c3p0-0.9.2.1 -- Dual licensed c3p0, LGPL v.2.1 and EPL 1.0. Modified license files, source headers, etc. c3p0-0.9.2 -- Updated documentation re hibernate configuration. (Documentation was several years stale.) -- Merged John Sumsion's remarkable integration of c3p0's full SourceForge history into the git repository. (Enormous, huge thanks to John Sumsion!) c3p0-0.9.2-pre8 -- Added logging (at level FINE, in com.mchange.v2.c3p0.impl.C3P0PooledConnectionPoolManager) when a pool is initialized for a new authentication within a DataSource. -- We now allow users to place an XML formatted config file in arbitrary locations under the classpath (i.e. as ClassLoader resource), including jar file META-INF directories. If the config property com.mchange.v2.c3p0.cfg.xml begins with "classloader:", the remainder of the String will be interpreted as a ClassLoader resource path. Thanks to Sam Razialruh for suggesting this feature. -- In DataSources.pooledDataSource( DataSource unpooledDataSource, Properties props ), switched from using keySet().iterator() to the propertyNames() Enumeration to properly capture keys set in the Properties object's defaults. Thanks to Jisakiel in SourceForge for calling attention to this issue. -- Modified DelegatorGenerator [in mchange-commons-java] to delegate reflectively at runtime via the main delegation interface (by default, and in c3p0's proxies), rather than via the runtime class, which may not be public. (Added a bit of API to DelegatorGenerator so that users can specify whether reflective delegation should be via the main delegation interface, some other expected superclass or interface, or the actual runtime class.) Many thanks to Kiran Kollipara for pointing out the risk of IllegalAccessExceptions under the previous implementation. c3p0-0.9.2-pre7 -- Added hooks [in mchange-commons-java] to com.mchange.v2.codegen.intc.DelegatorGenerator to permit reflective delegation of methods not declared by the main interface. Added some unproblematic JDBC4 methods to generated PreparedStatement proxies in order (hopefully) to workaround hibernate issues. (see https://hibernate.onjira.com/browse/HHH-7801 and https://hibernate.onjira.com/browse/HHH-7778 ) -- Added some extra logging (at level FINER [or DEBUG] to NewPooledConnection, in hopes that it will be helpful in tracking down Exceptions that occur during automatic cleanup of unclosed Statements and ResultSets. c3p0-0.9.2-pre6 -- Added some logic that continues to enforce sequential (i.e. nonsimultaneous) use of PooledConnections in Connection tests, without requiriing Threads to use NewPooledConnection's lock. Clients of NewPooledConnection should not hold its lock directly, to avoid potential deadlocks due to Connection eent handlers. [Many thanks to Jan Zuchhold for calling attention to this problem.] -- Added a DEBUG STACK TRACE at log level FINEST in BasicResourcePool for tracking the cause of resource exclusion. -- Added a README.md file for github. -- Updated documentation to include dataSourceName as a config parameter, and to describe its use in generating stable JMX identifers. -- Made dataSourceName a first-class config parameter, configurable in all the usual ways, to help support its use for stable JMX names. -- Included (excellent, very lightweight) patch by Bryan Varner [ https://github.com/bvarner ] that includes the property dataSourceName in the registered name of c3p0 JMX mbeans. As Varner writes, "This allows you to query mbeans by stable name patterns, allowing for reliable instrumentation via JMX between VM instances." Many thanks to Bryan Varner. -- Updated RELEASE_NOTES c3p0-0.9.2-pre5 -- Some fixes of issues with per-user config overrides, verified and updated docs with respect to per-user configs. -- Unsynchronized access to identityToken in the various identityTokenized beans, marking the property volatile instead. This should resolve an occasional deadlock. Many thanks to Phillip Henry, see https://sourceforge.net/tracker/?func=detail&atid=383690&aid=3552097&group_id=25357 -- Fixed a bug whereunder PoolBackedDataSources threw an Exception trying to bind per-user overrides that properly should be bound only to WrapperConnectionPoolDataSource (or to ComboPooledDataSource, which wraps that). Many thanks to Walter Marcelo Pedrozo Barboza for calling attention to this issue. -- Factored out VMID generation into mchange-commons-java. c3p0-0.9.2-pre4 -- Fixed broken version on Maven dependency to mchange-commons-java. Version was hardcoded, now uses version number that c3p0 was built against. c3p0-0.9.2-pre3 -- Added workaround for bug in Maven 2.2.1 that sometimes leads to corruption of deployed artifacts. See http://jira.codehaus.org/browse/MNG-4301 -- Eliminated bead RELEASE suffix from use in staging to Maven repository, which should fix managed dependency problems for Maven users. -- Required tests of PooledConnections to own the locks associated with those PooledConnections in order to prevent occasional deadlocks when PooledConnection.close() coincides with a Connection test. Many thanks to an anonymous SourceForge user for calling attention to this issue. c3p0-0.9.2-pre2 -- Added support for deployment to Maven central repository to build.xml, and noted this version's coordinates in the repository. -- Added a src directory to the distribution, containing jarred java sources (including codegenerated sources) intended for debuggers/IDEs. As a convenience, mchange-commons-java sources are included as well. -- Fixed issue where idle Connections being tested by the pool were not properly marked with the statement cache as "in-use". -- Updated the build file to make it easy to update versions and dates on source code headers. -- ResultSets are now automatically closed and their proxies dereferenced as soon as parent Statements are closed, rather than waiting for the parent Connection to close as we did before. Thanks to jo-hennig and soronthar for calling attention to this issue. -- Modified (in mchange commons library) ThreadPoolAsynchronousRunner to occasionally (stochastically) call Timer.purge() when maxAdministrativeTaskTime settings leads to frequent cancellations of TimerTasks. Thanks to Kevin Conaway, who observed memory issues from the piling up of canceled but unpurged TimerTasks. -- Modified (in mchange commons library) VersionUtils to be more tolerant of unusual version Strings. Thanks to martyhu for the suggestion. -- When a ProxyConnection is marked closed, we now fire a connectionClosed event even if an Exception occurred during cleanup, to be sure that proxies detach. We still fire a connectionErrorOccurred prior to connectionClosed, so that listeners (especially C3P0PooledConnectionPool) can invalidate the can't-be-cleaned-up PooledConnection. -- Modified GooGooStatementCache to call clearBatch on PreparedStatement checkin, so that stale batches from prior use of Statements are never visible to new users. Many thanks to David Carr for pointing out the problem and the fix. -- getWarnings and clearWarnings no longer set the txn_known_resolved flag to false. Thanks to Manuel Darveau for pointing out the unnecessary caution. -- Gave C3P0PooledConnectionPoolManager's timer a name. Thanks to Matt Kusnierz for the suggestion. -- Fixed an infinite loop in ComboPooledDataSource, which occurred following some Exceptions, which provoked calls to toString() to build the Exception message, which call itself provoked an Exception, ad infinitum. All potentially Exception-provoking attribute lookups are now excluded from toString(). Many thanks to Svante v. Erichsen for calling attention to this problem and suggesting a fix. -- Modified the build so that JDK 1.4 compatible versions of c3p0-0.9.2 can be generated easily. (c3p0-0.9.2 will be the last version of c3p0 to support JDK 1.4 builds.) -- Moved development onto github. See https://github.com/swaldman/c3p0, with a dependency against https://github.com/swaldman/mchange-commons-java c3p0-0.9.2-pre1 -- Rationalized management of the ConnectionEventListener that checks in PooledConnections on proxy Connection close(). Now added on check-out and removed on check-in, rather than being always present but temporarily removed during administrative tasks. -- Implemented asynchronous Statement destroyer, hopefully completing the task of making the statement cache robust to drivers that cannot deal with Statements being closed underneath Connections still in use (e.g. Oracle, JTDS). Note that this implementation requires at least one dedicated Thread for statement destruction (if we used the common Thread pool, there will be deadlocks as Statement close tasks await not-in-use Connections, while Connection-related tasks can't be completed because the Thread pool is saturated with Statement close tasks. Stats about the asynchronous Statement destroyer are available via the JMX MBean, prefixed statementDestroyer. Setting the new config parameter c3p0.statementCacheNumDeferredCloseThreads enables the fix. -- Resolved a potential race condition that could lead to pool freezes, especially when acquisitions occasionally fail and acquireIncrement is set to 1. [Many thanks to Brendan Dougherty for carefully describing this issue.] -- Added a guard to BasicResourcePool.doAcquire() to ensure that the pool has not been closed or broken before assimilating a task [Many thanks to Sean Rohead for tracking down this issue and suggesting the fix.] -- Made SCATTERED_ACQUIRE_TASK default to true. This provides much better overall performance for Connection acquisition from potentially unreliable sources -- Modifed to ensure that unresolved transaction settings apply to expired unreturned Connections. (see config params autoCommitOnClose and forceIgnoreUnresolvedTransactions) [Thanks to Matthew Lieder for calling attention to this issue.] -- Cleaned up Statement cache fix that ensures no statements are closed while their parent Connection is in use. By default, the fix is not enabled, because it's extra work that most databases don't need. [Most drivers support Statement close() while a parent Connection is in use, so the extra work is unnecessary.] -- Separated traditional build into two libraries, mchange-commons and c3p0. -- Modified GooGooStatementCache and C3P0PooledConnectionPool to ensure that 1) the Statement cache knows which Connections are currently in use by outside clients; and 2) the Statement cache refuses to cull Statements belonging to Connections in use. Theoretically, drivers should support asynchronous statement close. In practice, some drivers don't do so nicely, or block pending completion of other (potentially long) operations, leading to APPARENT DEADLOCKS. (Oracle users in particular have reported