asyncio: stop using get_event_loop(). introduce ~singleton loop.

asyncio.get_event_loop() became deprecated in python3.10. (see https://github.com/python/cpython/issues/83710) ``` .../electrum/electrum/daemon.py:470: DeprecationWarning: There is no current event loop self.asyncio_loop = asyncio.get_event_loop() .../electrum/electrum/network.py:276: DeprecationWarning: There is no current event loop self.asyncio_loop = asyncio.get_event_loop() ``` Also, according to that thread, "set_event_loop() [... is] not deprecated by oversight". So, we stop using get_event_loop() and set_event_loop() in our own code. Note that libraries we use (such as the stdlib for python <3.10), might call get_event_loop, which then relies on us having called set_event_loop e.g. for the GUI thread. To work around this, a custom event loop policy providing a get_event_loop implementation is used. Previously, we have been using a single asyncio event loop, created with util.create_and_start_event_loop, and code in many places got a reference to this loop using asyncio.get_event_loop(). Now, we still use a single asyncio event loop, but it is now stored as a global in util._asyncio_event_loop (access with util.get_asyncio_loop()). I believe these changes also fix https://github.com/spesmilo/electrum/issues/5376
2022-04-29 18:24:49 +02:00
parent 334da245dc
commit 2c57c78ebe
15 changed files with 120 additions and 64 deletions
--- a/electrum/commands.py
+++ b/electrum/commands.py
@@ -187,7 +187,7 @@ class Commands:
                kwargs.pop('wallet')

        coro = f(*args, **kwargs)
-        fut = asyncio.run_coroutine_threadsafe(coro, asyncio.get_event_loop())
+        fut = asyncio.run_coroutine_threadsafe(coro, util.get_asyncio_loop())
        result = fut.result()

        if self._callback:
--- a/electrum/daemon.py
+++ b/electrum/daemon.py
@@ -124,7 +124,7 @@ def request(config: SimpleConfig, endpoint, args=(), timeout=60):
        rpc_user, rpc_password = get_rpc_credentials(config)
        server_url = 'http://%s:%d' % (host, port)
        auth = aiohttp.BasicAuth(login=rpc_user, password=rpc_password)
-        loop = asyncio.get_event_loop()
+        loop = util.get_asyncio_loop()
        async def request_coroutine():
            if socktype == 'unix':
                connector = aiohttp.UnixConnector(path=path)
@@ -467,7 +467,7 @@ class Daemon(Logger):
        if 'wallet_path' in config.cmdline_options:
            self.logger.warning("Ignoring parameter 'wallet_path' for daemon. "
                                "Use the load_wallet command instead.")
-        self.asyncio_loop = asyncio.get_event_loop()
+        self.asyncio_loop = util.get_asyncio_loop()
        self.network = None
        if not config.get('offline'):
            self.network = Network(config, daemon=self)
--- a/electrum/exchange_rate.py
+++ b/electrum/exchange_rate.py
@@ -148,7 +148,7 @@ class ExchangeBase(Logger):
        if h is None:
            h = self.read_historical_rates(ccy, cache_dir)
        if h is None or h['timestamp'] < time.time() - 24*3600:
-            asyncio.get_event_loop().create_task(self.get_historical_rates_safe(ccy, cache_dir))
+            util.get_asyncio_loop().create_task(self.get_historical_rates_safe(ccy, cache_dir))

