Tools/TestWebKitAPI/Tests/WTF/RefCountedWithInlineWeakPtr.cpp

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#include "config.h"

#include <wtf/InlineWeakPtr.h>
#include <wtf/RefCountedWithInlineWeakPtr.h>
#include <wtf/RefPtr.h>

namespace {

class ObjectThatRefsItselfDuringDestruction final : public RefCountedWithInlineWeakPtr<ObjectThatRefsItselfDuringDestruction> {
public:
    static Ref<ObjectThatRefsItselfDuringDestruction> create(RefPtr<ObjectThatRefsItselfDuringDestruction>* escapeTo)
    {
        return createRefCountedWithInlineWeakPtr<ObjectThatRefsItselfDuringDestruction>(escapeTo);
    }

    explicit ObjectThatRefsItselfDuringDestruction(RefPtr<ObjectThatRefsItselfDuringDestruction>* escapeTo)
        : m_escapeTo(escapeTo)
    {
    }

    ~ObjectThatRefsItselfDuringDestruction()
    {
        // Take a strong reference during destruction. If m_escapeTo is null,
        // it's transient (dropped before this destructor returns); otherwise
        // it escapes and should trip RELEASE_ASSERT(m_strongCount == 1).
        RefPtr<ObjectThatRefsItselfDuringDestruction> strong(this);
        if (m_escapeTo)
            *m_escapeTo = WTF::move(strong);
    }

private:
    RefPtr<ObjectThatRefsItselfDuringDestruction>* m_escapeTo { nullptr };
};

} // namespace

namespace TestWebKitAPI {

TEST(WTF_RefCountedWithInlineWeakPtr, TransientRefDuringDestruction)
{
    unsigned weakCountAfterDeref = 0;
    {
        InlineWeakPtr<ObjectThatRefsItselfDuringDestruction> weak;
        {
            auto object = ObjectThatRefsItselfDuringDestruction::create(nullptr);
            weak = object.ptr();
            EXPECT_EQ(weak.get(), object.ptr());
        }
        // The transient ref()/deref() inside ~T() must not re-enter destruction,
        // and the strong count must reach zero afterward so the weak pointer clears.
        EXPECT_EQ(weak.get(), nullptr);
        weakCountAfterDeref = 1;
    }
    EXPECT_EQ(weakCountAfterDeref, 1u); // reached without crashing
}

#if !defined(NDEBUG) || defined(GTEST_HAS_DEATH_TEST)
TEST(WTF_RefCountedWithInlineWeakPtrDeathTest, RefEscapesDuringDestruction)
{
    auto shouldCrash = [] {
        RefPtr<ObjectThatRefsItselfDuringDestruction> escaped;
        {
            auto object = ObjectThatRefsItselfDuringDestruction::create(&escaped);
        }
        // Not reached: derefSlowCase() runs ~T(), then RELEASE_ASSERTs that no
        // strong reference escaped.
    };

    ASSERT_DEATH_IF_SUPPORTED(shouldCrash(), "");
}
#endif

} // namespace TestWebKitAPI