/ src / test / txrequest_tests.cpp
txrequest_tests.cpp
  1  // Copyright (c) 2020-present The Bitcoin Core developers
  2  // Distributed under the MIT software license, see the accompanying
  3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  4  
  5  
  6  #include <txrequest.h>
  7  #include <uint256.h>
  8  
  9  #include <test/util/random.h>
 10  #include <test/util/setup_common.h>
 11  
 12  #include <algorithm>
 13  #include <functional>
 14  #include <vector>
 15  
 16  #include <boost/test/unit_test.hpp>
 17  
 18  namespace {
 19  
 20  class Scenario;
 21  
 22  struct TxRequestTest : BasicTestingSetup {
 23      std::chrono::microseconds RandomTime8s();
 24      std::chrono::microseconds RandomTime1y();
 25      void BuildSingleTest(Scenario& scenario, int config);
 26      void BuildPriorityTest(Scenario& scenario, int config);
 27      void BuildBigPriorityTest(Scenario& scenario, int peers);
 28      void BuildRequestOrderTest(Scenario& scenario, int config);
 29      void BuildWtxidTest(Scenario& scenario, int config);
 30      void BuildTimeBackwardsTest(Scenario& scenario);
 31      void BuildWeirdRequestsTest(Scenario& scenario);
 32      void TestInterleavedScenarios();
 33  };
 34  
 35  constexpr std::chrono::microseconds MIN_TIME = std::chrono::microseconds::min();
 36  constexpr std::chrono::microseconds MAX_TIME = std::chrono::microseconds::max();
 37  constexpr std::chrono::microseconds MICROSECOND = std::chrono::microseconds{1};
 38  constexpr std::chrono::microseconds NO_TIME = std::chrono::microseconds{0};
 39  
 40  /** An Action is a function to call at a particular (simulated) timestamp. */
 41  using Action = std::pair<std::chrono::microseconds, std::function<void()>>;
 42  
 43  /** Object that stores actions from multiple interleaved scenarios, and data shared across them.
 44   *
 45   * The Scenario below is used to fill this.
 46   */
 47  struct Runner
 48  {
 49      /** The TxRequestTracker being tested. */
 50      TxRequestTracker txrequest;
 51  
 52      /** List of actions to be executed (in order of increasing timestamp). */
 53      std::vector<Action> actions;
 54  
 55      /** Which node ids have been assigned already (to prevent reuse). */
 56      std::set<NodeId> peerset;
 57  
 58      /** Which txhashes have been assigned already (to prevent reuse). */
 59      std::set<uint256> txhashset;
 60  
 61      /** Which (peer, gtxid) combinations are known to be expired. These need to be accumulated here instead of
 62       *  checked directly in the GetRequestable return value to avoid introducing a dependency between the various
 63       *  parallel tests. */
 64      std::multiset<std::pair<NodeId, GenTxid>> expired;
 65  };
 66  
 67  std::chrono::microseconds TxRequestTest::RandomTime8s() { return std::chrono::microseconds{1 + m_rng.randbits(23)}; }
 68  std::chrono::microseconds TxRequestTest::RandomTime1y() { return std::chrono::microseconds{1 + m_rng.randbits(45)}; }
 69  
 70  /** A proxy for a Runner that helps build a sequence of consecutive test actions on a TxRequestTracker.
 71   *
 72   * Each Scenario is a proxy through which actions for the (sequential) execution of various tests are added to a
 73   * Runner. The actions from multiple scenarios are then run concurrently, resulting in these tests being performed
 74   * against a TxRequestTracker in parallel. Every test has its own unique txhashes and NodeIds which are not
 75   * reused in other tests, and thus they should be independent from each other. Running them in parallel however
 76   * means that we verify the behavior (w.r.t. one test's txhashes and NodeIds) even when the state of the data
 77   * structure is more complicated due to the presence of other tests.
