lazuli.h File Reference

The public API of the Lazuli kernel. More...

#include <stdint.h>
#include <Lazuli/common.h>
#include <Lazuli/config.h>

Go to the source code of this file.

Data Structures
struct	Lz_TaskConfiguration
	Represents the configuration of a task. More...

Typedefs
typedef int8_t	lz_task_priority_t
	Represents the priority of a task, as a signed integer. More...
typedef uint16_t	lz_u_resolution_unit_t
	Represents the type used for the system clock resolution unit, as an unsigned integer.

Enumerations
enum	Lz_SchedulingPolicy {   CYCLIC_RT = 0,   PRIORITY_RT }
	Defines the possible scheduling policies for a Lazuli user task. More...

Functions
bool	Lz_RegisterTask (void(*const taskEntryPoint)(void), Lz_TaskConfiguration *taskConfiguration)
	Register a new task. More...
void	Lz_TaskConfiguration_Init (Lz_TaskConfiguration *const taskConfiguration)
	Initialize an Lz_TaskConfiguration with default values for all parameters. More...
void	Lz_Run (void)
	Run the scheduler. More...
void	Lz_Task_WaitInterrupt (uint8_t interruptCode)
	Wait for a specific interrupt to occur. More...
char const *	Lz_Task_GetName (void)
	Get the name of the calling task. More...
void	Lz_Task_Terminate (void)
	Terminate the calling task. More...
void	Lz_Task_WaitActivation (void)
	Set the calling task to wait for its next activation. More...
void	Lz_WaitTimer (lz_u_resolution_unit_t units)
	Set the calling task to wait for the specified number of time resolution units (time slices), using the software timer. More...

Detailed Description

The public API of the Lazuli kernel.

Copyright

2017-2020, Remi Andruccioli remi..nosp@m.andr.nosp@m.uccio.nosp@m.li@g.nosp@m.mail..nosp@m.com

This file describes the public (user) API of the Lazuli kernel. It defines public types and functions that can by used by user main code and tasks.

Definition in file lazuli.h.

Typedef Documentation

lz_task_priority_t

typedef int8_t lz_task_priority_t

Represents the priority of a task, as a signed integer.

The higher the value, the higher the priority.

Definition at line 30 of file lazuli.h.

Enumeration Type Documentation

Lz_SchedulingPolicy

enum Lz_SchedulingPolicy

Defines the possible scheduling policies for a Lazuli user task.

Attention

The constants are defined from the highest priority policy to the lowest. i.e. A lower value means a higher priority.

Enumerator
CYCLIC_RT	Cyclic real-time scheduling.
PRIORITY_RT	Priority time sliced real-time scheduling. Equivalent to POSIX SCHED_RR.

Definition at line 44 of file lazuli.h.

Function Documentation

Lz_RegisterTask()

bool Lz_RegisterTask	(	void(*)(void)	taskEntryPoint,
		Lz_TaskConfiguration *	taskConfiguration
	)

Register a new task.

If an error occured during registration of the task false is returned and the task is not included in the set of tasks that will be run.

Parameters

taskEntryPoint	The entry point of the task to register. i.e. A pointer to the function representing the task.
taskConfiguration	A pointer to an Lz_TaskConfiguration containing the configuration of the task being registered. If NULL is passed, then default values are applied for all parameters.

Returns

• true if the task has been registered without error.
• false if an error occured during registration.

Definition at line 758 of file scheduler.c.

Lz_TaskConfiguration_Init()

void Lz_TaskConfiguration_Init

(

Lz_TaskConfiguration *const

taskConfiguration

)

Initialize an Lz_TaskConfiguration with default values for all parameters.

No function is provided for allocating a new Lz_TaskConfiguration. So it is strongly advised to allocate the Lz_TaskConfiguration parameter on the stack before calling this function.

Parameters

taskConfiguration

A pointer to the Lz_TaskConfiguration to initialize.

Definition at line 746 of file scheduler.c.

Lz_Run()

void Lz_Run

(

void

)

Run the scheduler.

Start scheduling tasks.

Definition at line 765 of file scheduler.c.

Lz_Task_WaitInterrupt()

void Lz_Task_WaitInterrupt

(

uint8_t

interruptCode

)

Wait for a specific interrupt to occur.

Puts the calling task to sleep until the specified interrupt occurs.

Parameters

interruptCode

The code of the interrupt to wait for.

Attention

Only tasks with scheduling policy PRIORITY_RT can wait for interrupts.

Definition at line 793 of file scheduler.c.

Lz_Task_GetName()

char const* Lz_Task_GetName

(

void

)

Get the name of the calling task.

Returns

A pointer to a string containing the name of the current running task, or NULL if the task has no name.

Definition at line 779 of file scheduler.c.

Lz_Task_Terminate()

void Lz_Task_Terminate

(

void

)

Terminate the calling task.

The context of the task will be saved on its stack.

Calling this function has the same effect than returning from the task's main function.

The terminated task will never be scheduled again.

Definition at line 815 of file scheduler.c.

Lz_Task_WaitActivation()

void Lz_Task_WaitActivation

(

void

)

Set the calling task to wait for its next activation.

May be used if the task finnished its work without consuming all of its completion time.

Attention

Only tasks with scheduling policy CYCLIC_RT can wait for next activation.

Definition at line 785 of file scheduler.c.

Lz_WaitTimer()

void Lz_WaitTimer

(

lz_u_resolution_unit_t

units

)

Set the calling task to wait for the specified number of time resolution units (time slices), using the software timer.

As Lazuli is a time sliced operating system, the effective waiting will start at the end of the current time slice. This means that the real waiting time starting from the calling of this function will be:

units / clock resolution frequency <= waiting time AND waiting time < (units + 1) / clock resolution frequency

See the configuration option LZ_CONFIG_SYSTEM_CLOCK_RESOLUTION_FREQUENCY.

Parameters

units

The number of time slices to wait.

Warning

Only works for tasks with PRIORITY_RT policy.

Definition at line 804 of file scheduler.c.