qa: extend and harden p2p-tx-download

- Implements getmocktime instead of time.sleep to prevent races
- Enforce success of all mocktime operations
- Do not increment mocktime with 0 seconds
- Use fresh incoming peers for each test
- Explicitly do test teardown
- Remove TXID_RELAY_DELAY as this no longer exists in the dogecoind
  implementation
- Add the inflight throttling test to replace the removed inflight
  limit test
- Add an expiry fallback test

Cherry-picked from: a5a4e4b6
Github Pull Request: #3577

qa/rpc-tests/p2p-tx-download.py

@@ -16,10 +16,12 @@ TxDownload -- test transaction download logic
 GETDATA_TX_INTERVAL = 30  # seconds
 TX_EXPIRY_INTERVAL = 10 * GETDATA_TX_INTERVAL # 5 minutes
 INBOUND_PEER_TX_DELAY = 2  # seconds
-TXID_RELAY_DELAY = 2 # seconds
+OVERLOADED_PEER_DELAY = 2 # seconds
 MAX_GETDATA_IN_FLIGHT = 100
 MAX_PEER_TX_ANNOUNCEMENTS = 5000
 
+MAX_GETDATA_INBOUND_WAIT = GETDATA_TX_INTERVAL + INBOUND_PEER_TX_DELAY
+
 class TxDownloadTestNode(SingleNodeConnCB):
     def __init__(self):
         SingleNodeConnCB.__init__(self)
@@ -87,6 +89,8 @@ class TxDownloadTest(BitcoinTestFramework):
         self.test_disconnect_fallback()
         self.test_notfound_fallback()
         self.test_max_announcements()
+        self.test_inflight_throttling()
+        self.test_expiry_fallback()
 
     def setup_network(self):
         # set up full nodes
@@ -100,14 +104,10 @@ class TxDownloadTest(BitcoinTestFramework):
         connect_nodes(self.nodes[0], 1)
         self.sync_all()
 
-        # set up incoming (non-honest) peers
-        self.incoming_peers = []
-        for i in range(8):
-            self.incoming_peers.append(self.create_testnode())
-
+        # create a single control peer that is only used for ping sync
+        self.control_peer = self.create_testnode()
         NetworkThread().start()
-        for peer in self.incoming_peers:
-            peer.wait_for_verack()
+        self.control_peer.wait_for_verack()
 
     def create_testnode(self, node_idx=0):
         node = TxDownloadTestNode()
@@ -115,6 +115,20 @@ class TxDownloadTest(BitcoinTestFramework):
         node.add_connection(conn)
         return node
 
+    def connect_incoming_peers(self, num):
+        peers = []
+        for _ in range(num):
+            peer = self.create_testnode()
+            peer.wait_for_verack()
+            peers.append(peer)
+        return peers
+
+    def disconnect_incoming_peers(self, peers):
+        for peer in peers:
+            if not peer.disconnect():
+                return False
+        return True
+
     def any_received_getdata(self, hash, peers):
         for peer in peers:
             if hash in peer.tx_getdata_received:
@@ -135,6 +149,11 @@ class TxDownloadTest(BitcoinTestFramework):
             return True
         return wait_until(getdata_received, timeout=10)
 
+    def wait_for_mocktime(self, node):
+        def mocktime_is_good():
+            return node.getmocktime() >= self.mocktime
+        return wait_until(mocktime_is_good, timeout=10)
+
     def find_winning_peer(self, peers, hash):
         # detect which peer won a race for getting a getdata hash
         selected = None
@@ -154,15 +173,20 @@ class TxDownloadTest(BitcoinTestFramework):
         self.mocktime += delta_time
         for node in self.nodes:
             node.setmocktime(self.mocktime)
-        # give the nodes some time to process the new mocktime
-        # can be removed when we have getmocktime
-        time.sleep(0.1)
+            if not self.wait_for_mocktime(node):
+                return False
+        # sync the control peer with ping so that we're 100% sure we have
+        # entered a new message handling loop
+        self.control_peer.sync_with_ping()
+        return True
 
     def forward_mocktime_step2(self, iterations):
         # forward mocktime in steps of 2 seconds to allow the nodes
         # time to recognize they have to do something
         for i in range(iterations):
-            self.forward_mocktime(2)
+            if not self.forward_mocktime(2):
+                return False
+        return True
 
     def next_fake_txid(self):
         self.fake_txid += 1
@@ -170,24 +194,32 @@ class TxDownloadTest(BitcoinTestFramework):
 
     def test_tx_request(self):
         txid = self.next_fake_txid()
-        self.forward_mocktime(0)
+        assert self.forward_mocktime(1)
 
-        # use incoming peers 0 and 1
-        peerset = self.incoming_peers[0:4]
-        for peer in peerset:
+        # use 4 peers
+        peers = self.connect_incoming_peers(4)
+        for peer in peers:
             peer.send_tx_inv([txid])
 