 78   */
 79  class Scenario
 80  {
 81      FastRandomContext& m_rng;
 82      Runner& m_runner;
 83      std::chrono::microseconds m_now;
 84      std::string m_testname;
 85  
 86  public:
 87      Scenario(FastRandomContext& rng, Runner& runner, std::chrono::microseconds starttime) : m_rng(rng), m_runner(runner), m_now(starttime) {}
 88  
 89      /** Set a name for the current test, to give more clear error messages. */
 90      void SetTestName(std::string testname)
 91      {
 92          m_testname = std::move(testname);
 93      }
 94  
 95      /** Advance this Scenario's time; this affects the timestamps newly scheduled events get. */
 96      void AdvanceTime(std::chrono::microseconds amount)
 97      {
 98          assert(amount.count() >= 0);
 99          m_now += amount;
100      }
101  
102      /** Schedule a ForgetTxHash call at the Scheduler's current time. */
103      void ForgetTxHash(const uint256& txhash)
104      {
105          auto& runner = m_runner;
106          runner.actions.emplace_back(m_now, [=, &runner]() {
107              runner.txrequest.ForgetTxHash(txhash);
108              runner.txrequest.SanityCheck();
109          });
110      }
111  
112      /** Schedule a ReceivedInv call at the Scheduler's current time. */
113      void ReceivedInv(NodeId peer, const GenTxid& gtxid, bool pref, std::chrono::microseconds reqtime)
114      {
115          auto& runner = m_runner;
116          runner.actions.emplace_back(m_now, [=, &runner]() {
117              runner.txrequest.ReceivedInv(peer, gtxid, pref, reqtime);
118              runner.txrequest.SanityCheck();
119          });
120      }
121  
122      /** Schedule a DisconnectedPeer call at the Scheduler's current time. */
123      void DisconnectedPeer(NodeId peer)
124      {
125          auto& runner = m_runner;
126          runner.actions.emplace_back(m_now, [=, &runner]() {
127              runner.txrequest.DisconnectedPeer(peer);
128              runner.txrequest.SanityCheck();
129          });
130      }
131  
132      /** Schedule a RequestedTx call at the Scheduler's current time. */
133      void RequestedTx(NodeId peer, const uint256& txhash, std::chrono::microseconds exptime)
134      {
135          auto& runner = m_runner;
136          runner.actions.emplace_back(m_now, [=, &runner]() {
137              runner.txrequest.RequestedTx(peer, txhash, exptime);
138              runner.txrequest.SanityCheck();
139          });
140      }
141  
142      /** Schedule a ReceivedResponse call at the Scheduler's current time. */
143      void ReceivedResponse(NodeId peer, const uint256& txhash)
144      {
145          auto& runner = m_runner;
146          runner.actions.emplace_back(m_now, [=, &runner]() {
147              runner.txrequest.ReceivedResponse(peer, txhash);
148              runner.txrequest.SanityCheck();
149          });
150      }
151  
152      /** Schedule calls to verify the TxRequestTracker's state at the Scheduler's current time.
153       *
154       * @param peer       The peer whose state will be inspected.
155       * @param expected   The expected return value for GetRequestable(peer)
156       * @param candidates The expected return value CountCandidates(peer)
157       * @param inflight   The expected return value CountInFlight(peer)
158       * @param completed  The expected return value of Count(peer), minus candidates and inflight.
159       * @param checkname  An arbitrary string to include in error messages, for test identificatrion.
160       * @param offset     Offset with the current time to use (must be <= 0). This allows simulations of time going
161       *                   backwards (but note that the ordering of this event only follows the scenario's m_now.
162       */
163      void Check(NodeId peer, const std::vector<GenTxid>& expected, size_t candidates, size_t inflight,
164                 size_t completed, const std::string& checkname,
165                 std::chrono::microseconds offset = std::chrono::microseconds{0})
166      {
167          const auto comment = m_testname + " " + checkname;
168          auto& runner = m_runner;
169          const auto now = m_now;
170          assert(offset.count() <= 0);
171          runner.actions.emplace_back(m_now, [=, &runner]() {
172              std::vector<std::pair<NodeId, GenTxid>> expired_now;
173              auto ret = runner.txrequest.GetRequestable(peer, now + offset, &expired_now);
174              for (const auto& entry : expired_now) {
175                  runner.expired.insert(entry);
176              }
177              runner.txrequest.SanityCheck();
178              runner.txrequest.PostGetRequestableSanityCheck(now + offset);
179              size_t total = candidates + inflight + completed;
180              size_t real_total = runner.txrequest.Count(peer);
181              size_t real_candidates = runner.txrequest.CountCandidates(peer);
182              size_t real_inflight = runner.txrequest.CountInFlight(peer);
183              BOOST_CHECK_MESSAGE(real_total == total, strprintf("[%s] total %i (%i expected)", comment, real_total, total));
184              BOOST_CHECK_MESSAGE(real_inflight == inflight, strprintf("[%s] inflight %i (%i expected)", comment, real_inflight, inflight));
185              BOOST_CHECK_MESSAGE(real_candidates == candidates, strprintf("[%s] candidates %i (%i expected)", comment, real_candidates, candidates));
186              BOOST_CHECK_MESSAGE(ret == expected, strprintf("[%s] mismatching requestables", comment));
187          });
188      }
189  
190      /** Verify that an announcement for gtxid by peer has expired some time before this check is scheduled.
191       *
192       * Every expected expiration should be accounted for through exactly one call to this function.
