ardupilot/libraries/AP_HAL_ChibiOS/Semaphores.h

52 lines
1.7 KiB
C
Raw Normal View History

/*
* 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
*/
#pragma once
#include <stdint.h>
#include <AP_HAL/AP_HAL_Boards.h>
#include <AP_HAL/AP_HAL_Macros.h>
#include <AP_HAL/Semaphores.h>
#include "AP_HAL_ChibiOS_Namespace.h"
class ChibiOS::Semaphore : public AP_HAL::Semaphore {
public:
Semaphore();
virtual bool give() override;
virtual bool take(uint32_t timeout_ms) override;
virtual bool take_nonblocking() override;
// methods within HAL_ChibiOS only
bool check_owner(void);
void assert_owner(void);
protected:
// to avoid polluting the global namespace with the 'ch' variable,
// we declare the lock as a uint64_t, and cast inside the cpp file
uint64_t _lock[2];
};
// a recursive semaphore, allowing for a thread to take it more than
// once. It must be released the same number of times it is taken
class ChibiOS::Semaphore_Recursive : public ChibiOS::Semaphore {
public:
Semaphore_Recursive();
bool give() override;
bool take(uint32_t timeout_ms) override;
bool take_nonblocking() override;
private:
uint32_t count;
};