From: Fredrik Tolf Date: Fri, 29 Jun 2012 01:01:57 +0000 (+0200) Subject: Attempt to make the session database properly parallel. X-Git-Url: http://git.dolda2000.com/gitweb/?a=commitdiff_plain;h=b65f311ba08b247e241e29e5664759cd04a2d1d5;p=wrw.git Attempt to make the session database properly parallel. --- diff --git a/wrw/session.py b/wrw/session.py index cf2d792..428c93d 100644 --- a/wrw/session.py +++ b/wrw/session.py @@ -16,10 +16,10 @@ def gennonce(length): return nonce class session(object): - def __init__(self, expire = 86400 * 7): + def __init__(self, lock, expire = 86400 * 7): self.id = hexencode(gennonce(16)) self.dict = {} - self.lock = threading.RLock() + self.lock = lock self.ctime = self.atime = self.mtime = int(time.time()) self.expire = expire self.dctl = set() @@ -68,7 +68,7 @@ class session(object): def __setstate__(self, st): for k, v in st: self.__dict__[k] = v - self.lock = threading.Lock() + # The proper lock is set by the thawer class db(object): def __init__(self, backdb = None, cookiename = "wrwsess", path = "/"): @@ -83,19 +83,34 @@ class db(object): def clean(self): now = int(time.time()) with self.lock: - dlist = [] - for sess in self.live.itervalues(): - if sess.atime + self.freezetime < now: - try: - if sess.dirty(): - self.freeze(sess) - except: - if sess.atime + sess.expire < now: - dlist.append(sess) - else: - dlist.append(sess) - for sess in dlist: - del self.live[sess.id] + clist = self.live.keys() + for sessid in clist: + with self.lock: + try: + entry = self.live[sessid] + except KeyError: + continue + with entry[0]: + rm = False + if entry[1] == "retired": + pass + elif entry[1] is None: + pass + else: + sess = entry[1] + if sess.atime + self.freezetime < now: + try: + if sess.dirty(): + self.freeze(sess) + except: + if sess.atime + sess.expire < now: + rm = True + else: + rm = True + if rm: + entry[1] = "retired" + with self.lock: + del self.live[sessid] def cleanloop(self): try: @@ -108,6 +123,37 @@ class db(object): with self.lock: self.cthread = None + def _fetch(self, sessid): + while True: + now = int(time.time()) + with self.lock: + if sessid in self.live: + entry = self.live[sessid] + else: + entry = self.live[sessid] = [threading.RLock(), None] + with entry[0]: + if isinstance(entry[1], session): + entry[1].atime = now + return entry[1] + elif entry[1] == "retired": + continue + elif entry[1] is None: + try: + thawed = self.thaw(sessid) + if thawed.atime + thawed.expire < now: + raise KeyError() + thawed.lock = entry[0] + thawed.atime = now + entry[1] = thawed + return thawed + finally: + if entry[1] is None: + entry[1] = "retired" + with self.lock: + del self.live[sessid] + else: + raise Exception("Illegal session entry: " + repr(entry[1])) + def fetch(self, req): now = int(time.time()) sessid = cookie.get(req, self.cookiename) @@ -117,27 +163,20 @@ class db(object): self.cthread = threading.Thread(target = self.cleanloop) self.cthread.setDaemon(True) self.cthread.start() - try: - if sessid is None: - raise KeyError() - elif sessid in self.live: - sess = self.live[sessid] - else: - sess = self.thaw(sessid) - self.live[sessid] = sess - if sess.atime + sess.expire < now: - raise KeyError() - sess.atime = now - except KeyError: - sess = session() - new = True + try: + if sessid is None: + raise KeyError() + sess = self._fetch(sessid) + except KeyError: + sess = session(threading.RLock()) + new = True def ckfreeze(req): if sess.dirty(): if new: cookie.add(req, self.cookiename, sess.id, self.path) with self.lock: - self.live[sess.id] = sess + self.live[sess.id] = [sess.lock, sess] try: self.freeze(sess) except: @@ -157,7 +196,9 @@ class db(object): def freeze(self, sess): if self.backdb is None: raise TypeError() - self.backdb[sess.id] = pickle.dumps(sess, -1) + with sess.lock: + data = pickle.dumps(sess, -1) + self.backdb[sess.id] = data sess.frozen() def get(self, req):