D/AAudio: AAudioStreamBuilder_openStream() called ----------------------------------------
D/: PlayerBase::PlayerBase()
D/AAudio: AAudioStreamBuilder_openStream() returns 0 = AAUDIO_OK for (0x7c94c67680) ----------------
E/AudioEngine: _backend use count: 2
    x_ use count: 0
    _backend use count: 3
    x_ use count: 3
    _backend use count: 2
D/AAudio: AAudioStreamBuilder_openStream() called ----------------------------------------
D/: PlayerBase::PlayerBase()
D/AAudio: AAudioStreamBuilder_openStream() returns 0 = AAUDIO_OK for (0x7c94c67c80) ----------------
E/AudioEngine: _backend use count: 2
    x_ use count: 0
    _backend use count: 3
    x_ use count: 3
    _backend use count: 0
A/AudioEngine: Cannot create Audio/MIDI engine.
A/libc: Fatal signal 6 (SIGABRT), code -6 (SI_TKILL) in tid 2569 (123.aaudiotrack), pid 2569 (123.aaudiotrack)

    test_();
    engine = AudioEngine::create();
    engine->set_backend ("AAudio", "Unit-Test", "");
    LOGE("_backend use count: %ld", _backend.use_count());
    if (!engine->current_backend()) {
        LOGF("Cannot create Audio/MIDI engine.\n");
    }

TEST::AudioEngine * Tengine = nullptr;

void test_() {
    // let android studio connect so we do not immediately abort before logcat can appear
    usleep(5000*1000);
    Tengine = TEST::AudioEngine::create();
    Tengine->set_backend ("AAudio", "Unit-Test", "");
    LOGE("_backend use count: %ld", TEST::_backend.use_count());
    if (!Tengine->current_backend()) {
        LOGF("Cannot create Audio/MIDI engine.\n");
    }
}