deadlocks in which all pool threads are blocked on Statement close tasks.) [Many, many thanks to Ovidiu Feodorov for a very detailed account of problems that occur under c3p0 when very long queries are executed under Oracle!] -- Defined a NullMLogger, and modified Log4jMLog to use that, instead of a broken log4j MLogger, if c3p0's logging library fails to acquire a non-null Log4j logger. Thanks to Oli Glimmer for calling attention to this issue. (Strange NPEs due to apparently null log4j loggers have been encountered before, and previous attempts to resolve apparently weren't adequate.) -- Fixed a problem whereby ThreadPoolAsynchronousRunner was not robust to Errors provoked during task execution. [Thanks to George Khoshy for reporting this issue.] -- Made VersionUtils more robust to cases where some components of the java.version system property are non-integral [Thanks to Dirk Weigenand for calling attention to this problem, and suggesting a solution!] c3p0-0.9.1.2 -- Fixed a variety of latent, hidden bugs discovered by "findbugs". Many thanks to Carsten Heyl for running this utility and reporting the issues. -- Added lastAcquisitionFailureDefaultUser to ComboPooledDataSource's TO_STRING_IGNORE_PROPS, as some moments' Exception doesn't belong in a DataSource's toString(), and as trying to find this when stringifying close()ed DataSources provoked an infinte recursion (as an Exception was triggered trying to get the last failure info, which tries to include the stringified DataSource in its message, again provoking an Exception, ad infinitum.) Many thanks to Santiago Aguiar for finding and diagnosing this problem. -- Added better documentation of the com.mchange.v2.c3p0.cfg.xml configuration property. [Thanks to Legolas Wood for calling attention to this shortcoming.] -- Calling getHoldability() to find the default Connection holdability provokes an Error on some DB2 drivers. Added a "careful" check which catches and works around this. [Thanks to Lari Hotari for finding the problem, and providing a solution!] -- Refactored NewPooledConnection to not call event multicaster methods while holding the NewPooledConnection's lock. Holding locks while firing events is an old-fashioned way of provoking deadlocks, and it turns out c3p0 was not immune. Whoops! Another embarrassing one. Many thanks to Rhythm Tyagi and Pappu Sharadavani for finding this deadlock! c3p0-0.9.1.1 -- Marked variable "logger" in Log4jMLogger. Rare null pointer exceptions apparently result from a stale value of the previously set variable. Did the same for Log4jMLogger, although no analoguous issue has thus far been reported. [Thanks to Noa Resare and Denis on sourceforge for calling attention to this issue.] -- Hid the attribute "properties" from access via JMX, since it often contains password information. I don't think properties is particularly useful via JMX, and this seems like a better solution than returning properties with a hidden/modified password property, since users might break things unintuitively by resetting a property to a value that, according to the mbean, was the original value. [Thanks to John Sumsion for calling attention to this issue.] -- Fixed bug whereby setting any positive unreturnedConnectionTimeout forced c3p0's default effectivePropertyCycle down to 1 second. [Many thanks to Luke Dang for tracking down this bug.] -- Fixed an embarrassing bug whereby c3p0 was reflectively testing for methods (setHoldability and setReadOnly) whose argument types are primitive int and boolean, by looking for Integer.class instead of int.class and Boolean.class instead of boolean.class. [Many thanks to John Kristian for tracking down this subtle, and embarrassing issue very precisely and suggesting the fix.] c3p0-0.9.1 -- Modified logging of uncleared SQLWarnings, so that warnings are emitted at INFO rather than WARNING, and via a dedicated logger [com.mchange.v2.c3p0.SQLWarnings], so that users can easily turn this behavior off. [Thanks to Oleksandr Alesinskyy for calling attention to the annoyingness of unconditionally logging all of this at WARNING.] c3p0-0.9.1-pre12a -- Fixed a NullPointerException in DoubleWeakHashMap that showed up thanks to the newly implemented canonicalization of Jdk14MLog instances. [Many thanks to Carlos Cajina for finding and reporting this bug.] c3p0-0.9.1-pre12 -- Modified Jdk14MLog to canonicalize named MLogger instances. In doing so, put the getLogger() method behind a synchronization barrier, which hopefully will resolve an odd visibility issue bug reported by a user (wherein the underlying jdk Logger appeared occasionally to be null in threads that might have initialized prior to the logger) [Thanks to Denis on Sourcefore for reporting this subtle and interesting issue.] -- Added a lastAcquisitionFailure property to PooledDataSource (and the JMX view thereof). Thanks to Troy Whittier for the suggestion, and the patch! -- SQL Warnings present at Connection acquisition, or uncleared upon Connection checkin are now logged (at WARNING level) and cleared prior to being made available as part of the pool. This is necessary to sustain the invariant that all pooled Connections are identical and interchangible; warnings are Connection state that must be managed and homogenized. [Thanks to Naxe on the hibernate forums for calling attention to this issue!] -- Resolved a rare NullPointerException which occurs when a Statement cache is closed beneath an active, checked out Connection. A client tries to prepare a Statement, but the closed Statement cache throws an NPE. Resolved this by having the closed Statement cache throw a ResourceClosedException, and having c3p0's proxy Statement recover by generating an uncached PreparedStatement. [Thanks to Sven / ford_perfect on sourceforge for finding and calling attention to this issue.] -- Added c3p0 version to C3P0RegistryManagerMBean [Thanks to Sven / ford_perfect on sourceforge for the suggestion.] c3p0-0.9.1-pre11 -- Documentation updates, and style-sheet fixes for FireFox. -- Despite the ugliness, added logic to prepend a VMID to identity tokens generated for c3p0 DataSources. See the docs (Appendix A, other configuration properties) for more information. Though there's little harm in the longer, uglier identityTokens, users who dislike them can turn them off using the property com.mchange.v2.c3p0.VMID. -- Wrote ScatteringAcquireTask, which represents a significant change to how c3p0's underlying resource pool deals with Connections acquisition failures. c3p0 is designed to retry Connection acquisition up to "c3p0.acquireRetryAttempts" times (30 by default) with a delay of "c3p0.acquireRetryDelay" milliseconds (1000 by default) between tries. Should no Connection be successfully acquired after acquireRetryAttempts, c3p0 gives up, logs an error, and frees clients waiting to check out a Connection with an Exception (declaring the pool permanently broken iff c3p0.breakOnAcquireFailure is set to true). Connection acquisition is performed asynchronously by c3p0's thread pool. Under the old implementation, when database Connections could not be acquired, a single task dispatched to the thread pool would hog a thread for the full length of the cycle -- 30 seconds by default -- spending most of that time sleeping between retries. Under the new implementation, each acquisition attempt is its own separate task, and if an acquire attempt fails, a timer is used to schedule a retry adter acquireRetryDelay without hogging any thread. I think the new implementation is unambiguously superior to the old, as it permits clients to use smaller thread pools (c3p0.numHelperThreads) and diminishes the likelihood of apparent thread pool deadlocks. However, it is too significant a change to introduce this late in the "mature" c3p0-0.9.1 series, so the old implementation is enabled by default until the c3p0-0.9.2 development cycle begins. TO USE THE NEW IMPLEMENTATION WITH c3p0-0.9.1, set... com.mchange.v2.resourcepool.experimental.useScatteredAcquireTask=true in a c3p0.properties file or as a system property. Users are strongly encouraged to set this property. You'll see better resource utilization, and I'll get to hear issue reports if I've screwed anything up in the implementation. -- Modified BasicResourcePool so that checkin (and removal) of resources is always synchronous if the pool is marked broken. [Otherwise the check-ins to a closed or broken pool may fail, as they try to use an already close()ed asynchronous task runner.] -- Modified BasicResourcePool.AcquireTask so that an interrupt always forces the whole task to end, not just a single acquisition attempt. -- Exposed numThreadsAwaitingCheckout in PooledDataSource interface and its associated MBean. [Thanks to John Sumsion for suggesting this property.] -- Prevented password from being exposed via DynamicPooledDataSourceManagerMBean. [Thanks to John Sumsion for calling attention to this oversight!] -- Fixed an error whereby DataSources.pooledDataSource( ... ) methods failed to properly set configuration properties defined on PoolBackedDataSource [e.g. numHelperThreads]. Many thanks to John Sumsion for noticing the problem and sending the fix! -- Fixed AbstractConnectionCustomizer to implement (with no-op) methods the current definition of the ConnectionCustomizer interface. (Failed to update after modifying an early version of this interface.) -- Modified NewPooledConnection to only collect stack trace information on close() when we are debugging at FINEST or DEBUG (log4j) level. Previously, stack trace information was collected anytime a c3p0 PooledConnection was close()ed. This was unnecessary, although the performance cost was probably small to negligible, since PooledConnections are typically reused many times before they are close()ed. Stack trace information is still captured when PooledConnections are destroyed due to an error, rather than an ordinary call to close(). -- Hid the getLastXXXFailure(user, password) from the operations list of DynamicPooledDataSourceManagerMBean. The stack traces of failures are visible via the sampleLastXXXFailureStackTrace(); there's no need to expose the Throwbales as well via JMX. -- Added convenience methods getNumPooledDataSources() and getNumPoolsAllDataSources() to C3P0Registry and the related MBean. [Thanks to lukeda on hibernate forums for calling attention to the need for a pool count, since DataSources can wrap multiple pools associated with different authentications.] -- Eliminated the "trial Connection acquisition" added to c3p0-0.9.1-pre10 when PooledDataSources construct the pool with their default authentification information. Effectively we trust that the default auntentification is good, while we