当我们在配置c3p0之后出现以下这些错误：
警告: com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@513098 -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
2014-6-2 9:46:20 com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector run
警告: com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@513098 -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@23b5c3
on thread: C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#2
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@723c42
on thread: C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#0
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@1d2300e
on thread: C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#1
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@51207c
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@2bd615
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@1f43d69
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@1ebf1eb
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@157816a
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@1f16e6e
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@1890510
Pool thread stack traces:
Thread[C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#2,5,main]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:129)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2499)
com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1078)
com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2312)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2122)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:774)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:49)
sun.reflect.GeneratedConstructorAccessor13.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:375)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:289)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Thread[C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#0,5,main]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:129)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2499)
com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1078)
com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2312)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2122)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:774)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:49)
sun.reflect.GeneratedConstructorAccessor13.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:375)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:289)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Thread[C3P0PooledConnectionPoolManager[identityToken->2rw2z992p1flfi9zm77x|1f46b16]-HelperThread-#1,5,main]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:129)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2499)
com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:599)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1078)
com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2312)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2122)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:774)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:49)
sun.reflect.GeneratedConstructorAccessor13.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:375)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:289)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:146)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
com.mchange.v2.resourcepool.BasicResourcePool.doAcq
uireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
其实出现这些错误的原因是c3p0-config.xml配置出现错误，所以在配置文件的相关参数要配置正确。