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Merge branch 'stable'

* stable:
  Fixed race condition in 'repo sync -jN' that would open multiple masters.
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2 parents 13f3da5 + 0048b69 commit 9275fd43294e760e47736857113f32a2f189c6c6 @spearce spearce committed Dec 22, 2010
Showing with 90 additions and 61 deletions.
  1. +88 −60 git_config.py
  2. +2 −1 main.py
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@@ -18,6 +18,10 @@
import re
import subprocess
import sys
+try:
+ import threading as _threading
+except ImportError:
+ import dummy_threading as _threading
import time
import urllib2
@@ -371,76 +375,97 @@ def __str__(self):
_master_processes = []
_master_keys = set()
_ssh_master = True
+_master_keys_lock = None
+
+def init_ssh():
+ """Should be called once at the start of repo to init ssh master handling.
+
+ At the moment, all we do is to create our lock.
+ """
+ global _master_keys_lock
+ assert _master_keys_lock is None, "Should only call init_ssh once"
+ _master_keys_lock = _threading.Lock()
def _open_ssh(host, port=None):
global _ssh_master
- # Check to see whether we already think that the master is running; if we
- # think it's already running, return right away.
- if port is not None:
- key = '%s:%s' % (host, port)
- else:
- key = host
-
- if key in _master_keys:
- return True
+ # Acquire the lock. This is needed to prevent opening multiple masters for
+ # the same host when we're running "repo sync -jN" (for N > 1) _and_ the
+ # manifest <remote fetch="ssh://xyz"> specifies a different host from the
+ # one that was passed to repo init.
+ _master_keys_lock.acquire()
+ try:
- if not _ssh_master \
- or 'GIT_SSH' in os.environ \
- or sys.platform in ('win32', 'cygwin'):
- # failed earlier, or cygwin ssh can't do this
- #
- return False
+ # Check to see whether we already think that the master is running; if we
+ # think it's already running, return right away.
+ if port is not None:
+ key = '%s:%s' % (host, port)
+ else:
+ key = host
- # We will make two calls to ssh; this is the common part of both calls.
- command_base = ['ssh',
- '-o','ControlPath %s' % ssh_sock(),
- host]
- if port is not None:
- command_base[1:1] = ['-p',str(port)]
-
- # Since the key wasn't in _master_keys, we think that master isn't running.
- # ...but before actually starting a master, we'll double-check. This can
- # be important because we can't tell that that 'git@myhost.com' is the same
- # as 'myhost.com' where "User git" is setup in the user's ~/.ssh/config file.
- check_command = command_base + ['-O','check']
- try:
- Trace(': %s', ' '.join(check_command))
- check_process = subprocess.Popen(check_command,
- stdout=subprocess.PIPE,
- stderr=subprocess.PIPE)
- check_process.communicate() # read output, but ignore it...
- isnt_running = check_process.wait()
-
- if not isnt_running:
- # Our double-check found that the master _was_ infact running. Add to
- # the list of keys.
- _master_keys.add(key)
+ if key in _master_keys:
return True
- except Exception:
- # Ignore excpetions. We we will fall back to the normal command and print
- # to the log there.
- pass
-
- command = command_base[:1] + \
- ['-M', '-N'] + \
- command_base[1:]
- try:
- Trace(': %s', ' '.join(command))
- p = subprocess.Popen(command)
- except Exception, e:
- _ssh_master = False
- print >>sys.stderr, \
- '\nwarn: cannot enable ssh control master for %s:%s\n%s' \
- % (host,port, str(e))
- return False
- _master_processes.append(p)
- _master_keys.add(key)
- time.sleep(1)
- return True
+ if not _ssh_master \
+ or 'GIT_SSH' in os.environ \
+ or sys.platform in ('win32', 'cygwin'):
+ # failed earlier, or cygwin ssh can't do this
+ #
+ return False
+
+ # We will make two calls to ssh; this is the common part of both calls.
+ command_base = ['ssh',
+ '-o','ControlPath %s' % ssh_sock(),
+ host]
+ if port is not None:
+ command_base[1:1] = ['-p',str(port)]
+
+ # Since the key wasn't in _master_keys, we think that master isn't running.
+ # ...but before actually starting a master, we'll double-check. This can
+ # be important because we can't tell that that 'git@myhost.com' is the same
+ # as 'myhost.com' where "User git" is setup in the user's ~/.ssh/config file.
+ check_command = command_base + ['-O','check']
+ try:
+ Trace(': %s', ' '.join(check_command))
+ check_process = subprocess.Popen(check_command,
+ stdout=subprocess.PIPE,
+ stderr=subprocess.PIPE)
+ check_process.communicate() # read output, but ignore it...
+ isnt_running = check_process.wait()
+
+ if not isnt_running:
+ # Our double-check found that the master _was_ infact running. Add to
+ # the list of keys.
+ _master_keys.add(key)
+ return True
+ except Exception:
+ # Ignore excpetions. We we will fall back to the normal command and print
+ # to the log there.
+ pass
+
+ command = command_base[:1] + \
+ ['-M', '-N'] + \
+ command_base[1:]
+ try:
+ Trace(': %s', ' '.join(command))
+ p = subprocess.Popen(command)
+ except Exception, e:
+ _ssh_master = False
+ print >>sys.stderr, \
+ '\nwarn: cannot enable ssh control master for %s:%s\n%s' \
+ % (host,port, str(e))
+ return False
+
+ _master_processes.append(p)
+ _master_keys.add(key)
+ time.sleep(1)
+ return True
+ finally:
+ _master_keys_lock.release()
def close_ssh():
+ global _master_keys_lock
+
terminate_ssh_clients()
for p in _master_processes:
@@ -459,6 +484,9 @@ def close_ssh():
except OSError:
pass
+ # We're done with the lock, so we can delete it.
+ _master_keys_lock = None
+
URI_SCP = re.compile(r'^([^@:]*@?[^:/]{1,}):')
URI_ALL = re.compile(r'^([a-z][a-z+]*)://([^@/]*@?[^/]*)/')
View
@@ -28,7 +28,7 @@
import sys
from trace import SetTrace
-from git_config import close_ssh
+from git_config import init_ssh, close_ssh
from command import InteractiveCommand
from command import MirrorSafeCommand
from command import PagedCommand
@@ -212,6 +212,7 @@ def _Main(argv):
repo = _Repo(opt.repodir)
try:
try:
+ init_ssh()
repo._Run(argv)
finally:
close_ssh()

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