diff options
| -rw-r--r-- | include/ouroboros/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | include/ouroboros/rw_lock.h | 41 | ||||
| -rw-r--r-- | src/lib/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | src/lib/rw_lock.c | 125 |
4 files changed, 168 insertions, 0 deletions
diff --git a/include/ouroboros/CMakeLists.txt b/include/ouroboros/CMakeLists.txt index a42c65fd..f1276f51 100644 --- a/include/ouroboros/CMakeLists.txt +++ b/include/ouroboros/CMakeLists.txt @@ -16,6 +16,7 @@ set(HEADER_FILES irm.h list.h logs.h + rw_lock.h shm_ap_rbuff.h shm_du_map.h sockets.h diff --git a/include/ouroboros/rw_lock.h b/include/ouroboros/rw_lock.h new file mode 100644 index 00000000..03eee605 --- /dev/null +++ b/include/ouroboros/rw_lock.h @@ -0,0 +1,41 @@ +/* + * Ouroboros - Copyright (C) 2016 + * + * Read/Write locks + * + * Dimitri Staessens <dimitri.staessens@intec.ugent.be> + * + * This program 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. + * + * 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. + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef OUROBOROS_RWLOCK_H +#define OUROBOROS_RWLOCK_H + +#include <ouroboros/config.h> +#include <pthread.h> + +typedef struct rw_lock { + pthread_mutex_t lock; + pthread_mutex_t i_lock; + int i; +} rw_lock_t; + +int rw_lock_init(rw_lock_t * lock); +void rw_lock_destroy(rw_lock_t * lock); +int rw_lock_rdlock(rw_lock_t * lock); +int rw_lock_wrlock(rw_lock_t * lock); +int rw_lock_unlock(rw_lock_t * lock); + +#endif /* OUROBOROS_RWLOCK_H */ diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt index 53a7b354..72e32512 100644 --- a/src/lib/CMakeLists.txt +++ b/src/lib/CMakeLists.txt @@ -32,6 +32,7 @@ set(SOURCE_FILES ipcp.c irm.c list.c + rw_lock.c shm_ap_rbuff.c shm_du_map.c sockets.c diff --git a/src/lib/rw_lock.c b/src/lib/rw_lock.c new file mode 100644 index 00000000..cf471e60 --- /dev/null +++ b/src/lib/rw_lock.c @@ -0,0 +1,125 @@ +/* + * Ouroboros - Copyright (C) 2016 + * + * Read/Write locks + * + * Dimitri Staessens <dimitri.staessens@intec.ugent.be> + * + * This program 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. + * + * 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. + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <ouroboros/rw_lock.h> + +int rw_lock_init(rw_lock_t * lock) +{ + if (lock == NULL) + return -1; + + pthread_mutex_init(&lock->lock, NULL); + pthread_mutex_init(&lock->i_lock, NULL); + lock->i = 0; + + return 0; +} + +void rw_lock_destroy(rw_lock_t * lock) +{ + if (lock == NULL) + return; + + pthread_mutex_destroy(&lock->lock); + pthread_mutex_destroy(&lock->i_lock); + lock->i = -1; +} + +int rw_lock_rdlock(rw_lock_t * lock) +{ + int ret = 0; + + if (lock == NULL) + return -1; + + pthread_mutex_lock(&lock->i_lock); + + if (lock->i < 0) { + pthread_mutex_unlock(&lock->i_lock); + return -1; + } + + if (lock->i == 0) + ret = pthread_mutex_lock(&lock->lock); + + ++(lock->i); + + pthread_mutex_unlock(&lock->i_lock); + + return ret; +} + +int rw_lock_wrlock(rw_lock_t * lock) +{ + if (lock == NULL) + return -1; + + pthread_mutex_lock(&lock->i_lock); + + if (lock->i < 0) { + pthread_mutex_unlock(&lock->i_lock); + return -1; + } + + pthread_mutex_unlock(&lock->i_lock); + + while (1) { + pthread_mutex_lock(&lock->i_lock); + + if (lock->i == 0) { + pthread_mutex_unlock(&lock->i_lock); + break; + } + + pthread_mutex_unlock(&lock->i_lock); + + sched_yield(); + } + + ++(lock->i); + + return pthread_mutex_lock(&lock->lock); +} + +int rw_lock_unlock(rw_lock_t * lock) +{ + int ret = 0; + + if (lock == NULL) + return -1; + + pthread_mutex_lock(&lock->i_lock); + + if (lock->i < 0) { + pthread_mutex_unlock(&lock->i_lock); + return -1; + } + + --(lock->i); + + if (lock->i == 0) + ret = pthread_mutex_unlock(&lock->lock); + + pthread_mutex_unlock(&lock->i_lock); + + return ret; +} |