473,554 Members | 2,958 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

metaclass to create a thread-safe class ("monitor"), allright?

I created my first ever Python Meta Class to solve a
problem I'm having. I have an existing class that I want
to make thread-safe: all method calls should use a thread-lock
to avoid having multiple threads active in the class at the
same time. I don't want to change every method of the class
by adding lock.acquire(). ..try...finally ..lock.release( ) stuff,
so I decided to try it with a Meta Class.

Below is what I came up with (after a bit of googling).

Since it's my first attempt at a non-trivial meta class,
can you please comment on it? Is this the way to do things?

It appears to work, at least the example method call at the
bottom prints:
[E:\]python meta.py
got lock

irmen 42
<<released lock

which is what I wanted..

Irmen de Jong.
#----------Code follows-----------
from types import FunctionType
from threading import RLock

class MonitorMetaClas s(type):
def __new__(meta, name, bases, dict):
meta.convert_me thods(dict)
return super(MonitorMe taClass, meta).__new__(m eta, name, bases, dict)

def makeThreadsafeM ethod(func):
def threadsafemetho d(self, *args, **kwargs):
self._monitor_l ockObj.acquire( )
print ">>got lock"
return func(self, *args, **kwargs)
self._monitor_l ockObj.release( )
print "<<released lock"
return threadsafemetho d
makeThreadsafeM ethod = staticmethod(ma keThreadsafeMet hod)

def convert_methods (cls, dict):
methods=[ v for k,v in dict.iteritems( ) if isinstance(v, FunctionType) ]
for m in methods:
dict[m.__name__]=cls.makeThread safeMethod(m)
dict["_monitor_lockO bj"] = RLock()

convert_methods = classmethod(con vert_methods)
class MyClass(object) :
__metaclass__=M onitorMetaClass

def method(self, a1, a2):
print a1,a2

m.method("irmen ",42)
Jul 18 '05 #1
0 1207

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

by: achan | last post by:
As I was trying to create a metaclass, I found out that __init__ defined in it does not initializes at all: class CMeta(type): def __new__(cls, ClassName, BaseClass, ClassDict): def __init__(self): for k in self.__slots__: k = 'something' NewDict = {'__slots__': , '__init__': __init__} for k in ClassDict:
by: Paul Morrow | last post by:
One of the beautiful things about Python is its clear, minimal syntax. So we must resist adding new syntax to the language, especially where there is a reasonable alternative. I believe that Stefen Eischet's suggestion for automatically determining a method's type (class/instance/static) from the name of its first formal parameter is a...
by: Nicolas Fleury | last post by:
In the following example: class MyMetaclass(type): pass class MyBaseType(object): __metaclass__ = MyMetaclass class MyType(MyBaseType): x = 4 y = 5 z = 6 Is there any way to modify MyMetaclass to keep the order of x,y,z somewhere?
by: Antoine Pitrou | last post by:
Hi, I've been looking at writing parameterized metaclasses and here are the two solutions I've come to: (my goal was to build a way to automatically add a hash function that would take into account a selected list of object attributes) 1. all-in-one metametaclass: class Autohash2(type):
by: =?iso-8859-1?B?QW5kcuk=?= | last post by:
In my application, I make use of the Borg idiom, invented by Alex Martelli. class Borg(object): '''Borg Idiom, from the Python Cookbook, 2nd Edition, p:273 Derive a class form this; all instances of that class will share the same state, provided that they don't override __new__; otherwise, remember to use Borg.__new__ within the...
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main...
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. ...
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For...
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the...
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then...
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert...
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in...
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.