test: increases test coverage of near-tip parallel block dl

test/functional/p2p_ibd_stalling.py

@@ -154,38 +154,60 @@ def ibd_stalling(self):
 
     def near_tip_stalling(self):
         node = self.nodes[1]
-        peers = []
-        stall_block = self.blocks[0].sha256
-        self.log.info("Part 2: Test stalling close to the tip")
-        # only send 1024 headers, so that the window can't overshoot and the ibd stalling mechanism isn't triggered
-        headers_message = msg_headers()
-        headers_message.headers = [CBlockHeader(b) for b in self.blocks[:self.NUM_BLOCKS-1]]
-        self.log.info("Add three stalling peers")
-        for id in range(3):
-            peers.append(node.add_outbound_p2p_connection(P2PStaller(stall_block), p2p_idx=id, connection_type="outbound-full-relay"))
-            peers[-1].block_store = self.block_dict
-            peers[-1].send_message(headers_message)
 
-        self.wait_until(lambda: sum(len(peer['inflight']) for peer in node.getpeerinfo()) == 1)
-        self.all_sync_send_with_ping(peers)
-        assert_equal(sum(peer.stall_block_requested for peer in peers),  1)
+        self.log.info("Part 3: Test stalling close to the tip")
 
-        self.log.info("Check that after 30 seconds we request the block from a second peer")
-        self.mocktime = int(time.time()) + 31
-        node.setmocktime(self.mocktime)
-        self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 2)
+        # only send <= 1024 headers, so that the window can't overshoot and the ibd stalling mechanism isn't triggered
+        # make sure it works at different lengths
+        for header_length in [1, 10, 1024]:
+            peers = []
+            stall_block = self.blocks[0].sha256
+            headers_message = msg_headers()
+            headers_message.headers = [CBlockHeader(b) for b in self.blocks[:self.NUM_BLOCKS-1][:header_length]]
 
-        self.log.info("Check that after another 30 seconds we request the block from a third peer")
-        self.mocktime += 31
-        node.setmocktime(self.mocktime)
-        self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 3)
+            self.mocktime = int(time.time())
+            node.setmocktime(self.mocktime)
+
+            self.log.info(f"Add three stalling peers, sending {header_length} headers")
+            for id in range(4):
+                peers.append(node.add_outbound_p2p_connection(P2PStaller(stall_block), p2p_idx=id, connection_type="outbound-full-relay"))
+                peers[-1].block_store = self.block_dict
+                peers[-1].send_message(headers_message)
+
+            self.wait_until(lambda: sum(len(peer['inflight']) for peer in node.getpeerinfo()) == 1)
+            self.all_sync_send_with_ping(peers)
+            assert_equal(sum(peer.stall_block_requested for peer in peers),  1)
+
+            self.log.info("Check that after 30 seconds we request the block from a second peer")
+            self.mocktime += 31
+            node.setmocktime(self.mocktime)
+            self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 2)
+
+            self.log.info("Check that after another 30 seconds we request the block from a third peer")
+            self.mocktime += 31
+            node.setmocktime(self.mocktime)
+            self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 3)
+
+            self.log.info("Check that after another 30 seconds we aren't requesting it from a fourth peer yet")
+            self.mocktime += 31
+            node.setmocktime(self.mocktime)
+            self.all_sync_send_with_ping(peers)
+            self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 3)
+
+            self.log.info("Check that after another 20 minutes, first three stalling peers are disconnected")
+            # 10 minutes BLOCK_DOWNLOAD_TIMEOUT_BASE + 2*5 minutes BLOCK_DOWNLOAD_TIMEOUT_PER_PEER
+            self.mocktime += 20 * 60
+            node.setmocktime(self.mocktime)
+            # all peers have been requested
+            self.wait_until(lambda: sum(peer.stall_block_requested for peer in peers) == 4)
+
+            self.log.info("Check that after another 20 minutes, last stalling peer is disconnected")
+            # 10 minutes BLOCK_DOWNLOAD_TIMEOUT_BASE + 2*5 minutes BLOCK_DOWNLOAD_TIMEOUT_PER_PEER
+            self.mocktime += 20 * 60
+            node.setmocktime(self.mocktime)
+            for peer in peers:
+                peer.wait_for_disconnect()
 
-        self.log.info("Check that after another 20 minutes, all stalling peers are disconnected")
-        # 10 minutes BLOCK_DOWNLOAD_TIMEOUT_BASE + 2*5 minutes BLOCK_DOWNLOAD_TIMEOUT_PER_PEER
-        self.mocktime += 20 * 60
-        node.setmocktime(self.mocktime)
-        for peer in peers:
-            peer.wait_for_disconnect()
 
     def total_bytes_recv_for_blocks(self, node):
         total = 0