distrust client-specified (or JMX-queried) username/password combinations, and perform the extra check. This is a compromise, as users who frequently create and destroy DataSources don't like the extra overhead of the trial Connection acquisition, but we really want to avoid the initialization of bad pools when users misspecify authentification information. We've also prevented mere queries of pool status from triggering the initialization of a non-default-authentification pool. Only calls to getConnection(user, password) will provoke the initialization of a non-default-auth pool. Querying a non-default pool -- e.g. getNumBusyConnections( "steve", "test" ) -- will throw an Exception if no Conections have ever been requested for ("steve", "test") rather than initializing a new pool. [Thanks to Jiji Sasidharan for calling attention to this issue.] -- Finally rationalized C3P0Registry's Object retention policy. C3P0Registry retains references to all C3P0 DataSources, to provide a central point of client access for users, and to ensure that multiple JNDI lookups within a single VM result in the same DataSource instance. This is both intuitive, and avoids multiplying Threads and pools. In previous versions of c3p0, hard references were retained indefinitely. Closed DataSources hold no non-memory resources, and are small Objects, but in unusual scenarios wherein very many c3p0 DataSources are created and destroyed within the lifetime of a single VM, this amounts to a memory leak. C3P0Registry now retains hard references to DataSources so long as they have not been close()ed (or DataSources.destroy()ed). When they have been close()ed, only weak references to c3p0 DataSources persist, and they are eligible for garbage collection. [Thanks to Jeremy Grodberg for calling attention to this as a real-world issue.] -- Removed some of the new pool stat params which distractingly appear in ComboPooledDataSource's toString() method (and c3p0 pools' config dump). c3p0-0.9.1-pre10 -- Exposed statement pool stats via PooledDataSource interface and MBean. Added accessors to the statement cache, pool, pool manager, and AbstractPoolBackedDataSource. -- Fixed a bug whereby multiple near-simultaneous Connection requests failed to provoke sufficient pool growth/Connection acquisition. This is a bug reintroduced in c3p0-0.9.1-pre4, and is a duplicate of an early issue, resolved under the old pool size management scheme. c3p0 must (and does) keep track not only of its current size and pending growth, but also the number of potentially unserved recent Connection requests. c3p0-0.9.1-pre4 thru c3p0-0.9.1-pre9 failed to make use of the incoming request count when deciding whether and how much to grow the pool. Many thanks to John Kristian for calling attention to this subtle issue. -- Exposed information about Connection test failures (failure count of each type of test, stack trace of last failure and last failure of each type) via the PooledDataSource interface and its assiciated MBean. -- Fixed a rare situation where a Connection test on check-out could be performed by a Thread holding the pool's lock, if an initial attempt to checkout a Connection failed and a second checkout attempt is initiated internally. The recursive checkout is now performed without the pool's lock. -- Established a consisent policy re logging of Connection test failures. They are now logged at FINE level (DEBUG under log4j). Previously tests on checkin and checkout were logged at FINE, but idle tests were logged at INFO. Is it worth letting this be configurable, as some users may prefer to see test failures under normal operation? -- Modified C3P0PooledConnectionPoolManager to perform a trial Connection acquisition before trying to establish a pool, as pools established on bad database or authentification information churn indefinitely trying to acquire minPoolSize Connections, clogging up the thread pool and sometimes leading to "APPARENT DEADLOCKS" if users touch a pool with bad authentification information. -- Defined UnifiedConnectionTester (and AbstractConnectionTester) so that ConnectionTesters can provide any Exception associated with a failure, which will show up as the "root cause" of the Exception eventually thrown to signal the failure. -- Added logging at WARNING level when a Connection tester reports the database is invalid, triggering a reset of the Connection pool. c3p0-0.9.1-pre9 -- Updated the documentation. It is now fully current. -- Changed the name of the jboss configuration mbean from com.mchange.v2.c3p0.mbean.C3P0PooledDataSource to com.mchange.v2.c3p0.jboss.C3P0PooledDataSource, in order to distinguish the jboss configuration stuff from the normal management beans, which really are quite different. The old com.mchange.v2.c3p0.mbean.C3P0PooledDataSource still exists, so that existing users don't see anything break, but only the new version will be updated to support new parameters. -- Added a means by which users can suppress JMX MBean registration if they wish. Setting the property com.mchange.v2.c3p0.management.ManagementCoordinator to com.mchange.v2.c3p0.management.NullManagementCoordinator will prevent mbean registration. (Advanced users can also use this to install their own implementations of the ManagementCoordinator interface, though I doubt many people will find this useful.) -- Fixed infinitely loop in ComboPooledDataSource.setFactoryClassLocation( ... ) [introduced with the reorganization of ComboPooledDataSource to inherit from AbstractPoolBackedDataSource (?)] -- Added some code to warn on common spelling errors of c3p0.properties and c3p0-config.xml (Users have frequently mistaken the digit 0 for the letter O in c3p0.) -- Wrote a DynamicMBean for PooledDataSources. It seems to work, covers both ComboPooledDataSource and "wrapping" PoolBackedDataSources, and should cover new config parameters and accessors automatically. -- More refinements to connection test logic. We test proxy Connections when there's a statement cache and a test query (to save time, since the test query is likely cached), we test physical connections if we'll need to do the slow, default test (statement caching doesn't help), or if there is no statement cache. -- Removed the stub servlet I'd previously added. Although it jdk1.5+, the JMX approach is a better one for monitoring and modifying c3p0 pools at runtime, and I'm going to focus on that for now. (If there's a lot of clamor for it, I'll add back and flesh out the servlet. It just doesn't seem like a great use of my time for now.) -- Modified build to create a separate jdk1.3 compatable jar by stripping source of lines beginning with "assert". I want to start using assertions, but will keep them to recognizable, strippable one-liners. -- Modified DriverManagerDataSource to handle its driverClass parameter in a less fragile way. Rather than attempting to load the driverClass on property set, DriverManagerDataSource now lazily tries to load the class upon its first call to getConnection() after the property is initialized or updated. c3p0-0.9.1-pre8 -- Fixed bug whereby jdbcUrl and driverClass were not initialized properly if set in config files rather than in code. [Thanks to Felipe Dominguez for calling attention to this problem!] -- Changed AbstractPoolBackedDataSource from a non-public class in com.mchange.v2.c3p0 to a public class in com.mchange.v2.c3p0.impl to workaround fragilities associated with sun bug id #6342411, wherein reflective invocation of public methods on a non-public class fail, even when involed via a public base-class. -- Fixed NullPointerException (introduced on -pre7) on initializing with a named config. -- Continuing along the same lines, modified C3P0Registry and C3P0ManagementCoordinator to unregister (both from C3P0Registry and associated MBeans on DataSource close. When all PooledDataSources are unregistered, the C3P0RegistryManager MBean unregisters as well. -- Modified ActiveManagementCoordinator to check for, and unregister, the C3P0Registry mbean prior to registration, to prevent conflicts on undeploy/redepoloy cycle. [Thanks to Ben Groeneveld for calling attention to this problem, and suggesting the fix.] -- Modified C3P0PooledConnectionPool to perform Connection tests on the raw physical Connection rather than the proxy Connection, when possible (i.e. when we're using a C3P0 PooledConnection implementation that we know how to get underneath of). This is better because 1) it's slightly faster; 2) it's significantly faster on failure, as C3P0 PooledConnections test Connections after a failure with statusOnException(), leading to an unnecessary double-check; and 3) authors of custom ConnectionTesters can use vendor-specific API to test Connections if they wish. c3p0-0.9.1-pre7 -- Defined the ConnectionCustomizer interface as a hook through which clients can "set up" newly acquired or checked out connections (and clean up prior to check-in or destruction). Added config param connectionCustomizerClassName. -- Formerly unused config parameter propertyCycle now controls how frequently c3p0 checks timestamps against expiration parameters (maxIdleTime, maxIdleTimeExcessConnections, maxConnectionAge, unreturnedConnectionTimeout) -- Added config parameters unreturnedConnectionTimeout and debugUnreturnedConnectionStackTraces, reluctantly but by popular demand. If unreturnedConnectionTimeout is set, Connections will be automatically destroyed and removed from the pool if not returned in the given number of seconds. If debugUnreturnedConnectionStackTraces is also set, stack traces will be captured on check-out of any Connection, and the stack traces that were unreturned and cleaned up by the pool will be logged. Any clean-up of an unreturned Connection is logged at INFO level, in hopes of annoying people into cleaning up their code and close()-ing their Connections reliably. -- Added config parameter maxIdleTimeExcessConnections. Connections in excess of the pool's minimum size will be expired out if they remain idle for longer than maxIdleTimeExcessConnections. [Thanks to Navin M. and Ben Groeneveld for the suggestion.] -- Added configuration parameter maxConnectionAge to limit the absolute age of Connections (age in seconds from acquisition, rather than in seconds form last check-in). -- Put more status accessors in ThreadPoolAsynchronousRunner and exposed thread pool state via JMX (PooledDataSourceManagerMBean). -- Preliminary support for management via mbeans/jmx under jdk1.5+ is implemented. (These mbeans are distinct from the mbean designed for configuring c3p0 under jboss, and are in the package com.mchange.c3p0.management.) Currently, pool statistics are instrumented, as well as pool reset operations, but