blocking

问题 The question is similar to the following two questions. Java InputStream blocking read Why is the FileInputStream read() not blocking? But I still cannot fully understand it. So far I think the read() method in following code will block due to the empty file 'test.txt'. FileInputStream fis = new FileInputStream("c:/test.txt"); System.out.println(fis.read()); System.out.println("to the end"); Actually it will print -1, I want to know why. The javadoc says This method blocks if no input is yet

问题 I have a production setup for running celery workers for making a POST / GET request to remote service and storing result, It is handling load around 20k tasks per 15 min. The problem is that the workers go numb for no reason, no errors, no warnings. I have tried adding multiprocessing also, the same result. In log I see the increase in the time of executing task, like succeeded in s For more details look at https://github.com/celery/celery/issues/2621 回答1: If your celery worker get stuck

问题 I am writing a python program that sends packets for a specified amount of time. The sending script: import socket import time import networkparam import ray ray.init() transformer_sending_time = 0 final_message_sent = False @ray.remote def send_message(): """ Sends an abnormal measurement to the specified ip address or port number given by the networkparam module Parameters ---------- None, however we can consider the definitions in networkparam as the function args Returns ---------- None "

问题 I'm reading Socket InputStream, calling read() and available() works for few looping iterations. Later available() blocks indefinitely! What could be the issue? How can I make this non-blocking? Code: BufferedInputStream buffIn = new BufferedInputStream(in); while (true) { if (buffIn.available() > 0) { len = buffIn.read(buffer, 0, buffer.length); if (len == -1) { break; } baos.write(buffer, 0, len); } } 回答1: It is not blocking it is spinning. Once there is no data available you code might as

问题 I'm trying to understand a bit more about what happens under the surface during various blocking/waiting types of operations in Go. Take the following example: otherChan = make(chan int) t = time.NewTicker(time.Second) for { doThings() // OPTION A: Sleep time.Sleep(time.Second) // OPTION B: Blocking ticker <- t.C // OPTION C: Select multiple select { case <- otherChan: case <- t.C: } } From a low level view (system calls, cpu scheduling) what is the difference between these while waiting? My

问题 When I use Javaa's Socket class to send out a byte array, does the write call in the following code block until it has verified that the recipient has received the data? byte data[] = ...; Socket socket = ...; socket.getOutputStream().write(data); // blocking ? The reason I ask, is if I have a list of sockets that I want to send the same data to, I want to send it as efficiently as possible, i.e., is there a better way than this: ArrayList<Socket> sockets = ...; byte data[] = ...; for(int i =

问题 When I use Javaa's Socket class to send out a byte array, does the write call in the following code block until it has verified that the recipient has received the data? byte data[] = ...; Socket socket = ...; socket.getOutputStream().write(data); // blocking ? The reason I ask, is if I have a list of sockets that I want to send the same data to, I want to send it as efficiently as possible, i.e., is there a better way than this: ArrayList<Socket> sockets = ...; byte data[] = ...; for(int i =

问题 When I use Javaa's Socket class to send out a byte array, does the write call in the following code block until it has verified that the recipient has received the data? byte data[] = ...; Socket socket = ...; socket.getOutputStream().write(data); // blocking ? The reason I ask, is if I have a list of sockets that I want to send the same data to, I want to send it as efficiently as possible, i.e., is there a better way than this: ArrayList<Socket> sockets = ...; byte data[] = ...; for(int i =

问题 How do I make this a non-blocking call? osd_cat accepts input only as a PIPE which need p.communicate() call making the process to block. Is there any other way to set stdin in Popen ? p = subprocess.Popen(('osd_cat', '-d', '{}'.format(interval)), stdin=subprocess.PIPE) p.communicate(message) 回答1: The p.communicate method is a one-shot deal in terms of sending data to the process. Instead, write directly to p.stdin. If you want to get output, you can read lines from p.stdout. Make sure you

问题 I would like to have a server that connects to one client at a time, ignoring connection request when connected to a given client. I would also liked to avoid the server to get locked when listening for the first client, so that the program can be terminated cleanly. Apparently, sockets can be made non blocking: http://beej.us/guide/bgnet/output/html/singlepage/bgnet.html#blocking I created my socket accordingly (error management code removed for clarity) int sockfd; struct sockaddr_in self;