    def history_ccys(self) -> Sequence[str]:
        return []
@@ -471,7 +471,7 @@ def get_exchanges_and_currencies():
                for name, klass in exchanges.items():
                    exchange = klass(None, None)
                    await group.spawn(get_currencies_safe(name, exchange))
-    loop = asyncio.get_event_loop()
+    loop = util.get_asyncio_loop()
    try:
        loop.run_until_complete(query_all_exchanges_for_their_ccys_over_network())
    except Exception as e:
--- a/electrum/gui/kivy/main_window.py
+++ b/electrum/gui/kivy/main_window.py
@@ -394,7 +394,7 @@ class ElectrumWindow(App, Logger):
        self.is_exit = False
        self.wallet = None  # type: Optional[Abstract_Wallet]
        self.pause_time = 0
-        self.asyncio_loop = asyncio.get_event_loop()
+        self.asyncio_loop = util.get_asyncio_loop()
        self.password = None
        self._use_single_password = False
        self.resume_dialog = None
--- a/electrum/lnworker.py
+++ b/electrum/lnworker.py
@@ -496,7 +496,7 @@ class LNWorker(Logger, NetworkRetryManager[LNPeerAddr]):
            # Try DNS-resolving the host (if needed). This is simply so that
            # the caller gets a nice exception if it cannot be resolved.
            try:
-                await asyncio.get_event_loop().getaddrinfo(host, port)
+                await asyncio.get_running_loop().getaddrinfo(host, port)
            except socket.gaierror:
                raise ConnStringFormatError(_('Hostname does not resolve (getaddrinfo failed)'))
            # add peer
--- a/electrum/network.py
+++ b/electrum/network.py
@@ -273,7 +273,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
            init_retry_delay_urgent=1,
        )

-        self.asyncio_loop = asyncio.get_event_loop()
+        self.asyncio_loop = util.get_asyncio_loop()
        assert self.asyncio_loop.is_running(), "event loop not running"

        assert isinstance(config, SimpleConfig), f"config should be a SimpleConfig instead of {type(config)}"
@@ -381,9 +381,11 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
            self.channel_db = None
            self.path_finder = None

-    def run_from_another_thread(self, coro, *, timeout=None):
-        assert util.get_running_loop() != self.asyncio_loop, 'must not be called from network thread'
-        fut = asyncio.run_coroutine_threadsafe(coro, self.asyncio_loop)
+    @classmethod
+    def run_from_another_thread(cls, coro, *, timeout=None):
+        loop = util.get_asyncio_loop()
+        assert util.get_running_loop() != loop, 'must not be called from asyncio thread'
+        fut = asyncio.run_coroutine_threadsafe(coro, loop)
        return fut.result(timeout)

    @staticmethod
@@ -1321,7 +1323,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
            assert util.get_running_loop() != network.asyncio_loop
            loop = network.asyncio_loop
        else:
-            loop = asyncio.get_event_loop()
+            loop = util.get_asyncio_loop()
        coro = asyncio.run_coroutine_threadsafe(cls._send_http_on_proxy(method, url, **kwargs), loop)
        # note: _send_http_on_proxy has its own timeout, so no timeout here:
        return coro.result()
--- a/electrum/sql_db.py
+++ b/electrum/sql_db.py
@@ -26,7 +26,6 @@ class SqlDB(Logger):
    def __init__(self, asyncio_loop: asyncio.BaseEventLoop, path, commit_interval=None):
        Logger.__init__(self)
        self.asyncio_loop = asyncio_loop
-        asyncio.set_event_loop(asyncio_loop)
        self.stopping = False
        self.stopped_event = asyncio.Event()
        self.path = path
--- a/electrum/tests/test_lnpeer.py
+++ b/electrum/tests/test_lnpeer.py
@@ -15,6 +15,7 @@ from aiorpcx import timeout_after, TaskTimeout
 import electrum
 import electrum.trampoline
 from electrum import bitcoin
+from electrum import util
 from electrum import constants
 from electrum.network import Network
 from electrum.ecc import ECPrivkey
@@ -62,7 +63,7 @@ class MockNetwork:
        user_config = {}
        user_dir = tempfile.mkdtemp(prefix="electrum-lnpeer-test-")
        self.config = simple_config.SimpleConfig(user_config, read_user_dir_function=lambda: user_dir)
-        self.asyncio_loop = asyncio.get_event_loop()
+        self.asyncio_loop = util.get_asyncio_loop()
        self.channel_db = ChannelDB(self)
        self.channel_db.data_loaded.set()
        self.path_finder = LNPathFinder(self.channel_db)
@@ -1361,4 +1362,4 @@ class TestPeer(TestCaseForTestnet):


 def run(coro):
-    return asyncio.run_coroutine_threadsafe(coro, loop=asyncio.get_event_loop()).result()
+    return asyncio.run_coroutine_threadsafe(coro, loop=util.get_asyncio_loop()).result()
--- a/electrum/tests/test_lnrouter.py
+++ b/electrum/tests/test_lnrouter.py
@@ -4,6 +4,7 @@ import tempfile
 import shutil
 import asyncio

