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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set et sw=2 ts=2: */
/***************************************************************************
* connectionpool.cc
*
* Wed Dec 16 12:20:44 CET 2009
* Copyright 2009 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of Pracro.
*
* Pracro is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Pracro 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Pracro; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "connectionpool.h"
ConnectionPool::ConnectionPool()
{
}
void ConnectionPool::addDatabase(Database *db)
{
mutex.lock();
passivedbs.push_back(db);
semaphore.post();
mutex.unlock();
}
static inline bool contains(std::list<Database *> list, Database *db)
{
std::list<Database*>::iterator i = list.begin();
while(i != list.end()) {
if(*i == db) return true;
i++;
}
return false;
}
void ConnectionPool::removeDatabase(Database *db)
{
mutex.lock();
if(contains(passivedbs, db)) {
semaphore.post();
passivedbs.remove(db);
}
mutex.unlock();
}
bool ConnectionPool::testFree(Database *db)
{
bool testfree = false;
mutex.lock();
testfree = contains(passivedbs, db);
mutex.unlock();
return testfree;
}
int ConnectionPool::numFreeDatabases()
{
int num;
mutex.lock();
num = passivedbs.size();
mutex.unlock();
return num;
}
#include <stdio.h>
Database *ConnectionPool::borrowDatabase()
{
Database *db = NULL;
semaphore.wait();
mutex.lock();
db = passivedbs.front();
passivedbs.remove(db);
activedbs.push_back(db);
mutex.unlock();
return db;
}
void ConnectionPool::returnDatabase(Database *db)
{
mutex.lock();
if(contains(activedbs, db)) {
activedbs.remove(db);
passivedbs.push_back(db);
semaphore.post();
}
mutex.unlock();
}
AutoBorrower::AutoBorrower(ConnectionPool &p)
: pool(p)
{
_db = pool.borrowDatabase();
}
AutoBorrower::~AutoBorrower()
{
pool.returnDatabase(_db);
}
Database *AutoBorrower::db()
{
return _db;
}
#ifdef TEST_CONNECTIONPOOL
//deps: mutex.cc semaphore.cc
//cflags:
//libs: -lpthread
#include <test.h>
#include <unistd.h>
#include <pthread.h>
static void* thread_run(void *data)
{
ConnectionPool *pool = (ConnectionPool*)data;
Database *db1 = pool->borrowDatabase();
Database *db2 = pool->borrowDatabase();
Database *db3 = pool->borrowDatabase();
Database *db4 = pool->borrowDatabase();
usleep(100);
pool->returnDatabase(db1);
pool->returnDatabase(db2);
pool->returnDatabase(db3);
pool->returnDatabase(db4);
return NULL;
}
TEST_BEGIN;
ConnectionPool pool;
Database *db1 = (Database*)1;
Database *db2 = (Database*)2;
Database *db3 = (Database*)3;
Database *db4 = (Database*)4;
pool.addDatabase(db1);
pool.addDatabase(db2);
pool.addDatabase(db3);
pool.addDatabase(db4);
TEST_TRUE(pool.testFree(db1), "Testing if db1 is free.");
TEST_TRUE(pool.testFree(db2), "Testing if db2 is free.");
TEST_TRUE(pool.testFree(db3), "Testing if db3 is free.");
TEST_TRUE(pool.testFree(db4), "Testing if db4 is free.");
TEST_EQUAL(pool.numFreeDatabases(), 4, "Testing number of free databases.");
Database *b_db1 = pool.borrowDatabase();
TEST_FALSE(pool.testFree(b_db1), "Testing if borrowed db is free.");
Database *b_db2 = pool.borrowDatabase();
TEST_NOTEQUAL(b_db1, b_db2, "Testing if borrowed db is unique.");
pool.returnDatabase(b_db1);
TEST_TRUE(pool.testFree(b_db1), "Testing if returned db is free.");
pool.returnDatabase(b_db2);
TEST_EQUAL(pool.numFreeDatabases(), 4, "Testing number of free databases.");
pthread_attr_t attr;
pthread_t tid;
pthread_attr_init(&attr);
pthread_create(&tid, &attr, thread_run, &pool);
while(pool.numFreeDatabases() > 0) { usleep(10); }
Database *b_db3 = pool.borrowDatabase();
TEST_FALSE(pool.testFree(b_db3), "Testing if returned db is free (semaphore test).");
pool.returnDatabase(db3);
pthread_join(tid, NULL);
pthread_attr_destroy(&attr);
TEST_EQUAL(pool.numFreeDatabases(), 4, "Testing if all database are now available again");
{
TEST_EQUAL(pool.numFreeDatabases(), 4, "Testing if autoborrower has not yet borrowed a db.");
AutoBorrower b(pool);
TEST_EQUAL(pool.numFreeDatabases(), 3, "Testing if autoborrower has borrowed a db.");
TEST_FALSE(pool.testFree(b.db()), "Testing if the autoborrowed db is actually taken.");
}
TEST_EQUAL(pool.numFreeDatabases(), 4, "Testing if autoborrower has returned the db.");
TEST_END;
#endif/*TEST_CONNECTIONPOOL*/
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