-        # To make sure we eventually ask the tx from all 4 nodes that announced
+        # use 2 more peers that do not send invs
+        otherpeers = self.connect_incoming_peers(2)
+
+        # To make sure we eventually ask the tx from all 4 peers that announced
         # to us, we're now jumping 4 * (2 + 2 + 30) = 136 seconds to the future
-        warp = 4 * (INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY + GETDATA_TX_INTERVAL)
+        warp = 4 * MAX_GETDATA_INBOUND_WAIT
         self.forward_mocktime_step2(warp//2)
 
         # All peers that sent the inv should now have received a getdata request
-        assert self.wait_for_getdata([txid], peerset)
+        assert self.wait_for_getdata([txid], peers)
 
         # Make sure the other peers did not receive the getdata because they
         # didn't indicate they have the tx
-        assert not self.any_received_getdata(txid, self.incoming_peers[4:8])
+        assert not self.any_received_getdata(txid, otherpeers)
+
+        # cleanup
+        assert self.disconnect_incoming_peers(peers)
+        assert self.disconnect_incoming_peers(otherpeers)
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
 
     def test_invblock_resolution(self):
         inputs = [self.nodes[1].listunspent()[0]]
@@ -198,93 +230,187 @@ class TxDownloadTest(BitcoinTestFramework):
         tx.rehash()
         txid = int(tx.hash, 16)
 
-        self.forward_mocktime(0)
+        assert self.forward_mocktime(1)
 
         # make sure that node 1 is outbound for node 0
         assert self.nodes[0].getpeerinfo()[0]['inbound'] == False
 
-        # use all peers that only inv but never respond to getdata
-        for peer in self.incoming_peers:
+        # use 8 peers that only inv but never respond to getdata
+        peers = self.connect_incoming_peers(8)
+        for peer in peers:
             peer.send_tx_inv([txid])
 
         # send from our honest node last
         self.nodes[1].sendrawtransaction(tx_hex)
 
-        # We jump forward 2x (2 + 2) + 30 + 2 (margin) = 40 seconds to make sure
+        # We jump forward 2x max inbound wait time to make sure
         # that we get to the point where we re-evaluate the transaction in 2
         # second steps
-        warp = 2 * (INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY) + GETDATA_TX_INTERVAL + 2
-        self.forward_mocktime_step2(warp//2)
+        warp = 2 * MAX_GETDATA_INBOUND_WAIT
+        assert self.forward_mocktime_step2(warp//2)
 
         assert tx.hash in self.nodes[0].getrawmempool()
 
-    def test_notfound_fallback(self):
-        # use peer 4 and 5 to concurrently send 2 invs
-        peers = self.incoming_peers[4:6]
+        assert self.disconnect_incoming_peers(peers)
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
+    def test_inflight_throttling(self):
+        # First, forward time by 2x inflight timeout, so that we have clean
+        # registers for each peer
+        self.forward_mocktime(2 * TX_EXPIRY_INTERVAL)
+
+        # now send MAX_GETDATA_IN_FLIGHT (=100) invs with 1 peer
+        peer = self.connect_incoming_peers(1)[0]
+        invs = []
+        for i in range(MAX_GETDATA_IN_FLIGHT):
+            txid = self.next_fake_txid()
+            invs.append(txid)
+
+        peer.send_tx_inv(invs)
+
+        # warp forward 3 seconds in steps of 1 second
+        warp = INBOUND_PEER_TX_DELAY + 1
+        for _ in range(warp):
+            assert self.forward_mocktime(1)
+            peer.sync_with_ping()
+
+        # test that we got all the getdata
+        assert peer.wait_until_numgetdata(MAX_GETDATA_IN_FLIGHT)
+
+        peer.send_tx_inv([self.next_fake_txid()])
+
+        # warp forward 3 seconds again
+        warp = INBOUND_PEER_TX_DELAY + 1
+        for _ in range(warp):
+            assert self.forward_mocktime(1)
+            peer.sync_with_ping()
+
+        # test that we haven't received the getdata request yet
+        assert len(peer.tx_getdata_received) == MAX_GETDATA_IN_FLIGHT
+
+        # additionally warp the overloaded peer delay time second margin
+        warp = OVERLOADED_PEER_DELAY
+        for _ in range(warp):
+            assert self.forward_mocktime(1)
+            peer.sync_with_ping()
+
+        # test that we now received the getdata
+        assert peer.wait_until_numgetdata(MAX_GETDATA_IN_FLIGHT + 1)
+
+        # cleanup
+        assert self.disconnect_incoming_peers([peer])
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
+    def test_expiry_fallback(self):
+        # create 2 new peers
+        peers = self.connect_incoming_peers(2)
+
         txid = self.next_fake_txid()
-        self.forward_mocktime(1)
+        assert self.forward_mocktime(1)
 
         for peer in peers:
             peer.send_tx_inv([txid])
 