+from electrum import util
 from electrum.util import bh2u, bfh, create_and_start_event_loop
 from electrum.lnutil import ShortChannelID
 from electrum.lnonion import (OnionHopsDataSingle, new_onion_packet,
@@ -64,7 +65,7 @@ class Test_LNRouter(TestCaseForTestnet):
        """
        class fake_network:
            config = self.config
-            asyncio_loop = asyncio.get_event_loop()
+            asyncio_loop = util.get_asyncio_loop()
            trigger_callback = lambda *args: None
            register_callback = lambda *args: None
            interface = None
--- a/electrum/tests/test_lntransport.py
+++ b/electrum/tests/test_lntransport.py
@@ -1,5 +1,6 @@
 import asyncio

+from electrum import util
 from electrum.ecc import ECPrivkey
 from electrum.lnutil import LNPeerAddr
 from electrum.lntransport import LNResponderTransport, LNTransport
@@ -11,6 +12,15 @@ from .test_bitcoin import needs_test_with_all_chacha20_implementations

 class TestLNTransport(ElectrumTestCase):

+    def setUp(self):
+        super().setUp()
+        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()
+
+    def tearDown(self):
+        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
+        self._loop_thread.join(timeout=1)
+        super().tearDown()
+
    @needs_test_with_all_chacha20_implementations
    def test_responder(self):
        # local static
@@ -38,11 +48,11 @@ class TestLNTransport(ElectrumTestCase):
                    assert num_bytes == 66
                    return bytes.fromhex('00b9e3a702e93e3a9948c2ed6e5fd7590a6e1c3a0344cfc9d5b57357049aa22355361aa02e55a8fc28fef5bd6d71ad0c38228dc68b1c466263b47fdf31e560e139ba')
        transport = LNResponderTransport(ls_priv, Reader(), Writer())
-        asyncio.get_event_loop().run_until_complete(transport.handshake(epriv=e_priv))
+        asyncio.run_coroutine_threadsafe(
+            transport.handshake(epriv=e_priv), self.asyncio_loop).result()

    @needs_test_with_all_chacha20_implementations
    def test_loop(self):
-        loop = asyncio.get_event_loop()
        responder_shaked = asyncio.Event()
        server_shaked = asyncio.Event()
        responder_key = ECPrivkey.generate_random_key()
@@ -96,4 +106,4 @@ class TestLNTransport(ElectrumTestCase):
                server.close()
                await server.wait_closed()

-        loop.run_until_complete(f())
+        asyncio.run_coroutine_threadsafe(f(), self.asyncio_loop).result()
--- a/electrum/tests/test_network.py
+++ b/electrum/tests/test_network.py
@@ -8,6 +8,7 @@ from electrum import blockchain
 from electrum.interface import Interface, ServerAddr
 from electrum.crypto import sha256
 from electrum.util import bh2u
+from electrum import util

 from . import ElectrumTestCase

@@ -17,7 +18,9 @@ class MockTaskGroup:

 class MockNetwork:
    taskgroup = MockTaskGroup()
-    asyncio_loop = asyncio.get_event_loop()
+
+    def __init__(self):
+        self.asyncio_loop = util.get_asyncio_loop()

 class MockInterface(Interface):
    def __init__(self, config):
@@ -52,9 +55,15 @@ class TestNetwork(ElectrumTestCase):

    def setUp(self):
        super().setUp()
+        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()
        self.config = SimpleConfig({'electrum_path': self.electrum_path})
        self.interface = MockInterface(self.config)