viewing and modifying the pool configuration parameters is not supported. (I'll write a dynamic mbean to capture this stuff; there are too many config properties I'm already updating by hand in too many places. Later.) [Thanks to Ben Groeneveld for the suggestion, including some nice sample code!] -- Added configuration parameter maxAdministrativeTaskTime, which forces interrupt() to be called on pool administrative tasks (Connection acquisition, destruction and testing; prepared statement destruction) if these tasks seem to hang. This is one strategy for dealing with database that hang and lead to deadlock messages and eventually large memory footprints. It's useful only if the hanging operations respond to interrupt()s, not thread-monitor related deadlocks (which hopefully don't ever happen). c3p0 should recover from any Exceptions provoked by the interrupt() calls. (Hopefully improvements to GooGooStatementCache have rendered this parameter largely unnecessary by resolving the most common source of deadlocks.) -- Major revision to GooGooStatementCache that may eliminate most APPARENT DEADLOCK messages. c3p0-0.9.0 introduced a complicated implementation of closeAll(), in order to ensure that Statement and Connection close did not happen simultaneously. Upon review, there was a significant bug in the implementation, and even when corrected, the strategy is itself prone to deadlocks should the ThreadPool become saturated with destroy tasks, which block awaiting statement remove tasks. Rewrote closeAll() as a simple synchronous method, rather than simulating synchrony with wait()/notifyAll(), but with care not to hold the StatementCache's lock during Statement.close() calls. There is a slight loss of asynchrony, as Statement.close() methods are executed sequentially rather than simultaneously, but as a practical matter, since the sequential destruction occurs asynchronously in the thread pool and is invisible to clients, both client-observed and over-all performance should not suffer. (It may even be improved, as the 0.9.0.x strategy was complicated and had some overhead.) Note: This revision should also eliminate occasional ConcurrentModificationExceptions associated with the Statement cache. -- Changed asynchronous tasks implemented as anonymous inner classes to named inner classes, so that users reviewing active and pending tasks (usually in trying to make sense of an APPARENT DEADLOCK) have a better idea of what's going on. -- Major revision to GooGooStatementCache that may eliminate most APPARENT DEADLOCK messages. c3p0-0.9.0 introduced a complicated implementation of closeAll(), in order to ensure that Statement and Connection close did not happen simultaneously. Upon review, there was a significant bug in the implementation, and even when corrected, the strategy is itself prone to deadlocks should the ThreadPool become saturated with destroy tasks, which block awaiting statement remove tasks. Rewrote closeAll() as a simple synchronous method, rather than simulating synchrony with wait()/notifyAll(), but with care not to hold the StatementCache's lock during Statement.close() calls. There is a slight loss of asynchrony, as Statement.close() methods are executed sequentially rather than simultaneously, but as a practical matter, since the sequential destruction occurs asynchronously in the thread pool and is invisible to clients, both client-observed and over-all performance should not suffer. (It may even be improved, as the 0.9.0.x strategy was complicated and had some overhead.) -- Users still occasionally report seeing "APPARENT DEADLOCK" messages from ThreadPoolAsynchronousRunner. Previously, most reports had to do with cached PreparedStatements that hang when closed. Previous fixes (in 0.9.0) seemed to resolve these problems. Most new reports have to do with Connection acquisition or Connection close() tasks hanging indefinitely, with statement cacheing not necessarily involved. It's unclear whether these reports stem from a c3p0 bug, or rare situations in which various JDBC driver hangs hang c3p0. (If the condition is temporary, c3p0 recovers after the "APPARENT DEADLOCK" warning. In any case, ThreadPoolAsynchronousRunner has been modified to provide much better debug information, particularly in jdk1.5 environments, where hung Thread stack traces are dumped. -- Modified the build file and refactored C3P0Config / C3P0ConfigUtils / C3P0ConfigXmlUtils to make sure that c3p0 still runs under jdk1.3, even though it only builds under jdk 1.5. JMX support is 1.5 only, and XML config depends on the availability of standard XML extensions under jdk 1.3. (This is going to get harder, as I hope to start using assertions. For the moment, assertions are commented out. I think I'll have ant filter away the assertions for 1.3 builds and leave them in otherwise, based on a build property. -- Significantly reorganized (hopefully simplified) of C3P0Registry and ComboPooledDataSource. Much of the complication of all this is supporting the most annoying, least used, but nevertheless very important feature of supporting JNDI lookups across JVM boundaries via Serialization or JNDI References. -- Reorganized ComboPooledDataSource to inherit from PoolBackedDataSource. In doing so, changed setConnectionPoolDataSource() of PoolBackedDataSource to throw a PropertyVetoException. (It is a "constrained property" now.) The very, very few users who call this method directly may have to update their code to handle the potential Exception. This change does not affect compatability for clients that use ComboPooledDataSource or who create PoolBackedDataSources via the c3p0's factories (e.g. DataSources). -- Fixed bug whereby config parameter breakAfterAcquireFailure did not take effect at the ResourcePool level. -- Fixed bug whereby initialPoolSize parameter failed to take effect at the ResourcePool level. -- Fixed a bug whereby Connection tests on checkout held the pool's lock, preventing other activity during the Connection test. [Thanks to John Sumsion for calling attention to this subtle problem.] -- ThreadPoolAsynchronousRunner has seen some minor efficiency improvements (a task that calls interrupt() long-running tasks on post-deadlock blocked, replaced threads no longer runs when there are no post deadlock blocked, replaced threads). -- Previous versions used a Stringified identityHashCode() as a unique ID for various C3P0 objects. This was not correct (and bit at least one user in practice), as identityHashCode()s are not guaranteed unique, and in practice are not on 64-bit VMs. c3p0 now checks identityHashCodes to make sure they are not reused, and if seen before appends a count to keep unique IDs unique. [Many thanks to Prishan Makandurage for calling attention to this issue.] -- Fixed fact that statusOnException() in NewPooledConnection() ignored preferredTestQuery parameter, always using the very slow default connection test rather than the user-defined test. [Thanks to Andrea Luciano for calling attention to this issue.] -- C3P0PooledConnection (part of the "traditionalReflectiveProxies" codebase that's largely been superceded, but that is still nominally supported) held a static reference to a ClassLoader, in some cases preventing the ClassLoader from being garbage collected (for example when webapp contexts, with context specific Classloaders are undeployed by some app servers). This was entirely unnecessary, as the cached reference was used exactly once in the lifecycle of the class. The reference to the ClassLoader is no longer stored. [Many thanks to Michael Fortin for very specifically tracking down this subtle problem!] -- Added logic to log individual acquisition failures at INFO level if acquireRetryAttempts <= 0. if num_acq_attempts <= 0, we try to acquire forever, so the end-of-batch log message below will never be triggered if there is a persistent problem so in this case, it's better flag a higher-than-debug-level message for each failed attempt. [Thanks to Eric Crahen for calling attention to this issue.] c3p0-0.9.1-pre6 -- Wrote a stub of a status-monitoring servlet. Not yet documented, or even usefully functional, but hopefully will be soon. -- Updated documentation to include new config file format, including named and per-user config. Docs could still use some work, but the functionality is now described. -- For consistency, the parameters user and password are now configurable via config files and System properties. -- Modified DefaultC3P0ConfigFinder to properly give greater precedence to System properties than to XML-defined unspecified user, default config values. -- Added WARNING logging of create SQL and original database Exception when creation of an automaticTestTable fails. [Thanks to Alexander Grivnin.] -- Added logic so that the Exception assoicated with the last failed acquisition attempt in a round of attempts is logged along with the failure if the acquisition attempts. [Thanks to Barthel Steckemetz and Patrick Eger for calling attention to this issue.] -- Fixed a problem whereby modifying the config of a ComboPooledDataSource programmatically, while in use, causes previously checked-out Connections to be close()ed underneath the user. Changing configs midstream still causes a complete resetting of the pool (because the pool holds most config params as immutable to avoid having to synchronized for every config param read), but old Connections from superceded pools will remain valid until they are rechecked into the pool. [Thanks to hhu for noticing this problem!] -- Fixed a resource leak whereby Connections which could not be reset after client-initiated close() were properly "excluded" from future inclusion in the pool, but never checked back into the pool to be destroyed. (Excluded resources are simply marked for destruction rather than reassimilation on checkin.) [Many thanks to Levi Purvis for tracking this down!] c3p0-0.9.1-pre5a -- "test-classpath" was erroneously specified in build.xml to include some extra jar files, which rendered undetectable (to my tests) the fact that com.mchange.v1.lang.BooleanUtils was not jarred up into c3p0-0.9.1-pre5.jar as it needed to be. Very, very embarrrassing. [Thanks to Goksel Uyulmaz for calling attention to this gaffe.] c3p0-0.9.1-pre5 -- reorganized synchronization of getConnection() in DriverManagerDataSource, so that a lock-up in one Connection acquisition attempt does not prevent other threads from accessing the DataSource. [Thanks to Fabian Gonzalez for calling attention to this occasional deadlock.] c3p0-0.9.1-pre4 -- added overrideDefaultUser and overrideDefaultPassword parameters, and a pooledDataSource( ) factory method which specifies override authentification