stmos/src/kernel/task.h
Clyne Sullivan 2a01cc57c1 fork, getpid
2018-10-21 13:10:34 -04:00

70 lines
2.0 KiB
C

/**
* @file task.h
* Provides multitasking functionality
*
* Copyright (C) 2018 Clyne Sullivan
*
* 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 <https://www.gnu.org/licenses/>.
*/
#ifndef TASK_H_
#define TASK_H_
#include <stdint.h>
/**
* A structure to contain task data.
*/
typedef struct task_t {
struct task_t *next; /**< pointer to the next task_t instance */
uint32_t *sp; /**< pointer to the task's last sp register value */
uint32_t *stack; /**< pointer to the task's stack */
uint32_t sleep; /**< number of milliseconds task is sleeping for */
uint32_t pid;
} task_t;
/**
* Enters multitasking mode. The given function acts as the initial thread.
* This task is given a 4kb stack.
* @param init the initial thread to run
*/
void task_init(void (*init)(void), uint16_t stackSize);
/**
* Starts a new task.
* @param task the code to run
* @param stackSize how many bytes of stack to give the thread
*/
void task_start(void (*task)(void), uint16_t stackSize);
/**
* Allows task switching to be disabled, for low-level actions.
* Multiple holds can be placed, and all must be removed to continue task
* switching.
* @param hold non-zero for hold, zero to remove hold
*/
void task_hold(uint8_t hold);
/**
* Frees the task's resources and removes it from the running task list.
* @param code An unused exit code
*/
void _exit(int code);
void task_sleep(uint32_t ms);
uint32_t task_getpid(void);
#endif // TASK_H_