[Zodb-checkins] CVS: ZODB3/zdaemon - zdaemon.py:1.8
Guido van Rossum
guido@python.org
Mon, 11 Nov 2002 16:41:08 -0500
Update of /cvs-repository/ZODB3/zdaemon
In directory cvs.zope.org:/tmp/cvs-serv26742
Modified Files:
zdaemon.py
Log Message:
More refactoring: we now do no blocking actions on sockets (except
sends()).
Also cleaned up some error messages, using %r more.
=== ZODB3/zdaemon/zdaemon.py 1.7 => 1.8 ===
--- ZODB3/zdaemon/zdaemon.py:1.7 Mon Nov 11 15:17:45 2002
+++ ZODB3/zdaemon/zdaemon.py Mon Nov 11 16:41:07 2002
@@ -52,13 +52,14 @@
"""
XXX TO DO
-- Refactor the readcommand() to avoid blocking recv() calls.
-
- Rethink client commands; maybe start/restart/stop make more sense?
(Still need a way to send an arbitrary signal)
- Do the governor without actual sleeps, using event scheduling etc.
+- True OO design -- use multiple classes rather than folding
+ everything into one class.
+
- Add docstrings.
"""
@@ -115,7 +116,7 @@
try:
self.backofflimit = float(a)
except:
- self.usage("invalid number: %s" % repr(a))
+ self.usage("invalid number: %r" % a)
if o == "-c":
self.isclient += 1
if o == "-d":
@@ -139,10 +140,10 @@
try:
sock.connect(self.sockname)
except socket.error, msg:
- self.errwrite("Can't connect to %s: %s\n" %
- (repr(self.sockname), str(msg)))
+ self.errwrite("Can't connect to %r: %s\n" % (self.sockname, msg))
self.exit(1)
sock.send(self.command + "\n")
+ sock.shutdown(1) # We're not writing any more
lastdata = ""
while 1:
data = sock.recv(1000)
@@ -161,8 +162,7 @@
self.usage("missing 'program' argument")
self.filename = self.checkcommand(args[0])
self.args = args # A list of strings like for execvp()
- self.info("filename=%s; args=%s" %
- (repr(self.filename), repr(self.args)))
+ self.info("filename=%r; args=%r" % (self.filename, self.args))
def checkcommand(self, command):
if "/" in command:
@@ -170,7 +170,7 @@
try:
st = os.stat(filename)
except os.error:
- self.usage("can't stat program %s" % repr(command))
+ self.usage("can't stat program %r" % command)
else:
path = self.getpath()
for dir in path:
@@ -183,10 +183,10 @@
if mode & 0111:
break
else:
- self.usage("can't find program %s on PATH %s" %
- (repr(command), path))
+ self.usage("can't find program %r on PATH %s" %
+ (command, path))
if not os.access(filename, os.X_OK):
- self.usage("no permission to run program %s" % repr(filename))
+ self.usage("no permission to run program %r" % filename)
return filename
def getpath(self):
@@ -213,24 +213,43 @@
except os.error:
pass
- controlsocket = None
+ mastersocket = None
+ commandsocket = None
def opensocket(self):
+ self.checkopen()
try:
os.unlink(self.sockname)
except os.error:
pass
- self.controlsocket = socket.socket(socket.AF_UNIX,
- socket.SOCK_STREAM)
+ self.mastersocket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
oldumask = None
try:
oldumask = os.umask(077)
- self.controlsocket.bind(self.sockname)
+ self.mastersocket.bind(self.sockname)
finally:
if oldumask is not None:
os.umask(oldumask)
- self.controlsocket.listen(1)
- self.controlsocket.setblocking(0)
+ self.mastersocket.listen(1)
+ self.mastersocket.setblocking(0)
+
+ def checkopen(self):
+ s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+ try:
+ s.connect(self.sockname)
+ s.send("status\n")
+ data = s.recv(1000)