info, regardless of the user and password properties set on the DataSource. -- Reimplemented resource acquisition in BasicResourcePool so that each Connection acquisition is a separate asynchronous task, to avoid tying up the pool with very long, multiple acquisition tasks. Ended up being a total rewrite of pool size management. Pools should be much more conservative in acquiring new Connections. They won't grow to maxPoolSize as easily as before. This is a big change. We'll see how it holds up as people beat the crap out of it. c3p0-0.9.1-pre3 -- Added some extra logging of resource destruction, to help debug cases where the resources are removed from the pool, but appear not to have been properly cleaned up. -- Finished implementation of new C3P0Config, added constructor methods to various DataSource implementations that accept a configName parameter for named configurations, and modified the DataSources class to use the new configuration approach instead of PoolConfig wherever possible. c3p0-0.9.1-pre2 -- Continued implementation of new C3P0Config, including XML parsing and setting of default values. Still have to test XML config, and implement named and per-user configs. -- Changed policy of BasicResourcePool to keep accidentally overacquired resources so long as the pool is kept below maxPoolSize, rather than immediately discarding Connections beyond the number we intended to acquire. -- Fixed two issues whereby checking in resources to closed pools (both Connection and Statement pools) provoked Exceptions. Check-ins should succeed, even to close()ed pools, with resources silently destroyed if the pools ae closed. [Thanks to Chris Kessel for finding both of these issues.] -- Modified to a one-statement-cache-per-pool model, rather than a global-statement-cache-for-all-pools, consistent with the general philosophy that config parameters are on a per-auth-pool basis. -- Fixed a deadlock which could occur if a pool is closed at the same time as one of its Connections is closed. One thread gets the pool's lock, then tries to get a PooledConnections lock to close it. An ordinary client closes a Connection, which acquires the PooledConnection's lock, and then tries to check back in to the pool, requiring the pool's lock. Broke the deadlock by making the destruction of resources on pool close asynchronous, by a Thread without the resource pool's lock.. [Many thanks to Roger Westerlund for sending a full thread-stack dump capturing this deadlock!] -- Completed transformation to one C3P0PooledConnectionPoolManager per PoolBackedDataSource model. c3p0-0.9.1-pre1 [This is a half-assed internal release... it compiles and works, but mostly it's just a checkpoint as c3p0 undergoes significant transformations.] -- Deprecated PoolConfig, and began implementation of new C3P0Config approach to configuration. -- Partial transformation of C3P0PooledConnectionPoolManager from shared-manager for several DataSources model to simple one-pool-per-DataSource model enabled by canonicalization of DataSources. c3p0-0.9.0.4 -- In a subtle but major modification of BasicResourcePool, changed checkin/checkout behavior from FIFO to LIFO to increase the likelihood that unnecessary Connections pooled at peak times idle long enough to expire. [Many thanks to Vlad Ilyushchenko and hontvari on sourceforge for noticing this important issue and suggesting the fix.] c3p0-0.9.0.3 -- Added code to mbean C3P0PooledDataSource to automatically create JNDI subcontexts if a JNDI name is specified for which the full path has not been created (analogous to mkdir -p in UNIX). [Thanks to David D. Kilzer for noticing the issue, and for submitting the fix!] -- Added logic to GooGooStatementCache to ensure that multiple threads do not try to close the same PreparedStatement, in order to try to resolve longstanding PreparedStatement.close() freeze issues. [Thanks to cardgames on sourceforge for noticing that the freezes seem to occur when several threads are trying to close() just one statement!] -- Added some checks in DriverManagerDataSource (as well as WrapperConnectionPoolDataSource) so that a mismatch between JDBC URL and driver does not lead to null Connection references and downstrem NullPointerExceptions. [Thanks to Richard Maher for calling attention to this issue.] -- Undid some unnecessary synchronization in WrapperConnectionPoolDataSource, which would cause deadlocks when the acquisition of a Connection from the underlying driver froze for some Thread. (Other threads would then block trying to access the WrapperConnectionPoolDataSource.) [Thanks to Fabian Gonzales for calling attention to this issue, and for providing a VM thread stack dump to help chase it down!] -- modified BasicMultiPropertiesConfig to never attempt to read the resource "/", representing (in this case) System properties, as a stream, which under some classloaders caused ClassCastExceptions. [Thanks to Joost Schouten for calling attention to this issue.] -- fixed initial check of the readOnly and typeMap properties of Connections, so that users don't see disconcerting Exceptions at debug log levels if their drivers don't support these parameters. -- Added jar attributes Extension-Name, Specification-Vendor, Specification-Version, Implementation-Vendor-Id, Implementation-Vendor, and Implementation-Version [per request of Pascal Grange]. -- Added some extra debugging information for peculiar situation where an IdentityTokenized is constructed and registered with C3P0Registry, but coalesces to a different Object. This should never happen, as freshly constructed IdentityTokenizeds should have String versions of their identity hashcodes as tokens, and upon their registration, no copies should yet have been created and registered. [Thanks to Jose Rodriguez for noting this issue.] c3p0-0.9.0.2 -- added debug-level logging of connection tests and results -- tightened up means by which the readOnly and typeMap properties of Connections are reset, so that users don't see disconcerting Exceptions at debug log levels if their drivers don't support these parameters. -- fixed problem in BasicResourcePool that left the immediately-close-checked-out-connections option in the close() method ineffective, meaning Connections checked-out from a pool would leak unless clients remembered to check them into pool for destruction. -- fixed bug wherein connection-testing on checking occured in a thread holding the pool's lock, leading to pool hangs or deadlocks if a connection hangs. [Thanks to Tobias Jenkner for calling attention to this problem!] c3p0-0.9.0.1 -- modify BasicPropertiesConfig to not throw class cast Exceptions in the rare case that a Properties object (presumably System properties rather than a file derived props Object) contains (via the Map/Hastable API) non-String keys or values. [Thanks to Prima Upot for calling attention to this issue.] -- fixed a build issue where some classes required for code generation were not necessarily compiled prior to the code generation step, causing builds to fail. [Thanks to James Neville for calling attention to this issue.] c3p0-0.9.0 -- under some circumstances, the current list of ThreadPoolAsynchronousRunner's deadlock detector seems to hold onto a lot of memory... presumably this is when long pending task lists build up for some reason... nevertheless, we now dereference the "current" list in between deadlocker detector invocations. The "last" list has to be retained between invocations, but the "current" list need not be. [Thanks to Venkatesh Seetharamaiah for calling attention to this issue, and for documenting the apparent source of object retention.] -- modified log4j and jdk14logging MLog implementations to test for library classes upon classload (MLog class only tests for the presence of the mlog implementations, which doesn't notice if their dependant classes aren't there -- dependent classes must test for the presence of the libraries.) -- Modified GooGooStatementCache to warn as INFO (and with a descriptive message in debug) of multple PreparedStatement preparation. [Thanks to mxnmatch on hibernate's forum for calling attention to this issue.] -- Modified BasicResourcePool to not warn on expected InterruptExceptions that occur if clients are waiting for a Connection when the pool is closed. [Thanks to Blunted on hibernate's forum for calling attention to this issue.] c3p0-0.9.0-pre6 -- Modified thread pool's strategy for dealing with deadlocks to prevent OutOfMemoryErrors from sudden spawning of multiple threads to clear backlogged tasks. [Thanks to Greg Whalin for calling attention to this problem.] -- Fixed bugs in debug reporting of nested Exceptions/Warnings when converting or rethrowing SQLExceptions [thanks to an anonymous sourceforge poster for finding this] -- modified BasicResourcePool to shorten the period during which the pool's lock is held during resource acquisition -- maxIdleTime is generally enforced every (maxIdleTime / 8) seconds. Added logic to ensure that even for very long maxIdleTimes, the longest maxIdleTime will ever go unenforced is 15 minutes. -- Very tentative initial support in build for JUnit tests -- Fixed documentation typos and added sample config for Tomcat 5.5. [Thanks to David Newcomb for finding the typos and to Carl F. Hall for the sample config!] -- ProxyConnections were not properly resetting readOnly, holdability, catalog, and typeMap properties on Connection close. Fixed. [Thanks to Andy (bjorkmann?) for calling attention to this bug.] -- Added a complicated workaround to issues that may occur when a Connection and its child statements simultaneously try to close. GooGooStatementCache's closeAll(Connection c) method now wait()s for all Statements to close prior to returning, avoiding such issues (Oracle deadlock, mysql NullPointerException), though dramatically complicating the code. Grrr. Theoretically, drivers should be robust to the simultaneous closing of Statements and Connections, but they're not, so my code gets to be more complicated. [Thanks to Juan Perez, Daniel Edberg, and Damien Evans for calling attention to this issue.] c3p0-0.9.0-pre5 -- Proxy classes were overaggressively invalidating themselves in response to a signalled Connection error. This problem was very similar to the problem fixed in 0.8.5-pre9, except for rather than the PooledConnection too quickly closing its inner Connection, the proxies too quickly detached themselves from the pooled Connection, considering themselves broken, after a Connection error event. Users expect to be able to work with their Connections even after c3p0 has in its conservatism decided they no are no longer worthy of a place in the pool. [Thanks to "Geoff Fortytwo" for