diff --git a/include/pthread.h b/include/pthread.h index af6ef51e23e..a75cd9e9015 100644 --- a/include/pthread.h +++ b/include/pthread.h @@ -337,6 +337,27 @@ typedef struct pthread_barrier_s pthread_barrier_t; typedef bool pthread_once_t; #define __PTHREAD_ONCE_T_DEFINED 1 +struct pthread_rwlock_s +{ + pthread_mutex_t lock; + pthread_cond_t cv; + unsigned int num_readers; + unsigned int num_writers; + bool write_in_progress; +}; + +typedef struct pthread_rwlock_s pthread_rwlock_t; + +typedef int pthread_rwlockattr_t; + +#define PTHREAD_RWLOCK_INITIALIZER {PTHREAD_MUTEX_INITIALIZER, \ + PTHREAD_COND_INITIALIZER, \ + 0, 0} + +#define PTHREAD_MUTEX_INITIALIZER {NULL, SEM_INITIALIZER(1), -1, \ + __PTHREAD_MUTEX_DEFAULT_FLAGS, \ + PTHREAD_MUTEX_DEFAULT, 0} + #ifdef CONFIG_PTHREAD_CLEANUP /* This type describes the pthread cleanup callback (non-standard) */ @@ -539,8 +560,8 @@ int pthread_barrierattr_setpshared(FAR pthread_barrierattr_t *attr, int pthread_barrier_destroy(FAR pthread_barrier_t *barrier); int pthread_barrier_init(FAR pthread_barrier_t *barrier, - FAR const pthread_barrierattr_t *attr, - unsigned int count); + FAR const pthread_barrierattr_t *attr, + unsigned int count); int pthread_barrier_wait(FAR pthread_barrier_t *barrier); /* Pthread initialization */ @@ -548,6 +569,21 @@ int pthread_barrier_wait(FAR pthread_barrier_t *barrier); int pthread_once(FAR pthread_once_t *once_control, CODE void (*init_routine)(void)); +/* Pthread rwlock */ + +int pthread_rwlock_destroy(FAR pthread_rwlock_t *rw_lock); +int pthread_rwlock_init(FAR pthread_rwlock_t *rw_lock, + FAR const pthread_rwlockattr_t *attr); +int pthread_rwlock_rdlock(pthread_rwlock_t *lock); +int pthread_rwlock_timedrdlock(FAR pthread_rwlock_t *lock, + FAR const struct timespec *abstime); +int pthread_rwlock_tryrdlock(FAR pthread_rwlock_t *lock); +int pthread_rwlock_wrlock(FAR pthread_rwlock_t *lock); +int pthread_rwlock_timedwrlock(FAR pthread_rwlock_t *lock, + FAR const struct timespec *abstime); +int pthread_rwlock_trywrlock(FAR pthread_rwlock_t *lock); +int pthread_rwlock_unlock(FAR pthread_rwlock_t *lock); + /* Pthread signal management APIs */ int pthread_kill(pthread_t thread, int sig); diff --git a/libc/pthread/Make.defs b/libc/pthread/Make.defs index b8be2927d2f..291dfdfd4e6 100644 --- a/libc/pthread/Make.defs +++ b/libc/pthread/Make.defs @@ -52,6 +52,7 @@ CSRCS += pthread_mutexattr_settype.c pthread_mutexattr_gettype.c CSRCS += pthread_mutexattr_setrobust.c pthread_mutexattr_getrobust.c CSRCS += pthread_setcancelstate.c pthread_setcanceltype.c CSRCS += pthread_testcancel.c +CSRCS += pthread_rwlock.c pthread_rwlock_rdlock.c pthread_rwlock_wrlock.c ifeq ($(CONFIG_SMP),y) CSRCS += pthread_attr_getaffinity.c pthread_attr_setaffinity.c diff --git a/libc/pthread/pthread_rwlock.c b/libc/pthread/pthread_rwlock.c new file mode 100644 index 00000000000..b40b655b26d --- /dev/null +++ b/libc/pthread/pthread_rwlock.c @@ -0,0 +1,128 @@ +/**************************************************************************** + * libc/pthread/pthread_rwlock.c + * + * Copyright (C) 2017 Mark Schulte. All rights reserved. + * Author: Mark Schulte + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include + +#include +#include +#include +#include + +#include + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +int pthread_rwlock_init(FAR pthread_rwlock_t *lock, + FAR const pthread_rwlockattr_t *attr) +{ + int err; + + if (attr != NULL) + { + return -ENOSYS; + } + + lock->num_readers = 0; + lock->num_writers = 0; + lock->write_in_progress = false; + + err = pthread_cond_init(&lock->cv, NULL); + if (err != 0) + { + return err; + } + + err = pthread_mutex_init(&lock->lock, NULL); + if (err != 0) + { + pthread_cond_destroy(&lock->cv); + return err; + } + + return err; +} + +int pthread_rwlock_destroy(FAR pthread_rwlock_t *lock) +{ + int cond_err = pthread_cond_destroy(&lock->cv); + int mutex_err = pthread_mutex_destroy(&lock->lock); + + if (mutex_err) + { + return mutex_err; + } + + return cond_err; +} + +int pthread_rwlock_unlock(FAR pthread_rwlock_t *rw_lock) +{ + int err; + + err = pthread_mutex_lock(&rw_lock->lock); + if (err != 0) + { + return err; + } + + if (rw_lock->num_readers > 0) + { + rw_lock->num_readers--; + + if (rw_lock->num_readers == 0) + { + err = pthread_cond_broadcast(&rw_lock->cv); + } + } + else if (rw_lock->write_in_progress) + { + rw_lock->write_in_progress = false; + + err = pthread_cond_broadcast(&rw_lock->cv); + } + else + { + err = EINVAL; + } + + pthread_mutex_unlock(&rw_lock->lock); + return err; +} diff --git a/libc/pthread/pthread_rwlock_rdlock.c b/libc/pthread/pthread_rwlock_rdlock.c new file mode 100644 index 00000000000..9fd461a758e --- /dev/null +++ b/libc/pthread/pthread_rwlock_rdlock.c @@ -0,0 +1,143 @@ +/**************************************************************************** + * libc/pthread/pthread_rwlockread.c + * + * Copyright (C) 2017 Mark Schulte. All rights reserved. + * Author: Mark Schulte + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include + +#include +#include +#include +#include + +#include + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +static int tryrdlock(FAR pthread_rwlock_t *rw_lock) +{ + int err; + + if (rw_lock->num_writers > 0 || rw_lock->write_in_progress) + { + err = EBUSY; + } + else if (rw_lock->num_readers == UINT_MAX) + { + err = EAGAIN; + } + else + { + rw_lock->num_readers++; + err = OK; + } + + return err; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: pthread_rwlock_rdlock + * + * Description: + * Locks a read/write lock for reading + * + * Parameters: + * None + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +int pthread_rwlock_tryrdlock(FAR pthread_rwlock_t *rw_lock) +{ + int err = pthread_mutex_trylock(&rw_lock->lock); + + if (err != 0) + { + return err; + } + + err = tryrdlock(rw_lock); + + pthread_mutex_unlock(&rw_lock->lock); + return err; +} + +int pthread_rwlock_timedrdlock(FAR pthread_rwlock_t *rw_lock, + FAR const struct timespec *ts) +{ + int err = pthread_mutex_lock(&rw_lock->lock); + + if (err != 0) + { + return err; + } + + while ((err = tryrdlock(rw_lock)) == EBUSY) + { + if (ts != NULL) + { + err = pthread_cond_timedwait(&rw_lock->cv, &rw_lock->lock, ts); + } + else + { + err = pthread_cond_wait(&rw_lock->cv, &rw_lock->lock); + } + + if (err != 0) + { + break; + } + } + + pthread_mutex_unlock(&rw_lock->lock); + return err; +} + +int pthread_rwlock_rdlock(FAR pthread_rwlock_t * rw_lock) +{ + return pthread_rwlock_timedrdlock(rw_lock, NULL); +} diff --git a/libc/pthread/pthread_rwlock_wrlock.c b/libc/pthread/pthread_rwlock_wrlock.c new file mode 100644 index 00000000000..ecda4cb25be --- /dev/null +++ b/libc/pthread/pthread_rwlock_wrlock.c @@ -0,0 +1,148 @@ +/**************************************************************************** + * libc/pthread/pthread_rwlockwrite.c + * + * Copyright (C) 2017 Mark Schulte. All rights reserved. + * Author: Mark Schulte + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include + +#include +#include +#include +#include + +#include + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: pthread_rwlock_rdlock + * + * Description: + * Locks a read/write lock for reading + * + * Parameters: + * None + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +int pthread_rwlock_trywrlock(FAR pthread_rwlock_t *rw_lock) +{ + int err = pthread_mutex_trylock(&rw_lock->lock); + + if (err != 0) + { + return err; + } + + if (rw_lock->num_readers > 0 || rw_lock->write_in_progress) + { + err = EBUSY; + } + else + { + rw_lock->write_in_progress = true; + } + + pthread_mutex_unlock(&rw_lock->lock); + return err; +} + +int pthread_rwlock_timedwrlock(FAR pthread_rwlock_t *rw_lock, + FAR const struct timespec *ts) +{ + int err = pthread_mutex_lock(&rw_lock->lock); + + if (err != 0) + { + return err; + } + + if (rw_lock->num_writers == UINT_MAX) + { + err = EAGAIN; + goto exit_with_mutex; + } + + rw_lock->num_writers++; + + while (rw_lock->write_in_progress || rw_lock->num_readers > 0) + { + if (ts != NULL) + { + err = pthread_cond_timedwait(&rw_lock->cv, &rw_lock->lock, ts); + } + else + { + err = pthread_cond_wait(&rw_lock->cv, &rw_lock->lock); + } + + if (err != 0) + { + break; + } + } + + if (err == 0) + { + rw_lock->write_in_progress = true; + } + + else + { + /* In case of error, notify any blocked readers. */ + + (void) pthread_cond_broadcast(&rw_lock->cv); + } + + rw_lock->num_writers--; + +exit_with_mutex: + pthread_mutex_unlock(&rw_lock->lock); + return err; +} + +int pthread_rwlock_wrlock(FAR pthread_rwlock_t *rw_lock) +{ + return pthread_rwlock_timedwrlock(rw_lock, NULL); +}