nonblocking | 易学教程

non-blocking “toast” like notifications for Microsoft Access (VBA)

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问题 I'm going to ASK and answer a question that I think will be useful to someone who is interested in some cool UI functions in MS Access. Answering own question Question: How to show non-blocking "toast" like notifications in Microsoft Access? that does have some sort of animation and should not block the host application!. 回答1: My friend asked me about non-blocking toast like notifications for ms access. My first thought was, check google you will find plenty of samples. He wasn't happy with

non-blocking “toast” like notifications for Microsoft Access (VBA)

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Is non-blocking I/O really faster than multi-threaded blocking I/O? How?

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问题 I searched the web on some technical details about blocking I/O and non blocking I/O and I found several people stating that non-blocking I/O would be faster than blocking I/O. For example in this document. If I use blocking I/O, then of course the thread that is currently blocked can't do anything else... Because it's blocked. But as soon as a thread starts being blocked, the OS can switch to another thread and not switch back until there is something to do for the blocked thread. So as long

Read timeout using either urllib2 or any other http library

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问题 I have code for reading an url like this: from urllib2 import Request, urlopen req = Request(url) for key, val in headers.items(): req.add_header(key, val) res = urlopen(req, timeout = timeout) # This line blocks content = res.read() The timeout works for the urlopen() call. But then the code gets to the res.read() call where I want to read the response data and the timeout isn't applied there. So the read call may hang almost forever waiting for data from the server. The only solution I've

PySerial non-blocking read loop

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问题 I am reading serial data like this: connected = False port = 'COM4' baud = 9600 ser = serial.Serial(port, baud, timeout=0) while not connected: #serin = ser.read() connected = True while True: print("test") reading = ser.readline().decode() The problem is that it prevents anything else from executing including bottle py web framework. Adding sleep() won't help. Changing "while True"" to "while ser.readline():" doesn't print "test", which is strange since it worked in Python 2.7. Any ideas

What does Python's socket.recv() return for non-blocking sockets if no data is received until a timeout occurs?

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问题 Basically, I've read in several places that socket.recv() will return whatever it can read, or an empty string signalling that the other side has shut down (the official docs don't even mention what it returns when the connection is shut down... great!). This is all fine and dandy for blocking sockets, since we know that recv() only returns when there actually is something to receive, so when it returns an empty string, it MUST mean the other side has closed the connection, right? Okay, fine,

五大I/O模型详解

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 同步与异步&阻塞与非阻塞五大I/O模型详解 java I/O模型简述前文在同步与异步&阻塞与非阻塞中，简要的介绍一些基础概念，但这些概念最终是为IO所服务，是为文件所服务。按照Linux一句话来说，一切皆文件。一、Unix IO模型 Unxi大师Richard Stevens在 UNIX® Network Programming 中讲述了五种I/O 模型 blocking IO nonblocking IO IO multiplexing signal driven IO asynchronous IO 而本文也是基于这五种I/O模型，以及交叉着同步与异步&阻塞与非阻塞的概念。但在探讨I/O模型之前，先要了解一下I/O模型发生的对象和步骤。对于一个文件IO的操作(这里以read为例子)，会涉及到两个对象：一个是调用这个IO的进程process 另外一个就是系统内核kernel 当一个read操作发生时，会经历两个阶段进程等待内核数据准备(Waiting for the data to be ready) 将数据从内核拷贝到进程中 (Copying the data from the kernel to the process) 二、五大I/O模型 1.blocking IO(阻塞IO) 1.1

How java nio ServerSocketChannel accept works?

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问题 I can't get how NIO works under the hood. Here is a sample code: // Create the server socket channel ServerSocketChannel server = ServerSocketChannel.open(); // nonblocking I/O server.configureBlocking(false); // host-port 8000 server.socket().bind(new java.net.InetSocketAddress(host,8000)); // Create the selector Selector selector = Selector.open(); // Recording server to selector (type OP_ACCEPT) server.register(selector,SelectionKey.OP_ACCEPT); while (true) { selector.select(); // blocking

What is the best way to control Twisted's reactor so that it is nonblocking?

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问题 Instead of running reactor.run(), I'd like to call something else (I dunno, like reactor.runOnce() or something) occasionally while maintaining my own main loop. Is there a best-practice for this with twisted? 回答1: Yes. The best practice is that this is a bad idea, and that you never really need to do it. It doesn't work with all reactors, and you certainly can't have two different libraries which want to do this. Why do you need to maintain your own main loop? Chances are, it's something

Non blocking IO - Programming model

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问题 In non blocking IO programming model, a thread blocked on data available channels, as shown below, in python, while True: readers, _, _ = select.select([sys.stdin, sock], [], []) # blocked select() for reader in readers: if reader is sock: print(sock.recv(1000).decode('utf-8')) else: msg = sys.stdin.readline() sock.send(msg.encode('utf-8')) in java, public void run() { while(true){ try{ executeCycle(); } catch(IOException e){ e.printStackTrace(); } try { Thread.sleep(100); } catch