+ s.close()
+ except socket.error:
+ pass
+ else:
+ if not data.endswith("\n"):
+ data += "\n"
+ msg = ("Another zdaemon is already up using socket %r:\n%s" %
+ (self.sockname, data))
+ self.errwrite(msg)
+ self.panic(msg)
+ self.exit(1)
def setsignals(self):
signal.signal(signal.SIGTERM, self.sigexit)
@@ -239,12 +258,15 @@
signal.signal(signal.SIGCHLD, self.sigchild)
def sigexit(self, sig, frame):
- self.info("daemon manager killed by signal %s(%d)" %
- (self.signame(sig), sig))
+ self.info("daemon manager killed by %s" % self.signame(sig))
self.exit(1)
+ waitstatus = None
+
def sigchild(self, sig, frame):
- pass
+ pid, sts = os.waitpid(-1, os.WNOHANG)
+ if pid:
+ self.waitstatus = pid, sts
def daemonize(self):
pid = os.fork()
@@ -270,7 +292,11 @@
while 1:
if not self.appid:
self.forkandexec()
- r, w, x = [self.controlsocket], [], []
+ if self.waitstatus:
+ self.reportstatus()
+ r, w, x = [self.mastersocket], [], []
+ if self.commandsocket:
+ r.append(self.commandsocket)
timeout = 30
try:
r, w, x = select.select(r, w, x, timeout)
@@ -278,42 +304,50 @@
if err[0] != errno.EINTR:
raise
r = w = x = []
- wpid, wsts = os.waitpid(-1, os.WNOHANG)
- if wpid != 0:
- if wpid == self.appid:
- self.appid = 0
- self.reportstatus(wpid, wsts)
- if r:
- self.readcommand()
-
- conn = None
-
- def readcommand(self):
- try:
- conn, addr = self.controlsocket.accept()
- self.conn = conn
- try:
- data = conn.recv(1000)
- if not data:
- self.sendreply("No input")
- return
- line = data
- while "\n" not in line:
- data = conn.recv(1000)
- if not data:
- self.sendreply("Input not terminated by newline")
- return
- line += data
- self.docommand(line)
- finally:
- conn.close()
- self.conn = None
- except socket.error, msg:
- self.problem("socket error: %s" % str(msg),
- error=sys.exc_info())
+ if self.waitstatus:
+ self.reportstatus()
+ if self.commandsocket and self.commandsocket in r:
+ try:
+ self.dorecv()
+ except socket.error, msg:
+ self.problem("socket.error in dorecv(): %s" % str(msg),
+ error=sys.exc_info())
+ self.commandsocket = None
+ if self.mastersocket in r:
+ try:
+ self.doaccept()
+ except socket.error, msg:
+ self.problem("socket.error in doaccept(): %s" % str(msg),
+ error=sys.exc_info())
+ self.commandsocket = None
+
+ def doaccept(self):
+ if self.commandsocket:
+ # Give up on previous command socket!
+ self.sendreply("Command superseded by new command")
+ self.commandsocket.close()
+ self.commandsocket = None
+ self.commandsocket, addr = self.mastersocket.accept()
+ self.commandbuffer = ""
+
+ def dorecv(self):
+ data = self.commandsocket.recv(1000)
+ if not data:
+ self.sendreply("Command not terminated by newline")
+ self.commandsocket.close()
+ self.commandsocket = None
+ self.commandbuffer += data
+ if "\n" in self.commandbuffer:
+ self.docommand()
+ self.commandsocket.close()
+ self.commandsocket = None
+ elif len(self.commandbuffer) > 10000:
+ self.sendreply("Command exceeds 10 KB")
+ self.commandsocket.close()
+ self.commandsocket = None
- def docommand(self, line):
- lines = line.split("\n")
+ def docommand(self):
+ lines = self.commandbuffer.split("\n")
args = lines[0].split()
if not args:
self.sendreply("Empty command")
@@ -324,14 +358,14 @@
if method:
method(args)
else:
- self.sendreply("Unknown command %s" % (`args[0]`))
