X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=python%2Fovs%2Fdaemon.py;h=6dff3a02fcbd8e430a2c45f2ce7e21b58538e84c;hb=a01ef04ced0d3e04e7d5e5038ef76c861b5c1da3;hp=a8373cfd0168c42e7ea6c9e0eb8559eb8089afc6;hpb=991559357f6a03c3a5b70c053c8c2554aa8d5ee4;p=openvswitch

diff --git a/python/ovs/daemon.py b/python/ovs/daemon.py
index a8373cfd..6dff3a02 100644
--- a/python/ovs/daemon.py
+++ b/python/ovs/daemon.py
@@ -35,6 +35,10 @@ _detach = False
 # --pidfile: Name of pidfile (null if none).
 _pidfile = None
 
+# Our pidfile's inode and device, if we have created one.
+_pidfile_dev = None
+_pidfile_ino = None
+
 # --overwrite-pidfile: Create pidfile even if one already exists and is locked?
 _overwrite_pidfile = False
 
@@ -48,6 +52,8 @@ _monitor = False
 # File descriptor used by daemonize_start() and daemonize_complete().
 _daemonize_fd = None
 
+RESTART_EXIT_CODE = 5
+
 def make_pidfile_name(name):
     """Returns the file name that would be used for a pidfile if 'name' were
     provided to set_pidfile()."""
@@ -163,7 +169,7 @@ def _make_pidfile():
             logging.error("%s: create failed: %s"
                           % (tmpfile, os.strerror(e.errno)))
             return
-            
+
         try:
             fcntl.lockf(file, fcntl.LOCK_EX | fcntl.LOCK_NB)
         except IOError, e:
@@ -191,6 +197,10 @@ def _make_pidfile():
             file.close()
             return
 
+        s = os.fstat(file.fileno())
+        _pidfile_dev = s.st_dev
+        _pidfile_ino = s.st_ino
+
 def daemonize():
     """If configured with set_pidfile() or set_detach(), creates the pid file
     and detaches from the foreground session."""
@@ -258,6 +268,11 @@ def _fork_notify_startup(fd):
         os.close(fd)
 
 def _should_restart(status):
+    global RESTART_EXIT_CODE
+
+    if os.WIFEXITED(status) and os.WEXITSTATUS(status) == RESTART_EXIT_CODE:
+        return True
+
     if os.WIFSIGNALED(status):
         for signame in ("SIGABRT", "SIGALRM", "SIGBUS", "SIGFPE", "SIGILL",
                         "SIGPIPE", "SIGSEGV", "SIGXCPU", "SIGXFSZ"):
@@ -368,6 +383,19 @@ Daemon options:
 def read_pidfile(pidfile):
     """Opens and reads a PID from 'pidfile'.  Returns the nonnegative PID if
     successful, otherwise a negative errno value."""
+    if _pidfile_dev is not None:
+        try:
+            s = os.stat(pidfile)
+            if s.st_ino == _pidfile_ino and s.st_dev == _pidfile_dev:
+                # It's our own pidfile.  We can't afford to open it,
+                # because closing *any* fd for a file that a process
+                # has locked also releases all the locks on that file.
+                #
+                # Fortunately, we know the associated pid anyhow.
+                return os.getpid()
+        except OSError:
+            pass
+
     try:
         file = open(pidfile, "r")
     except IOError, e: