deadlock

问题 Maybe there is other interpretation of "Dead Lock" but AFAIK : reference A deadlock happens when two threads each wait for a resource held by the other , so neither can proceed. But I've seen couple of answers here on SO which claims that a long wait ( without waiting for each other) is also a deadlock : Example #1 namespace ConsoleApplication7 { public class Program { public static void Main(string[] args) { LockableClass lockable = new LockableClass(); new Thread(new

问题 I have a central database server and several "worker" servers which are executing queries like this concurrently: UPDATE job_queue SET worker = '108.166.81.112', attempts = attempts + 1, started = '2014-01-14 10:34:03', token = '13eb3e6a8c3e1becb34051e08f19fd62' WHERE completed = '0000-00-00 00:00:00' AND (started = '0000-00-00 00:00:00' OR started < '2014-01-14 10:29:03') AND attempts < 2 ORDER BY priority DESC, inserted LIMIT 1 Occasionally my job_queue table locks up and if I run "SHOW

问题 I have deadlock detected error in my code and don't understand why. Could someone please tell me what am I doing wrong? #!/usr/bin/ruby ENV['RAILS_ENV'] = ARGV.first || ENV['RAILS_ENV'] || 'development' require File.expand_path(File.dirname(__FILE__) + "/config/environment") mutex = Mutex.new threads = [] 1.upto(10) do |i| threads << Thread.new(i) do |id| mutex.synchronize do # here I want to take 1 record from "class Product < ActiveRecord::Base" Product.first end # and to do here some stuff

问题 The question is how function-level statics are constructed when the function is called on multiple threads? Problem Description: Deadlock occurs and my application doesn't get terminated. During initialization of local static variable it tries to acquire MSVCR80!_lock and never gets hold on the lock. !locks command in WinDbg gives the following output. CritSec ntdll!LdrpLoaderLock+0 at 7c97e178 LockCount 0 RecursionCount 1 OwningThread 1998 EntryCount d ContentionCount d *** Locked CritSec

问题 Here's some simple code that demonstrates what I'm trying to do myVar = 1 reader = () -> getDataFromServer1().then -> # uses myVar and does stuff according to its value # returns promise writer = () -> getDataFromServer2().then -> # assigns to myVar # returns promise Q.all([reader(), reader(), reader(), writer(), writer(), writer()]).done -> console.log 'done' So I have multiple threads running at the same time. some of them change the value of myVar and some read the value and rely on it.

问题 I'm using JDBC (through Spring's JDBCTemplate) to access a small number of tables in a database. Although I haven't had anything happen yet, I'm concerned about the possibility of deadlock. I was under the impression there was a way to specify a lock order for queries that access multiple tables for deadlock avoidance, but I don't know if this is the type of thing that gets set up at the DB level when creating my tables, or if I have to do something explicitly with my JDBC queries. i.e. is

问题 I have a java process that is hanging in a call to IOUtils.toString with the following code: String html = ""; try { html = IOUtils.toString(someUrl.openStream(), "utf-8"); // process hangs on this line } catch (Exception e) { return null; } It can't reproduce this reliably. It's part of a web crawler and so executes this line thousands of times successfully but ultimately causes the process to hang here after a few days. Output from jstack: 2013-09-25 09:09:36 Full thread dump OpenJDK 64-Bit

问题 I need somebody help me to figure out the cause of following deadlock. the involved tables are parent/child and child table has indexed FK. parent:PK_FMS_FC_MAIN_FLD_INPUT_LIMIT chile:FMS_FC_REL_FLD_INPUT_LIMIT Deadlock graph: ---------Blocker(s)-------- ---------Waiter(s)--------- Resource Name process session holds waits process session holds waits TX-0019000b-0000b486 22 2755 X 57 492 S TX-00010019-00061e13 57 492 X 22 2755 S session 2755: DID 0001-0016-00000FCE session 492: DID 0001-0039

问题 Consider the following async method that I'm going to wait synchronously. Wait a second, I know. I know that it's considered bad practice and causes deadlocks, but I'm fully conscious of that and taking measures to prevent deadlocks via wrapping code with Task.Run. private async Task<string> BadAssAsync() { HttpClient client = new HttpClient(); WriteInfo("BEFORE AWAIT"); var response = await client.GetAsync("http://google.com"); WriteInfo("AFTER AWAIT"); string content = await response

问题 We have problems with deadlock situations in our application. I have read a lot about blocking, locking and deadlocks the last few days to try to get an understanding about the problem in order to solve it. Now when I read the error log information about the deadlocks I can't understand how this situation can exist. Look at this (I have renamed the table names but the important one is the one called OurTable in the log message): deadlock-list deadlock victim=process1e2ac02c8 process-list