Merge pull request Tencent#1870 from ylavic/allocators_rvalues

Add rvalue copy and assignment to MemoryPoolAllocator and StdAllocator.

Author: miloyip

.travis.yml

@@ -40,10 +40,10 @@ matrix:
     - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=OFF
       compiler: gcc
       arch: amd64
-    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=ON
+    - env: CONF=debug   ARCH=x86    CXX11=OFF CXX17=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
       compiler: gcc
-      arch: amd64
-    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=ON
+      arch: amd64/
+    - env: CONF=debug   ARCH=x86_64 CXX11=OFF CXX17=ON CXX_FLAGS='-D_GLIBCXX_DEBUG'
       compiler: gcc
       arch: amd64
     - env: CONF=release ARCH=aarch64 CXX11=ON CXX17=OFF
@@ -84,7 +84,7 @@ matrix:
       compiler: clang
       arch: arm64
     # coverage report
-    - env: CONF=debug   ARCH=x86    CXX11=ON CXX17=OFF GCOV_FLAGS='--coverage'
+    - env: CONF=debug   ARCH=x86     GCOV_FLAGS='--coverage' CXX_FLAGS='-O0' CXX11=OFF CXX17=OFF
       compiler: gcc
       arch: amd64
       cache:
@@ -93,7 +93,7 @@ matrix:
       after_success:
         - pip install --user cpp-coveralls
         - coveralls -r .. --gcov-options '\-lp' -e thirdparty -e example -e test -e build/CMakeFiles -e include/rapidjson/msinttypes -e include/rapidjson/internal/meta.h -e include/rapidjson/error/en.h
-    - env: CONF=debug   ARCH=x86_64 GCOV_FLAGS='--coverage'
+    - env: CONF=debug   ARCH=x86_64  GCOV_FLAGS='--coverage' CXX_FLAGS='-O0' CXX11=ON CXX17=OFF
       compiler: gcc
       arch: amd64
       cache:
@@ -102,7 +102,7 @@ matrix:
       after_success:
         - pip install --user cpp-coveralls
         - coveralls -r .. --gcov-options '\-lp' -e thirdparty -e example -e test -e build/CMakeFiles -e include/rapidjson/msinttypes -e include/rapidjson/internal/meta.h -e include/rapidjson/error/en.h
-    - env: CONF=debug   ARCH=aarch64 GCOV_FLAGS='--coverage'
+    - env: CONF=debug   ARCH=aarch64 GCOV_FLAGS='--coverage' CXX_FLAGS='-O0' CXX11=OFF CXX17=ON
       compiler: gcc
       arch: arm64
       cache:
@@ -150,7 +150,7 @@ script:
       -DRAPIDJSON_BUILD_CXX17=$CXX17
       -DCMAKE_VERBOSE_MAKEFILE=ON
       -DCMAKE_BUILD_TYPE=$CONF
-      -DCMAKE_CXX_FLAGS="$ARCH_FLAGS $GCOV_FLAGS"
+      -DCMAKE_CXX_FLAGS="$ARCH_FLAGS $GCOV_FLAGS $CXX_FLAGS"
       -DCMAKE_EXE_LINKER_FLAGS=$GCOV_FLAGS
       ..)
   - cd build

include/rapidjson/allocators.h

@@ -222,18 +222,42 @@ class MemoryPoolAllocator {
     {
         RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
         ++rhs.shared_->refcount;
+        this->~MemoryPoolAllocator();
+        baseAllocator_ = rhs.baseAllocator_;
+        chunk_capacity_ = rhs.chunk_capacity_;
+        shared_ = rhs.shared_;
+        return *this;
+    }
 
