Method BuildPriorityTest

src/test/txrequest_tests.cpp:325–383

Add to scenario a test with a single tx announced by two peers, to verify the * right peer is selected for requests. * * config is an integer in [0, 32), which controls which variant of the test is used. */

 * config is an integer in [0, 32), which controls which variant of the test is used.
 */
void TxRequestTest::BuildPriorityTest(Scenario& scenario, int config)
{
    scenario.SetTestName(strprintf("Priority(config=%i)", config));

    // Two peers. They will announce in order {peer1, peer2}.
    auto peer1 = scenario.NewPeer(), peer2 = scenario.NewPeer();
    // Construct a transaction that under random rules would be preferred by peer2 or peer1,
    // depending on configuration.
    bool prio1 = config & 1;
    auto gtxid = prio1 ? scenario.NewGTxid({{peer1, peer2}}) : scenario.NewGTxid({{peer2, peer1}});
    bool pref1 = config & 2, pref2 = config & 4;

    scenario.ReceivedInv(peer1, gtxid, pref1, MIN_TIME);
    scenario.Check(peer1, {gtxid}, 1, 0, 0, "p1");
    if (m_rng.randbool()) {
        scenario.AdvanceTime(RandomTime8s());
        scenario.Check(peer1, {gtxid}, 1, 0, 0, "p2");
    }

    scenario.ReceivedInv(peer2, gtxid, pref2, MIN_TIME);
    bool stage2_prio =
        // At this point, peer2 will be given priority if:
        // - It is preferred and peer1 is not
        (pref2 && !pref1) ||
        // - They're in the same preference class,
        //   and the randomized priority favors peer2 over peer1.
        (pref1 == pref2 && !prio1);
    NodeId priopeer = stage2_prio ? peer2 : peer1, otherpeer = stage2_prio ? peer1 : peer2;
    scenario.Check(otherpeer, {}, 1, 0, 0, "p3");
    scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p4");
    if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
    scenario.Check(otherpeer, {}, 1, 0, 0, "p5");
    scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p6");

    // We possibly request from the selected peer.
    if (config & 8) {
        scenario.RequestedTx(priopeer, gtxid.ToUint256(), MAX_TIME);
        scenario.Check(priopeer, {}, 0, 1, 0, "p7");
        scenario.Check(otherpeer, {}, 1, 0, 0, "p8");
        if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
    }

    // The peer which was selected (or requested from) now goes offline, or a NOTFOUND is received from them.
    if (config & 16) {
        scenario.DisconnectedPeer(priopeer);
    } else {
        scenario.ReceivedResponse(priopeer, gtxid.ToUint256());
    }
    if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
    scenario.Check(priopeer, {}, 0, 0, !(config & 16), "p8");
    scenario.Check(otherpeer, {gtxid}, 1, 0, 0, "p9");
    if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());

    // Now the other peer goes offline.
    scenario.DisconnectedPeer(otherpeer);
    if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
    scenario.Check(peer1, {}, 0, 0, 0, "p10");
    scenario.Check(peer2, {}, 0, 0, 0, "p11");