Add WTF::makeCancellable

third_party/WebKit/Source/wtf/MakeCancellableTest.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "wtf/MakeCancellable.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "wtf/Compiler.h"
+
+namespace WTF {
+namespace {
+
+void add(int* x, int y) { *x += y; }
+
+class DestructionCounter {
+public:
+    explicit DestructionCounter(int* counter) : m_counter(counter) { }
+    ~DestructionCounter()
+    {
+        if (m_counter)
+            ++*m_counter;
+    }
+
+    DestructionCounter(DestructionCounter&& other) : m_counter(other.m_counter)
+    {
+        other.m_counter = nullptr;
+    }
+
+private:
+    int* m_counter;
+};
+
+class RefCountedDestructionCounter : public RefCounted<RefCountedDestructionCounter>, public DestructionCounter {
+public:
+    explicit RefCountedDestructionCounter(int* counter) : DestructionCounter(counter) {}
+};
+
+} // namespace
+
+TEST(MakeCancellableTest, NotCancelled)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    auto result = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, v);
+    (*result.function)(3);
+    EXPECT_EQ(3, v);
+}
+
+TEST(MakeCancellableTest, ExplicitCancel)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    auto result = makeCancellable(std::move(f));
+
+    EXPECT_TRUE(result.canceller.isActive());
+    result.canceller.cancel();
+    EXPECT_FALSE(result.canceller.isActive());
+
+    EXPECT_EQ(0, v);
+    (*result.function)(3);
+    EXPECT_EQ(0, v);
+}
+
+TEST(MakeCancellableTest, ScopeOutCancel)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    {
+        auto result = makeCancellable(std::move(f));
+        f = std::move(result.function);
+
+        ScopedFunctionCanceller scopedCanceller = std::move(result.canceller);
+        EXPECT_TRUE(scopedCanceller.isActive());
+    }
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(0, v);
+}
+
+TEST(MakeCancellableTest, Detach)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    {
+        auto result = makeCancellable(std::move(f));
+        f = std::move(result.function);
+
+        ScopedFunctionCanceller scopedCanceller = std::move(result.canceller);
+        EXPECT_TRUE(scopedCanceller.isActive());
+        scopedCanceller.detach();
+        EXPECT_FALSE(scopedCanceller.isActive());
+    }
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(3, v);
+}
+
+TEST(MakeCancellableTest, MultiCall)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    auto result = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, v);
+    (*result.function)(2);
+    EXPECT_EQ(2, v);
+    (*result.function)(3);
+    EXPECT_EQ(5, v);
+}
+
+TEST(MakeCancellableTest, DestroyOnCancel)
+{
+    int counter = 0;
+    auto f = bind([](const DestructionCounter&) {}, DestructionCounter(&counter));
+    auto result = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, counter);
+    result.canceller.cancel();
+    EXPECT_EQ(1, counter);
+}
+
+TEST(MakeCancellableTest, DestroyOnWrapperDestruction)
+{
+    int counter = 0;
+    auto f = bind([](const DestructionCounter&) {}, DestructionCounter(&counter));
+    auto result = makeCancellable(std::move(f));
+
+    EXPECT_TRUE(result.canceller.isActive());
+
+    EXPECT_EQ(0, counter);
+    result.function = nullptr;
+    EXPECT_EQ(1, counter);
+
+    EXPECT_FALSE(result.canceller.isActive());
+}
+
+TEST(MakeCancellableTest, SelfAssignment)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    auto result = makeCancellable(std::move(f));
+
+    ScopedFunctionCanceller scopedCanceller = std::move(result.canceller);
+    EXPECT_TRUE(scopedCanceller.isActive());
+
+#if COMPILER(CLANG)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wself-move"
+    scopedCanceller = std::move(scopedCanceller);
+#pragma clang diagnostic pop
+#else
+    scopedCanceller = std::move(scopedCanceller);
+#endif
+
+    EXPECT_TRUE(scopedCanceller.isActive());
+    EXPECT_EQ(0, v);
+    (*result.function)(1);
+    EXPECT_EQ(1, v);
+}
+
+} // namespace WTF