sync: kill git fetch process before SSH control master process
If the SSH control master process is killed while an active git
fetch is using its network socket, the underlying SSH client may
not realize the connection was broken. This can lead to both the
client and the server waiting indefinitely for network messages
which will never be sent.
Work around the problem by keeping track of any processes that use
the tunnels we establish. If we are about to kill any of the SSH
control masters that we started, ensure the clients using them are
successfully killed first.
Change-Id: Ida6c124dcb0c6a26bf7dd69cba2fbdc2ecd5b2fc
Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/git_command.py b/git_command.py
index 3309f37..4ad908f 100644
--- a/git_command.py
+++ b/git_command.py
@@ -17,6 +17,7 @@
import sys
import subprocess
import tempfile
+from signal import SIGTERM
from error import GitError
from trace import REPO_TRACE, IsTrace, Trace
@@ -29,6 +30,7 @@
_ssh_proxy_path = None
_ssh_sock_path = None
+_ssh_clients = []
def ssh_sock(create=True):
global _ssh_sock_path
@@ -51,6 +53,24 @@
'git_ssh')
return _ssh_proxy_path
+def _add_ssh_client(p):
+ _ssh_clients.append(p)
+
+def _remove_ssh_client(p):
+ try:
+ _ssh_clients.remove(p)
+ except ValueError:
+ pass
+
+def terminate_ssh_clients():
+ global _ssh_clients
+ for p in _ssh_clients:
+ try:
+ os.kill(p.pid, SIGTERM)
+ p.wait()
+ except OSError:
+ pass
+ _ssh_clients = []
class _GitCall(object):
def version(self):
@@ -188,6 +208,9 @@
except Exception, e:
raise GitError('%s: %s' % (command[1], e))
+ if ssh_proxy:
+ _add_ssh_client(p)
+
self.process = p
self.stdin = p.stdin
@@ -210,4 +233,8 @@
else:
p.stderr = None
- return self.process.wait()
+ try:
+ rc = p.wait()
+ finally:
+ _remove_ssh_client(p)
+ return rc