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jbpm4.3 数据库使用MySql异常 could not delete

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解决方案：修改属性：jbpm.hibernate.cfg.xml <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property> InnoDB 给 MySQL 提供了具有事务(commit)、回滚(rollback)和崩溃修复能力(crash recovery capabilities)、多版本并发控制(multi-versioned concurrency control)的事务安全(transaction-safe (ACID compliant))型表。InnoDB 提供了行级锁(locking on row level)，提供与 Oracle 类似的不加锁读取(non-locking read in SELECTs)。InnoDB锁定在行级并且也在SELECT语句提供一个Oracle风格一致的非锁定读。另外InnoDB是为处理巨大数据量时的最大性能设计。它的CPU效率可能是任何其它基于磁盘的关系数据库引擎所不能匹敌的。MySQLInnoDBDialect基于上也就有InnoDB相同的功能. 来源：

Custom Lock Screen Delay When Wake

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I'm trying to make a custom lock screen app, but I'm not sure if I'm going about it the right way. I have a broadcast receiver that listens to when the screen is turned on and starts my lock screen activity. This receiver is registered inside a service, which also disables the default lock screen. The problem is, there is a slight delay between when the screen is turned on and the lock screen activity shows up. How would I go about doing it so that it shows up right away? My code for the service: @Override public void onCreate() { super.onCreate(); IntentFilter filter = new IntentFilter(Intent

database lock issue in HTC Desire

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In my application one service is getting data from server and inserting it to table A . If I go to particular UI, I need to list data from another table B if background operation is doing it will generate database locked exception. I got two database operation done in parallel each on two different table. It is working fine in samsung gt15801. But htc desire it will generate database locked error. HTC desire - insertion process takes 91 seconds. Samsung gt15801 - insertion process takes 21 seconds. Try to use one SqliteDatabaseHelper and make it single instance. After that don't close the

Trouble with locking an image between threads

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问题 I need to obtain a lock in two different threads in order to access a Bitmap (which is populated from a webcam) in EmguCv. I have a "GetFrame" functions that queries the camera and places what it returns into a .NET Bitmap. I have two threads which need to access this Bitmap, one needs to write to the Bitmap and assign the Bitmap to a picture box, and the other needs to read the Bitmap, convert it to an Image object and assign that to an EMGU ImageBox. I first lock on an arbitrary Object,

Java 6 JVM Hang

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问题 Apologies for the long post, but I wonder if I could get some more eyeballs on this before I submit a bug report to Sun. JVM: 6u11 O/S: Windows XP SP3 Hardware: AMD Athlon 64 X2 4600+ @ 2.41GHz, with 3.25 GB RAM. I believe I have encountered a fault in the JVM where no thread is given a monitor. In the following thread traces, the monitor <0x12a8f9f8> was acquired by RelayedMessages-0000000001 , which ended up waiting on it; that thread was subsequently notified. However, even though all of

Java 6 JVM Hang

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Apologies for the long post, but I wonder if I could get some more eyeballs on this before I submit a bug report to Sun. JVM: 6u11 O/S: Windows XP SP3 Hardware: AMD Athlon 64 X2 4600+ @ 2.41GHz, with 3.25 GB RAM. I believe I have encountered a fault in the JVM where no thread is given a monitor. In the following thread traces, the monitor <0x12a8f9f8> was acquired by RelayedMessages-0000000001 , which ended up waiting on it; that thread was subsequently notified. However, even though all of the threads listed are contending for the monitor, none are getting it. I promise the thread dump is

Return unlocked rows in a “select top n” query

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问题 I need to have a MsSql database table and another 8 (identical) processes accessing the same table in parallel - making a select top n, processing those n rows, and updating a column of those rows. The problem is that I need to select and process each row just once. This means that if one process got to the database and selected the top n rows, when the second process comes it should find those rows locked and select the rows from n to 2*n rows, and so on... Is it possible to put a lock on

SQL Server ROWLOCK over a SELECT if not exists INSERT transaction

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问题 I have upgraded from SQL Server 2005 to 2008. I remember that in 2005, ROWLOCK simply did not work and I had to use PAGELOCK or XLOCK to achieve any type of actual locking. I know a reader of this will ask "what did you do wrong?" Nothing. I conclusively proved that I could edit a "ROWLOCKED" row, but couldn't if I escalated the lock level. I haven't had a chance to see if this works in SQL 2008. My first question is has anyone come across this issue in 2008? My second question is as follows.

java: wait(), notify() and synchronized blocks

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问题 I learned that calling an Object's wait() method will release the object monitor, if present. But I have some questions regarding calling notify() on this object by another thread: (when) will the waiting thread wake up, if another (a 3rd) thread owns the object monitor in the meanwhile? will the waiting thread wake up, if a 3rd thread called wait() on this object? is it possible to determine if a thread is waiting for notifying a particular object (java 1.4/java 5) What's happening if wait()

SQL Server ROWLOCK over a SELECT if not exists INSERT transaction

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I have upgraded from SQL Server 2005 to 2008. I remember that in 2005, ROWLOCK simply did not work and I had to use PAGELOCK or XLOCK to achieve any type of actual locking. I know a reader of this will ask "what did you do wrong?" Nothing. I conclusively proved that I could edit a "ROWLOCKED" row, but couldn't if I escalated the lock level. I haven't had a chance to see if this works in SQL 2008. My first question is has anyone come across this issue in 2008? My second question is as follows. I want to test if a value exists and if so, perform an update on relevant columns, rather than an