deadlock

问题 I'm currently taking Operating Systems and our teacher assigned this problem for our lab but he's not very helpful. So I need to show a basic example of deadlock with semaphores and my output needs to demonstrate the occurence of the deadlock. I'm assuming he means if my exception is caught. This is as close as I've gotten. import java.util.concurrent.Semaphore; public class deadlockTest2 { private Semaphore sem1=new Semaphore(1); private Semaphore sem2=new Semaphore(1); private int num;

问题 The problem I have a RabbitMQ Server that serves as a queue hub for one of my systems. In the last week or so, its producers come to a complete halt every few hours. What have I tried Brute force Stopping the consumers releases the lock for a few minutes, but then blocking returns. Restarting RabbitMQ solved the problem for a few hours. I have some automatic script that does the ugly restarts, but it's obviously far from a proper solution. Allocating more memory Following cantSleepNow's

问题 I came across a strange Boost (v1.38) mutex deadlock in a preexisting .NET (C#, 3.5) application that makes calls to a C++ library. An exception is [properly] thrown at a point after a read lock is obtained and that exception goes unhandled all the way back to the managed .NET code (where it is handled). The next call to the c++ library that attempts to use a setter method hangs on the unique lock aquisition indefinately (presumably the read lock was not released): ntdll.dll

问题 I'm helping troubleshoot some deadlocking in a .NET application that uses SQL Server 2005. I have the XML data from the trace below. What really puzzles me is the RangeX-X lock on PK_Exp_Experience_PriorFirm when the transaction isolation level is read committed. Everything I've read indicates that you only get a key-range lock of you are using the transaction isolation level "serializable". So far, I can't find any places in our application where we set the isolation level to anything other

问题 I hava command line which process more than 5 mins. when I invoke command line with ProcessBuilder, it works the command completes the job with in 5 mins. Whereas the process hangs if it takes more than 5 mins and shows no improvement on process until I quit the process. p = new ProcessBuilder("myprogram","with","parameter").start(); p.waitFor(); Please let me know if you doesn't understand the above question? 回答1: The problem might be, that command "myprogram" produces some output, and you

问题 I have a batch in .NET that reads a lot of files and stores their content into a single MySQL InnoDB table with the following structure: `id` int(11) NOT NULL AUTO_INCREMENT, `Source` varchar(2) NOT NULL, `Period` char(1) NOT NULL, `idItem` int(11) NOT NULL, `StartDate` datetime NOT NULL, `MoreData` varchar(255) PRIMARY KEY (`id`), UNIQUE KEY `Combination` (`Source`,`Period`,`idItem`,`StartDate`), Where idItem is a foreign key Source, Period, and idItem are indices Combination is a unique

问题 I've strange deadlock graph where the victim chosen by MSSQL server 2008 isn't part of the deadlock loop. This deadlock is between select and insert . The deadlock resource is a single table where all select s want waitresource = "KEY: 6:72057594098810880 (ffffffffffff)" Question1 : Does ffffffffffff here mean they want a full range lock on whole table? Or whole key range? Or something else? We are following a rule where table will never have a row with primary key id = 0. There are few

问题 I've got an OS X app (Yosemite, 10.10) that performs long-running jobs involving heavy use of sqlite across multiple threads. And I've hit a deadlock across 8 threads, all of which are stuck in sqlite code connecting to different database files. There is no apparent resource-related connection between them. I'm debugging it on a new Mac Pro (late 2013). Four of them are at this stack. Of those, three are operating on the same table (again, different database files); three are updating and one

问题 I have 3 threads, that are currently running simultaneously. def f1(): print "running first thread\n" sleep(10) def f2(): print "running second thread\n" sleep(10) def f3(): print "running third thread\n" sleep(10) if __name__ == "__main__": thread1 = Thread(target = f1) thread2 = Thread(target = f2) thread3 = Thread(target = f3) try: thread1 = Thread(target = f1) thread1.start() thread2 = Thread(target = f2) thread2.start() thread3 = Thread(target = f3) thread3.start() while(thread1.isAlive(

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . Can anyone explain me on details the difference of Deadlock and Lockwait errors found on MySQL 5.1. Is it just the same? When does the deadlock error occur and when does the lockwait timeout occur? 回答1: A deadlock occurs where a circular dependency exists amongst the locks that transactions must acquire in order