Merge pull request #7845 from haberman/sync-stage

Integrate from Piper for C++, Java, and Python

java/core/src/test/java/com/google/protobuf/ExtensionRegistryFactoryTest.java

@@ -30,7 +30,6 @@
 
 package com.google.protobuf;
 
-import org.junit.Ignore;
 import protobuf_unittest.NonNestedExtension;
 import protobuf_unittest.NonNestedExtensionLite;
 import java.lang.reflect.Method;
@@ -42,6 +41,7 @@
 import junit.framework.Test;
 import junit.framework.TestCase;
 import junit.framework.TestSuite;
+import org.junit.Ignore;
 
 /**
  * Tests for {@link ExtensionRegistryFactory} and the {@link ExtensionRegistry} instances it
@@ -58,6 +58,7 @@
  * behavior in Java 11. That seems to have broken the way the test uses a custom ClassLoader to
  * exercise Lite functionality.
  */
+@SuppressWarnings("JUnit4ClassUsedInJUnit3")
 @Ignore
 public class ExtensionRegistryFactoryTest extends TestCase {
 

python/google/protobuf/descriptor.py

@@ -227,7 +227,8 @@ def CopyToProto(self, proto):
       proto: An empty proto instance from descriptor_pb2.
 
     Raises:
-      Error: If self couldn't be serialized, due to to few constructor arguments.
+      Error: If self couldn't be serialized, due to to few constructor
+        arguments.
     """
     if (self.file is not None and
         self._serialized_start is not None and

python/google/protobuf/internal/message_test.py

@@ -1059,7 +1059,7 @@ def testAssignByteStringToUnicodeField(self, message_module):
     self.assertIsInstance(m.optional_string, six.text_type)
 
   def testLongValuedSlice(self, message_module):
-    """It should be possible to use long-valued indices in slices
+    """It should be possible to use long-valued indices in slices.
 
     This didn't used to work in the v2 C++ implementation.
     """

src/google/protobuf/compiler/cpp/cpp_helpers.cc

@@ -1415,9 +1415,7 @@ class ParseLoopGenerator {
       format_.Set("has_bits", "_has_bits_");
     }
 
-    if (descriptor->file()->options().cc_enable_arenas()) {
-      format_("$p_ns$::Arena* arena = GetArena(); (void)arena;\n");
-    }
+    format_("$p_ns$::Arena* arena = GetArena(); (void)arena;\n");
     GenerateParseLoop(descriptor, ordered_fields);
     format_.Outdent();
     format_("success:\n");
@@ -1469,8 +1467,7 @@ class ParseLoopGenerator {
       // Open source doesn't support other ctypes;
       ctype = field->options().ctype();
     }
-    if (field->file()->options().cc_enable_arenas() && !field->is_repeated() &&
-        !options_.opensource_runtime &&
+    if (!field->is_repeated() && !options_.opensource_runtime &&
         GetOptimizeFor(field->file(), options_) != FileOptions::LITE_RUNTIME &&
         // For now only use arena string for strings with empty defaults.
         field->default_value_string().empty() &&

src/google/protobuf/compiler/importer_unittest.cc

@@ -469,7 +469,8 @@ TEST_F(DiskSourceTreeTest, DiskFileToVirtualFileCanonicalization) {
                                                &shadowing_disk_file));
 
 #ifdef WIN32
-  // "C:\foo" is not mapped (it should not be misinterpreted as being under ".").
+  // "C:\foo" is not mapped (it should not be misinterpreted as being under
+  // ".").
   EXPECT_EQ(DiskSourceTree::NO_MAPPING,
             source_tree_.DiskFileToVirtualFile("C:\\foo", &virtual_file,
                                                &shadowing_disk_file));

src/google/protobuf/generated_message_reflection.cc

@@ -1884,6 +1884,15 @@ bool Reflection::InsertOrLookupMapValue(Message* message,
       ->InsertOrLookupMapValue(key, val);
 }
 
+bool Reflection::LookupMapValue(const Message& message,
+                                const FieldDescriptor* field, const MapKey& key,
+                                MapValueConstRef* val) const {
+  USAGE_CHECK(IsMapFieldInApi(field), "LookupMapValue",
+              "Field is not a map field.");
+  val->SetType(field->message_type()->FindFieldByName("value")->cpp_type());
+  return GetRaw<MapFieldBase>(message, field).LookupMapValue(key, val);
+}
+
 bool Reflection::DeleteMapValue(Message* message, const FieldDescriptor* field,
                                 const MapKey& key) const {
   USAGE_CHECK(IsMapFieldInApi(field), "DeleteMapValue",

src/google/protobuf/map_field.cc

@@ -44,20 +44,24 @@ MapFieldBase::~MapFieldBase() {
 }
 
 const RepeatedPtrFieldBase& MapFieldBase::GetRepeatedField() const {
+  ConstAccess();
   SyncRepeatedFieldWithMap();
   return *reinterpret_cast<RepeatedPtrFieldBase*>(repeated_field_);
 }
 