+    def tearDown(self):
+        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
+        self._loop_thread.join(timeout=1)
+        super().tearDown()
+
    def test_fork_noconflict(self):
        blockchain.blockchains = {}
        self.interface.q.put_nowait({'block_height': 8, 'mock': {'catchup':1, 'check': lambda x: False, 'connect': lambda x: False}})
@@ -66,7 +75,8 @@ class TestNetwork(ElectrumTestCase):
        self.interface.q.put_nowait({'block_height': 5, 'mock': {'binary':1,'check':lambda x: True, 'connect': lambda x: True}})
        self.interface.q.put_nowait({'block_height': 6, 'mock': {'binary':1,'check':lambda x: True, 'connect': lambda x: True}})
        ifa = self.interface
-        self.assertEqual(('fork', 8), asyncio.get_event_loop().run_until_complete(ifa.sync_until(8, next_height=7)))
+        fut = asyncio.run_coroutine_threadsafe(ifa.sync_until(8, next_height=7), util.get_asyncio_loop())
+        self.assertEqual(('fork', 8), fut.result())
        self.assertEqual(self.interface.q.qsize(), 0)

    def test_fork_conflict(self):
@@ -80,7 +90,8 @@ class TestNetwork(ElectrumTestCase):
        self.interface.q.put_nowait({'block_height': 5, 'mock': {'binary':1,'check':lambda x: True, 'connect': lambda x: True}})
        self.interface.q.put_nowait({'block_height': 6, 'mock': {'binary':1,'check':lambda x: True, 'connect': lambda x: True}})
        ifa = self.interface
-        self.assertEqual(('fork', 8), asyncio.get_event_loop().run_until_complete(ifa.sync_until(8, next_height=7)))
+        fut = asyncio.run_coroutine_threadsafe(ifa.sync_until(8, next_height=7), util.get_asyncio_loop())
+        self.assertEqual(('fork', 8), fut.result())
        self.assertEqual(self.interface.q.qsize(), 0)

    def test_can_connect_during_backward(self):
@@ -93,7 +104,8 @@ class TestNetwork(ElectrumTestCase):
        self.interface.q.put_nowait({'block_height': 3, 'mock': {'catchup':1, 'check': lambda x: False, 'connect': lambda x: True}})
        self.interface.q.put_nowait({'block_height': 4, 'mock': {'catchup':1, 'check': lambda x: False, 'connect': lambda x: True}})
        ifa = self.interface
-        self.assertEqual(('catchup', 5), asyncio.get_event_loop().run_until_complete(ifa.sync_until(8, next_height=4)))
+        fut = asyncio.run_coroutine_threadsafe(ifa.sync_until(8, next_height=4), util.get_asyncio_loop())
+        self.assertEqual(('catchup', 5), fut.result())
        self.assertEqual(self.interface.q.qsize(), 0)

    def mock_fork(self, bad_header):
@@ -113,7 +125,8 @@ class TestNetwork(ElectrumTestCase):
        self.interface.q.put_nowait({'block_height': 5, 'mock': {'catchup':1, 'check': lambda x: False, 'connect': lambda x: True}})
        self.interface.q.put_nowait({'block_height': 6, 'mock': {'catchup':1, 'check': lambda x: False, 'connect': lambda x: True}})
        ifa = self.interface
-        self.assertEqual(('catchup', 7), asyncio.get_event_loop().run_until_complete(ifa.sync_until(8, next_height=6)))
+        fut = asyncio.run_coroutine_threadsafe(ifa.sync_until(8, next_height=6), util.get_asyncio_loop())
+        self.assertEqual(('catchup', 7), fut.result())
        self.assertEqual(self.interface.q.qsize(), 0)


--- a/electrum/tests/test_storage_upgrade.py
+++ b/electrum/tests/test_storage_upgrade.py
@@ -20,12 +20,9 @@ class TestStorageUpgrade(WalletTestCase):

    def setUp(self):
        super().setUp()
-        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()

    def tearDown(self):
        super().tearDown()
-        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
-        self._loop_thread.join(timeout=1)

    def testnet_wallet(func):
        # note: it's ok to modify global network constants in subclasses of SequentialTestCase
--- a/electrum/tests/test_wallet.py
+++ b/electrum/tests/test_wallet.py
@@ -35,6 +35,7 @@ class WalletTestCase(ElectrumTestCase):

    def setUp(self):
        super(WalletTestCase, self).setUp()
+        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()
        self.user_dir = tempfile.mkdtemp()
        self.config = SimpleConfig({'electrum_path': self.user_dir})

