deadlock

问题 I am having an issue with some process wrapping, and it's only occurring in Windows XP. This code works perfectly in Windows 7. I'm really stumped as to why the streams are empty in XP. I've also tried using the String[] version of Process.Exec() and it made no difference. I am using the following class to read from the process' STDOUT and STDERR (an instance for each stream): import java.util.*; import java.io.*; public class ThreadedStreamReader extends Thread{ InputStream in; Queue

问题 Ive got a thread that does some work in the background and passes updates to the Form using the Invoke, BeginInvoke methods. The thread is created after the form is displayed so no issue there. The issue is how to correctly shutdown. My worker thread has the ability to be asked to exit, and will exit some time soon after that (miliseconds). However if the form has closed first the Invoke stuff breaks. I tried adding a Thread.Join to the forms closing event, but of course this causes a

问题 I've programmed in a number of languages, but I am not aware of deadlocks in my code. I took this to mean it doesn't happen. Does this happen frequently (in programming, not in the databases) enough that I should be concerned about it? 回答1: Deadlocks could arise if two conditions are true: you have mutilple theads, and they contend for more than one resource. Do you write multi-threaded code? You might do this explicitly by starting your own threads, or you might work in a framework where the

问题 I'd like to start using the Task Parallel Library, as this is the recommended framework going forward for performing asynchronous operations. One thing I haven't been able to find is any means of forcible Abort, such as what Thread.Abort provides. My particular concern is that I schedule tasks running code that I don't wish to completely trust. In particular, I can't be sure this untrusted code won't deadlock and therefore I can't be certain if a Task I schedule using this code will ever

问题 C++17 introduced both std::shared_mutex and std::scoped_lock . My problem is now, that it seems, that scoped_lock will lock a shared mutex always in exclusive (writer) mode, when it is passed as an argument, and not in shared (reader) mode. In my app, I need to update an object dst with data from an object src . I want to lock src shared and dst exclusive. Unfortunately, this has the potential for deadlock, if a call to another update method with src and dst switched occurs at the same time.

问题 I have a process that appears to be deadlocked: # strace -p 5075 Process 5075 attached - interrupt to quit futex(0x419cf9d0, FUTEX_WAIT, 5095, NULL It is sitting on the "futex" system call, and seems to be indefinitely waiting on a lock. The process is shown to be consuming a large amount of CPU when "top" is run: # top -b -n 1 top - 23:13:18 up 113 days, 4:19, 1 user, load average: 1.69, 1.74, 1.72 Tasks: 269 total, 1 running, 268 sleeping, 0 stopped, 0 zombie Cpu(s): 8.1%us, 0.1%sy, 0.0%ni,

问题 A multi threaded application freezes. Perhaps it was caused by a deadlock. If yes, then how do we find the cause for the deadlock ? Any tools and strategies for doing this systematically ? 回答1: When possible, use a lock-free data structure like a ConcurrentLinkedQueue. By definition, a lock-free data structure cannot cause a deadlock. Always acquire locks in the same order. If your resources are A, B, and C, then all threads should acquire them in the order of A -> B -> C, or A -> C, or B ->

问题 I have two stored procedures running in separate threads, running on SQL Server 2005. One procedure inserts new rows into a set of tables and the other procedure deletes old data from the same set of tables. These procedures are running into a deadlock on the tables DLevel and Model . Here is the schema: (source: barramsoft.com) Table DFile : Primary Key = DFileID Table DLevel : Primary Key = DLevelID, Foreign Key: DFileID Table Model : Primary Key = ModelID, Foreign Key: DFileID Table

问题 The issue of PFUser deadlocking from thread contention via parse background calls has been raised numerous times by the Parse community, but Parse has chosen not to deal with this giant bug in the framework. Does anyone know of a work around for this issue? Other apparent reports of this issue: https://developers.facebook.com/bugs/649920188390439/ https://www.parse.com/questions/ios-api-apparent-deadlock-in-main-thread-v1213 https://www.parse.com/questions/occasional-freezing-at-pfuser

问题 i have a stored procedure that performs a join of TableB to TableA : SELECT <--- Nested <--- TableA Loop <-- | ---TableB At the same time, in a transaction, rows are inserted into TableA , and then into TableB . This situation is occasionally causing deadlocks, as the stored procedure select grabs rows from TableB , while the insert adds rows to TableA , and then each wants the other to let go of the other table: INSERT SELECT ========= ======== Lock A Lock B Insert A Select B Want B Want A .