ardupilot/libraries/AP_HAL_FLYMAPLE/Semaphores.cpp

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/*
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 3 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, see <http://www.gnu.org/licenses/>.
*/
/*
Flymaple port by Mike McCauley
*/
#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_FLYMAPLE
#include "Semaphores.h"
using namespace AP_HAL_FLYMAPLE_NS;
#include "AP_HAL_FLYMAPLE.h"
#include "Semaphores.h"
#include "Scheduler.h"
#include "FlymapleWirish.h"
extern const AP_HAL::HAL& hal;
// Constructor
FLYMAPLESemaphore::FLYMAPLESemaphore() : _taken(false) {}
bool FLYMAPLESemaphore::give() {
if (!_taken) {
return false;
} else {
_taken = false;
return true;
}
}
bool FLYMAPLESemaphore::take(uint32_t timeout_ms) {
if (hal.scheduler->in_timerprocess()) {
AP_HAL::panic("PANIC: FLYMAPLESemaphore::take used from "
"inside timer process");
return false; /* Never reached - panic does not return */
}
return _take_from_mainloop(timeout_ms);
}
bool FLYMAPLESemaphore::take_nonblocking() {
if (hal.scheduler->in_timerprocess()) {
return _take_nonblocking();
} else {
return _take_from_mainloop(0);
}
}
bool FLYMAPLESemaphore::_take_from_mainloop(uint32_t timeout_ms) {
/* Try to take immediately */
if (_take_nonblocking()) {
return true;
} else if (timeout_ms == 0) {
/* Return immediately if timeout is 0 */
return false;
}
do {
/* Delay 1ms until we can successfully take, or we timed out */
hal.scheduler->delay(1);
timeout_ms--;
if (_take_nonblocking()) {
return true;
}
} while (timeout_ms > 0);
return false;
}
bool FLYMAPLESemaphore::_take_nonblocking() {
bool result = false;
noInterrupts();
if (!_taken) {
_taken = true;
result = true;
}
interrupts();
return result;
}
#endif