tdns hacks on windows: resolve A and AAAA records in parallel - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
DIR Refs
DIR Submodules
---
DIR commit cb88a3b6e45e1261d4926d6d385f8f779a84a2d9
DIR parent a5cd34dc089698ace69d43b3c3f54ffa0f70e18d
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Wed, 1 Jan 2020 07:00:16 +0100
dns hacks on windows: resolve A and AAAA records in parallel
Diffstat:
M electrum/network.py | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
---
DIR diff --git a/electrum/network.py b/electrum/network.py
t@@ -228,6 +228,8 @@ class UntrustedServerReturnedError(NetworkException):
return f"<UntrustedServerReturnedError original_exception: {repr(self.original_exception)}>"
+_dns_threads_executor = None # type: Optional[concurrent.futures.Executor]
+
_INSTANCE = None
t@@ -567,10 +569,13 @@ class Network(Logger):
# On Windows, socket.getaddrinfo takes a mutex, and might hold it for up to 10 seconds
# when dns-resolving. To speed it up drastically, we resolve dns ourselves, outside that lock.
# see #4421
- socket.getaddrinfo = self._fast_getaddrinfo
resolver = dns.resolver.get_default_resolver()
if resolver.cache is None:
resolver.cache = dns.resolver.Cache()
+ global _dns_threads_executor
+ if _dns_threads_executor is None:
+ _dns_threads_executor = concurrent.futures.ThreadPoolExecutor(max_workers=20)
+ socket.getaddrinfo = self._fast_getaddrinfo
else:
socket.getaddrinfo = socket._getaddrinfo
self.trigger_callback('proxy_set', self.proxy)
t@@ -588,20 +593,23 @@ class Network(Logger):
return True
def resolve_with_dnspython(host):
addrs = []
- expected_dnspython_errors = (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer)
+ expected_errors = (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer,
+ concurrent.futures.CancelledError, concurrent.futures.TimeoutError)
+ ipv6_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.AAAA)
+ ipv4_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.A)
# try IPv6
try:
- answers = dns.resolver.query(host, dns.rdatatype.AAAA)
+ answers = ipv6_fut.result()
addrs += [str(answer) for answer in answers]
- except expected_dnspython_errors as e:
+ except expected_errors as e:
pass
except BaseException as e:
_logger.info(f'dnspython failed to resolve dns (AAAA) for {repr(host)} with error: {repr(e)}')
# try IPv4
try:
- answers = dns.resolver.query(host, dns.rdatatype.A)
+ answers = ipv4_fut.result()
addrs += [str(answer) for answer in answers]
- except expected_dnspython_errors as e:
+ except expected_errors as e:
# dns failed for some reason, e.g. dns.resolver.NXDOMAIN this is normal.
# Simply report back failure; except if we already have some results.
if not addrs: