Changeset 21151 in vbox for trunk/src/VBox/VMM/PDMQueue.cpp

Timestamp:

Jul 2, 2009 11:47:24 AM (16 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

49434

Message:

PDMQueue: Fixed leaking the last pending item when the consume returned false. Also, be more paranoid whe returning unconsumed items to the pending list.

File:

• trunk/src/VBox/VMM/PDMQueue.cpp (modified) (6 diffs)

trunk/src/VBox/VMM/PDMQueue.cpp

@@ -674 +674 @@
         &&  !pItemsRC
         &&  !pItemsR0)
-        /* Somebody was racing us. */
+        /* Somebody may be racing us ... never mind. */
         return true;
 
@@ -723 +723 @@
             while (pItems)
             {
+                if (!pQueue->u.Dev.pfnCallback(pQueue->u.Dev.pDevIns, pItems))
+                    break;
                 pCur = pItems;
                 pItems = pItems->pNextR3;
-                if (!pQueue->u.Dev.pfnCallback(pQueue->u.Dev.pDevIns, pCur))
-                    break;
                 pdmR3QueueFree(pQueue, pCur);
             }
@@ -734 +734 @@
             while (pItems)
             {
+                if (!pQueue->u.Drv.pfnCallback(pQueue->u.Drv.pDrvIns, pItems))
+                    break;
                 pCur = pItems;
                 pItems = pItems->pNextR3;
-                if (!pQueue->u.Drv.pfnCallback(pQueue->u.Drv.pDrvIns, pCur))
-                    break;
                 pdmR3QueueFree(pQueue, pCur);
             }
@@ -745 +745 @@
             while (pItems)
             {
+                if (!pQueue->u.Int.pfnCallback(pQueue->pVMR3, pItems))
+                    break;
                 pCur = pItems;
                 pItems = pItems->pNextR3;
-                if (!pQueue->u.Int.pfnCallback(pQueue->pVMR3, pCur))
-                    break;
                 pdmR3QueueFree(pQueue, pCur);
             }
@@ -756 +756 @@
             while (pItems)
             {
+                if (!pQueue->u.Ext.pfnCallback(pQueue->u.Ext.pvUser, pItems))
+                    break;
                 pCur = pItems;
                 pItems = pItems->pNextR3;
-                if (!pQueue->u.Ext.pfnCallback(pQueue->u.Ext.pvUser, pCur))
-                    break;
                 pdmR3QueueFree(pQueue, pCur);
             }
@@ -775 +775 @@
     {
         /*
-         * Shit, no!
-         *      1. Insert pCur.
-         *      2. Reverse the list.
-         *      3. Insert the LIFO at the tail of the pending list.
+         * Reverse the list.
          */
-        pCur->pNextR3 = pItems;
-        pItems = pCur;
-
-        //pCur = pItems;
+        pCur = pItems;
         pItems = NULL;
         while (pCur)
         {
             PPDMQUEUEITEMCORE pInsert = pCur;
-            pCur = pCur->pNextR3;
+            pCur = pInsert->pNextR3;
             pInsert->pNextR3 = pItems;
             pItems = pInsert;
         }
 
-        if (!ASMAtomicCmpXchgPtr((void * volatile *)&pQueue->pPendingR3, pItems, NULL))
-        {
-            pCur = pQueue->pPendingR3;
-            while (pCur->pNextR3)
-                pCur = pCur->pNextR3;
-            pCur->pNextR3 = pItems;
+        /*
+         * Insert the list at the tail of the pending list.
+         */
+        for (;;)
+        {
+            if (ASMAtomicCmpXchgPtr((void * volatile *)&pQueue->pPendingR3, pItems, NULL))
+                break;
+            PPDMQUEUEITEMCORE pPending = (PPDMQUEUEITEMCORE)ASMAtomicXchgPtr((void * volatile *)&pQueue->pPendingR3, NULL);
+            if (pPending)
+            {
+                pCur = pPending;
+                while (pCur->pNextR3)
+                    pCur = pCur->pNextR3;
+                pCur->pNextR3 = pItems;
+                pItem = pPending;
+            }
         }
         return false;