 RepeatedPtrFieldBase* MapFieldBase::MutableRepeatedField() {
+  MutableAccess();
   SyncRepeatedFieldWithMap();
   SetRepeatedDirty();
   return reinterpret_cast<RepeatedPtrFieldBase*>(repeated_field_);
 }
 
 size_t MapFieldBase::SpaceUsedExcludingSelfLong() const {
+  ConstAccess();
   mutex_.Lock();
   size_t size = SpaceUsedExcludingSelfNoLock();
   mutex_.Unlock();
+  ConstAccess();
   return size;
 }
 
@@ -70,30 +74,35 @@ size_t MapFieldBase::SpaceUsedExcludingSelfNoLock() const {
 }
 
 bool MapFieldBase::IsMapValid() const {
+  ConstAccess();
   // "Acquire" insures the operation after SyncRepeatedFieldWithMap won't get
   // executed before state_ is checked.
   int state = state_.load(std::memory_order_acquire);
   return state != STATE_MODIFIED_REPEATED;
 }
 
 bool MapFieldBase::IsRepeatedFieldValid() const {
+  ConstAccess();
   int state = state_.load(std::memory_order_acquire);
   return state != STATE_MODIFIED_MAP;
 }
 
 void MapFieldBase::SetMapDirty() {
+  MutableAccess();
   // These are called by (non-const) mutator functions. So by our API it's the
   // callers responsibility to have these calls properly ordered.
   state_.store(STATE_MODIFIED_MAP, std::memory_order_relaxed);
 }
 
 void MapFieldBase::SetRepeatedDirty() {
+  MutableAccess();
   // These are called by (non-const) mutator functions. So by our API it's the
   // callers responsibility to have these calls properly ordered.
   state_.store(STATE_MODIFIED_REPEATED, std::memory_order_relaxed);
 }
 
 void MapFieldBase::SyncRepeatedFieldWithMap() const {
+  ConstAccess();
   // acquire here matches with release below to ensure that we can only see a
   // value of CLEAN after all previous changes have been synced.
   switch (state_.load(std::memory_order_acquire)) {
@@ -106,6 +115,7 @@ void MapFieldBase::SyncRepeatedFieldWithMap() const {
         state_.store(CLEAN, std::memory_order_release);
       }
       mutex_.Unlock();
+      ConstAccess();
       break;
     case CLEAN:
       mutex_.Lock();
@@ -122,6 +132,7 @@ void MapFieldBase::SyncRepeatedFieldWithMap() const {
         state_.store(CLEAN, std::memory_order_release);
       }
       mutex_.Unlock();
+      ConstAccess();
       break;
     default:
       break;
@@ -135,6 +146,7 @@ void MapFieldBase::SyncRepeatedFieldWithMapNoLock() const {
 }
 
 void MapFieldBase::SyncMapWithRepeatedField() const {
+  ConstAccess();
   // acquire here matches with release below to ensure that we can only see a
   // value of CLEAN after all previous changes have been synced.
   if (state_.load(std::memory_order_acquire) == STATE_MODIFIED_REPEATED) {
@@ -146,6 +158,7 @@ void MapFieldBase::SyncMapWithRepeatedField() const {
       state_.store(CLEAN, std::memory_order_release);
     }
     mutex_.Unlock();
+    ConstAccess();
   }
 }
 
@@ -245,6 +258,19 @@ bool DynamicMapField::InsertOrLookupMapValue(const MapKey& map_key,
   return false;
 }
 
+bool DynamicMapField::LookupMapValue(const MapKey& map_key,
+                                     MapValueConstRef* val) const {
+  const Map<MapKey, MapValueRef>& map = GetMap();
+  Map<MapKey, MapValueRef>::const_iterator iter = map.find(map_key);
+  if (iter == map.end()) {
+    return false;
+  }
+  // map_key is already in the map. Make sure (*map)[map_key] is not called.
+  // [] may reorder the map and iterators.
+  val->CopyFrom(iter->second);
+  return true;
+}
+
 bool DynamicMapField::DeleteMapValue(const MapKey& map_key) {
   MapFieldBase::SyncMapWithRepeatedField();
   Map<MapKey, MapValueRef>::iterator iter = map_.find(map_key);