Delay free(), keep removed elems for "old value"

diff --git a/ThermoBeaconDisplay.cpp b/ThermoBeaconDisplay.cpp
index ac9f098ac884895f614563f06bbe36b483c11bfa..6b0230ad15487e377be3f66ad068322070e56477 100644 (file)
--- a/ThermoBeaconDisplay.cpp
+++ b/ThermoBeaconDisplay.cpp
@@ -209,6 +209,7 @@ void updateCache(struct entry *newentry)
     struct elem *cur = *cur_p;
     struct elem *slots[SLOTS] = { NULL };
     struct elem *target = NULL;
+    struct elem *to_remove = NULL;
     int pos = 0;
     bool not_yet_placed = true;
 
@@ -217,6 +218,7 @@ void updateCache(struct entry *newentry)
        bool at_the_end = !cur;
        if (pos < SLOTS)
            slots[pos] = cur;
+       pos++;
        // First handle insertion because it _can_ happen with cur == NULL
        if (not_yet_placed &&
                (at_the_end || cur->entry.rssi < newentry->rssi)) {
@@ -257,10 +259,9 @@ void updateCache(struct entry *newentry)
                } else {
                    dbgOp(pos, "really delete", &(cur->entry), "", NULL);
                    (*cur_p) = cur->next;
-                   free(cur);
+                   cur->next = to_remove;
+                   to_remove = cur;
                    cur = *cur_p;
-                   if (pos < SLOTS)
-                       slots[pos] = NULL;
                    step_ahead = false;  // Don't advance in the list
                }
            }
@@ -269,7 +270,6 @@ void updateCache(struct entry *newentry)
        if (step_ahead) {
            cur_p = &(cur->next);
            cur = *cur_p;
-           pos++;
        }
     }
     for (; pos < SLOTS; pos++) slots[pos] = NULL;
@@ -299,6 +299,12 @@ void updateCache(struct entry *newentry)
        target->entry = *newentry;
        target->age = 0;
     }
+    // And free elements that we took off the cache
+    for (cur = to_remove; cur; ) {
+       struct elem *next = cur->next;
+       free(cur);
+       cur = next;
+    }
 }
 
 void dbgDevEv(BLEDevice peripheral)