@@ -45,6 +46,8 @@ class WalletTestCase(ElectrumTestCase):
        sys.stdout = self._stdout_buffer

    def tearDown(self):
+        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
+        self._loop_thread.join(timeout=1)
        super(WalletTestCase, self).tearDown()
        shutil.rmtree(self.user_dir)
        # Restore the "real" stdout
@@ -241,12 +244,9 @@ class TestWalletPassword(WalletTestCase):

    def setUp(self):
        super().setUp()
-        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()

    def tearDown(self):
        super().tearDown()
-        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
-        self._loop_thread.join(timeout=1)

    def test_update_password_of_imported_wallet(self):
        wallet_str = '{"addr_history":{"1364Js2VG66BwRdkaoxAaFtdPb1eQgn8Dr":[],"15CyDgLffJsJgQrhcyooFH4gnVDG82pUrA":[],"1Exet2BhHsFxKTwhnfdsBMkPYLGvobxuW6":[]},"addresses":{"change":[],"receiving":["1364Js2VG66BwRdkaoxAaFtdPb1eQgn8Dr","1Exet2BhHsFxKTwhnfdsBMkPYLGvobxuW6","15CyDgLffJsJgQrhcyooFH4gnVDG82pUrA"]},"keystore":{"keypairs":{"0344b1588589958b0bcab03435061539e9bcf54677c104904044e4f8901f4ebdf5":"L2sED74axVXC4H8szBJ4rQJrkfem7UMc6usLCPUoEWxDCFGUaGUM","0389508c13999d08ffae0f434a085f4185922d64765c0bff2f66e36ad7f745cc5f":"L3Gi6EQLvYw8gEEUckmqawkevfj9s8hxoQDFveQJGZHTfyWnbk1U","04575f52b82f159fa649d2a4c353eb7435f30206f0a6cb9674fbd659f45082c37d559ffd19bea9c0d3b7dcc07a7b79f4cffb76026d5d4dff35341efe99056e22d2":"5JyVyXU1LiRXATvRTQvR9Kp8Rx1X84j2x49iGkjSsXipydtByUq"},"type":"imported"},"pruned_txo":{},"seed_version":13,"stored_height":-1,"transactions":{},"tx_fees":{},"txi":{},"txo":{},"use_encryption":false,"verified_tx3":{},"wallet_type":"standard","winpos-qt":[100,100,840,405]}'
--- a/electrum/tests/test_wallet_vertical.py
+++ b/electrum/tests/test_wallet_vertical.py
@@ -9,6 +9,7 @@ import copy
 from electrum import storage, bitcoin, keystore, bip32, slip39, wallet
 from electrum import Transaction
 from electrum import SimpleConfig
+from electrum import util
 from electrum.address_synchronizer import TX_HEIGHT_UNCONFIRMED, TX_HEIGHT_UNCONF_PARENT
 from electrum.wallet import (sweep, Multisig_Wallet, Standard_Wallet, Imported_Wallet,
                             restore_wallet_from_text, Abstract_Wallet, BumpFeeStrategy)
@@ -18,6 +19,7 @@ from electrum.util import (
 from electrum.transaction import (TxOutput, Transaction, PartialTransaction, PartialTxOutput,
                                  PartialTxInput, tx_from_any, TxOutpoint)
 from electrum.mnemonic import seed_type
+from electrum.network import Network

 from electrum.plugins.trustedcoin import trustedcoin

@@ -699,8 +701,14 @@ class TestWalletSending(TestCaseForTestnet):

    def setUp(self):
        super().setUp()
+        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()
        self.config = SimpleConfig({'electrum_path': self.electrum_path})

