refs #5393, make fix, still need to fix cachetable-simple-pin-cheap.cc

git-svn-id: file:///svn/toku/tokudb@47055 c7de825b-a66e-492c-adef-691d508d4ae1

ft/cachetable.cc

@@ -1454,35 +1454,9 @@ static bool try_pin_pair(
         ct->list.read_list_lock();
     }
 
-    if (lock_type != PL_READ) {
-        ct->list.read_pending_cheap_lock();
-        bool p_checkpoint_pending = p->checkpoint_pending;
-        p->checkpoint_pending = false;
-        for (uint32_t i = 0; i < num_dependent_pairs; i++) {
-            dep_checkpoint_pending[i] = dependent_pairs[i]->checkpoint_pending;
-            dependent_pairs[i]->checkpoint_pending = false;
-        }
-        ct->list.read_pending_cheap_unlock();
-        checkpoint_pair_and_dependent_pairs(
-            ct,
-            p,
-            p_checkpoint_pending,
-            num_dependent_pairs,
-            dependent_pairs,
-            dep_checkpoint_pending,
-            dependent_dirty
-            );
-    }
-
     bool partial_fetch_required = pf_req_callback(p->value_data,read_extraargs);
-    // shortcutting a path to getting the user the data
-    // helps scalability for in-memory workloads
-    if (!partial_fetch_required) {
-        try_again = false;
-        goto exit;
-    }
     
-    // at this point, a partial fetch is required    
+    if (partial_fetch_required) {    
         if (ct->ev.should_client_thread_sleep() && !already_slept) {
             pair_lock(p);
             unpin_pair(p, (lock_type == PL_READ));
@@ -1541,6 +1515,27 @@ static bool try_pin_pair(
             pair_unlock(p);
         }
         ct->list.read_list_lock();
+    }
+
+    if (lock_type != PL_READ) {
+        ct->list.read_pending_cheap_lock();
+        bool p_checkpoint_pending = p->checkpoint_pending;
+        p->checkpoint_pending = false;
+        for (uint32_t i = 0; i < num_dependent_pairs; i++) {
+            dep_checkpoint_pending[i] = dependent_pairs[i]->checkpoint_pending;
+            dependent_pairs[i]->checkpoint_pending = false;
+        }
+        ct->list.read_pending_cheap_unlock();
+        checkpoint_pair_and_dependent_pairs(
+            ct,
+            p,
+            p_checkpoint_pending,
+            num_dependent_pairs,
+            dependent_pairs,
+            dep_checkpoint_pending,
+            dependent_dirty
+            );
+    }
 
     try_again = false;
 exit:
@@ -1731,16 +1726,6 @@ beginning:
             p->value_rwlock.read_lock();
             pair_unlock(p);
         }
-        // because we grabbed an expensive lock for the fetch,
-        // we ought to downgrade it back to cheap if we have to
-        // once we are done with the fetch
-        else if (lock_type == PL_WRITE_CHEAP) {
-            pair_lock(p);
-            p->value_rwlock.write_unlock();
-            p->value_rwlock.write_lock(false);
-            pair_unlock(p);
-        }
-
         // We need to be holding the read list lock when we exit.
         // We grab it here because we released it earlier to 
         // grab the write list lock because the checkpointing and

ft/tests/cachetable-pin-checkpoint.cc

@@ -149,7 +149,7 @@ static void *move_numbers(void *arg) {
             &v1,
             &s1,
             wc, fetch, def_pf_req_callback, def_pf_callback,
-            PL_WRITE_EXPENSIVE,
+            PL_WRITE_CHEAP,
             NULL,
             0, //num_dependent_pairs
             NULL,
@@ -171,7 +171,7 @@ static void *move_numbers(void *arg) {
             &v1,
             &s1,
             wc, fetch, def_pf_req_callback, def_pf_callback, 
-            PL_WRITE_EXPENSIVE,
+            PL_WRITE_CHEAP,
             NULL,
             1, //num_dependent_pairs
             &f1,
@@ -205,7 +205,7 @@ static void *move_numbers(void *arg) {
                 &v1,
                 &s1,
                 wc, fetch, def_pf_req_callback, def_pf_callback,
-                PL_WRITE_EXPENSIVE,
+                PL_WRITE_CHEAP,
                 NULL,
                 1, //num_dependent_pairs
                 &f1,