193       */
194      void CheckExpired(NodeId peer, GenTxid gtxid)
195      {
196          const auto& testname = m_testname;
197          auto& runner = m_runner;
198          runner.actions.emplace_back(m_now, [=, &runner]() {
199              auto it = runner.expired.find(std::pair<NodeId, GenTxid>{peer, gtxid});
200              BOOST_CHECK_MESSAGE(it != runner.expired.end(), "[" + testname + "] missing expiration");
201              if (it != runner.expired.end()) runner.expired.erase(it);
202          });
203      }
204  
205      /** Generate a random txhash, whose priorities for certain peers are constrained.
206       *
207       * For example, NewTxHash({{p1,p2,p3},{p2,p4,p5}}) will generate a txhash T such that both:
208       *  - priority(p1,T) > priority(p2,T) > priority(p3,T)
209       *  - priority(p2,T) > priority(p4,T) > priority(p5,T)
210       * where priority is the predicted internal TxRequestTracker's priority, assuming all announcements
211       * are within the same preferredness class.
212       */
213      uint256 NewTxHash(const std::vector<std::vector<NodeId>>& orders = {})
214      {
215          uint256 ret;
216          bool ok;
217          do {
218              ret = m_rng.rand256();
219              ok = true;
220              for (const auto& order : orders) {
221                  for (size_t pos = 1; pos < order.size(); ++pos) {
222                      uint64_t prio_prev = m_runner.txrequest.ComputePriority(ret, order[pos - 1], true);
223                      uint64_t prio_cur = m_runner.txrequest.ComputePriority(ret, order[pos], true);
224                      if (prio_prev <= prio_cur) {
225                          ok = false;
226                          break;
227                      }
228                  }
229                  if (!ok) break;
230              }
231              if (ok) {
232                  ok = m_runner.txhashset.insert(ret).second;
233              }
234          } while(!ok);
235          return ret;
236      }
237  
238      /** Generate a random GenTxid; the txhash follows NewTxHash; the transaction identifier is random. */
239      GenTxid NewGTxid(const std::vector<std::vector<NodeId>>& orders = {})
240      {
241          const uint256 txhash{NewTxHash(orders)};
242          return m_rng.randbool() ? GenTxid{Wtxid::FromUint256(txhash)} : GenTxid{Txid::FromUint256(txhash)};
243      }
244  
245      /** Generate a new random NodeId to use as peer. The same NodeId is never returned twice
246       *  (across all Scenarios combined). */
247      NodeId NewPeer()
248      {
249          bool ok;
250          NodeId ret;
251          do {
252              ret = m_rng.randbits(63);
253              ok = m_runner.peerset.insert(ret).second;
254          } while(!ok);
255          return ret;
256      }
257  
258      std::chrono::microseconds Now() const { return m_now; }
259  };
260  
261  /** Add to scenario a test with a single tx announced by a single peer.
262   *
263   * config is an integer in [0, 32), which controls which variant of the test is used.
264   */
265  void TxRequestTest::BuildSingleTest(Scenario& scenario, int config)
266  {
267      auto peer = scenario.NewPeer();
268      auto gtxid = scenario.NewGTxid();
269      bool immediate = config & 1;
270      bool preferred = config & 2;
271      auto delay = immediate ? NO_TIME : RandomTime8s();
272  
273      scenario.SetTestName(strprintf("Single(config=%i)", config));
274  
275      // Receive an announcement, either immediately requestable or delayed.
276      scenario.ReceivedInv(peer, gtxid, preferred, immediate ? MIN_TIME : scenario.Now() + delay);
277      if (immediate) {
278          scenario.Check(peer, {gtxid}, 1, 0, 0, "s1");
279      } else {
280          scenario.Check(peer, {}, 1, 0, 0, "s2");
281          scenario.AdvanceTime(delay - MICROSECOND);
282          scenario.Check(peer, {}, 1, 0, 0, "s3");
283          scenario.AdvanceTime(MICROSECOND);
284          scenario.Check(peer, {gtxid}, 1, 0, 0, "s4");
285      }
286  
287      if (config >> 3) { // We'll request the transaction
288          scenario.AdvanceTime(RandomTime8s());
289          auto expiry = RandomTime8s();
290          scenario.Check(peer, {gtxid}, 1, 0, 0, "s5");
291          scenario.RequestedTx(peer, gtxid.ToUint256(), scenario.Now() + expiry);
292          scenario.Check(peer, {}, 0, 1, 0, "s6");
293  
294          if ((config >> 3) == 1) { // The request will time out
295              scenario.AdvanceTime(expiry - MICROSECOND);
296              scenario.Check(peer, {}, 0, 1, 0, "s7");
297              scenario.AdvanceTime(MICROSECOND);
298              scenario.Check(peer, {}, 0, 0, 0, "s8");
299              scenario.CheckExpired(peer, gtxid);
300              return;
301          } else {
302              scenario.AdvanceTime(std::chrono::microseconds{m_rng.randrange(expiry.count())});
303              scenario.Check(peer, {}, 0, 1, 0, "s9");
304              if ((config >> 3) == 3) { // A response will arrive for the transaction
305                  scenario.ReceivedResponse(peer, gtxid.ToUint256());
306                  scenario.Check(peer, {}, 0, 0, 0, "s10");
307                  return;
308              }
309          }
310      }
311  
312      if (config & 4) { // The peer will go offline
313          scenario.DisconnectedPeer(peer);
314      } else { // The transaction is no longer needed
315          scenario.ForgetTxHash(gtxid.ToUint256());
316      }
317      scenario.Check(peer, {}, 0, 0, 0, "s11");
318  }
319  
320  /** Add to scenario a test with a single tx announced by two peers, to verify the
321   *  right peer is selected for requests.
