Remove "next" argument from materializeMutations

VersionedMap.cpp

@@ -263,7 +263,7 @@ struct MemManager {
     if (next == firstUnaddressable) {
       mprotectSafe(base + firstUnaddressable, kUpsizeBytes,
                    PROT_READ | PROT_WRITE);
-      VALGRIND_MAKE_MEM_UNDEFINED(base + firstUnaddressable, kUpsizeBytes);
+      VALGRIND_MAKE_MEM_NOACCESS(base + firstUnaddressable, kUpsizeBytes);
       firstUnaddressable += kUpsizeNodes;
 #if SHOW_MEMORY
       mmapBytes = getBytes();
@@ -278,6 +278,7 @@ struct MemManager {
       }
     }
 
+    VALGRIND_MAKE_MEM_UNDEFINED(base + next, sizeof(Node));
     return next++;
   }
 
@@ -954,7 +955,10 @@ struct __attribute__((__visibility__("hidden"))) VersionedMap::Impl {
           if (engulfLeft && engulfRight) {
             insert({next->getKey(), next->keyLen}, {}, /*endRange*/ true, copy);
             if (found) {
-              remove(iter);
+              move<std::memory_order_relaxed, false>(copy, latestVersion);
+              // Point to the same entry as iter pointed to, but it's not
+              // invalidated
+              remove(copy);
             }
           } else if (engulfLeft) {
             assert(found);
@@ -963,6 +967,10 @@ struct __attribute__((__visibility__("hidden"))) VersionedMap::Impl {
                    /*endRange*/ true, iter);
           } else if (engulfRight) {
             insert({m.param1, m.param1Len}, {}, /*endRange*/ false, iter);
+            move<std::memory_order_relaxed, true>(iter, latestVersion);
+            assert(iter.searchPathSize() > 0 &&
+                   mm.base[iter.backNode()].entry == next);
+            insert({next->getKey(), next->keyLen}, {}, /*endRange*/ true, iter);
           } else {
             insert({m.param1, m.param1Len}, {{nullptr, -1}}, /*endRange*/ false,
                    iter);
@@ -1200,8 +1208,8 @@ VersionedMap::Iterator::operator*() const {
   return impl->mutations[impl->mutationIndex];
 }
 
-void materializeMutations(VersionedMap::Iterator::Impl *impl, const Entry *prev,
+void materializeMutations(VersionedMap::Iterator::Impl *impl,
-                          const Entry *next) {
+                          const Entry *prev) {
   if (prev == nullptr) {
     Finger copy;
     impl->finger.copyTo(copy);
@@ -1212,14 +1220,6 @@ void materializeMutations(VersionedMap::Iterator::Impl *impl, const Entry *prev,
       assert(!impl->map->mm.base[impl->finger.backNode()].entry->clearTo());
     }
   }
-  if (next == nullptr) {
-    Finger copy;
-    impl->finger.copyTo(copy);
-    impl->map->move<std::memory_order_acquire, true>(copy, impl->version);
-    if (copy.searchPathSize() > 0) {
-      next = impl->map->mm.base[copy.backNode()].entry;
-    }
-  }
 
   const auto &entry = *impl->map->mm.base[impl->finger.backNode()].entry;
   impl->mutationCount = 0;
@@ -1234,7 +1234,6 @@ void materializeMutations(VersionedMap::Iterator::Impl *impl, const Entry *prev,
   }
   if (entry.pointMutation()) {
     if (entry.valLen < 0 /* pointClear */) {
-      assert(next == nullptr || !next->clearTo());
       impl->mutations[impl->mutationCount++] = {
           entry.getKey(),      nullptr,           entry.keyLen, 0,
           VersionedMap::Clear, entry.pointVersion};
@@ -1260,7 +1259,7 @@ VersionedMap::Iterator &VersionedMap::Iterator::operator++() {
     if (impl->finger.searchPathSize() == 0) {
       break;
     }
-    materializeMutations(impl, &entry, nullptr);
+    materializeMutations(impl, &entry);
   } while (impl->mutationCount == 0);
   impl->mutationIndex = 0;
 
@@ -1294,13 +1293,11 @@ VersionedMap::Iterator &VersionedMap::Iterator::operator--() {
       impl->finger.push(c, true);
     }
 
-    const Entry *next = nullptr;
     for (;;) {
-      materializeMutations(impl, nullptr, next);
+      materializeMutations(impl, nullptr);
       if (impl->mutationCount > 0) {
         break;
       }
-      next = impl->map->mm.base[impl->finger.backNode()].entry;
       impl->map->move<std::memory_order_acquire, false>(impl->finger,
                                                         impl->version);
     }
@@ -1309,13 +1306,12 @@ VersionedMap::Iterator &VersionedMap::Iterator::operator--() {
   }
 
   do {
-    const Entry *entry = impl->map->mm.base[impl->finger.backNode()].entry;
     impl->map->move<std::memory_order_acquire, false>(impl->finger,
                                                       impl->version);
     if (impl->finger.searchPathSize() == 0) {
       break;
     }
-    materializeMutations(impl, nullptr, entry);
+    materializeMutations(impl, nullptr);
   } while (impl->mutationCount == 0);
   impl->mutationIndex = impl->mutationCount - 1;
   return *this;
@@ -1390,7 +1386,7 @@ void VersionedMap::Impl::StepwiseFirstGeq::end() {
     if (finger.searchPathSize() == 0) {
       break;
     } else {
-      materializeMutations(iterator->impl, prev, nullptr);
+      materializeMutations(iterator->impl, prev);
       for (int j = 0; j < iterator->impl->mutationCount; ++j) {
         if (geq(iterator->impl->mutations[j], *key)) {
           iterator->impl->mutationIndex = j;
@@ -1542,7 +1538,7 @@ VersionedMap::Iterator VersionedMap::begin(int64_t version) const {
   const Entry *prev = nullptr;
   for (;;) {
     if (result.impl->finger.searchPathSize() > 0) {
-      materializeMutations(result.impl, prev, nullptr);
+      materializeMutations(result.impl, prev);
       if (result.impl->mutationCount > 0) {
         break;
       }
@@ -1682,4 +1678,4 @@ int main() {
 }
 #endif
 
-// GCOVR_EXCL_STOP
+// GCOVR_EXCL_STOP