From f74d220ba0723b38faeef5aeca39cd627dc3340d Mon Sep 17 00:00:00 2001 From: deva Date: Thu, 17 Dec 2009 12:45:20 +0000 Subject: Added connection pool class. Using semaphores (also added) --- server/src/connectionpool.cc | 215 +++++++++++++++++++++++++++++++++++++++++++ server/src/connectionpool.h | 70 ++++++++++++++ server/src/semaphore.cc | 47 ++++++++++ server/src/semaphore.h | 44 +++++++++ 4 files changed, 376 insertions(+) create mode 100644 server/src/connectionpool.cc create mode 100644 server/src/connectionpool.h create mode 100644 server/src/semaphore.cc create mode 100644 server/src/semaphore.h diff --git a/server/src/connectionpool.cc b/server/src/connectionpool.cc new file mode 100644 index 0000000..09dd5d1 --- /dev/null +++ b/server/src/connectionpool.cc @@ -0,0 +1,215 @@ +/* -*- 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 list, Database *db) +{ + std::list::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 +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 +#include +#include + +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*/ diff --git a/server/src/connectionpool.h b/server/src/connectionpool.h new file mode 100644 index 0000000..548d76a --- /dev/null +++ b/server/src/connectionpool.h @@ -0,0 +1,70 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set et sw=2 ts=2: */ +/*************************************************************************** + * connectionpool.h + * + * 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. + */ +#ifndef __PRACRO_CONNECTIONPOOL_H__ +#define __PRACRO_CONNECTIONPOOL_H__ + +#include + +#include "mutex.h" +#include "semaphore.h" + +class Database; + +class ConnectionPool { +public: + ConnectionPool(); + + void addDatabase(Database *db); + void removeDatabase(Database *db); + + bool testFree(Database *db); + int numFreeDatabases(); + + Database *borrowDatabase(); + void returnDatabase(Database *db); + +private: + Semaphore semaphore; + Mutex mutex; + std::list activedbs; + std::list passivedbs; +}; + +class AutoBorrower { +public: + AutoBorrower(ConnectionPool &pool); + ~AutoBorrower(); + + Database *db(); + +private: + ConnectionPool &pool; + Database *_db; +}; + +#endif/*__PRACRO_CONNECTIONPOOL_H__*/ diff --git a/server/src/semaphore.cc b/server/src/semaphore.cc new file mode 100644 index 0000000..e5f1f31 --- /dev/null +++ b/server/src/semaphore.cc @@ -0,0 +1,47 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * semaphore.cc + * + * Sat Oct 8 17:44:13 CEST 2005 + * Copyright 2005 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 "semaphore.h" + +Semaphore::Semaphore() +{ + sem_init(&semaphore, 0, 0); +} + +Semaphore::~Semaphore() +{ + sem_destroy(&semaphore); +} + +void Semaphore::post() +{ + sem_post(&semaphore); +} + +void Semaphore::wait() +{ + sem_wait(&semaphore); +} diff --git a/server/src/semaphore.h b/server/src/semaphore.h new file mode 100644 index 0000000..72121f9 --- /dev/null +++ b/server/src/semaphore.h @@ -0,0 +1,44 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * semaphore.h + * + * Sat Oct 8 17:44:13 CEST 2005 + * Copyright 2005 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. + */ +#ifndef __PRACRO_SEMAPHORE_H__ +#define __PRACRO_SEMAPHORE_H__ + +#include + +class Semaphore { +public: + Semaphore(); + ~Semaphore(); + + void post(); + void wait(); + +private: + sem_t semaphore; +}; + +#endif/*__PRACRO_SEMAPHORE_H__*/ -- cgit v1.2.3