322   *
323   * config is an integer in [0, 32), which controls which variant of the test is used.
324   */
325  void TxRequestTest::BuildPriorityTest(Scenario& scenario, int config)
326  {
327      scenario.SetTestName(strprintf("Priority(config=%i)", config));
328  
329      // Two peers. They will announce in order {peer1, peer2}.
330      auto peer1 = scenario.NewPeer(), peer2 = scenario.NewPeer();
331      // Construct a transaction that under random rules would be preferred by peer2 or peer1,
332      // depending on configuration.
333      bool prio1 = config & 1;
334      auto gtxid = prio1 ? scenario.NewGTxid({{peer1, peer2}}) : scenario.NewGTxid({{peer2, peer1}});
335      bool pref1 = config & 2, pref2 = config & 4;
336  
337      scenario.ReceivedInv(peer1, gtxid, pref1, MIN_TIME);
338      scenario.Check(peer1, {gtxid}, 1, 0, 0, "p1");
339      if (m_rng.randbool()) {
340          scenario.AdvanceTime(RandomTime8s());
341          scenario.Check(peer1, {gtxid}, 1, 0, 0, "p2");
342      }
343  
344      scenario.ReceivedInv(peer2, gtxid, pref2, MIN_TIME);
345      bool stage2_prio =
346          // At this point, peer2 will be given priority if:
347          // - It is preferred and peer1 is not
348          (pref2 && !pref1) ||
349          // - They're in the same preference class,
350          //   and the randomized priority favors peer2 over peer1.
351          (pref1 == pref2 && !prio1);
352      NodeId priopeer = stage2_prio ? peer2 : peer1, otherpeer = stage2_prio ? peer1 : peer2;
353      scenario.Check(otherpeer, {}, 1, 0, 0, "p3");
354      scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p4");
355      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
356      scenario.Check(otherpeer, {}, 1, 0, 0, "p5");
357      scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p6");
358  
359      // We possibly request from the selected peer.
360      if (config & 8) {
361          scenario.RequestedTx(priopeer, gtxid.ToUint256(), MAX_TIME);
362          scenario.Check(priopeer, {}, 0, 1, 0, "p7");
363          scenario.Check(otherpeer, {}, 1, 0, 0, "p8");
364          if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
365      }
366  
367      // The peer which was selected (or requested from) now goes offline, or a NOTFOUND is received from them.
368      if (config & 16) {
369          scenario.DisconnectedPeer(priopeer);
370      } else {
371          scenario.ReceivedResponse(priopeer, gtxid.ToUint256());
372      }
373      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
374      scenario.Check(priopeer, {}, 0, 0, !(config & 16), "p8");
375      scenario.Check(otherpeer, {gtxid}, 1, 0, 0, "p9");
376      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
377  
378      // Now the other peer goes offline.
379      scenario.DisconnectedPeer(otherpeer);
380      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
381      scenario.Check(peer1, {}, 0, 0, 0, "p10");
382      scenario.Check(peer2, {}, 0, 0, 0, "p11");
383  }
384  
385  /** Add to scenario a randomized test in which N peers announce the same transaction, to verify
386   *  the order in which they are requested. */
387  void TxRequestTest::BuildBigPriorityTest(Scenario& scenario, int peers)
388  {
389      scenario.SetTestName(strprintf("BigPriority(peers=%i)", peers));
390  
391      // We will have N peers announce the same transaction.
392      std::map<NodeId, bool> preferred;
393      std::vector<NodeId> pref_peers, npref_peers;
394      int num_pref = m_rng.randrange(peers + 1) ; // Some preferred, ...
395      int num_npref = peers - num_pref; // some not preferred.
