Added ReCreate. Also added try catch to api eval of rpc method.

[nodemanager.git] / tools.py

diff --git a/tools.py b/tools.py
index 6b3a84b..f4496e1 100644 (file)
--- a/tools.py
+++ b/tools.py
@@ -6,6 +6,7 @@ import os
 import pwd
 import tempfile
 import threading
+import fcntl
 
 import logger
 
@@ -34,7 +35,10 @@ 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)
+    crashlog = os.open('/root/nm.stderr', 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."""
@@ -85,3 +89,17 @@ 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):
+        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):
+        fcntl.lockf(self.fd, fcntl.LOCK_EX)
+    def release(self):
+        fcntl.lockf(self.fd, fcntl.LOCK_UN)