finding and helping to track down this issue.] -- Fixed issue that prevented user-defined ConnectionTesters from being used. c3p0-0.9.0-pre4 -- Fixed NullPointerException on double-close of proxy Statements. [Thanks to Stephen Waud for finding this bug and tracking it down.] -- Modified C3P0PooledConnectionPool to generate a more informative Exception (one that includes the stack trace of the initial problem) when a Connection test fails. [Thanks to novotny from the hibernate forums for calling attention to this issue.] ` -- PooledDataSources now set SQLState 08001 on SQLExceptions resulting from a determination by the pool that the database is down or unavailable. [Thanks to ml2709 on the hibernate forums for calling attention to this issue.] -- Modified ThreadPoolAsynchronousRunner to enforce its max task time even on one-off "emergency threads" used to flush the pool of tasks after an apparent deadlock. Hopefully this will help to eliminate the OutOfMemoryErrors that users occasionally see if some Database operation starts to fail by blocking indefinitely, and is attempted many many times. As long as these operations are susceptable to interrupt(), this should resolve the problem. (If tasks block in a way that is immune to interrupt(), there is little c3p0 can do to recover the Threads and prevent the number of blocked Threads from growing until memory runs out.) [Thanks to Jean-Christophe Rousseau and Arup Vidyerthy for calling attention to this issue.] -- Wrapped System.getProperties() calls in try / catch blocks that catch and log the SecurityExceptions, and ignore System properties if access to them is forbidden. c3p0.properties configuration should work fine in security-controlled apps, but you won't be able to configure c3p0 using "java -Dc3p0.xxxx=yyy ..." Since most users use c3p0.properties for configuration, I don't think this will be a major problem. In the future, I may be able to work around the restriction by having ask only for c3p0-specific System properties, rather than calling the unrestricted System.getProperties() method. [Thanks to zambak on SourceForge for calling attention to this issue.] c3p0-0.9.0-pre3 -- Modified generated proxy classes to properly report the type of the closed Object if used after call to close(). -- Fixed a really embarrassing oversight, wherein cached PreparedStatements were being physically close()ed prior to their return to the cache! Tests on psql failed to reveal this, because psql-7.4 Statement.close() does nothing to invalidate the Statement! [Many thanks to tbayboy on hibernate's forum for discovering this issue, and to fassev, also on hibernate's forum, for correctly deducing the cause!] -- Fixed an embarrassing oversight where operations of proxy Statements and ResultSets failed to mark transactions as potentially dirty, leading to the possibility that Connections with unresolved transactional work could be checked into the pool. -- Modified c3p0 Statements to no longer permit calls to getConnection() after Statement close, and to null out the backreference to the parent Connection. [Thanks to Edward Bridges for pointing out the issue.] -- NewPooledConnection threw a NullPointerException on close() of a ResultSet whose creating Statement had already been closed. Fixed. [Thanks to Edward Bridges for pointing out the problem.] -- Modified PoolConfig to trim() read-in c3p0.properties to avoid NumberFormatExceptions if there is extra spacing in the file. [Thanks to johnchan for calling attention to this issue.] c3p0-0.9.0-pre2 -- Documentation updates and improvements -- Integrated configurable wrapper logging library, so that c3p0 can log to log4j or jdk14logging. c3p0-0.9.0-pre1 -- First pass at documentation of JBoss integration. -- Better one-per-JVM canonicalization (IdentityTokenized, IdentityTokenResolvable, C3P0Registry) -- First implementation of MBean for JBoss compatability -- Fixed JNDI ref-based DataSources c3p0-0.8.5.1 -- Fixed a really embarrassing bug that made Statement pooling worse than useless where users have set maxStatements but not maxStatementsPerConnection. maxStatementsPerConnection -- that is, 0 -- was being used in place of maxStatements on Statement cache initialization. [Thanks to Gwendal Tanguy for not only, calling attention to this issue, but tracking down the precise location of the bug!] c3p0-0.8.5 -- Documentation updates and improvements -- Fixed an issue where failures on reset() of a pooled Connection caused a Connection error to be signalled, without updating the status of the PooledConnection to indicate that it is broken. Thanks to Henry Le for calling attention to this issue. c3p0-0.8.5-pre9 -- Modified c3p0's behavior on detecting an apparently broken Connection. Previously c3p0 would very aggressively close any Connections that, after an Exception, failed to pass a Connection test. This sometimes surprised and confused users, when Conections they expected to remain open were closed from underneath them. Under normal circumstances, a Connection which has failed its Connection test is broken anyway, so closing it does no harm. But under some circumstances, a Connection may fail its Connection test, but still be partly functional from the application's point of view. So, now c3p0 simply marks Connections that fail their Connection test following an Exception as broken, and excludes them from future re-entry into the pool, but leaves those Connections open for users to continue working with them prior to their explicit close() of the Connection. [Thanks to Julian Legeny for calling attention to this issue.] -- Modified c3p0's logging behavior to be a little bit less annoying. Rather than frequently printing duplicate stack traces to be sure root cause Exceptions are logged as well as converted, rethrown Exceptions, c3p0 now checks the Java version, and uses the initCause() method to log the root cause in versions 1.4 and above. Also, some Exceptions that were expected and thrown without information as to the cause now use the initCause() method to provide this in JDK 1.4 and above. [Thanks to Ruslan Gainutdinov, Anthiny Pereira, Carsten ????, and Eric Hsieh for calling attention to these issues.] -- Fixed bug whereby proxy wrappers were sometimes placed around null return values from native Objects, particularly Statement's getResultSets() method. [Thanks to Ruslan Gainutdinov for calling attention to this issue.] -- Fixed bug in NewProxyConnection whereby setTransactionIsolation was called even if the Connections' isolation level had not been changed from its default. [Thanks to Levent Aksu for reporting this bug.] c3p0-0.8.5-pre8 -- Added C3P0ProxyStatement and rawStatementOperations for accessing vendor-specific Statement API. -- Fixed bug whereby recently added properties could not be configured properly via a PoolConfig Object passed to the DataSources factory method. [Thanks to Julian Legeny for finding this bug.] -- Undid new behavior whereby c3p0 warns when it detects that a transaction has not been comitted or rolled-back prior to close and must be automatically rolled-back. Because c3p0 autorollsback conservatively, whenever it is possible that there may be any transactional resources held by the Connection being checked in, users who make read-only queries, then close without commit or rollback, saw the warning, and became annoyed. Warning when it's "right" is hard, and would involve paying attention to the substance of user-queries, as well as the transaction's isolation level. In the future, when c3p0 offers better control over logging, we'll make the warning optional. Note that this release only undoes the warning -- the new logic that detects potential transactional work and only rollsback when there has been some remains. [Thanks to David Graham for calling attention to this issue.] -- Synchronized StatementCacheKey.find( ... ) method. Subclasses of StatementCacheKey have always explicitly relied upon this method being synchronized in the parent class, but somehow it was not... [Thanks to Manfred Hutt for reporting this bug.] -- Modified both PooledConnection implementations to reset the transaction isolation level on PooledConnection.reset() -- Finalized PooledDataSource api for pool stats and resets. c3p0-0.8.5-pre7a -- Fixed some bugs in new Proxy classes relating to close(), methods, especially NullPointerExceptions on duplicate close() operations. -- Fixed some misleading documentation re: testConnectionOnCheckin and automaticTestTable vs. preferredTestQuery -- Changed wording of warning message on purge of idle-test-failing resource to no longer suggest that some user action is required. [Thanks to Krishna Kuchibhotla for calling attention to this issue.] -- Modified GooGooStatementCache so that its close() is synchronous, since when the Statement cache is closed, it's asynchronous runner has often been closed already underneath it. (Actually changed as of c3p0-0.8.5-pre7, but forgot to log it.) c3p0-0.8.5-pre7 -- Added flag (in both new and tradional reflective proxies) to prevent automatic rollbacks on Connection close()es immediately post- commit(), rollback(), or setAutoCommit(). -- DatabaseMetaData now properly returns proxy rather than naked raw Connection. [Thanks to jhoeller on the hibernate forums] -- In response to an apparent BEA WebLogic specific problem with DriverManager.getConnection( ... ), DriverManagerDataSource now caches its driver and uses Driver.connect( ... ) rather than DriverManager.getConnection() when acquiring Connections. Thanks to Lars Torunski for calling attention to this issue. -- Fixed some missing synchroniztion that really should be provided for accessors and mutators of DataSource bean properties. -- Added config parameter automaticTestTable, which takes the name of a table that c3p0 will create and use as the basis for Connection tests. It's easier to use than preferred test query, because you don't have to ensure the existance of any tables in the schema prior to using a Pooled data source. -- Fixed idiotic oversight whereby Connections didn't get their transaction status resolved and reset on check-in... c3p0-0.8.5-pre6 -- Modified resource pools to only conditionally support async ResourcePoolEvent generation. Since c3p0 doesn't use ResourcePoolEvents, we can do without the superfluous CarefulRunnableQueue, and its associated Thread, which was serving as an event queue. -- Fixed bug where asynchronous refurbishment (testing) of resources would be attempted even on check-in to a closed pool, whose async threads had terminated. -- c3p0 now supports the following new configuraion parameters: preferredTestQuery, testConnectionOnCheckin, checkoutTimeout, and maxStatementsPerConnection. preferredTestQuery should allow c3p0 to test Connections (whether on checkout, checkin, or after a specified idle time) much more efficiently than with it's default test [a call to getTables(...) on the Connection's DatabaseMetaData.]