Attachment 890809 Details for Bug 1091404 – patch for the lock breaking

[patch] patch for the lock breaking

0001-cache.py-break-lock-when-locking-process-no-longer-r.patch (text/plain), 2.04 KB, created by Ales Zelinka on 2014-04-29 14:06:27 UTC

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Creator: Ales Zelinka

Created: 2014-04-29 14:06:27 UTC

Size: 2.04 KB

patch

obsolete

>From 54ec89dfa41032b58ad8aeef0ac4e12ec6f7b9bf Mon Sep 17 00:00:00 2001
>From: Ales Zelinka <azelinka@redhat.com>
>Date: Tue, 29 Apr 2014 16:05:28 +0200
>Subject: [PATCH] cache.py: break lock when locking process no longer runs
>
>---
> source/cache.py | 28 ++++++++++++++++++++++------
> 1 file changed, 22 insertions(+), 6 deletions(-)
>
>diff --git a/source/cache.py b/source/cache.py
>index 60f3da8..217c9f2 100644
>--- a/source/cache.py
>+++ b/source/cache.py
>@@ -332,16 +332,32 @@ class Cache(object):
>         # Nothing to do when persistent caching is off
>         if get_cache_level() < config.CACHE_PERSISTENT:
>             return
>+        # Is cache already locked?
>+        locked=True
>         # Setup the cache
>         self.setup(filename)
>+        if os.path.exists(self._lock):
>+            # Check if lock isn't stale
>+            try:
>+                lock = open(self._lock)
>+                lock_pid=lock.readline().strip()
>+                lock.close()
>+                lock_pid=int(lock_pid)
>+                log.cache("Found lock PID {0}".format(lock_pid))
>+                if not os.path.exists("/proc/{0}".format(lock_pid)):
>+                    log.cache("Breaking stale lock".format(lock_pid))
>+                    locked=False
>+            except ValueError:
>+                log.warn("Malformed cache lock PID: {0}".format(lock_pid))
>+        else:
>+            locked=False
>         # Check for existing cache lock, set mode appropriately
>-        try:
>-            lock = open(self._lock)
>-            log.warn("Found lock {0}, opening read-only".format(self._lock))
>-            lock.close()
>+        if locked:
>+            log.warn("Found active lock {0}, opening read-only".format(
>+                self._lock))
>             self._mode = "read-only"
>-        except IOError:
>-            log.cache("Creating cache lock {0}".format(self._lock))
>+        else:
>+            log.cache("Creating new cache lock {0}".format(self._lock))
>             lock = open(self._lock, "w")
>             lock.write("{0}\n".format(os.getpid()))
>             lock.close()
>-- 
>1.8.3.1
>

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Attachments on bug 1091404: 890809 | 890842