基于java的开发源码-数据库连接池 C3P0.src.zip

/* * Distributed as part of c3p0 v.0.9.2-pre3 * * Copyright (C) 2012 Machinery For Change, Inc. * * Author: Steve Waldman <swaldman@mchange.com> * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1, as * published by the Free Software Foundation. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this software; see the file LICENSE. If not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. */ package com.mchange.v2.resourcepool; import java.util.*; import com.mchange.v2.async.*; import com.mchange.v2.log.*; import com.mchange.v2.lang.ThreadUtils; import com.mchange.v2.util.ResourceClosedException; class BasicResourcePool implements ResourcePool { private final static MLogger logger = MLog.getLogger( BasicResourcePool.class ); final static int AUTO_CULL_FREQUENCY_DIVISOR = 4; final static int AUTO_MAX_CULL_FREQUENCY = (15 * 60 * 1000); //15 mins final static int AUTO_MIN_CULL_FREQUENCY = (1 * 1000); //15 mins //XXX: temporary -- for selecting between AcquireTask types // remove soon, and use only ScatteredAcquireTask, // presuming no problems appear final static String USE_SCATTERED_ACQUIRE_TASK_KEY = "com.mchange.v2.resourcepool.experimental.useScatteredAcquireTask"; final static boolean USE_SCATTERED_ACQUIRE_TASK; static { String checkScattered = com.mchange.v2.cfg.MultiPropertiesConfig.readVmConfig().getProperty(USE_SCATTERED_ACQUIRE_TASK_KEY); if (checkScattered != null && checkScattered.trim().toLowerCase().equals("false")) { USE_SCATTERED_ACQUIRE_TASK = false; if ( logger.isLoggable( MLevel.INFO ) ) logger.info(BasicResourcePool.class.getName() + " using traditional, Thread-blocking AcquireTask. Yuk. Why?"); } else USE_SCATTERED_ACQUIRE_TASK = true; } // end temporary switch between acquire task types //MT: unchanged post c'tor final Manager mgr; final int start; final int min; final int max; final int inc; final int num_acq_attempts; final int acq_attempt_delay; final long check_idle_resources_delay; //milliseconds final long max_resource_age; //milliseconds final long max_idle_time; //milliseconds final long excess_max_idle_time; //milliseconds final long destroy_unreturned_resc_time; //milliseconds final long expiration_enforcement_delay; //milliseconds final boolean break_on_acquisition_failure; final boolean debug_store_checkout_exceptions; final long pool_start_time = System.currentTimeMillis(); //MT: not-reassigned, thread-safe, and independent final BasicResourcePoolFactory factory; final AsynchronousRunner taskRunner; final RunnableQueue asyncEventQueue; final ResourcePoolEventSupport rpes; //MT: protected by this' lock Timer cullAndIdleRefurbishTimer; TimerTask cullTask; TimerTask idleRefurbishTask; HashSet acquireWaiters = new HashSet(); HashSet otherWaiters = new HashSet(); int pending_acquires; int pending_removes; int target_pool_size; /* keys are all valid, managed resources, value is a PunchCard */ HashMap managed = new HashMap(); /* all valid, managed resources currently available for checkout */ LinkedList unused = new LinkedList(); /* resources which have been invalidated somehow, but which are */ /* still checked out and in use. */ HashSet excluded = new HashSet(); Map formerResources = new WeakHashMap(); Set idleCheckResources = new HashSet(); boolean force_kill_acquires = false; boolean broken = false; // long total_acquired = 0; long failed_checkins = 0; long failed_checkouts = 0; long failed_idle_tests = 0; Throwable lastCheckinFailure = null; Throwable lastCheckoutFailure = null; Throwable lastIdleTestFailure = null; Throwable lastResourceTestFailure = null; Throwable lastAcquisitionFailiure = null; //DEBUG only! Object exampleResource; public long getStartTime() { return pool_start_time; } public long getUpTime() { return System.currentTimeMillis() - pool_start_time; } public synchronized long getNumFailedCheckins() { return failed_checkins; } public synchronized long getNumFailedCheckouts() { return failed_checkouts; } public synchronized long getNumFailedIdleTests() { return failed_idle_tests; } public synchronized Throwable getLastCheckinFailure() { return lastCheckinFailure; } //must be called from a pre-existing sync'ed block private void setLastCheckinFailure(Throwable t) { assert ( Thread.holdsLock(this)); this.lastCheckinFailure = t; this.lastResourceTestFailure = t; } public synchronized Throwable getLastCheckoutFailure() { return lastCheckoutFailure; } //must be called from a pre-existing sync'ed block private void setLastCheckoutFailure(Throwable t) { assert ( Thread.holdsLock(this)); this.lastCheckoutFailure = t; this.lastResourceTestFailure = t; } public synchronized Throwable getLastIdleCheckFailure() { return lastIdleTestFailure; } //must be called from a pre-existing sync'ed block private void setLastIdleCheckFailure(Throwable t) { assert ( Thread.holdsLock(this)); this.lastIdleTestFailure = t; this.lastResourceTestFailure = t; } public synchronized Throwable getLastResourceTestFailure() { return lastResourceTestFailure; } public synchronized Throwable getLastAcquisitionFailure() { return lastAcquisitionFailiure; } // ought not be called while holding this' lock private synchronized void setLastAcquisitionFailure( Throwable t ) { this.lastAcquisitionFailiure = t; } public synchronized int getNumCheckoutWaiters() { return acquireWaiters.size(); } public synchronized int getNumPendingAcquireTasks() { return pending_acquires; } public synchronized int getNumPendingRemoveTasks() { return pending_removes; } public synchronized int getNumThreadsWaitingForResources() { return acquireWaiters.size(); } public synchronized String[] getThreadNamesWaitingForResources() { int len = acquireWaiters.size(); String[] out = new String[len]; int i = 0; for (Iterator ii = acquireWaiters.iterator(); ii.hasNext(); ) out[i++] = ((Thread) ii.next()).getName(); Arrays.sort( out ); return out; } public synchronized int getNumThreadsWaitingForAdministrativeTasks() { return otherWaiters.size(); } public synchronized String[] getThreadNamesWaitingForAdministrativeTasks() { int len = otherWaiters.size(); String[] out = new String[len]; int i = 0; for (Iterator ii = otherWaiters.iterator(); ii.hasNext(); ) out[i++] = ((Thread) ii.next()).getName(); Arrays.sort( out ); return out; } private void addToFormerResources( Object resc ) { formerResources.put( resc, null ); } private boolean isFormerResource( Object resc ) { return formerResources.keySet().contains( resc ); } /** * @param factory may be null */ public BasicResourcePool(Manager mgr, int start, int min,