396      for (int i = 0; i < num_pref; ++i) {
397          pref_peers.push_back(scenario.NewPeer());
398          preferred[pref_peers.back()] = true;
399      }
400      for (int i = 0; i < num_npref; ++i) {
401          npref_peers.push_back(scenario.NewPeer());
402          preferred[npref_peers.back()] = false;
403      }
404      // Make a list of all peers, in order of intended request order (concatenation of pref_peers and npref_peers).
405      std::vector<NodeId> request_order;
406      request_order.reserve(num_pref + num_npref);
407      for (int i = 0; i < num_pref; ++i) request_order.push_back(pref_peers[i]);
408      for (int i = 0; i < num_npref; ++i) request_order.push_back(npref_peers[i]);
409  
410      // Determine the announcement order randomly.
411      std::vector<NodeId> announce_order = request_order;
412      std::shuffle(announce_order.begin(), announce_order.end(), m_rng);
413  
414      // Find a gtxid whose txhash prioritization is consistent with the required ordering within pref_peers and
415      // within npref_peers.
416      auto gtxid = scenario.NewGTxid({pref_peers, npref_peers});
417  
418      // Decide reqtimes in opposite order of the expected request order. This means that as time passes we expect the
419      // to-be-requested-from-peer will change every time a subsequent reqtime is passed.
420      std::map<NodeId, std::chrono::microseconds> reqtimes;
421      auto reqtime = scenario.Now();
422      for (int i = peers - 1; i >= 0; --i) {
423          reqtime += RandomTime8s();
424          reqtimes[request_order[i]] = reqtime;
425      }
426  
427      // Actually announce from all peers simultaneously (but in announce_order).
428      for (const auto peer : announce_order) {
429          scenario.ReceivedInv(peer, gtxid, preferred[peer], reqtimes[peer]);
430      }
431      for (const auto peer : announce_order) {
432          scenario.Check(peer, {}, 1, 0, 0, "b1");
433      }
434  
435      // Let time pass and observe the to-be-requested-from peer change, from nonpreferred to preferred, and from
436      // high priority to low priority within each class.
437      for (int i = peers - 1; i >= 0; --i) {
438          scenario.AdvanceTime(reqtimes[request_order[i]] - scenario.Now() - MICROSECOND);
439          scenario.Check(request_order[i], {}, 1, 0, 0, "b2");
440          scenario.AdvanceTime(MICROSECOND);
441          scenario.Check(request_order[i], {gtxid}, 1, 0, 0, "b3");
442      }
443  
444      // Peers now in random order go offline, or send NOTFOUNDs. At every point in time the new to-be-requested-from
445      // peer should be the best remaining one, so verify this after every response.
446      for (int i = 0; i < peers; ++i) {
447          if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
448          const int pos = m_rng.randrange(request_order.size());
449          const auto peer = request_order[pos];
450          request_order.erase(request_order.begin() + pos);
451          if (m_rng.randbool()) {
452              scenario.DisconnectedPeer(peer);
453              scenario.Check(peer, {}, 0, 0, 0, "b4");
454          } else {
455              scenario.ReceivedResponse(peer, gtxid.ToUint256());
456              scenario.Check(peer, {}, 0, 0, request_order.size() > 0, "b5");
457          }
458          if (request_order.size()) {
459              scenario.Check(request_order[0], {gtxid}, 1, 0, 0, "b6");
460          }
461      }
462  
463      // Everything is gone in the end.
464      for (const auto peer : announce_order) {
465          scenario.Check(peer, {}, 0, 0, 0, "b7");
466      }
467  }
468  
469  /** Add to scenario a test with one peer announcing two transactions, to verify they are
470   *  fetched in announcement order.
471   *
472   *  config is an integer in [0, 4) inclusive, and selects the variant of the test.
473   */
474  void TxRequestTest::BuildRequestOrderTest(Scenario& scenario, int config)
475  {
476      scenario.SetTestName(strprintf("RequestOrder(config=%i)", config));
477  
478      auto peer = scenario.NewPeer();
479      auto gtxid1 = scenario.NewGTxid();
480      auto gtxid2 = scenario.NewGTxid();
481  
482      auto reqtime2 = scenario.Now() + RandomTime8s();
483      auto reqtime1 = reqtime2 + RandomTime8s();
484  
485      scenario.ReceivedInv(peer, gtxid1, config & 1, reqtime1);
486      // Simulate time going backwards by giving the second announcement an earlier reqtime.
