreferences();
 
@@ -228,7 +228,6 @@ private:
   PageMode pageMode;		// page mode
   PageLayout pageLayout;	// page layout
 
-  void createPages();       // create pages for caching
   GBool cachePageTree(int page); // Cache first <page> pages.
   Object *findDestInTree(Object *tree, GooString *name, Object *obj);