+    def tearDown(self):
+        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
+        self._loop_thread.join(timeout=1)
+        super().tearDown()
+
    def create_standard_wallet_from_seed(self, seed_words, *, config=None, gap_limit=2):
        if config is None:
            config = self.config
@@ -1369,14 +1377,7 @@ class TestWalletSending(TestCaseForTestnet):
                    raise Exception("unexpected txid")
            def has_internet_connection(self):
                return True
-            def run_from_another_thread(self, coro, *, timeout=None):
-                loop, stop_loop, loop_thread = create_and_start_event_loop()
-                fut = asyncio.run_coroutine_threadsafe(coro, loop)
-                try:
-                    return fut.result(timeout)
-                finally:
-                    loop.call_soon_threadsafe(stop_loop.set_result, 1)
-                    loop_thread.join(timeout=1)
+            run_from_another_thread = Network.run_from_another_thread
            def get_local_height(self):
                return 0
            def blockchain(self):
@@ -1429,14 +1430,7 @@ class TestWalletSending(TestCaseForTestnet):
                    raise Exception("unexpected txid")
            def has_internet_connection(self):
                return True
-            def run_from_another_thread(self, coro, *, timeout=None):
-                loop, stop_loop, loop_thread = create_and_start_event_loop()
-                fut = asyncio.run_coroutine_threadsafe(coro, loop)
-                try:
-                    return fut.result(timeout)
-                finally:
-                    loop.call_soon_threadsafe(stop_loop.set_result, 1)
-                    loop_thread.join(timeout=1)
+            run_from_another_thread = Network.run_from_another_thread
            def get_local_height(self):
                return 0
            def blockchain(self):
@@ -1844,8 +1838,8 @@ class TestWalletSending(TestCaseForTestnet):
        network = NetworkMock()
        dest_addr = 'tb1q3ws2p0qjk5vrravv065xqlnkckvzcpclk79eu2'
        sweep_coro = sweep(privkeys, network=network, config=self.config, to_address=dest_addr, fee=5000, locktime=1325785, tx_version=1)
-        loop = asyncio.get_event_loop()
-        tx = loop.run_until_complete(sweep_coro)
+        loop = util.get_asyncio_loop()
+        tx = asyncio.run_coroutine_threadsafe(sweep_coro, loop).result()

        tx_copy = tx_from_any(tx.serialize())
        self.assertEqual('010000000129349e5641d79915e9d0282fdbaee8c3df0b6731bab9d70bf626e8588bde24ac010000004847304402206bf0d0a93abae0d5873a62ebf277a5dd2f33837821e8b93e74d04e19d71b578002201a6d729bc159941ef5c4c9e5fe13ece9fc544351ba531b00f68ba549c8b38a9a01fdffffff01b82e0f00000000001600148ba0a0bc12b51831f58c7ea8607e76c5982c071fd93a1400',
@@ -2199,14 +2193,7 @@ class TestWalletSending(TestCaseForTestnet):
                    raise Exception("unexpected txid")
            def has_internet_connection(self):
                return True
-            def run_from_another_thread(self, coro, *, timeout=None):
-                loop, stop_loop, loop_thread = create_and_start_event_loop()
-                fut = asyncio.run_coroutine_threadsafe(coro, loop)
-                try:
-                    return fut.result(timeout)
-                finally:
-                    loop.call_soon_threadsafe(stop_loop.set_result, 1)
-                    loop_thread.join(timeout=1)
+            run_from_another_thread = Network.run_from_another_thread
            def get_local_height(self):
                return 0
            def blockchain(self):
@@ -3284,8 +3271,14 @@ class TestWalletHistory_DoubleSpend(TestCaseForTestnet):

    def setUp(self):
        super().setUp()
+        self.asyncio_loop, self._stop_loop, self._loop_thread = util.create_and_start_event_loop()
        self.config = SimpleConfig({'electrum_path': self.electrum_path})

+    def tearDown(self):
+        self.asyncio_loop.call_soon_threadsafe(self._stop_loop.set_result, 1)
+        self._loop_thread.join(timeout=1)
+        super().tearDown()
+
    @mock.patch.object(wallet.Abstract_Wallet, 'save_db')
    def test_restoring_wallet_without_manual_delete(self, mock_save_db):
        w = restore_wallet_from_text("small rapid pattern language comic denial donate extend tide fever burden barrel",
--- a/electrum/util.py
+++ b/electrum/util.py
@@ -1031,7 +1031,7 @@ def parse_URI(uri: str, on_pr: Callable = None, *, loop=None) -> dict:
                request = await pr.get_payment_request(r)
            if on_pr:
                on_pr(request)
-        loop = loop or asyncio.get_event_loop()
+        loop = loop or get_asyncio_loop()
        asyncio.run_coroutine_threadsafe(get_payment_request(), loop)

    return out
@@ -1319,7 +1319,6 @@ class NetworkJobOnDefaultServer(Logger, ABC):
    """
    def __init__(self, network: 'Network'):
        Logger.__init__(self)
-        asyncio.set_event_loop(network.asyncio_loop)
        self.network = network
        self.interface = None  # type: Interface
        self._restart_lock = asyncio.Lock()
@@ -1384,9 +1383,41 @@ class NetworkJobOnDefaultServer(Logger, ABC):
        return s