. checkoutTimeout allows clients to break out of a getConnection() call after a a specified time period, rather than waiting (potentially indefinitely) for a new Connection to be acquired from the database, or a checked-out Connection to be rechecked in. testConnectionOnCheckin should be self-explanatory. maxStatementsPerConnections allows users to specify how many statements to cache on a per-connection base instead of, or in addition to, the global limit maxStatements. -- Fixed various bugs relating to the referenceMaker and getReference() method of ComboPooledDataSource. -- Added TestUtils class to util package (modified from an old C3P0TestUtils class now removed from the test directory), which now contains facilities for establishing the identity of the physical Connection beneath a proxy, so that tests can check to see when they are seeing the same physical Connections recycled. [Thanks to Julian Legeny for calling attention to this issue.] -- Modified code generators so that inner objects of all NewProxy classes go to null on object close(). Closed proxies should be hopelessly broken. -- Added missing parameter "usesTraditionalReflectiveProxies" to ComboPooledDataSource -- Fixed bug whereby CarefulRunnableQueue threads linger indefinitely, even though their close() method has been called. [Thanks to muirwa on the hibernate forums for calling attention to this issue.] c3p0-0.8.5-pre5 -- added utility class for Oracle users who wish to access vendor specific Connection API relating to BLOBs and CLOBs. [Thanks to Dave Smith for calling attention to this issue.] -- modified ThreadPoolAsynchronousRunner to provide more information should an "apparent deadlock" occur, and fixed that class' recovery strategy from such an event. [Thanks to Damien Evans for calling attention to this issue.] c3p0-0.8.5-pre4 -- added config parameter usesTraditionalReflectiveProxies, which defaults to false, and stitched in the 'new' codegenerated, non-reflective proxy implementation for the default case. c3p0-0.8.5-pre3 -- Added new config parameters breakAfterAcquireFailure, acquireRetryAttempts, and acquireRetryDelay to ComboPoolBackedDataSource (forget to modify this class when I added the params earlier.) -- Added description of raw connection operations to docs. c3p0-0.8.5-pre2 -- Defined AuthMaskedProperties object, and used this to prevent usernames and passwords from being dumped to logs (a security issue). [Thanks to Zac Jacobson for calling attention to this issue.] -- Made BasicResourcePool's refurbishment of checked-in resources asynchronous, and used this to add a test of the resource on check-in. But since the extra test may slow stuff down substantially, I've disabled it pending a testConnectionsOnCheckin config parameter. -- Fixed NullPointerException in C3P0ImplUtils.findAuth(Object o) which occurred when the Object at issue had write-only properties. [Thanks to mrfekson for calling attention to this issue.] -- Added acquireRetryAttempts, acquireRetryDelay, and breakAfterAcquireFailure as configurable properties. Supporting breakAfterAcquireFailure == false required substantial changes to BasicResourcePool. [Thanks to Zac Jacobson for suggesting the behavior for breakAfterAcquireFailure == false.] -- Added poolOwnerIdentityToken property to PoolBackedDataSource, which becomes part of the state of C3P0PooledConectionPoolManager, to avoid possibility that multiple, identically configured pools that users create separately and consider distinct would be closed if any one of them were closed. This parameter ensures that for each user-created DataSource, there will be a distinct C3P0PooledConectionPoolManager. Multiple copies, as often arise via deserialization and/or dereferencing JNDI DataSources, will still share a single pool and configuration. -- Added reset methods, hard and soft, to PooledDataSource and its implementations. Also added some extra aggregate pool statistics methods. [Thanks to Travis Reeder for suggesting the hardReset() behavior.] -- Fixed bug that PoolBackedDataSource always provided statistics for the default authentication pool, even when alternate usernames and passwords were provided. c3p0-0.8.5-pre1 -- Defined the C3P0ProxyConnection interface, and modified both reflective and unreflective proxy Connection code to implement it. The interface provides a method through which advanced users can work with the raw, unproxied database Connection. This was motivated by some Oracle-specific API that could not be passed through the generic Connections returned by c3p0 pools. Thanks to Dave Smith for calling attention to this issue. -- Fixed a NullPointerException that resulted when users called DriverManagerDataSource's getConnection( username, password ) with either username or password as null. Users will now see the SQLException provided by their database for bad authentication, which should make the problem more obvious. c3p0-0.8.4.5 -- Modified all variants of StatementCacheKey, as well as C3P0PooledConnection (proxy Statements) to support jdbc3.0 API for autogenerated keys and ResultSet holdability. All jdbc 3.0 API is now supported. c3p0-0.8.4.2 -- Fixed bug in which proxy Statements and ResultSets returned their naked, unproxied parents from their getConnection() / getStatement() methods. Thanks to Christian Josefsson for noticing this! -- Added check to ensure that ResourcePools are not broken prior to posting asynchronous events. It'd be better to factor the (as yet unutilized async event stuff into a subclass to simplify BasicResourcePool). -- Fixed documentation typo that said default numHelperThreads was "false"... now it's correctly set to "3". -- Added extra System.err information to instrument the causes of broken resource pools. -- finalize() method of BasicResourcePool checks to be sure user has not already closed the pool before closing, to avoid spurious multiple close warnings. Thanks to Gavin King. c3p0-0.8.4.1 -- Added (hopefully not too annoying) dump of DataSource configuration on pool initialization to assist user debugging. -- Added methods to force destroy all resources used by a PooledDataSource, even if other DataSource instances are sharing those resources. This is intended primarily for applications that wish to discard the ClassLoader that loaded c3p0, regardless of whatever's currently going on. -- Turned off annoying trace messages when a C3P0PooledConnection closes. -- Fixed issue in statement cache whereby statements that fail to check-in properly (that throw an exception in "clearParameters") cause an exception in removeStatement, because removeStatement sees a statement that appears neither to be checked-out, nor in the deathmarch for checked-in statements. Resolved by re-adding truculent statement to the checkedOut set, and then destroying using removeStatement's codepath for removing and (force-)destroying checked-out statements. Thanks to Zach Scott for calling attention to this issue. c3p0-0.8.4 -- Updated and HTML-ized documentation, updated READMEs. c3p0-0.8.4-test5 -- Includes, but does not yet use, cleaner, nonreflective reimplementation of C3P0PooledConnection and all of the JDBC proxy wrappers. (c3p0-0.8.4 will stick with the old, tested implementation, c3p0-0.8.5 will replace.) -- Removed temporary debug wrapper around acquired Connections added in c3p0-0.8.4-test4-3. c3p0-0.8.4-test4-3 -- Fixed race condition in BasicResourcePool close(), whereby pooled resources were to be destroyed by an asynchronous thread that itself was shut down by the close() method, so the resource closures did not necessarily occur. Pooled resources are now destroyed synchronously in BasicResourcePool.close() -- Fixed erroneous call to C3P0PooledConnection reset() even when the PooledConnection is known to be broken. -- Added temporary debug wrapper that dumps a stack trace on physical Connection close() to help Adrian track down a stubborn issue. c3p0-0.8.4-test4 -- Made sure PooledConnection's that are known to be broken are not reset() when the ProxyConnection that noticed the break cleans itself up. -- Fixed a problem in C3P0PooledConnection's ProxyConnectionInvocationHandler when Connection-invalidating exceptions occurred inside the factored-out doSilentClose() method rather than in the invoke() method. This could lead to broken PooledConnections not being noticed and expunged from the pool prior to recheck-out. -- Ensured stack-trace of any Connection-invalidating Exceptions are logged. (Previously only the messages were logged.) -- Access to ProxyConnections is now synchronized to avoid a possible race condition where a Connection could close while another method was in progress. -- Cleaned up C3P0PooledConnection a bit, got rid of no longer used reflective code, modified to use new SQL interface filter classes. -- Reorganized bean generation stuff to sit under com.mchange.v2.codegen -- Added com.mchange.v2.sql.filter package, and code generation stuff so that abstract filter classes that implement JDBC interfaces can be easily regenerated from current versions. (This is preparation for JDK 1.4.x build support.) c3p0-0.8.4-test3 -- Reorganized C3P0PooledConnection and C3P0PooledConnectionPool so that PooledConnections only fire connectionErrorOccurred events on errors that signal the Connection is invalid. (Previously we fired the event in all cases, then tested the validity of the connection in the event handler.) -- Fixed a bug where SQLExceptions that do not signal invalid Connections (such as an exception on transaction commit under optimistic concurrency) caused Connections to be closed, but still returned to the pool, leaving the pool corrupt. [Thanks to Adrian Petru Dimulescu for discovering and reporting this subtle problem!] c3p0-0.8.4-test2 -- Backed off a binary incompatible change to DataSources API. Users interested in statistics about running DataSources will need to cast the result of DataSources.pooledDataSource() to a com.mchange.v2.c3p0.PooledDataSource object. Other users should be able to use DataSources without recompilinbg libraries that depend upon it. -- Defined com.mchange.v2.c3p0.ComboPooledDataSource, a single, directly-instantiable JavaBean-style DataSource backed by a c3p0 pool, which makes integration with various app servers easier (e.g. works with Tomcat), and which may provide a more straightforward API for users than DataSources and PoolConfig. c3p0-0.8.4-test1 -- Switched various classes from using RoundRobinAsynchronousRunner to