/* -*- mode: C; c-basic-offset: 4 -*- */ #ident "$Id$" /* COPYING CONDITIONS NOTICE: This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation, and provided that the following conditions are met: * Redistributions of source code must retain this COPYING CONDITIONS NOTICE, the COPYRIGHT NOTICE (below), the DISCLAIMER (below), the UNIVERSITY PATENT NOTICE (below), the PATENT MARKING NOTICE (below), and the PATENT RIGHTS GRANT (below). * Redistributions in binary form must reproduce this COPYING CONDITIONS NOTICE, the COPYRIGHT NOTICE (below), the DISCLAIMER (below), the UNIVERSITY PATENT NOTICE (below), the PATENT MARKING NOTICE (below), and the PATENT RIGHTS GRANT (below) in the documentation and/or other materials provided with the distribution. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. COPYRIGHT NOTICE: TokuDB, Tokutek Fractal Tree Indexing Library. Copyright (C) 2007-2013 Tokutek, Inc. DISCLAIMER: This program 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. UNIVERSITY PATENT NOTICE: The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it. PATENT MARKING NOTICE: This software is covered by US Patent No. 8,185,551. This software is covered by US Patent No. 8,489,638. PATENT RIGHTS GRANT: "THIS IMPLEMENTATION" means the copyrightable works distributed by Tokutek as part of the Fractal Tree project. "PATENT CLAIMS" means the claims of patents that are owned or licensable by Tokutek, both currently or in the future; and that in the absence of this license would be infringed by THIS IMPLEMENTATION or by using or running THIS IMPLEMENTATION. "PATENT CHALLENGE" shall mean a challenge to the validity, patentability, enforceability and/or non-infringement of any of the PATENT CLAIMS or otherwise opposing any of the PATENT CLAIMS. Tokutek hereby grants to you, for the term and geographical scope of the PATENT CLAIMS, a non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, transfer, and otherwise run, modify, and propagate the contents of THIS IMPLEMENTATION, where such license applies only to the PATENT CLAIMS. This grant does not include claims that would be infringed only as a consequence of further modifications of THIS IMPLEMENTATION. If you or your agent or licensee institute or order or agree to the institution of patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that THIS IMPLEMENTATION constitutes direct or contributory patent infringement, or inducement of patent infringement, then any rights granted to you under this License shall terminate as of the date such litigation is filed. If you or your agent or exclusive licensee institute or order or agree to the institution of a PATENT CHALLENGE, then Tokutek may terminate any rights granted to you under this License. */ #ident "Copyright (c) 2010-2013 Tokutek Inc. All rights reserved." #include <errno.h> #include <stdlib.h> #include <string.h> #include <sys/time.h> #include <sys/types.h> #include <toku_portability.h> #include <toku_assert.h> #include <portability/toku_fair_rwlock.h> #include <portability/toku_pthread.h> #include <portability/toku_time.h> #include <util/frwlock.h> #include <util/frwlock.cc> #include <util/rwlock.h> #include "rwlock_condvar.h" toku_mutex_t mutex; toku::frwlock w; static void grab_write_lock(bool expensive) { toku_mutex_lock(&mutex); w.write_lock(expensive); toku_mutex_unlock(&mutex); } static void release_write_lock(void) { toku_mutex_lock(&mutex); w.write_unlock(); toku_mutex_unlock(&mutex); } static void grab_read_lock(void) { toku_mutex_lock(&mutex); w.read_lock(); toku_mutex_unlock(&mutex); } static void release_read_lock(void) { toku_mutex_lock(&mutex); w.read_unlock(); toku_mutex_unlock(&mutex); } static void *do_cheap_wait(void *arg) { grab_write_lock(false); release_write_lock(); return arg; } static void *do_expensive_wait(void *arg) { grab_write_lock(true); release_write_lock(); return arg; } static void *do_read_wait(void *arg) { grab_read_lock(); release_read_lock(); return arg; } static void launch_cheap_waiter(void) { toku_pthread_t tid; int r = toku_pthread_create(&tid, NULL, do_cheap_wait, NULL); assert_zero(r); toku_pthread_detach(tid); sleep(1); } static void launch_expensive_waiter(void) { toku_pthread_t tid; int r = toku_pthread_create(&tid, NULL, do_expensive_wait, NULL); assert_zero(r); toku_pthread_detach(tid); sleep(1); } static void launch_reader(void) { toku_pthread_t tid; int r = toku_pthread_create(&tid, NULL, do_read_wait, NULL); assert_zero(r); toku_pthread_detach(tid); sleep(1); } static bool locks_are_expensive(void) { toku_mutex_lock(&mutex); assert(w.write_lock_is_expensive() == w.read_lock_is_expensive()); bool is_expensive = w.write_lock_is_expensive(); toku_mutex_unlock(&mutex); return is_expensive; } static void test_write_cheapness(void) { toku_mutex_init(&mutex, NULL); w.init(&mutex); // single expensive write lock grab_write_lock(true); assert(locks_are_expensive()); release_write_lock(); assert(!locks_are_expensive()); // single cheap write lock grab_write_lock(false); assert(!locks_are_expensive()); release_write_lock(); assert(!locks_are_expensive()); // multiple read locks grab_read_lock(); assert(!locks_are_expensive()); grab_read_lock(); grab_read_lock(); assert(!locks_are_expensive()); release_read_lock(); release_read_lock(); release_read_lock(); assert(!locks_are_expensive()); // expensive write lock and cheap writers waiting grab_write_lock(true); launch_cheap_waiter(); assert(locks_are_expensive()); launch_cheap_waiter(); launch_cheap_waiter(); assert(locks_are_expensive()); release_write_lock(); sleep(1); assert(!locks_are_expensive()); // cheap write lock and expensive writer waiter grab_write_lock(false); launch_expensive_waiter(); assert(locks_are_expensive()); release_write_lock(); sleep(1); // expensive write lock and expensive waiter grab_write_lock(true); launch_expensive_waiter(); assert(locks_are_expensive()); release_write_lock(); sleep(1); // cheap write lock and cheap waiter grab_write_lock(false); launch_cheap_waiter(); assert(!locks_are_expensive()); release_write_lock(); sleep(1); // read lock held and cheap waiter grab_read_lock(); launch_cheap_waiter(); assert(!locks_are_expensive()); // add expensive waiter launch_expensive_waiter(); assert(locks_are_expensive()); release_read_lock(); sleep(1); // read lock held and expensive waiter grab_read_lock(); launch_expensive_waiter(); assert(locks_are_expensive()); // add expensive waiter launch_cheap_waiter(); assert(locks_are_expensive()); release_read_lock(); sleep(1); // cheap write lock held and waiting read grab_write_lock(false); launch_reader(); assert(!locks_are_expensive()); launch_expensive_waiter(); toku_mutex_lock(&mutex); assert(w.write_lock_is_expensive()); // tricky case here, because we have a launched reader // that should be in the queue, a new read lock // should piggy back off that assert(!w.read_lock_is_expensive()); toku_mutex_unlock(&mutex); release_write_lock(); sleep(1); // expensive write lock held and waiting read grab_write_lock(true); launch_reader(); assert(locks_are_expensive()); launch_cheap_waiter(); assert(locks_are_expensive()); release_write_lock(); sleep(1); w.deinit(); toku_mutex_destroy(&mutex); } int main (int UU(argc), const char* UU(argv[])) { test_write_cheapness(); return 0; }