487      scenario.ReceivedInv(peer, gtxid2, config & 2, reqtime2);
488  
489      scenario.AdvanceTime(reqtime2 - MICROSECOND - scenario.Now());
490      scenario.Check(peer, {}, 2, 0, 0, "o1");
491      scenario.AdvanceTime(MICROSECOND);
492      scenario.Check(peer, {gtxid2}, 2, 0, 0, "o2");
493      scenario.AdvanceTime(reqtime1 - MICROSECOND - scenario.Now());
494      scenario.Check(peer, {gtxid2}, 2, 0, 0, "o3");
495      scenario.AdvanceTime(MICROSECOND);
496      // Even with time going backwards in between announcements, the return value of GetRequestable is in
497      // announcement order.
498      scenario.Check(peer, {gtxid1, gtxid2}, 2, 0, 0, "o4");
499  
500      scenario.DisconnectedPeer(peer);
501      scenario.Check(peer, {}, 0, 0, 0, "o5");
502  }
503  
504  /** Add to scenario a test that verifies behavior related to both txid and wtxid with the same
505   *  hash being announced.
506   *
507   *  config is an integer in [0, 4) inclusive, and selects the variant of the test used.
508  */
509  void TxRequestTest::BuildWtxidTest(Scenario& scenario, int config)
510  {
511      scenario.SetTestName(strprintf("Wtxid(config=%i)", config));
512  
513      auto peerT = scenario.NewPeer();
514      auto peerW = scenario.NewPeer();
515      auto txhash = scenario.NewTxHash();
516      auto txid{Txid::FromUint256(txhash)};
517      auto wtxid{Wtxid::FromUint256(txhash)};
518  
519      auto reqtimeT = m_rng.randbool() ? MIN_TIME : scenario.Now() + RandomTime8s();
520      auto reqtimeW = m_rng.randbool() ? MIN_TIME : scenario.Now() + RandomTime8s();
521  
522      // Announce txid first or wtxid first.
523      if (config & 1) {
524          scenario.ReceivedInv(peerT, txid, config & 2, reqtimeT);
525          if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
526          scenario.ReceivedInv(peerW, wtxid, !(config & 2), reqtimeW);
527      } else {
528          scenario.ReceivedInv(peerW, wtxid, !(config & 2), reqtimeW);
529          if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
530          scenario.ReceivedInv(peerT, txid, config & 2, reqtimeT);
531      }
532  
533      // Let time pass if needed, and check that the preferred announcement (txid or wtxid)
534      // is correctly to-be-requested (and with the correct wtxidness).
535      auto max_reqtime = std::max(reqtimeT, reqtimeW);
536      if (max_reqtime > scenario.Now()) scenario.AdvanceTime(max_reqtime - scenario.Now());
537      if (config & 2) {
538          scenario.Check(peerT, {txid}, 1, 0, 0, "w1");
539          scenario.Check(peerW, {}, 1, 0, 0, "w2");
540      } else {
541          scenario.Check(peerT, {}, 1, 0, 0, "w3");
542          scenario.Check(peerW, {wtxid}, 1, 0, 0, "w4");
543      }
544  
545      // Let the preferred announcement be requested. It's not going to be delivered.
546      auto expiry = RandomTime8s();
547      if (config & 2) {
548          scenario.RequestedTx(peerT, txid.ToUint256(), scenario.Now() + expiry);
549          scenario.Check(peerT, {}, 0, 1, 0, "w5");
550          scenario.Check(peerW, {}, 1, 0, 0, "w6");
551      } else {
552          scenario.RequestedTx(peerW, wtxid.ToUint256(), scenario.Now() + expiry);
553          scenario.Check(peerT, {}, 1, 0, 0, "w7");
554          scenario.Check(peerW, {}, 0, 1, 0, "w8");
555      }
556  
557      // After reaching expiration time of the preferred announcement, verify that the
558      // remaining one is requestable
559      scenario.AdvanceTime(expiry);
560      if (config & 2) {
561          scenario.Check(peerT, {}, 0, 0, 1, "w9");
562          scenario.Check(peerW, {wtxid}, 1, 0, 0, "w10");
563          scenario.CheckExpired(peerT, txid);
564      } else {
565          scenario.Check(peerT, {txid}, 1, 0, 0, "w11");
566          scenario.Check(peerW, {}, 0, 0, 1, "w12");
567          scenario.CheckExpired(peerW, wtxid);
568      }
569  
570      // If a good transaction with either that hash as wtxid or txid arrives, both
571      // announcements are gone.
572      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
573      scenario.ForgetTxHash(txhash);
574      scenario.Check(peerT, {}, 0, 0, 0, "w13");
575      scenario.Check(peerW, {}, 0, 0, 0, "w14");
576  }
577  
578  /** Add to scenario a test that exercises clocks that go backwards. */
579  void TxRequestTest::BuildTimeBackwardsTest(Scenario& scenario)
580  {
581      auto peer1 = scenario.NewPeer();
582      auto peer2 = scenario.NewPeer();
583      auto gtxid = scenario.NewGTxid({{peer1, peer2}});
584  
585      // Announce from peer2.