-        # warp forward 2 + 2 + 2 (margin) = 6 seconds in steps of 2
-        warp = INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY + 2
-        self.forward_mocktime_step2(warp//2)
+        # warp forward 2 + 2 (margin) = 4 seconds in steps of 2
+        warp = INBOUND_PEER_TX_DELAY + 2
+        assert self.forward_mocktime_step2(warp//2)
+
+        winner, loser = self.find_winning_peer(peers, txid)
+
+        # expire the request from the winning peer by doing nothing
+        assert self.forward_mocktime_step2(MAX_GETDATA_INBOUND_WAIT//2)
+
+        # the losing peer is now the fallback and received a getdata message
+        assert self.wait_for_getdata([txid], [loser])
+
+        #cleanup
+        assert self.disconnect_incoming_peers(peers)
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
+    def test_notfound_fallback(self):
+        # use 2 peers to concurrently send 2 invs
+        peers = self.connect_incoming_peers(2)
+        txid = self.next_fake_txid()
+        assert self.forward_mocktime(1)
+
+        for peer in peers:
+            peer.send_tx_inv([txid])
+
+        # warp forward 2 + 2 (margin) = 4 seconds in steps of 2
+        warp = INBOUND_PEER_TX_DELAY + 2
+        assert self.forward_mocktime_step2(warp//2)
 
         winner, loser = self.find_winning_peer(peers, txid)
 
         # send a reject message from the peer that won the race
         winner.send_tx_notfound([txid])
 
-        # warp forward 30 + 2 + 2 + 2 (margin) = 36 seconds in steps of 2
-        warp = GETDATA_TX_INTERVAL + INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY + 2
-        self.forward_mocktime_step2(warp//2)
+        # warp forward the max wait time in steps of 2
+        assert self.forward_mocktime_step2(MAX_GETDATA_INBOUND_WAIT//2)
 
         # the losing peer is now the fallback and received a getdata message
         assert self.wait_for_getdata([txid], [loser])
 
+        #cleanup
+        assert self.disconnect_incoming_peers(peers)
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
     def test_disconnect_fallback(self):
-        # use peer 6 and 7 to concurrently send 2 invs
-        peers = self.incoming_peers[6:8]
+        # use 2 peers to concurrently send 2 invs
+        peers = self.connect_incoming_peers(2)
         txid = self.next_fake_txid()
-        self.forward_mocktime(1)
+        assert self.forward_mocktime(1)
 
         for peer in peers:
             peer.send_tx_inv([txid])
 
-        # warp forward 2 + 2 + 2 (margin) = 6 seconds in steps of 2
-        warp = INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY + 2
-        self.forward_mocktime_step2(warp//2)
+        # warp forward 2 + 2 (margin) = 4 seconds in steps of 2
+        warp = INBOUND_PEER_TX_DELAY + 2
+        assert self.forward_mocktime_step2(warp//2)
 
         winner, loser = self.find_winning_peer(peers, txid)
 
         # drop connection from the peer that won the race
         assert winner.disconnect()
 
-        # warp forward 30 + 2 + 2 + 2 (margin) = 36 seconds in steps of 2
-        warp = GETDATA_TX_INTERVAL + INBOUND_PEER_TX_DELAY + TXID_RELAY_DELAY + 2
-        self.forward_mocktime_step2(warp//2)
+        # warp forward the max wait time in steps of 2
+        assert self.forward_mocktime_step2(MAX_GETDATA_INBOUND_WAIT//2)
 
         # the losing peer is now the fallback and received a getdata message
         assert self.wait_for_getdata([txid], [loser])
 
+        #cleanup
+        assert self.disconnect_incoming_peers(peers)
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
     def test_max_announcements(self):
         # create a test node
-        peer = self.create_testnode()
-        peer.wait_for_verack()
+        peer = self.connect_incoming_peers(1)[0]
+
+        assert self.forward_mocktime(1)
 
         hashes = []
         for _ in range(MAX_PEER_TX_ANNOUNCEMENTS):
             hashes.append(self.next_fake_txid())
 
         peer.send_tx_inv(hashes)
-        peer.wait_until_numgetdata(MAX_PEER_TX_ANNOUNCEMENTS)
+
+        # wait the maximum time before expiry minus 2 seconds to receive all
+        # getdata requests with this peer
+        warp = MAX_GETDATA_INBOUND_WAIT - 2
+        assert self.forward_mocktime_step2(warp//2)
+        assert peer.wait_until_numgetdata(MAX_PEER_TX_ANNOUNCEMENTS)
         peer.sync_with_ping()
 
-        # send one more - this should never come back.
+        # send one more and wait the maximum time - this should never come back.
         extratx = self.next_fake_txid()
         peer.send_tx_inv([extratx])
+        assert self.forward_mocktime_step2(MAX_GETDATA_INBOUND_WAIT//2)
         assert not self.any_received_getdata(extratx, [peer])
 
+        #cleanup
+        assert self.disconnect_incoming_peers([peer])
+        assert self.forward_mocktime(TX_EXPIRY_INTERVAL)
+
 if __name__ == '__main__':
     TxDownloadTest().main()