synchronization

问题 for writing an offline client to the Google Reader service I would like to know how to best sync with the service. There doesn't seem to be official documentation yet and the best source I found so far is this: http://code.google.com/p/pyrfeed/wiki/GoogleReaderAPI Now consider this: With the information from above I can download all unread items, I can specify how many items to download and using the atom-id I can detect duplicate entries that I already downloaded. What's missing for me is a

问题 What's the best way to wait (without spinning) until something is available in either one of two (multiprocessing) Queues, where both reside on the same system? 回答1: It doesn't look like there's an official way to handle this yet. Or at least, not based on this: http://bugs.python.org/issue3831 You could try something like what this post is doing -- accessing the underlying pipe filehandles: http://haltcondition.net/?p=2319 and then use select. 回答2: Actually you can use multiprocessing.Queue

问题 Do you know any applications to synchronize two databases - during development sometimes it's required to add one or two table rows or new table or column. Usually I write every sql statement in some file and during uploading path I evecute those lines on my production database (earlier backing it up). I work with mySQL and postreSQL databases. What is your practise and what applications helps you in that. 回答1: You asked for a tool or application answer, but what you really need is a a

问题 Question How can I make sure my application is thread-safe? Are their any common practices, testing methods, things to avoid, things to look for? Background I'm currently developing a server application that performs a number of background tasks in different threads and communicates with clients using Indy (using another bunch of automatically generated threads for the communication). Since the application should be highly availabe, a program crash is a very bad thing and I want to make sure

问题 I was debugging a multi-threaded application and found the internal structure of CRITICAL_SECTION . I found data member LockSemaphore of CRITICAL_SECTION an interesting one. It looks like LockSemaphore is an auto-reset event (not a semaphore as the name suggests) and operating system creates this event silently when first time a thread waits on Critcal Section which is locked by some other thread. Now, I am wondering is Critical Section always faster? Event is a kernel object and each

问题 Suppose that thread Alpha is writing to variable A without locking. A second thread Beta is waiting for Alpha to terminate, then reads the variable A in turn. Is it possible that the contents of A will not be fresh? Can memory writes be delayed beyond the thread lifetime? Won't the standard mechanism of waiting for thread Alpha termination implicitly work as a memory barrier? UPDATE 1 Are there any examples of waiting which does not include a memory barrier? 回答1: Almost certainly (the API

问题 I am looking for methods, built-in functions, good practices... to append new data to a matrix - when the rows and columns are not the same The data I deal with is structured as follows: A.values: Ta x Ma matrix of values A.dates: Ta x 1 vector of datenum A.id: 1 x Ma cell array of ids Now the challenge is how to deal with new (potentially overlapping) data B that I load in and would like to append to a new matrix C : When new data comes in, it can expand both horizontally and vertically due

问题 I want to continually sync every 30 mins or less around 380000 rows of data from 11 tables from a SQL Server database to a MySQL database. How can I do this? What programs can do this? This post, which is often used to close questions like these as a duplicate, does not work for me, for the following reasons. The SQL Server is part of a CRM system, I'm not sure if it may be a lite version or something, but long story short I do not have access to the SQL Server Management Studio. The MySQL

问题 I have been developing an Android app on a Windows machine. Now I would like to continue development on another Ubuntu 10.04 LTS machine. I would like to move between computers maintaining a recent copy of the project files on each computer. I am using SpiderOak to create a synchronization of the workspace directories of Eclipse which I am using for development. When the files were copied from the Windows machine onto the Ubuntu machine and I ran Eclipse, an error was presented that the path

问题 I'm running in a loop and kicking off tasks in the following manner: var iResult = new List<Task>(); foreach(var i in myCollection) { var task = Task.Factory.StartNew(() => DoSomething(), TaskCreationOptions.LongRunning); task.ContinueWith(m => myResponseHandler(m.Result)); iResult.Add(task); } Within my DoSomething() method, I have a timer: public static myMsg DoSomething() { var timer = System.Diagnostics.Stopwatch.StartNew(); DoLongRunningTask(); //If it matters this hits a REST endpoint