+_asyncio_event_loop = None  # type: Optional[asyncio.AbstractEventLoop]
+def get_asyncio_loop() -> asyncio.AbstractEventLoop:
+    """Returns the global asyncio event loop we use."""
+    if _asyncio_event_loop is None:
+        raise Exception("event loop not created yet")
+    return _asyncio_event_loop
+
+
 def create_and_start_event_loop() -> Tuple[asyncio.AbstractEventLoop,
                                           asyncio.Future,
                                           threading.Thread]:
+    global _asyncio_event_loop
+    if _asyncio_event_loop is not None:
+        raise Exception("there is already a running event loop")
+
+    # asyncio.get_event_loop() became deprecated in python3.10. (see https://github.com/python/cpython/issues/83710)
+    # We set a custom event loop policy purely to be compatible with code that
+    # relies on asyncio.get_event_loop().
+    # - in python 3.8-3.9, asyncio.Event.__init__, asyncio.Lock.__init__,
+    #   and similar, calls get_event_loop. see https://github.com/python/cpython/pull/23420
+    class MyEventLoopPolicy(asyncio.DefaultEventLoopPolicy):
+        def get_event_loop(self):
+            # In case electrum is being used as a library, there might be other
+            # event loops in use besides ours. To minimise interfering with those,
+            # if there is a loop running in the current thread, return that:
+            running_loop = get_running_loop()
+            if running_loop is not None:
+                return running_loop
+            # Otherwise, return our global loop:
+            return get_asyncio_loop()
+    asyncio.set_event_loop_policy(MyEventLoopPolicy())
+
+    loop = asyncio.new_event_loop()
+    _asyncio_event_loop = loop
+
    def on_exception(loop, context):
        """Suppress spurious messages it appears we cannot control."""
        SUPPRESS_MESSAGE_REGEX = re.compile('SSL handshake|Fatal read error on|'
@@ -1396,13 +1427,21 @@ def create_and_start_event_loop() -> Tuple[asyncio.AbstractEventLoop,
            return
        loop.default_exception_handler(context)

-    loop = asyncio.get_event_loop()
+    def run_event_loop():
+        try:
+            loop.run_until_complete(stopping_fut)
+        finally:
+            # clean-up
+            global _asyncio_event_loop
+            _asyncio_event_loop = None
+
    loop.set_exception_handler(on_exception)
    # loop.set_debug(1)
    stopping_fut = loop.create_future()
-    loop_thread = threading.Thread(target=loop.run_until_complete,
-                                         args=(stopping_fut,),
-                                         name='EventLoop')
+    loop_thread = threading.Thread(
+        target=run_event_loop,
+        name='EventLoop',
+    )
    loop_thread.start()
    return loop, stopping_fut, loop_thread

@@ -1558,7 +1597,7 @@ class CallbackManager:
        on the event loop.
        """
        if self.asyncio_loop is None:
-            self.asyncio_loop = asyncio.get_event_loop()
+            self.asyncio_loop = get_asyncio_loop()
            assert self.asyncio_loop.is_running(), "event loop not running"
        with self.callback_lock:
            callbacks = self.callbacks[event][:]
@@ -1643,7 +1682,7 @@ class NetworkRetryManager(Generic[_NetAddrType]):
 class MySocksProxy(aiorpcx.SOCKSProxy):

    async def open_connection(self, host=None, port=None, **kwargs):
-        loop = asyncio.get_event_loop()
+        loop = asyncio.get_running_loop()
        reader = asyncio.StreamReader(loop=loop)
        protocol = asyncio.StreamReaderProtocol(reader, loop=loop)
        transport, _ = await self.create_connection(
@@ -1753,6 +1792,7 @@ class nullcontext:


 def get_running_loop() -> Optional[asyncio.AbstractEventLoop]:
+    """Returns the asyncio event loop that is *running in this thread*, if any."""
    try:
        return asyncio.get_running_loop()
    except RuntimeError: