[Blends-commit] r2983 - in /blends/trunk/webtools: blendstasktools.py tasks.py

[tille at users.alioth.debian.org]

Author: tille
Date: Thu Oct 20 11:05:49 2011
New Revision: 2983

URL: http://svn.debian.org/wsvn/blends/?sc=1&rev=2983
Log:
Implement locking to make sure that not more than one instance is running.  This became necessary since udd.debian.net has serious IO performance problems and jobs do not end properly in a reasonable time frame.

Modified:
    blends/trunk/webtools/blendstasktools.py
    blends/trunk/webtools/tasks.py

Modified: blends/trunk/webtools/blendstasktools.py
URL: http://svn.debian.org/wsvn/blends/blends/trunk/webtools/blendstasktools.py?rev=2983&op=diff
==============================================================================
--- blends/trunk/webtools/blendstasktools.py (original)
+++ blends/trunk/webtools/blendstasktools.py Thu Oct 20 11:05:49 2011
@@ -204,6 +204,35 @@
                         'contrib'  : 'DFSG free, but needs non-free components',
                         'non-free' : 'non-free'
             }
+
+import psutil
+
+LOCKFILE='/var/lock/blends.lock'
+def LockBlendsTools():
+    """Locking mechanism to make sure the scripts will not run in parallel
+       which happened because of IO problems on udd.debian.org"""
+    if os.path.exists(LOCKFILE):
+        try:
+            lf = open(LOCKFILE, 'r')
+            pid = int(lf.readline())
+            lf.close()
+            if pid in psutil.get_pid_list():
+                print >>stderr, "Another process rebuilding web sentinal pages with PID %i is running. Exit." % pid
+                exit()
+            else:
+                print >>stderr, "Warning: Process with PID %i is not running any more but lockfile remained.  Removing %s ..." % (pid, LOCKFILE)
+                os.unlink(LOCKFILE)
+        except IOError as e:
+            pass
+    pid = os.getpid()
+    lf = open(LOCKFILE, 'w')
+    print >>lf, pid
+    lf.close()
+
+def UnlockBlendsTools():
+    """Unlock previousely locked file"""
+    if os.path.exists(LOCKFILE):
+        os.unlink(LOCKFILE)
 
 def GetDependencies2Use(dependencystatus=[], max_order='prospective'):
     # Create a list of status of dependencies out of pkgstatus dictionary

Modified: blends/trunk/webtools/tasks.py
URL: http://svn.debian.org/wsvn/blends/blends/trunk/webtools/tasks.py?rev=2983&op=diff
==============================================================================
--- blends/trunk/webtools/tasks.py (original)
+++ blends/trunk/webtools/tasks.py Thu Oct 20 11:05:49 2011
@@ -17,7 +17,7 @@
 from genshi import Markup
 from genshi.template.eval import UndefinedError
 
-from blendstasktools import Tasks, GetDependencies2Use, pkgstatus, pkgstatus_sortedkeys
+from blendstasktools import Tasks, GetDependencies2Use, pkgstatus, pkgstatus_sortedkeys, LockBlendsTools, UnlockBlendsTools
 from blendsunicode   import to_unicode
 from blendslanguages import languages, language_dict
 
@@ -26,6 +26,7 @@
                         % argv[0]
 	exit(-1)
 
+LockBlendsTools()
 tasks    = Tasks(argv[1])
 tasks.GetAllDependencies()
 packages = tasks.GetNamesOnlyDict()
@@ -294,3 +295,5 @@
 print >> htafp
 
 htafp.close()
+
+UnlockBlendsTools()