deadlock

问题 I've been getting a Deadlock found when trying to get lock; try restarting transaction error on my InnoDB tables. Here is the query: UPDATE views SET visit_cnt = visit_cnt + 1 WHERE visit_day = DATE(NOW()) AND article_id = '4838' This query also triggers this via ON UPDATE trigger: UPDATE articles SET views = views + 1 WHERE id = NEW.article.id Here is how I tried to fixed it: $attempts_left = 5; do { mysql_query ($query); // if we found a deadlock, we will try this query 4 more times if

问题 Let's say we execute... SELECT * FROM MY_TABLE FOR UPDATE ...and there is more than one row in MY_TABLE. Theoretically, if two concurrent transactions execute this statement, but it happens to traverse (and therefore lock) the rows in different order, a deadlock may occur. For example: Transaction 1: Locks row A. Transaction 2: Locks row B. Transaction 1: Attempts to lock row B and blocks. Transaction 2: Attempts to lock row A and deadlocks. The way to resolve this is to use ORDER BY to

问题 I have a multithreaded .NET Windows Service that hangs intermittently -- maybe once every two weeks of 24/7 operation. When the hangs occurs the threadpool is completely saturated because calls to our custom tracelistener start blocking for some reason. There aren't any locks in the offending code nor anything blocking according to windbg, but they're definitely blocking somewhere. There aren't any exceptions on the stack either. There is a Thread.Sleep(1) that will occasionally be hit in the

问题 I have the classes below. public class AzureMobileDataContext : IAsyncInitialization { private static readonly Lazy<AzureMobileDataContext> lazy = new Lazy<AzureMobileDataContext> (() => new AzureMobileDataContext( new MobileServiceClient( "http://myservice.azure-mobile.net/", "123456789ABCDEFGHIJKLMNOP"))); public static AzureMobileDataContext Instance { get { return lazy.Value; } } public Task Initialization { get; private set; } public IMobileServiceClient Context { get; private set; }

问题 I created a table in my SQL Server 2005 database and populated it with summary and calculated values. The purpose is to avoid extensive joins and groupings on every call to the database. I would like this table to refresh every hour, but I am not sure the best way to do this while the website is under load. If I delete every record and repopulate the table in one transaction will that do the trick or will there be deadlocks and other trouble lurking? 回答1: The way I have done this in a few

问题 Since I've started programming in Java I have been wondering this (about a year or two). In C, we must know the different method to correctly avoid deadlock between thread and thus there is much more choice between synchronization method. So what about Java? When we synchronize, how does it avoid putting thread in deadlock situation? How does it work internally? Does the deadlock are avoided because we synchronized on higher level than in C ( or C++)? Any documentation about deadlock and

问题 I'm learning about deadlocks in Java, and there's this sample code from Sun's official tutorial: Alphonse and Gaston are friends, and great believers in courtesy. A strict rule of courtesy is that when you bow to a friend, you must remain bowed until your friend has a chance to return the bow. Unfortunately, this rule does not account for the possibility that two friends might bow to each other at the same time. public class Deadlock { static class Friend { private final String name; public

问题 I'm learning about deadlocks in Java, and there's this sample code from Sun's official tutorial: Alphonse and Gaston are friends, and great believers in courtesy. A strict rule of courtesy is that when you bow to a friend, you must remain bowed until your friend has a chance to return the bow. Unfortunately, this rule does not account for the possibility that two friends might bow to each other at the same time. public class Deadlock { static class Friend { private final String name; public

问题 I'm experimenting with MPI and was wondering if this code could cause a deadlock. MPI_Comm_rank (comm, &my_rank); if (my_rank == 0) { MPI_Send (sendbuf, count, MPI_INT, 1, tag, comm); MPI_Recv (recvbuf, count, MPI_INT, 1, tag, comm, &status); } else if (my_rank == 1) { MPI_Send (sendbuf, count, MPI_INT, 0, tag, comm); MPI_Recv (recvbuf, count, MPI_INT, 0, tag, comm, &status); } 回答1: MPI_Send may or may not block. It will block until the sender can reuse the sender buffer. Some implementations

问题 I'm experimenting with MPI and was wondering if this code could cause a deadlock. MPI_Comm_rank (comm, &my_rank); if (my_rank == 0) { MPI_Send (sendbuf, count, MPI_INT, 1, tag, comm); MPI_Recv (recvbuf, count, MPI_INT, 1, tag, comm, &status); } else if (my_rank == 1) { MPI_Send (sendbuf, count, MPI_INT, 0, tag, comm); MPI_Recv (recvbuf, count, MPI_INT, 0, tag, comm, &status); } 回答1: MPI_Send may or may not block. It will block until the sender can reuse the sender buffer. Some implementations