X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tools.py;h=776a8d48f94aa131fd990754383aea17437d5fc3;hb=2ea95268ac45ee96f6657ad424e3268ed915fc7e;hp=994089e1bb69fe5ab4ee43b35106d09b4c4a43e2;hpb=28de48d05b66c4e7826d959a3ad48e87e8f13ee4;p=nodemanager.git

diff --git a/tools.py b/tools.py
index 994089e..776a8d4 100644
--- a/tools.py
+++ b/tools.py
@@ -6,6 +6,7 @@ import os
 import pwd
 import tempfile
 import threading
+import fcntl
 
 import logger
 
@@ -34,7 +35,11 @@ def daemon():
     os.chdir('/')
     os.umask(0)
     devnull = os.open(os.devnull, os.O_RDWR)
-    for fd in range(3): os.dup2(devnull, fd)
+    os.dup2(devnull, 0)
+    # xxx fixme - this is just to make sure that nothing gets stupidly lost - should use devnull
+    crashlog = os.open('/var/log/nm.daemon', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
+    os.dup2(crashlog, 1)
+    os.dup2(crashlog, 2)
 
 def fork_as(su, function, *args):
     """fork(), cd / to avoid keeping unused directories open, close all nonstandard file descriptors (to avoid capturing open sockets), fork() again (to avoid zombies) and call <function> with arguments <args> in the grandchild process.  If <su> is not None, set our group and user ids appropriately in the child process."""
@@ -43,9 +48,10 @@ def fork_as(su, function, *args):
         try:
             os.chdir('/')
             close_nonstandard_fds()
-            pw_ent = pwd.getpwnam(su)
-            os.setegid(pw_ent[3])
-            os.seteuid(pw_ent[2])
+            if su:
+                pw_ent = pwd.getpwnam(su)
+                os.setegid(pw_ent[3])
+                os.seteuid(pw_ent[2])
             child_pid = os.fork()
             if child_pid == 0: function(*args)
         except:
@@ -84,3 +90,20 @@ def write_temp_file(do_write, mode=None, uidgid=None):
     try: do_write(f)
     finally: f.close()
     return temporary_filename
+
+
+class NMLock:
+    def __init__(self, file):
+        logger.log("Lock %s initialized." % file, 2)
+        self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+        flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+        flags |= fcntl.FD_CLOEXEC
+        fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+    def __del__(self):
+        os.close(self.fd)
+    def acquire(self):
+        logger.log("Lock acquired.", 2)
+        fcntl.lockf(self.fd, fcntl.LOCK_SH)
+    def release(self):
+        logger.log("Lock released.", 2)
+        fcntl.lockf(self.fd, fcntl.LOCK_UN)