installed

src/libCom/cxxTemplates/tsFreeList.h

@@ -0,0 +1,121 @@
+
+/*  $Id$
+ *
+ *                    L O S  A L A M O S
+ *              Los Alamos National Laboratory
+ *               Los Alamos, New Mexico 87545
+ *
+ *  Copyright, 1986, The Regents of the University of California.
+ *
+ *  Author: Jeff Hill
+ */
+
+#include "osiMutex.h"
+
+#if defined(_MSC_VER) && _MSC_VER <= 1200
+#   pragma warning( disable : 4291 )  
+#endif
+
+template < class T >
+class tsFreeListItem {
+public:
+    union {
+        tsFreeListItem < T > *pNext;
+        char pad[ sizeof (T) ];
+    };
+};
+
+template < class T, unsigned N = 0x400 >
+class tsFreeListChunk {
+public:
+    tsFreeListChunk < T, N > *pNext;
+    tsFreeListItem < T > items [N];
+};
+
+template < class T, unsigned N >
+class tsFreeList : private osiMutex {
+public:
+    tsFreeList ();
+    ~tsFreeList ();
+    void * allocate ( size_t size );
+    void release ( void *p, size_t size );
+private:
+    tsFreeListItem < T > *pFreeList;
+    tsFreeListChunk < T, N > *pChunkList;
+};
+
+template < class T, unsigned N >
+inline tsFreeList < T, N >::tsFreeList () : 
+    pFreeList (0), pChunkList (0) {}
+
+template < class T, unsigned N >
+tsFreeList < T, N >::~tsFreeList ()
+{
+    tsFreeListChunk < T, N > *pChunk;
+
+    this->lock ();
+
+    while ( ( pChunk = this->pChunkList ) ) {
+        this->pChunkList = this->pChunkList->pNext;
+        delete pChunk;
+    }
+
+    this->unlock();
+}
+
+template < class T, unsigned N >
+void * tsFreeList < T, N >::allocate (size_t size)
+{
+    tsFreeListItem < T > *p;
+
+    if (size != sizeof (*p) ) {
+        return ::operator new (size);
+    }
+
+    this->lock ();
+
+    p = this->pFreeList;
+
+    if ( p ) {
+        this->pFreeList = p->pNext;
+    }
+    else {
+        unsigned i;
+
+        tsFreeListChunk<T,N> *pChunk = new ( tsFreeListChunk < T, N > );
+        if ( ! pChunk) {
+            return 0;
+        }
+
+        for ( i=1u; i < N-1; i++ ) {
+            pChunk->items[i].pNext = &pChunk->items[i+1];
+        }
+        pChunk->items[N-1].pNext = 0;
+        p = &pChunk->items[0];
+        this->pFreeList = &pChunk->items[1u];
+        pChunk->pNext = this->pChunkList;
+        this->pChunkList = pChunk;
+    }
+
+    this->unlock ();
+
+    return static_cast <void *> (p);
+}
+
+template < class T, unsigned N >
+void tsFreeList < T, N >::release (void *pCadaver, size_t size)
+{
+    if ( size != sizeof (tsFreeListItem<T>) ) {
+        ::operator delete (pCadaver);
+    }
+    else {
+        if ( pCadaver ) {
+            this->lock ();
+            tsFreeListItem<T> *p = 
+                static_cast < tsFreeListItem < T > *> (pCadaver);
+            p->pNext = this->pFreeList;
+            this->pFreeList = p;
+            this->unlock ();
+        }
+    }
+}