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libkern/c++/OSSymbol.cpp xnu-792.6.70 xnu-344
--- xnu/xnu-792.6.70/libkern/c++/OSSymbol.cpp
+++ xnu/xnu-344/libkern/c++/OSSymbol.cpp
@@ -93,7 +93,7 @@
     inline void closeGate() { mutex_lock(poolGate); };
     inline void openGate()  { mutex_unlock(poolGate); };
 
-    OSSymbol *findSymbol(const char *cString) const;
+    OSSymbol *findSymbol(const char *cString, OSSymbol ***replace) const;
     OSSymbol *insertSymbol(OSSymbol *sym);
     void removeSymbol(OSSymbol *sym);
 
@@ -210,7 +210,7 @@
         insertSymbol(insert);
 }
 
-OSSymbol *OSSymbolPool::findSymbol(const char *cString) const
+OSSymbol *OSSymbolPool::findSymbol(const char *cString, OSSymbol ***replace) const
 {
     Bucket *thisBucket;
     unsigned int j, inLen, hash;
@@ -220,6 +220,8 @@
     thisBucket = &buckets[hash % nBuckets];
     j = thisBucket->count;
 
+    *replace = NULL;
+
     if (!j)
         return 0;
 
@@ -227,16 +229,28 @@
         probeSymbol = (OSSymbol *) thisBucket->symbolP;
 
         if (inLen == probeSymbol->length
-        &&  (strcmp(probeSymbol->string, cString) == 0))
-            return probeSymbol;
+        &&  (strcmp(probeSymbol->string, cString) == 0)) {
+	    probeSymbol->retain();
+	    if (probeSymbol->getRetainCount() != 0xffff)
+		return probeSymbol;
+	    else
+		// replace this one
+		*replace = (OSSymbol **) &thisBucket->symbolP;
+        }
 	return 0;
     }
 
     for (list = thisBucket->symbolP; j--; list++) {
         probeSymbol = *list;
         if (inLen == probeSymbol->length
-        &&  (strcmp(probeSymbol->string, cString) == 0))
-            return probeSymbol;
+        &&  (strcmp(probeSymbol->string, cString) == 0)) {
+	    probeSymbol->retain();
+	    if (probeSymbol->getRetainCount() != 0xffff)
+		return probeSymbol;
+	    else
+		// replace this one
+		*replace = list;
+	}
     }
 
     return 0;
@@ -257,7 +271,7 @@
         thisBucket->symbolP = (OSSymbol **) sym;
         thisBucket->count++;
         count++;
-        return sym;
+        return 0;
     }
 
     if (j == 1) {
@@ -278,7 +292,7 @@
         if (count > nBuckets)
             reconstructSymbols();
 
-        return sym;
+        return 0;
     }
 
     for (list = thisBucket->symbolP; j--; list++) {
@@ -301,7 +315,7 @@
     if (count > nBuckets)
         reconstructSymbols();
 
-    return sym;
+    return 0;
 }
 
 void OSSymbolPool::removeSymbol(OSSymbol *sym)
@@ -425,62 +439,48 @@
 
 const OSSymbol *OSSymbol::withCString(const char *cString)
 {
+    OSSymbol **replace;
+
     pool->closeGate();
 
-    OSSymbol *oldSymb = pool->findSymbol(cString);
-    if (!oldSymb) {
-        OSSymbol *newSymb = new OSSymbol;
-        if (!newSymb) {
-            pool->openGate();
-            return newSymb;
-        }
-
-	if (newSymb->OSString::initWithCString(cString))
-	    oldSymb = pool->insertSymbol(newSymb);
-        
-        if (newSymb == oldSymb) {
-            pool->openGate();
-            return newSymb;	// return the newly created & inserted symbol.
-        }
-        else
-            // Somebody else inserted the new symbol so free our copy
+    OSSymbol *newSymb = pool->findSymbol(cString, &replace);
+    if (!newSymb && (newSymb = new OSSymbol) ) {
+	if (newSymb->OSString::initWithCString(cString)) {
+	    if (replace)
+		*replace = newSymb;
+	    else
+		pool->insertSymbol(newSymb);
+	} else {
 	    newSymb->OSString::free();
-    }
-    
-    oldSymb->retain();	// Retain the old symbol before releasing the lock.
-
+	    newSymb = 0;
+	}
+    }
     pool->openGate();
-    return oldSymb;
+
+    return newSymb;
 }
 
 const OSSymbol *OSSymbol::withCStringNoCopy(const char *cString)
 {
+    OSSymbol **replace;
+
     pool->closeGate();
 
-    OSSymbol *oldSymb = pool->findSymbol(cString);
-    if (!oldSymb) {
-        OSSymbol *newSymb = new OSSymbol;
-        if (!newSymb) {
-            pool->openGate();
-            return newSymb;
-        }
-
-	if (newSymb->OSString::initWithCStringNoCopy(cString))
-	    oldSymb = pool->insertSymbol(newSymb);
-        
-        if (newSymb == oldSymb) {
-            pool->openGate();
-            return newSymb;	// return the newly created & inserted symbol.
-        }
-        else
-            // Somebody else inserted the new symbol so free our copy
+    OSSymbol *newSymb = pool->findSymbol(cString, &replace);
+    if (!newSymb && (newSymb = new OSSymbol) ) {
+	if (newSymb->OSString::initWithCStringNoCopy(cString)) {
+	    if (replace)
+		*replace = newSymb;
+	    else
+		pool->insertSymbol(newSymb);
+	} else {
 	    newSymb->OSString::free();
-    }
-    
-    oldSymb->retain();	// Retain the old symbol before releasing the lock.
-
+	    newSymb = 0;
+	}
+    }
     pool->openGate();
-    return oldSymb;
+
+    return newSymb;
 }
 
 void OSSymbol::checkForPageUnload(void *startAddr, void *endAddr)
@@ -503,21 +503,12 @@
     pool->openGate();
 }
 
-void OSSymbol::taggedRelease(const void *tag) const
-{
-    super::taggedRelease(tag);
-}
-
-void OSSymbol::taggedRelease(const void *tag, const int when) const
+void OSSymbol::free()
 {
     pool->closeGate();
-    super::taggedRelease(tag, when);
+    pool->removeSymbol(this);
     pool->openGate();
-}
-
-void OSSymbol::free()
-{
-    pool->removeSymbol(this);
+    
     super::free();
 }