Changeset 22273 in vbox for trunk/src/VBox/Runtime/common/alloc

Timestamp:

Aug 14, 2009 11:00:51 PM (15 years ago)

Author:

vboxsync

Message:

IPRT: Added RTHeapSimpleRelocate for saving and restoring of the heap.

File:

• trunk/src/VBox/Runtime/common/alloc/heapsimple.cpp (modified) (3 diffs)

trunk/src/VBox/Runtime/common/alloc/heapsimple.cpp

@@ -144 +144 @@
     /** The typical magic (RTHEAPSIMPLE_MAGIC). */
     size_t                  uMagic;
-    /** The heap size. (This structure is not included!) */
+    /** The heap size. (This structure is included!) */
     size_t                  cbHeap;
     /** Pointer to the end of the heap. */
@@ -285 +285 @@
  * Initializes the heap.
  *
- * @returns IPRT status code on success.
+ * @returns IPRT status code.
  * @param   pHeap       Where to store the heap anchor block on success.
  * @param   pvMemory    Pointer to the heap memory.
@@ -346 +346 @@
 }
 RT_EXPORT_SYMBOL(RTHeapSimpleInit);
+
+
+/** 
+ * Relocater the heap internal structures after copying it to a new location. 
+ *  
+ * This can be used when loading a saved heap. 
+ *  
+ * @returns IPRT status code. 
+ * @param   hHeap       Heap handle that has already been adjusted by to the new
+ *                      location.  That is to say, when calling
+ *                      RTHeapSimpleInit, the caller must note the offset of the
+ *                      returned heap handle into the heap memory.  This offset
+ *                      must be used when calcuating the handle value for the
+ *                      new location.  The offset may in some cases not be zero!
+ * @param   offDelta    The delta between the new and old location, i.e. what 
+ *                      should be added to the internal pointers.
+ */
+RTDECL(int) RTHeapSimpleRelocate(RTHEAPSIMPLE hHeap, uintptr_t offDelta)
+{
+    PRTHEAPSIMPLEINTERNAL   pHeapInt = hHeap;
+    PRTHEAPSIMPLEFREE       pCur;
+
+    /*
+     * Validate input.
+     */
+    AssertPtrReturn(pHeapInt, VERR_INVALID_HANDLE);
+    AssertReturn(pHeapInt->uMagic == RTHEAPSIMPLE_MAGIC, VERR_INVALID_HANDLE);
+    AssertMsgReturn((uintptr_t)pHeapInt - (uintptr_t)pHeapInt->pvEnd + pHeapInt->cbHeap == offDelta, 
+                    ("offDelta=%p, expected=%p\n", offDelta, (uintptr_t)pHeapInt->pvEnd - pHeapInt->cbHeap - (uintptr_t)pHeapInt), 
+                    VERR_INVALID_PARAMETER);
+
+    /*
+     * Relocate the heap anchor block.
+     */
+#define RELOCATE_IT(var, type, offDelta)    do { if (RT_UNLIKELY((var) != NULL)) { (var) = (type)((uintptr_t)(var) + offDelta); } } while (0)
+    RELOCATE_IT(pHeapInt->pvEnd,     void *,            offDelta);
+    RELOCATE_IT(pHeapInt->pFreeHead, PRTHEAPSIMPLEFREE, offDelta);
+    RELOCATE_IT(pHeapInt->pFreeTail, PRTHEAPSIMPLEFREE, offDelta);
+
+    /*
+     * Walk the heap blocks.
+     */
+    for (pCur = PRTHEAPSIMPLEFREE(pHeapInt + 1); 
+         pCur && (uintptr_t)pCur < (uintptr_t)pHeapInt->pvEnd; 
+         pCur = (PRTHEAPSIMPLEFREE)pCur->Core.pNext)
+    {
+        RELOCATE_IT(pCur->Core.pNext, PRTHEAPSIMPLEBLOCK,    offDelta);
+        RELOCATE_IT(pCur->Core.pPrev, PRTHEAPSIMPLEBLOCK,    offDelta);
+        RELOCATE_IT(pCur->Core.pHeap, PRTHEAPSIMPLEINTERNAL, offDelta);
+        if (RTHEAPSIMPLEBLOCK_IS_FREE(&pCur->Core))
+        {
+            RELOCATE_IT(pCur->pNext, PRTHEAPSIMPLEFREE, offDelta);
+            RELOCATE_IT(pCur->pPrev, PRTHEAPSIMPLEFREE, offDelta);
+        }
+    }
+#undef RELOCATE_IT
+
+#ifdef RTHEAPSIMPLE_STRICT
+    /*
+     * Give it a once over before we return.
+     */
+    rtHeapSimpleAssertAll(pHeapInt);
+#endif
+    return VINF_SUCCESS; 
+}
+RT_EXPORT_SYMBOL(RTHeapSimpleRelocate);