I am trying to write a function which uses Task and TaskCompletion. My problem is that after login, the result is not returned. I used similar code before and it was working. I do not know what causes for this situation. public async Task<byte[]> Si
I came across this line which states that "However, even though all operations are thread-safe, retrieval operations do not entail locking, and there is not any support for locking the entire table in a way that prevents all access"in the overal
For my programming languages class we have been given a simple Java deadlock example and are asked to solve it. I don't directly want the answer to this problem, I mainly want to know where my understanding is lacking. Here's the code: import java.ap
I have added comments in code to explain from where deadlock is occurring. Basically, There are two threads. Each thread acquires lock on an Manager object and then go for acquiring lock on static resource, which is a map of all the Manager objects i
I have written a Kernel module that is interacting with net-filter hooks. The net-filter hooks operate in Softirq context. I am accessing a global data structure "Hash Table" from the softirq context as well as from Process context. The process
How do I use the mysql statement "UNLOCK TABLES" using mysqli in php? I can't put it at the end the existing statement just by using a semi-colon, I get an error doing it that way. Here's what I tried to do "UPDATE blah blah; UNLOCK TABLES;
I'm running into a deadlock situation when calling StackExchange.Redis. I don't know exactly what is going on, which is very frustrating, and I would appreciate any input that could help resolve or workaround this problem. In case you have this probl
In SQL it is relatively easy to replicate a transaction deadlock. ==SESSION1== begin tran update table1 set ... where ... [hold off further action - begin on next session] ==SESSION2== begin update table1 set ... where ... [hold off further action -
This is the example in java tutorial of Oracle about Lock object. Someone please confirms whether I interpreted the code correctly. I will consider only the first thread, because the other works the same way. First, it acquires the lock of alphonse,
I'm working on a php program that forks itself several times, resulting in several worker processes which then autonomously work off a table of tasks. Each process opens it's own mysql connection (this is a must because of php's forking architecture)
I'm using blueprints-neo4j-graph-2.5.0 from maven repositories. While using the graph from different threads, neo4j freezes. The code that recreates the problem, and the call stack is attached. Any resolutions around this, or any usage patterns would
this is my query: SELECT DISTINCT (game.game_id) AS gid, game_link.is_linked, game_link.game_id1, game_bet_settings.bet_type_id AS bet_type FROM game LEFT JOIN kiosk_to_game ON ( kiosk_to_game.game_id = game.game_id ) LEFT JOIN game_bet_settings ON (
Question: Updated: Why does inserting a row into table A with a foreign key constraint to table B and then updating the row in table B that the inserted row in table A references in a transaction cause a deadlock? Scenario: reservation.time_slot_id h
In our project, we need to implement os dependent abstractions (like file, socket, thread...) for each os (linux, android, osx and win). The general iter for implementing os abstraction is: Write an os independent class header which defines methods t
Why is there a deadlock even tho I just pass one and get one output from the channel? package main import "fmt" import "math/cmplx" func max(a []complex128, base int, ans chan float64, index chan int) { fmt.Printf("called for %d,%
I can't figure this one out, think i have stared my self blind on the problem. I have the following scenario on MsSql server 2012. In 10 threads (C# + NHibernate) i do this: Begin transaction (ReadCommitted) Select count(*) from MyTable1 where ... (c
I've found that including a call to System.out.format in the classic Java Deadlock Tutorial will prevent deadlock from occurring, and I can't figure out why. The code below is the same as that of the tutorial, with the addition to main of System.out.
I insert in one table with many concurrent threads, in this Table is a AFTER INSERT Trigger which updates one field on the inserted Row. When this is executed in one thread everything is fine, but with many ones I got a Deadlock. Is there something I
On Mysql (Amazon RDS), when I try to run the following SQL query UPDATE table1 INNER JOIN table2 USING (CommonColumn) SET table1.col1 = table2.x, table1.col2 = table2.y I get this error after around 52 seconds consistently: Error Code: 1205. Lock wai
Here is a question my study group is arguing about: (g) Consider the following C# code: public class Demo { private static readonly object a = new object(); private static readonly object b = new object(); public static void Main (string[] args) { De
Does anyone know how to simulate a deadlock using a stored procedure inserting or updating values? I could only do so in sybase using individual commands. Thanks, VerCreate two stored procedures. The first should start a transaction, modify table 1 (
My application is blocking indefinitely on a call to lock ( obj ), but there are no other threads in the threads window that have any code to browse at all. Isn't it kind of necessary for there to be another thread involved? Why isn't it showing up,
I'm learning about threads in C#, and i get this behavior that i cant understand. The code simulates I/O operations, like files or serial port, where only one thread can access it at time, and it blocks until finishes. Four threads are started. Each
I have a loading posgres server with a large amount of update operations. In postgres.conf I set the deadlock_timeout= 8s. In the log I see the following: process 3588 acquired ShareRowExclusiveLock on relation 17360 of database 16392 after 8000.000
I've written a test of what I think should be a valid case for a deadlock. It appears that once the lock has been acquired by an instance of the a class, that instance doesn't need to re-acquire the lock anymore even if I explicitly try to call anoth
I've tried to read an article on locks and deadlocks, and it just doesn't land, al the different kind of locks. We're running 2 different processes which try to edit records in the same table. The first process reads the new data and sends it to an e
I've got a problem with multiple deadlocks on SQL server 2005. This one is between an INSERT and a SELECT statement. There are two tables. Table 1 and Table2. Table2 has Table1's PK (table1_id) as foreign key. Index on table1_id is clustered. The INS
One of my co-workers has a stored procedure that does the following Begin tran 1) Dynamically generate a select statement. 2) Insert into table x 3) Execute the select statement End tran If this stored procedure is ran by two septate threads simultan
If following situation a bug in mysql?. Mysql Version: mysql.x86_64 5.0.77-4.el5_4.1 Kernel: Linux box2 2.6.18-128.el5 #1 SMP Wed Jan 21 10:41:14 EST 2009 x86_64 x86_64 x86_64 GNU/Linux ------------------------ LATEST DETECTED DEADLOCK --------------
I'm writing some code for testing multithreaded programs (student homework--likely buggy), and want to be able to detect when they deadlock. When running properly, the programs regularly produce output to stdout, so that makes it fairly straightforwa
