nonblocking

问题 I have a serial port external device for getting data. I set two timers. One of them has to be for plotting(0.5sn) and the other for writing to a text file(15sn). Timers shouldn't get data from each other by list or array. Because sometimes I need to close plotting button. So I have to get data from the same resource (coming continuous data), right? But when I try this, it blocked. And how to get data without blocking? As an example the below code runs without blocking: # -*- coding: utf-8 -*

问题 I'm working on a non-blocking script and it's works fine but when i try to load jQuery, its loads but i cant execute jQuery functions like this simple alert: $(document).ready(function(){ alert('jQuery loaded !'); }); Here is what im trying: var xhrObj = XMLHttpRequest(); xhrObj.onreadystatechange = function(){ if(xhrObj.readyState == 4){ var element = document.createElement("script"); document.getElementsByTagName('head')[0].appendChild(element); element.text = xhrObj.responseText; } };

问题 I am trying to find a document in a MongoDB collection in a NodeJS environment. Is there any way to do the following? This is not working: var foo = function (id) { // find document var document = database.find(id); // do whatever with the document ... } This way creates a block : var foo = function (id) { // find document var document = database.find(id); while (!database.find.done) { //wait } // do whatever with the document ... } What I want to do : var foo = function (id) { // find

问题 Here http://marc.info/?l=openssl-users&m=124386218929227 It states that "...This is why it is very important to understand that any possible forward progress on any port (and a write operation that returns WANT_READ may have made forward progress!) requires you to retry all pending operations on all ports...." So am I correct in understanding that an SSL_read() that returned WANT_READ may have made forward progress (even if it did not return any data)? I have an event driven single threaded

问题 I have this code segment that is designed to connect to a server using a socket connection. However if it can not connect to the server within a certain amount of time I would like it to stop trying. I tried to do this with this nonblocking socket and the select command but select is always returning 1 indicating that the server exists when nothing exists at the address I give it. Any Ideas? SOCKET tcp_client( char *hname, char *sname ) { fd_set fdset; struct sockaddr_in peer; SOCKET s; FD

问题 I'm trying to understand the idea of non-blocking web server and it seems like there is something I miss. I can understand there are several reasons for "block" web request(psuedocode): CPU bound string on_request(arg) { DO_SOME_HEAVY_CPU_CALC return "done"; } IO bound string on_request(arg) { DO_A_CALL_TO_EXTERNAL_RESOURCE_SUCH_AS_WEB_IO return "done"; } sleep string on_request(arg) { sleep(VERY_VERY_LONG_TIME); return "done"; } are all the three can benefit from non-blocking server? how the

问题 All I need to do is just to read all available bytes from socket. But there is one condition: there is a method which reads n bytes from non-blocking socket which I have to use for implementation of another method which is going to read all available bytes. Non-blocking reading of some data with defined size: ssize_t read(void* buf, size_t len) { ssize_t bytesRead = 0; ssize_t bytesTotallyRead = 0; size_t bytesLeftToRead = len; while (bytesTotallyRead < len) { bytesRead = ::recv(handle, (char

问题 Is there a way to do shutdown(SHUT_WR) on socket asynchronously? I.e. start the operation, then wait for its completion using poll? 回答1: It's asynchronous anyway. It just queues a FIN behind the current contents of the socket send buffer, if any, which really just amounts to setting a bit somewhere. There's no poll() operation for completion of any send, let alone this one. 来源： https://stackoverflow.com/questions/42343331/sockets-non-blocking-shutdownshut-wr

问题 Right now I do a lot of research about concurrency and parallelism. Could you tell me if I understand correctly (on os level): Blocking io: When I explicitly wait for connection (ie. in Ruby:) conn = socket.accept So my thread is blocked until I get something to socket, right? (And I understand that I am pooling socket in some loop in accept for data, right?) Non blocking: I have thread that is asking from time to time all registered fd (filedescriptors) if they have something I need. But

问题 I'm putting together a client server app on RPi. It has a main thread which creates a comms thread to talk to an iOS device. The main thread creates an asyncio event loop and a sendQ and a recvQ and passes them as args to the commsDelegate main method in the comms thread. The trouble I'm having is when iOS device connects, it needs to receive unsolicited data from this Python app as soon as the data becomes available and it needs to be able to send data up to the Python app. So send and