test: use tagged ephemeral MiniWallet instance in fill_mempool

test/functional/mempool_limit.py

@@ -95,7 +95,7 @@ class MempoolLimitTest(BitcoinTestFramework):
         assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
         assert_equal(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
 
-        fill_mempool(self, node, self.wallet)
+        fill_mempool(self, node)
         current_info = node.getmempoolinfo()
         mempoolmin_feerate = current_info["mempoolminfee"]
 
@@ -185,7 +185,7 @@ class MempoolLimitTest(BitcoinTestFramework):
         assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
         assert_equal(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
 
-        fill_mempool(self, node, self.wallet)
+        fill_mempool(self, node)
         current_info = node.getmempoolinfo()
         mempoolmin_feerate = current_info["mempoolminfee"]
 
@@ -259,7 +259,7 @@ class MempoolLimitTest(BitcoinTestFramework):
         assert_equal(node.getmempoolinfo()['minrelaytxfee'], Decimal('0.00001000'))
         assert_equal(node.getmempoolinfo()['mempoolminfee'], Decimal('0.00001000'))
 
-        fill_mempool(self, node, self.wallet)
+        fill_mempool(self, node)
 
         # Deliberately try to create a tx with a fee less than the minimum mempool fee to assert that it does not get added to the mempool
         self.log.info('Create a mempool tx that will not pass mempoolminfee')

test/functional/p2p_1p1c_network.py

@@ -47,8 +47,7 @@ class PackageRelayTest(BitcoinTestFramework):
         self.supports_cli = False
 
     def raise_network_minfee(self):
-        filler_wallet = MiniWallet(self.nodes[0])
+        fill_mempool(self, self.nodes[0])
-        fill_mempool(self, self.nodes[0], filler_wallet)
 
         self.log.debug("Wait for the network to sync mempools")
         self.sync_mempools()

test/functional/p2p_opportunistic_1p1c.py

@@ -388,8 +388,7 @@ class PackageRelayTest(BitcoinTestFramework):
         self.generate(self.wallet_nonsegwit, 10)
         self.generate(self.wallet, 20)
 
-        filler_wallet = MiniWallet(node)
+        fill_mempool(self, node)
-        fill_mempool(self, node, filler_wallet)
 
         self.log.info("Check opportunistic 1p1c logic when parent (txid != wtxid) is received before child")
         self.test_basic_parent_then_child(self.wallet)

test/functional/p2p_tx_download.py

@@ -250,7 +250,7 @@ class TxDownloadTest(BitcoinTestFramework):
     def test_rejects_filter_reset(self):
         self.log.info('Check that rejected tx is not requested again')
         node = self.nodes[0]
-        fill_mempool(self, node, self.wallet)
+        fill_mempool(self, node)
         self.wallet.rescan_utxos()
         mempoolminfee = node.getmempoolinfo()['mempoolminfee']
         peer = node.add_p2p_connection(TestP2PConn())

test/functional/rpc_packages.py

@@ -390,7 +390,7 @@ class RPCPackagesTest(BitcoinTestFramework):
         ])
         self.wallet.rescan_utxos()
 
-        fill_mempool(self, node, self.wallet)
+        fill_mempool(self, node)
 
         minrelay = node.getmempoolinfo()["minrelaytxfee"]
         parent = self.wallet.create_self_transfer(

test/functional/test_framework/mempool_util.py

@@ -14,9 +14,12 @@ from .util import (
     create_lots_of_big_transactions,
     gen_return_txouts,
 )
+from .wallet import (
+    MiniWallet,
+)
 
 
-def fill_mempool(test_framework, node, miniwallet):
+def fill_mempool(test_framework, node):
     """Fill mempool until eviction.
 
     Allows for simpler testing of scenarios with floating mempoolminfee > minrelay
@@ -25,8 +28,8 @@ def fill_mempool(test_framework, node, miniwallet):
     It will not ensure mempools become synced as it
     is based on a single node and assumes -minrelaytxfee
     is 1 sat/vbyte.
-    To avoid unintentional tx dependencies, it is recommended to use separate miniwallets for
+    To avoid unintentional tx dependencies, the mempool filling txs are created with a
-    mempool filling vs transactions in tests.
+    tagged ephemeral miniwallet instance.
     """
     test_framework.log.info("Fill the mempool until eviction is triggered and the mempoolminfee rises")
     txouts = gen_return_txouts()
@@ -39,19 +42,20 @@ def fill_mempool(test_framework, node, miniwallet):
     # Generate UTXOs to flood the mempool
     # 1 to create a tx initially that will be evicted from the mempool later
     # 75 transactions each with a fee rate higher than the previous one
-    test_framework.generate(miniwallet, 1 + (num_of_batches * tx_batch_size))
+    ephemeral_miniwallet = MiniWallet(node, tag_name="fill_mempool_ephemeral_wallet")
+    test_framework.generate(ephemeral_miniwallet, 1 + num_of_batches * tx_batch_size)
 
     # Mine enough blocks so that the UTXOs are allowed to be spent
     test_framework.generate(node, COINBASE_MATURITY - 1)
 
     # Get all UTXOs up front to ensure none of the transactions spend from each other, as that may
     # change their effective feerate and thus the order in which they are selected for eviction.
-    confirmed_utxos = [miniwallet.get_utxo(confirmed_only=True) for _ in range(num_of_batches * tx_batch_size + 1)]
+    confirmed_utxos = [ephemeral_miniwallet.get_utxo(confirmed_only=True) for _ in range(num_of_batches * tx_batch_size + 1)]
     assert_equal(len(confirmed_utxos), num_of_batches * tx_batch_size + 1)
 
     test_framework.log.debug("Create a mempool tx that will be evicted")
-    tx_to_be_evicted_id = miniwallet.send_self_transfer(from_node=node, utxo_to_spend=confirmed_utxos[0], fee_rate=relayfee)["txid"]
+    tx_to_be_evicted_id = ephemeral_miniwallet.send_self_transfer(
-    del confirmed_utxos[0]
+        from_node=node, utxo_to_spend=confirmed_utxos.pop(0), fee_rate=relayfee)["txid"]
 
     # Increase the tx fee rate to give the subsequent transactions a higher priority in the mempool
     # The tx has an approx. vsize of 65k, i.e. multiplying the previous fee rate (in sats/kvB)
@@ -63,7 +67,7 @@ def fill_mempool(test_framework, node, miniwallet):
         for batch_of_txid in range(num_of_batches):
             fee = (batch_of_txid + 1) * base_fee
             utxos = confirmed_utxos[:tx_batch_size]
-            create_lots_of_big_transactions(miniwallet, node, fee, tx_batch_size, txouts, utxos)
+            create_lots_of_big_transactions(ephemeral_miniwallet, node, fee, tx_batch_size, txouts, utxos)
             del confirmed_utxos[:tx_batch_size]
 
     test_framework.log.debug("The tx should be evicted by now")