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    MemoryPoolAllocator(MemoryPoolAllocator&& rhs) RAPIDJSON_NOEXCEPT :
+        chunk_capacity_(rhs.chunk_capacity_),
+        baseAllocator_(rhs.baseAllocator_),
+        shared_(rhs.shared_)
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
+        rhs.shared_ = 0;
+    }
+    MemoryPoolAllocator& operator=(MemoryPoolAllocator&& rhs) RAPIDJSON_NOEXCEPT
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
         this->~MemoryPoolAllocator();
         baseAllocator_ = rhs.baseAllocator_;
         chunk_capacity_ = rhs.chunk_capacity_;
         shared_ = rhs.shared_;
+        rhs.shared_ = 0;
         return *this;
     }
+#endif
 
     //! Destructor.
     /*! This deallocates all memory chunks, excluding the user-supplied buffer.
     */
     ~MemoryPoolAllocator() RAPIDJSON_NOEXCEPT {
+        if (!shared_) {
+            // do nothing if moved
+            return;
+        }
         if (shared_->refcount > 1) {
             --shared_->refcount;
             return;
@@ -449,6 +473,17 @@ class StdAllocator :
         baseAllocator_(rhs.baseAllocator_)
     { }
 
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    StdAllocator(StdAllocator&& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(std::move(rhs)),
+        baseAllocator_(std::move(rhs.baseAllocator_))
+    { }
+#endif
+#if RAPIDJSON_HAS_CXX11
+    using propagate_on_container_move_assignment = std::true_type;
+    using propagate_on_container_swap = std::true_type;
+#endif
+
     /* implicit */
     StdAllocator(const BaseAllocator& allocator) RAPIDJSON_NOEXCEPT :
         allocator_type(),
@@ -549,6 +584,10 @@ class StdAllocator :
         deallocate<value_type>(p, n);
     }
 
+#if RAPIDJSON_HAS_CXX11
+    using is_always_equal = std::is_empty<BaseAllocator>;
+#endif
+
     template<typename U>
     bool operator==(const StdAllocator<U, BaseAllocator>& rhs) const RAPIDJSON_NOEXCEPT
     {
@@ -561,6 +600,7 @@ class StdAllocator :
     }
 
     //! rapidjson Allocator concept
+    static const bool kNeedFree = BaseAllocator::kNeedFree;
     void* Malloc(size_t size)
     {
         return baseAllocator_.Malloc(size);

test/unittest/allocatorstest.cpp

@@ -16,8 +16,10 @@
 
 #include "rapidjson/allocators.h"
 
+#include <map>
 #include <string>
-#include <cstring>
+#include <utility>
+#include <functional>
 
 using namespace rapidjson;
 
@@ -141,12 +143,34 @@ void TestStdAllocator(const Allocator& a) {
 
     typedef StdAllocator<char, Allocator> CharAllocator;
     typedef std::basic_string<char, std::char_traits<char>, CharAllocator> String;
+#if RAPIDJSON_HAS_CXX11
+    String s(CharAllocator{a});
+#else
     CharAllocator ca(a);
     String s(ca);
+#endif
     for (int i = 0; i < 26; i++) {
         s.push_back(static_cast<char>('A' + i));
     }
     EXPECT_TRUE(s == "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+
+    typedef StdAllocator<std::pair<const int, bool>, Allocator> MapAllocator;
+    typedef std::map<int, bool, std::less<int>, MapAllocator> Map;
+#if RAPIDJSON_HAS_CXX11
+    Map map(std::less<int>(), MapAllocator{a});
+#else
+    MapAllocator ma(a);
+    Map map(std::less<int>(), ma);
+#endif
+    for (int i = 0; i < 10; i++) {
+        map.insert(std::make_pair(i, (i % 2) == 0));
+    }
+    EXPECT_TRUE(map.size() == 10);
+    for (int i = 0; i < 10; i++) {
+        typename Map::iterator it = map.find(i);
+        EXPECT_TRUE(it != map.end());
+        EXPECT_TRUE(it->second == ((i % 2) == 0));
+    }
 }
 
 TEST(Allocator, CrtAllocator) {