a new ThreadPoolAsynchronousRunner. -- Defined PoolingDataSource interface, which permits clients to access statistics about the state of underlying pools, and made C3P0 pool-backed DataSources implement that interface. -- fixed a subtle bug with respect to ownership of shared resources in which finalize() methods for discarded DataSources could cause helper threads and other resources to be cleaned up prematurely, while they are still in use by other DataSources. -- major reorganization of code generation for DataSources and the resulting objects. -- reorganization of Serializable and Referenceable code of DataSources for JNDI Binding -- made PoolConfig defaults (which are set by system properties, a c3p0.properties file, or else hardcoded defaults) apply to DataSources that are directly instantiated rather than created via the com.mchange.v2.c3p0.DataSources factory class. -- organized scattered stuff into a self-contained, distributable build directly, and divided source and binary distributions -- relicensed library; now available under LGPL. -- THERE ARE SOME MAJOR REORGANIZATIONS IN THIS RELEASE. ANY HELP IN TESTING AND FEEDBACK WOULD BE APPRECIATED! THANKS! c3p0-0.8.3.1 -- take greater care to abort if a helper thread wakes from wait() inside of a broken resource pool -- log more debug information if a pool unexpectedly breaks c3p0-0.8.3 -- resolved a deadlock arising from ConnectionEventSupport objects calling event listener methods while holding the ConnectionEventSupport's lock. (Thanks to an anonymous Sourceforge bug submitter for tracking this down.) -- added two configuration parameters to modify how c3p0 deals with potentially unresolved transactions on transaction close -- autoCommitOnClose and forceIgnoreUnresolvedTransactions. c3p0's default behavior is as it always was (and as I think it nearly always should be) -- by default we roll back any uncommitted work on close. See PoolConfig class for complete documentation. -- fixed stupid build error that made unzipping c3p0 archives messy since c3p0-0.8.2. (SORRY!) c3p0-0.8.3-pre-travis -- fixed problem with c3p0 trying endlessly to connect to a database that is down or not present. c3p0 now tries thirty time, once per second, then gives up. if there's demand, I'll make the delay and number of attempts user configurable. Thanks to Alfonso da Silva for calling attention to this problem. -- modified RoundRobinAsynchronousRunner to die more gracefully if, somehow, one of its CarefulAsynchronousRunners somehow dies. Thanks to Travis Reeder for calling attention to this issue. -- modified ResourcePools to allow resources to be tested periodically and asynchronously while they are idle in the pool. -- added to a new configuration property to PoolConfig and related classes, idleConnectionTestPeriod, which if set to a greater-than-zero value will cause c3p0 to periodically test idle, pooled connection, and remove them from the pool if they are broken. Thanks to Travis Reeder for calling attention to this issue. -- removed SQLState 08S01 from the set of SQL states presumed to mean all connections in the pool have become invalid. Apparently MySQL uses this SQLState to indicate the timing out of idle, individual connections. Thanks to Travis Reeder for calling attention to this issue. -- many (!) bug-fixes, small tweaks and improvements. -- temporarily sprinkled some debugging output prefixed "c3p0-TRAVIS" to try to resolve some issues for Travis Reeder c3p0-0.8.2 -- Addressed a rare problem that ocurred when application servers or other external code calls interrupt() on c3p0 helper threads. Thanks to Travis Reeder for reporting this issue! The endless cascade of ArrayIndexOutOfBoundsException that would occasionallY result has been fixed, and c3p0 helper threads now ignore interupts, which should almost completely prevent such interrupts() from leaving c3p0 pools in a corrupt state. [In the very, very unlikely event that multiple, well-timed interrupts() cause a pool to diagnose itself broken, c3p0 will start throwing clear exceptions to indicate that -- there shouldn't be any deadlock or any subtle kind of corruption.] -- Deprecated PoolBackedDataSourceFactory and DriverManagerDataSourceFactory in favor of the newer DataSources class. -- Updated example code and documentation. -- Moved constants from DataSources to PoolConfig where they belong! c3p0-0.8.2-pre10 -- Removed use of properties default mechanism in setting up JDBC properties for DriverManagerDataSource, as some drivers use get() rather than getProperties(), and the Properties.get() method ignores defaults. [Thanks go to Michael Jakl <mj@int-x.org> for both finding and fixing this problem!!!] -- Fixed subtle problem whereby the introspective constructor of C3P0PooledConnectionPoolManager would inadvertently check out an extra pooled connection, by treating the getPooledConnection() as a simple property read and invoking it. [Thanks go to Michael Jakl <mj@int-x.org> for both finding and fixing this bug!!!] c3p0-0.8.2-pre9 -- Finished DataSources static factory for, um, DataSources. -- Added PoolConfig class to encapsulate all configuration information from factories -- Set up PoolConfig to pay attention to (in order): 1) explicit, user-defined parameters 2) parameters defined as System properties 3) parameters defined in a Properties file resource, at resource pasth /c3p0.properties in PoolConfig's classloader 4) Hardcoded defaults from the C3P0Defaults class -- Defined a new pool configuration property, "testConnectionOnCheckout". If set to true (it defaults to false), each pooled Connection will be verified at checkout time, before being supplied to clients. THIS SLOWS CONNECTION CHECKOUT DRAMATICALLY (by an order of magnitude on my machine), but some folks may want it. The expensive, verified Connections are still faster to acquire than brand new ones. -- If a Connection experiences an SQLException with a defined SQL State of 08001, 08007, or 08S01, the entire database is considered to have been shutdown, and the pool whose connection experienced the problem is reset -- i.e. all existing Connections are discarded, and new Connections are acquired for the pool. (Thanks! to Gavin King for suggesting the SQL State approach to detecting disconnects.) -- ConnectionTester interface and its default implementation were modified to support reporting DATABASE_IS_INVALID (rather than simply testing a disconnected, individual Connection). c3p0-0.8.2-pre8 -- Fixed some really stupid bugs from pre-7, in particular the static factory methods of the DataSources class were not declared static. Oops. c3p0-0.8.2-pre7 -- Major reorganization of data source implementations. These are now generated from XML templates, because it was becoming difficult to keep multiple versions of multiple types of datasources in sync with one another -- a new factory / utility class has been added, com.mchange.v2.c3p0.DataSources. Soon the older factories (DriverManagerDataSourceFactory and PoolBackedDataSourceFactory) will be deprecated in favor of this. -- Began adding support for wrapper DataSources that lazily bind to an unpooled DataSource specified via JNDI. (Current wrappers require an actual instance, not a mere reference in order to construct a PoolBacked or ConnectionPoolDataSource). c3p0-0.8.2-pre6 -- Fixed bug that led to ConcurrentModificationException when Connection.close() iterates through and closes its unclosed Statements. -- Fixed bug that caused uncached Statements to sometimes be closed twice, as they were not properly removed from the set of Connection-associated statements on user- initiated Statement.close(), and would thus be closed again on Connection.close(). -- Reorganized classes to clean up top-level com.mchange.v2.c3p0 package. The gory innards of c3p0 now live in an impl package. -- Reorganized DataSources so that there are "Base" versions suitable for DBMS-specific subclassing. c3p0-0.8.2-pre5 -- DataSources looked up by JNDI now "coalesce" -- i.e., if two separate calls look-up the same JNDI bound DataSource, they will both see the same DataSource instance in the local VM. This is especially important for PoolBackedDataSources, as they own "helper threads" that help to manage the pool. Now each logical DataSource shares the same pool of helper threads, regardless of whether it is looked up once and cached, or looked up multiple times and at multiple places by an application. -- Number of helper-threads managing a PoolBackedDataSource is now user-configurable c3p0-0.8.2-pre4 -- Fixed BAD memory leak -- cachedStatements were being retained on close. This brings a performance improvement to the StatementCache as well. -- Set-up StatementCacheKey to coalesce, such that its equals method can look like {return (this == o);}. Unfortunately, I did not see the kind of performance increase I'd anticipated from this... in fact, whatever performance changes I did see were pretty negligable. Performed some other, mostly useless, optimizations to the process of acquiring StatementCacheKeys. (I can't decide... I've got 3 usuable, broadly similar versions of StatementCacheKey now.) -- Fixed bugs having to do with when to create and the daemon status of Timers -- Appropriately synchronized access to PoolBackedDataSource. (This should permit me to pull back on synchronization / marking of volatile in some dependent classes, as access to these is now controlled via PoolBackedDataSource.) -- Made instantion of C3P0PooledConnectionPoolManager by WrapperPoolBackedDataSource "lazy", so that Timer / Async task threads are only started up when a Connection is actually requested from a DataSource. This is useful especially for the instance residing in the JNDI server VM, whose purpose is likely only to serve as an instance to be looked up over the network. There's no reason why it should keep several stalled Threads open. -- Fixed DefaultConnectionTester, whose logic was bass-ackwards. c3p0-0.8.2-pre3 -- Factory method for StatementCacheKeys now "coalesce" equivalent instances to conserve memory and to enable a fast (this == o) test to usually work in equals methods. [Value test remains for when identity test fails... maybe later I'll be more comfortable with a 1 instance per value guarantee, and remove the rest of the test. As the constructor is private, the factory method coalesces, and the class is not Serializable, an identity test should suffice. But I'm paranoid.] -- All asynchronous tasks are now distributed to 3 helper threads per DataSource rather than queuing on just one. (Culing of expired Connections is still managed by a single java.util.Timer... I don't think this will be a problem.) c3p0-0.8.2-pre2 -- Total rewite of Statement cache!