refs #5672 use a valgrind suppression to ignore the race on the clock

git-svn-id: file:///svn/toku/tokudb@50717 c7de825b-a66e-492c-adef-691d508d4ae1

ft/ft-internal.h

@@ -270,17 +270,11 @@ struct ftnode {
 // that have a read lock on an internal node may try to touch the clock
 // simultaneously
 //
-#define BP_TOUCH_CLOCK(node, i) do {                                    \
-        TOKU_VALGRIND_HG_DISABLE_CHECKING(&(node)->bp[i].clock_count, sizeof (node)->bp[i].clock_count); \
-        TOKU_DRD_IGNORE_VAR((node)->bp[i].clock_count);                 \
-        (node)->bp[i].clock_count = 1;                                  \
-        TOKU_DRD_STOP_IGNORING_VAR((node)->bp[i].clock_count);          \
-        TOKU_VALGRIND_HG_ENABLE_CHECKING(&(node)->bp[i].clock_count, sizeof (node)->bp[i].clock_count); \
-    } while (0)
+#define BP_TOUCH_CLOCK(node, i) ((node)->bp[i].clock_count = 1)
 #define BP_SWEEP_CLOCK(node, i) ((node)->bp[i].clock_count = 0)
 #define BP_SHOULD_EVICT(node, i) ((node)->bp[i].clock_count == 0)
 // not crazy about having these two here, one is for the case where we create new
-// nodes, such as in splits and creating new roots, and the other is for when 
+// nodes, such as in splits and creating new roots, and the other is for when
 // we are deserializing a node and not all bp's are touched
 #define BP_INIT_TOUCHED_CLOCK(node, i) ((node)->bp[i].clock_count = 1)
 #define BP_INIT_UNTOUCHED_CLOCK(node, i) ((node)->bp[i].clock_count = 0)

ft/ft-ops.cc

@@ -1038,6 +1038,14 @@ exit:
     return 0;
 }
 
+// We touch the clock while holding a read lock.
+// DRD reports a race but we want to ignore it.
+// Using a valgrind suppressions file is better than the DRD_IGNORE_VAR macro because it's more targeted.
+// We need a function to have something a drd suppression can reference
+// see src/tests/drd.suppressions (unsafe_touch_clock)
+static inline void unsafe_touch_clock(FTNODE node, int i) {
+    BP_TOUCH_CLOCK(node, i);
+}
 
 // Callback that states if a partial fetch of the node is necessary
 // Currently, this function is responsible for the following things:
@@ -1067,7 +1075,7 @@ bool toku_ftnode_pf_req_callback(void* ftnode_pv, void* read_extraargs) {
     else if (bfe->type == ftnode_fetch_all) {
         retval = false;
         for (int i = 0; i < node->n_children; i++) {
-            BP_TOUCH_CLOCK(node,i);
+            unsafe_touch_clock(node,i);
             // if we find a partition that is not available,
             // then a partial fetch is required because
             // the entire node must be made available
@@ -1090,7 +1098,7 @@ bool toku_ftnode_pf_req_callback(void* ftnode_pv, void* read_extraargs) {
             node,
             bfe->search
             );
-        BP_TOUCH_CLOCK(node,bfe->child_to_read);
+        unsafe_touch_clock(node,bfe->child_to_read);
         // child we want to read is not available, must set retval to true
         retval = (BP_STATE(node, bfe->child_to_read) != PT_AVAIL);
     }

src/tests/drd.suppressions

@@ -77,3 +77,10 @@
    ...
    fun:random
 }
+
+{
+   unsafe_touch_clock
+   drd:ConflictingAccess
+   fun:_ZL18unsafe_touch_clockP6ftnodei
+   ...
+}