From 6e7890028213b30939327e7cf885bf097fc14472 Mon Sep 17 00:00:00 2001
From: Andrew Svetlov <andrew.svetlov@gmail.com>
Date: Thu, 16 May 2019 16:30:16 +0300
Subject: [PATCH] bpo-35589: Prevent buffer copy in sock_sendall() (GH-11418)
No NEWs is needed since the problem was introduced on master only and never released.
https://bugs.python.org/issue35589
---
Lib/asyncio/selector_events.py | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index 29968214f8..6461d30776 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -428,32 +428,35 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
if n == len(data):
# all data sent
return
- else:
- data = bytearray(memoryview(data)[n:])
fut = self.create_future()
fd = sock.fileno()
fut.add_done_callback(
functools.partial(self._sock_write_done, fd))
- self.add_writer(fd, self._sock_sendall, fut, sock, data)
+ # use a trick with a list in closure to store a mutable state
+ self.add_writer(fd, self._sock_sendall, fut, sock,
+ memoryview(data), [n])
return await fut
- def _sock_sendall(self, fut, sock, data):
+ def _sock_sendall(self, fut, sock, view, pos):
if fut.done():
# Future cancellation can be scheduled on previous loop iteration
return
+ start = pos[0]
try:
- n = sock.send(data)
+ n = sock.send(view[start:])
except (BlockingIOError, InterruptedError):
return
except Exception as exc:
fut.set_exception(exc)
return
- if n == len(data):
+ start += n
+
+ if start == len(view):
fut.set_result(None)
else:
- del data[:n]
+ pos[0] = start
async def sock_connect(self, sock, address):
"""Connect to a remote socket at address.
--
2.49.0