ardupilot/libraries/AP_HAL_ChibiOS/Semaphores.cpp

137 lines
3.4 KiB
C++

/*
* This file 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 3 of the License, or
* (at your option) any later version.
*
* This file 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, see <http://www.gnu.org/licenses/>.
*
* Code by Andrew Tridgell and Siddharth Bharat Purohit
*/
#include <AP_HAL/AP_HAL.h>
#include "Semaphores.h"
#include <hal.h>
#include <chsem.h>
#include "AP_HAL_ChibiOS.h"
#include <AP_Math/AP_Math.h>
#if CH_CFG_USE_MUTEXES == TRUE
extern const AP_HAL::HAL& hal;
using namespace ChibiOS;
// constructor
Semaphore::Semaphore()
{
static_assert(sizeof(_lock) >= sizeof(mutex_t), "invalid mutex size");
mutex_t *mtx = (mutex_t *)_lock;
chMtxObjectInit(mtx);
}
bool Semaphore::give()
{
mutex_t *mtx = (mutex_t *)_lock;
chMtxUnlock(mtx);
return true;
}
bool Semaphore::take(uint32_t timeout_ms)
{
mutex_t *mtx = (mutex_t *)_lock;
if (timeout_ms == HAL_SEMAPHORE_BLOCK_FOREVER) {
chMtxLock(mtx);
return true;
}
if (take_nonblocking()) {
return true;
}
uint64_t start = AP_HAL::micros64();
do {
hal.scheduler->delay_microseconds(200);
if (take_nonblocking()) {
return true;
}
} while ((AP_HAL::micros64() - start) < timeout_ms*1000);
return false;
}
bool Semaphore::take_nonblocking()
{
mutex_t *mtx = (mutex_t *)_lock;
return chMtxTryLock(mtx);
}
bool Semaphore::check_owner(void)
{
mutex_t *mtx = (mutex_t *)_lock;
return mtx->owner == chThdGetSelfX();
}
void Semaphore::assert_owner(void)
{
osalDbgAssert(check_owner(), "owner");
}
#if CH_CFG_USE_SEMAPHORES == TRUE
BinarySemaphore::BinarySemaphore(bool initial_state) :
AP_HAL::BinarySemaphore(initial_state)
{
static_assert(sizeof(_lock) >= sizeof(semaphore_t), "invalid semaphore_t size");
auto *sem = (binary_semaphore_t *)_lock;
/*
the initial_state in ChibiOS binary semaphores is 'taken', so we
need to negate it for the ArduPilot semantics
*/
chBSemObjectInit(sem, !initial_state);
}
bool BinarySemaphore::wait(uint32_t timeout_us)
{
auto *sem = (binary_semaphore_t *)_lock;
if (timeout_us == 0) {
return chBSemWaitTimeout(sem, TIME_IMMEDIATE) == MSG_OK;
}
// loop waiting for 60ms at a time. This ensures we can wait for
// any amount of time even on systems with a 16 bit timer
while (timeout_us > 0) {
const uint32_t us = MIN(timeout_us, 60000U);
if (chBSemWaitTimeout(sem, TIME_US2I(us)) == MSG_OK) {
return true;
}
timeout_us -= us;
}
return false;
}
bool BinarySemaphore::wait_blocking(void)
{
auto *sem = (binary_semaphore_t *)_lock;
return chBSemWait(sem) == MSG_OK;
}
void BinarySemaphore::signal(void)
{
auto *sem = (binary_semaphore_t *)_lock;
chBSemSignal(sem);
}
void BinarySemaphore::signal_ISR(void)
{
auto *sem = (binary_semaphore_t *)_lock;
chSysLockFromISR();
chBSemSignalI(sem);
chSysUnlockFromISR();
}
#endif // CH_CFG_USE_SEMAPHORES == TRUE
#endif // CH_CFG_USE_MUTEXES