From ef48715051f60b3cc7ae7e75bdaa0385c88b72cb Mon Sep 17 00:00:00 2001 From: Lorenz Meier Date: Sat, 19 Sep 2015 18:22:00 +0200 Subject: [PATCH] POSIX: Add pthread mutex based semaphores --- src/platforms/posix/px4_layer/CMakeLists.txt | 1 + src/platforms/posix/px4_layer/px4_sem.cpp | 98 ++++++++++++++++++++ src/platforms/px4_posix.h | 35 +++++++ 3 files changed, 134 insertions(+) create mode 100644 src/platforms/posix/px4_layer/px4_sem.cpp diff --git a/src/platforms/posix/px4_layer/CMakeLists.txt b/src/platforms/posix/px4_layer/CMakeLists.txt index 295e882532..402e66e097 100644 --- a/src/platforms/posix/px4_layer/CMakeLists.txt +++ b/src/platforms/posix/px4_layer/CMakeLists.txt @@ -37,6 +37,7 @@ px4_add_module( SRCS px4_posix_impl.cpp px4_posix_tasks.cpp + px4_sem.cpp lib_crc32.c drv_hrt.c px4_log.c diff --git a/src/platforms/posix/px4_layer/px4_sem.cpp b/src/platforms/posix/px4_layer/px4_sem.cpp new file mode 100644 index 0000000000..c938389de4 --- /dev/null +++ b/src/platforms/posix/px4_layer/px4_sem.cpp @@ -0,0 +1,98 @@ +/**************************************************************************** + * + * Copyright (c) 2015 PX4 Development Team. All rights reserved. + * + * 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 PX4 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. + * + ****************************************************************************/ + +/** + * @file px4_sem.cpp + * + * PX4 Middleware Wrapper Linux Implementation + */ + +#include +#include +#include +#include +#include +#include + +#ifdef __PX4_DARWIN + +#include + +#include + +int px4_sem_init(px4_sem_t *s, int pshared, unsigned value) +{ + // We do not used the process shared arg + (void)pshared; + s->value = value; + pthread_cond_init(&(s->wait), NULL); + pthread_mutex_init(&(s->lock), NULL); + + return 0; +} + +int px4_sem_wait(px4_sem_t *s) +{ + pthread_mutex_lock(&(s->lock)); + s->value--; + if(s->value < 0) { + pthread_cond_wait(&(s->wait), &(s->lock)); + } + pthread_mutex_unlock(&(s->lock)); + + return 0; +} + +int px4_sem_post(px4_sem_t *s) +{ + pthread_mutex_lock(&(s->lock)); + s->value++; + if(s->value <= 0) { + pthread_cond_signal(&(s->wait)); + } + pthread_mutex_unlock(&(s->lock)); + + return 0; +} + +int px4_sem_destroy(px4_sem_t *s) +{ + pthread_mutex_lock(&(s->lock)); + pthread_cond_destroy(&(s->wait)); + pthread_mutex_unlock(&(s->lock)); + pthread_mutex_destroy(&(s->lock)); + + return 0; +} + +#endif diff --git a/src/platforms/px4_posix.h b/src/platforms/px4_posix.h index d4309b11b0..e2d0143a0e 100644 --- a/src/platforms/px4_posix.h +++ b/src/platforms/px4_posix.h @@ -48,6 +48,41 @@ #include +/* Semaphore handling */ + +#ifdef __PX4_DARWIN + +__BEGIN_DECLS + +typedef struct +{ + pthread_mutex_t lock; + pthread_cond_t wait; + int value; +} px4_sem_t; + +__EXPORT int px4_sem_init(px4_sem_t *s, int pshared, unsigned value); +__EXPORT int px4_sem_wait(px4_sem_t *s); +__EXPORT int px4_sem_post(px4_sem_t *s); +__EXPORT int px4_sem_destroy(px4_sem_t *s); + +__END_DECLS + +#else + +typedef px4_sem_t sem_t + +#define px4_sem_init _GLOBAL sem_init +#define px4_sem_wait _GLOBAL sem_wait +#define px4_sem_post _GLOBAL px4_sem_post +#define px4_sem_destroy _GLOBAL sem_destroy + + + +#endif + +//################################### + #ifdef __PX4_NUTTX #define PX4_F_RDONLY 1