Regularly check the resource handle list.

src/resource_handle.c

@@ -116,6 +116,78 @@ static int listInit = 0;
 
 #endif
 
+#ifdef CDI_CHECK_RESOURCE_LISTS
+static void
+checkListLinear(const char *caller, int nsp)
+{
+  const listElem_t *restrict r = resHList[nsp].resources;
+  for (int i = 0; i < resHList[nsp].size; i++)
+    {
+      if (r[i].status != RESH_UNUSED) continue;
+
+      int prev = r[i].res.free.prev;
+      int next = r[i].res.free.next;
+
+      if (prev < -1 || prev >= resHList[nsp].size) xabortC(caller, "error: found invalid back-link in free-list!");
+      if (prev != -1)
+        {
+          if (r[prev].res.free.next != i) xabortC(caller, "error: found incomplete back link in free-list!");
+          if (r[prev].status & RESH_IN_USE_BIT) xabortC(caller, "error: found in-use back link element in free-list!");
+        }
+
+      if (next < -1 || next >= resHList[nsp].size) xabortC(caller, "error: found invalid forward-link in free-list!");
+      if (next != -1)
+        {
+          if (r[next].res.free.prev != i) xabortC(caller, "error: found incomplete forward link in free-list!");
+          if (r[next].status & RESH_IN_USE_BIT) xabortC(caller, "error: found in-use next element in free-list!");
+        }
+    }
+}
+
+static void
+checkListFwdBwd(const char *caller, int nsp)
+{
+  const listElem_t *restrict r = resHList[nsp].resources;
+
+  int next = resHList[nsp].freeHead, loopLimit = resHList[nsp].size + 1;
+  int i = 0, cur = -1;
+  while (next != -1)
+    {
+      if (next < 0 || next >= resHList[nsp].size) xabortC(caller, "error: found invalid index in free-list!");
+      if (r[next].status & RESH_IN_USE_BIT) xabortC(caller, "error: found in-use next element in free-list!");
+
+      cur = next;
+      next = r[next].res.free.next;
+
+      if (++i > loopLimit) xabortC(caller, "error: found loop in free-list!");
+    }
+
+  i = 0;
+  int prev = cur;
+  while (prev != -1)
+    {
+      if (prev < 0 || prev >= resHList[nsp].size) xabortC(caller, "error: found invalid index in free-list!");
+      if (r[prev].status & RESH_IN_USE_BIT) xabortC(caller, "error: found in-use prev element in free-list!");
+
+      cur = prev;
+      prev = r[prev].res.free.prev;
+
+      if (prev == -1) break;
+
+      if (++i > loopLimit) xabortC(caller, "error: found loop in free-list!");
+    }
+}
+
+static void
+checkList(const char *caller, int nsp)
+{
+  checkListLinear(caller, nsp);
+  checkListFwdBwd(caller, nsp);
+}
+#else
+#define checkList(caller, nsp)
+#endif
+
 /**************************************************************/
 
 static void
@@ -133,9 +205,11 @@ listInitResources(int nsp)
       p[i].res.free.prev = i - 1;
       p[i].status = RESH_UNUSED;
     }
-
   p[size - 1].res.free.next = -1;
   resHList[nsp].freeHead = 0;
+
+  checkList(__func__, nsp);
+
   int oldNsp = namespaceGetActive();
   namespaceSetActive(nsp);
   instituteDefaultEntries();
@@ -237,6 +311,7 @@ static void
 listSizeExtend()
 {
   int nsp = namespaceGetActive();
+  checkList(__func__, nsp);
   int oldSize = resHList[nsp].size;
   size_t newListSize = (size_t) oldSize + MIN_LIST_SIZE;
 
@@ -255,6 +330,8 @@ listSizeExtend()
   r[oldSize].res.free.prev = -1;
   resHList[nsp].freeHead = oldSize;
   resHList[nsp].size = (int) newListSize;
+
+  checkList(__func__, nsp);
 }
 
 /**************************************************************/
@@ -262,6 +339,8 @@ listSizeExtend()
 static void
 reshPut_(int nsp, int entry, void *p, const resOps *ops)
 {
+  checkList(__func__, nsp);
+
   listElem_t *newListElem = resHList[nsp].resources + entry;
   int next = newListElem->res.free.next, prev = newListElem->res.free.prev;
   if (next != -1) resHList[nsp].resources[next].res.free.prev = prev;
@@ -272,6 +351,8 @@ reshPut_(int nsp, int entry, void *p, const resOps *ops)
   newListElem->res.v.val = p;
   newListElem->res.v.ops = ops;
   newListElem->status = RESH_DESYNC_IN_USE;
+
+  checkList(__func__, nsp);
 }
 
 int
@@ -300,6 +381,8 @@ reshPut(void *p, const resOps *ops)
 static void
 reshRemove_(int nsp, int idx, const char *caller)
 {
+  checkList(__func__, nsp);
+
   int curFree = resHList[nsp].freeHead;
   listElem_t *r = resHList[nsp].resources;
   if (!(r[idx].status & RESH_IN_USE_BIT)) xabortC(caller, "Attempting to remove an item that is already removed.");
@@ -308,6 +391,8 @@ reshRemove_(int nsp, int idx, const char *caller)
   if (curFree != -1) r[curFree].res.free.prev = idx;
   r[idx].status = RESH_DESYNC_DELETED;
   resHList[nsp].freeHead = idx;
+
+  checkList(__func__, nsp);
 }
 
 void
@@ -359,6 +444,9 @@ reshReplace(cdiResH resH, void *p, const resOps *ops)
   LIST_INIT(1);
   LIST_LOCK();
   int nsp = namespaceGetActive();
+
+  checkList(__func__, nsp);
+
   namespaceTuple_t nspT = namespaceResHDecode(resH);
   while (resHList[nsp].size <= nspT.idx) listSizeExtend();
   listElem_t *q = resHList[nsp].resources + nspT.idx;
@@ -369,6 +457,8 @@ reshReplace(cdiResH resH, void *p, const resOps *ops)
     }
   reshPut_(nsp, nspT.idx, p, ops);
   LIST_UNLOCK();
+
+  checkList(__func__, nsp);
 }
 
 static listElem_t *