586      auto reqtime = scenario.Now() + RandomTime8s();
587      scenario.ReceivedInv(peer2, gtxid, true, reqtime);
588      scenario.Check(peer2, {}, 1, 0, 0, "r1");
589      scenario.AdvanceTime(reqtime - scenario.Now());
590      scenario.Check(peer2, {gtxid}, 1, 0, 0, "r2");
591      // Check that if the clock goes backwards by 1us, the transaction would stop being requested.
592      scenario.Check(peer2, {}, 1, 0, 0, "r3", -MICROSECOND);
593      // But it reverts to being requested if time goes forward again.
594      scenario.Check(peer2, {gtxid}, 1, 0, 0, "r4");
595  
596      // Announce from peer1.
597      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
598      scenario.ReceivedInv(peer1, gtxid, true, MAX_TIME);
599      scenario.Check(peer2, {gtxid}, 1, 0, 0, "r5");
600      scenario.Check(peer1, {}, 1, 0, 0, "r6");
601  
602      // Request from peer1.
603      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
604      auto expiry = scenario.Now() + RandomTime8s();
605      scenario.RequestedTx(peer1, gtxid.ToUint256(), expiry);
606      scenario.Check(peer1, {}, 0, 1, 0, "r7");
607      scenario.Check(peer2, {}, 1, 0, 0, "r8");
608  
609      // Expiration passes.
610      scenario.AdvanceTime(expiry - scenario.Now());
611      scenario.Check(peer1, {}, 0, 0, 1, "r9");
612      scenario.Check(peer2, {gtxid}, 1, 0, 0, "r10"); // Request goes back to peer2.
613      scenario.CheckExpired(peer1, gtxid);
614      scenario.Check(peer1, {}, 0, 0, 1, "r11", -MICROSECOND); // Going back does not unexpire.
615      scenario.Check(peer2, {gtxid}, 1, 0, 0, "r12", -MICROSECOND);
616  
617      // Peer2 goes offline, meaning no viable announcements remain.
618      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
619      scenario.DisconnectedPeer(peer2);
620      scenario.Check(peer1, {}, 0, 0, 0, "r13");
621      scenario.Check(peer2, {}, 0, 0, 0, "r14");
622  }
623  
624  /** Add to scenario a test that involves RequestedTx() calls for txhashes not returned by GetRequestable. */
625  void TxRequestTest::BuildWeirdRequestsTest(Scenario& scenario)
626  {
627      auto peer1 = scenario.NewPeer();
628      auto peer2 = scenario.NewPeer();
629      auto gtxid1 = scenario.NewGTxid({{peer1, peer2}});
630      auto gtxid2 = scenario.NewGTxid({{peer2, peer1}});
631  
632      // Announce gtxid1 by peer1.
633      scenario.ReceivedInv(peer1, gtxid1, true, MIN_TIME);
634      scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q1");
635  
636      // Announce gtxid2 by peer2.
637      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
638      scenario.ReceivedInv(peer2, gtxid2, true, MIN_TIME);
639      scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q2");
640      scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q3");
641  
642      // We request gtxid2 from *peer1* - no effect.
643      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
644      scenario.RequestedTx(peer1, gtxid2.ToUint256(), MAX_TIME);
645      scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q4");
646      scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q5");
647  
648      // Now request gtxid1 from peer1 - marks it as REQUESTED.
649      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
650      auto expiryA = scenario.Now() + RandomTime8s();
651      scenario.RequestedTx(peer1, gtxid1.ToUint256(), expiryA);
652      scenario.Check(peer1, {}, 0, 1, 0, "q6");
653      scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q7");
654  
655      // Request it a second time - nothing happens, as it's already REQUESTED.
656      auto expiryB = expiryA + RandomTime8s();
657      scenario.RequestedTx(peer1, gtxid1.ToUint256(), expiryB);
658      scenario.Check(peer1, {}, 0, 1, 0, "q8");
659      scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q9");
660  
661      // Also announce gtxid1 from peer2 now, so that the txhash isn't forgotten when the peer1 request expires.
662      scenario.ReceivedInv(peer2, gtxid1, true, MIN_TIME);
663      scenario.Check(peer1, {}, 0, 1, 0, "q10");
664      scenario.Check(peer2, {gtxid2}, 2, 0, 0, "q11");
665  
666      // When reaching expiryA, it expires (not expiryB, which is later).
