Merge "init/epoll_test: Improve this test"

#include <unordered_set>

#include <android-base/file.h>

#include <android-base/logging.h>

#include <gtest/gtest.h>

namespace android {

class CatchDtor final {

  public:

    CatchDtor() { sValidObjects.emplace(this); }

    CatchDtor(const CatchDtor&) { sValidObjects.emplace(this); }

    ~CatchDtor() {

        auto iter = sValidObjects.find(this);

        if (iter != sValidObjects.end()) {

            sValidObjects.erase(iter);

        }

    }

    CatchDtor() { CHECK(sValidObjects.emplace(this).second); }

    CatchDtor(const CatchDtor&) { CHECK(sValidObjects.emplace(this).second); }

    CatchDtor(const CatchDtor&&) { CHECK(sValidObjects.emplace(this).second); }

    ~CatchDtor() { CHECK_EQ(sValidObjects.erase(this), size_t{1}); }

};

TEST(epoll, UnregisterHandler) {

    ASSERT_EQ(pipe(fds), 0);

    CatchDtor catch_dtor;

    bool handler_invoked;

    bool handler_invoked = false;

    auto handler = [&, catch_dtor]() -> void {

        auto result = epoll.UnregisterHandler(fds[0]);

        ASSERT_EQ(result.ok(), !handler_invoked);

        handler_invoked = true;

        // The assert statement below verifies that the UnregisterHandler() call

        // above did not destroy the current std::function<> instance.

        ASSERT_NE(sValidObjects.find((void*)&catch_dtor), sValidObjects.end());

    };