+ self.sendreply("Unknown command %r; 'help' for a list" % args[0])
def cmd_kill(self, args):
if args[1:]:
try:
sig = int(args[1])
except:
- self.sendreply("Bad signal %s" % repr(args[1]))
+ self.sendreply("Bad signal %r" % args[1])
return
else:
sig = signal.SIGTERM
@@ -341,7 +375,7 @@
try:
os.kill(self.appid, sig)
except os.error, msg:
- self.sendreply("Kill %d failed: %s" % (sig, str(msg)))
+ self.sendreply("Kill %d failed: %s" % (sig, msg))
else:
self.sendreply("Signal %d sent" % sig)
@@ -353,8 +387,8 @@
self.sendreply("status=%s\n" % status +
"manager=%d\n" % os.getpid() +
"application=%d\n" % self.appid +
- "filename=%s\n" % repr(self.filename) +
- "args=%s\n" % repr(self.args))
+ "filename=%r\n" % self.filename +
+ "args=%r\n" % self.args)
def cmd_help(self, args):
self.sendreply(
@@ -366,16 +400,18 @@
)
def sendreply(self, msg):
- if not msg.endswith("\n"):
- msg = msg + "\n"
- conn = self.conn
- if hasattr(conn, "sendall"):
- conn.sendall(msg)
- else:
- # This is quadratic, but msg is rarely more than 100 bytes :-)
- while msg:
- sent = conn.send(msg)
- msg = msg[sent:]
+ try:
+ if not msg.endswith("\n"):
+ msg = msg + "\n"
+ if hasattr(self.commandsocket, "sendall"):
+ self.commandsocket.sendall(msg)
+ else:
+ # This is quadratic, but msg is rarely more than 100 bytes :-)
+ while msg:
+ sent = self.commandsocket.send(msg)
+ msg = msg[sent:]
+ except socket.error, msg:
+ self.problem("Error sending reply: %s" % str(msg))
backoff = 0
lasttime = None
@@ -391,7 +427,7 @@
if self.forever:
self.backoff = self.backofflimit
else:
- self.problem("restarting too often; quit")
+ self.error("restarting too often; quit")
self.exit(1)
self.info("sleep %s to avoid rapid restarts" % self.backoff)
time.sleep(self.backoff)
@@ -417,12 +453,15 @@
try:
os.execv(self.filename, self.args)
except os.error, err:
- self.panic("can't exec %s: %s" %
- (repr(self.filename), str(err)))
+ self.panic("can't exec %r: %s" % (self.filename, err))
finally:
os._exit(127)
- def reportstatus(self, pid, sts):
+ def reportstatus(self):
+ pid, sts = self.waitstatus
+ self.waitstatus = None
+ if pid == self.appid:
+ self.appid = 0
if os.WIFEXITED(sts):
es = os.WEXITSTATUS(sts)
msg = "pid %d: exit status %s" % (pid, es)
@@ -430,10 +469,10 @@
self.info(msg)
self.exit(0)
elif es == 2:
- self.problem(msg)
+ self.error(msg)
self.exit(es)
else:
- self.warning(msg)
+ self.problem(msg)
elif os.WIFSIGNALED(sts):
sig = os.WTERMSIG(sts)
msg = ("pid %d: terminated by %s" % (pid, self.signame(sig)))
@@ -443,10 +482,10 @@
iscore = s & 0x80
if iscore:
msg += " (core dumped)"
- self.warning(msg)
+ self.problem(msg)
else:
msg = "pid %d: unknown termination cause 0x%04x" % (pid, sts)
- self.warning(msg)
+ self.problem(msg)
signames = None
@@ -473,7 +512,7 @@
# Error handling
def usage(self, msg):
- self.problem(str(msg))
+ self.error(str(msg))
self.errwrite("Error: %s\n" % str(msg))
self.errwrite("For help, use zdaemon.py -h\n")
self.exit(2)
@@ -498,10 +537,10 @@
def info(self, msg):
self.log(msg, zLOG.INFO)
- def warning(self, msg):
- self.log(msg, zLOG.WARNING)
+ def problem(self, msg):
+ self.log(msg, zLOG.PROBLEM)
- def problem(self, msg, error=None):
+ def error(self, msg, error=None):
self.log(msg, zLOG.ERROR, error)
def panic(self, msg, error=None):