667      scenario.AdvanceTime(expiryA - scenario.Now());
668      scenario.Check(peer1, {}, 0, 0, 1, "q12");
669      scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q13");
670      scenario.CheckExpired(peer1, gtxid1);
671  
672      // Requesting it yet again from peer1 doesn't do anything, as it's already COMPLETED.
673      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
674      scenario.RequestedTx(peer1, gtxid1.ToUint256(), MAX_TIME);
675      scenario.Check(peer1, {}, 0, 0, 1, "q14");
676      scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q15");
677  
678      // Now announce gtxid2 from peer1.
679      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
680      scenario.ReceivedInv(peer1, gtxid2, true, MIN_TIME);
681      scenario.Check(peer1, {}, 1, 0, 1, "q16");
682      scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q17");
683  
684      // And request it from peer1 (weird as peer2 has the preference).
685      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
686      scenario.RequestedTx(peer1, gtxid2.ToUint256(), MAX_TIME);
687      scenario.Check(peer1, {}, 0, 1, 1, "q18");
688      scenario.Check(peer2, {gtxid1}, 2, 0, 0, "q19");
689  
690      // If peer2 now (normally) requests gtxid2, the existing request by peer1 becomes COMPLETED.
691      if (m_rng.randbool()) scenario.AdvanceTime(RandomTime8s());
692      scenario.RequestedTx(peer2, gtxid2.ToUint256(), MAX_TIME);
693      scenario.Check(peer1, {}, 0, 0, 2, "q20");
694      scenario.Check(peer2, {gtxid1}, 1, 1, 0, "q21");
695  
696      // If peer2 goes offline, no viable announcements remain.
697      scenario.DisconnectedPeer(peer2);
698      scenario.Check(peer1, {}, 0, 0, 0, "q22");
699      scenario.Check(peer2, {}, 0, 0, 0, "q23");
700  }
701  
702  void TxRequestTest::TestInterleavedScenarios()
703  {
704      // Create a list of functions which add tests to scenarios.
705      std::vector<std::function<void(Scenario&)>> builders;
706      // Add instances of every test, for every configuration.
707      for (int n = 0; n < 64; ++n) {
708          builders.emplace_back([this, n](Scenario& scenario) { BuildWtxidTest(scenario, n); });
709          builders.emplace_back([this, n](Scenario& scenario) { BuildRequestOrderTest(scenario, n & 3); });
710          builders.emplace_back([this, n](Scenario& scenario) { BuildSingleTest(scenario, n & 31); });
711          builders.emplace_back([this, n](Scenario& scenario) { BuildPriorityTest(scenario, n & 31); });
712          builders.emplace_back([this, n](Scenario& scenario) { BuildBigPriorityTest(scenario, (n & 7) + 1); });
713          builders.emplace_back([this](Scenario& scenario) { BuildTimeBackwardsTest(scenario); });
714          builders.emplace_back([this](Scenario& scenario) { BuildWeirdRequestsTest(scenario); });
715      }
716      // Randomly shuffle all those functions.
717      std::shuffle(builders.begin(), builders.end(), m_rng);
718  
719      Runner runner;
720      auto starttime = RandomTime1y();
721      // Construct many scenarios, and run (up to) 10 randomly-chosen tests consecutively in each.
722      while (builders.size()) {
723          // Introduce some variation in the start time of each scenario, so they don't all start off
724          // concurrently, but get a more random interleaving.
725          auto scenario_start = starttime + RandomTime8s() + RandomTime8s() + RandomTime8s();
726          Scenario scenario(m_rng, runner, scenario_start);
727          for (int j = 0; builders.size() && j < 10; ++j) {
728              builders.back()(scenario);
729              builders.pop_back();
730          }
731      }
732      // Sort all the actions from all those scenarios chronologically, resulting in the actions from
733      // distinct scenarios to become interleaved. Use stable_sort so that actions from one scenario
734      // aren't reordered w.r.t. each other.
735      std::stable_sort(runner.actions.begin(), runner.actions.end(), [](const Action& a1, const Action& a2) {
736          return a1.first < a2.first;
737      });
738  
739      // Run all actions from all scenarios, in order.
740      for (auto& action : runner.actions) {
741          action.second();
742      }
743  
744      BOOST_CHECK_EQUAL(runner.txrequest.Size(), 0U);
745      BOOST_CHECK(runner.expired.empty());
746  }
747  
748  }  // namespace
749  
750  BOOST_FIXTURE_TEST_SUITE(txrequest_tests, TxRequestTest)
751  
752  BOOST_AUTO_TEST_CASE(TxRequestTest)
753  {
754      for (int i = 0; i < 5; ++i) {
755          TestInterleavedScenarios();
756      }
757  }
758  
759  BOOST_AUTO_TEST_SUITE_END()