sys

This chapter describes sys system scheduling for LuatOS

Introduction

sys The library is a built-in library for system scheduling in LuatOS. Through the sys library, you can create LuatOS tasks, create new timers, and send and subscribe to messages in the system.

Hardware preparation

Any LuatOS-SOC development board

Software part

Interface documentation can be found in:SYS Library

Initialize a LuatOS task and start it

The code is as follows

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

function test()
    log.info(PROJECT, "test running...")
end

-- Create a task test and execute it
sys.taskInit(test)

-- Start system scheduling
sys.run()

The log is as follows

I/user.SYS test running...

Create a loop in a task and use a delay function

The code is as follows

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

function test()
    while true do
        log.info(PROJECT, "test running...")
        -- Use wait for 1S delay in task function
        sys.wait(1000)
    end
end

-- Create a task test and execute it
sys.taskInit(test)

-- Start system scheduling
sys.run()

The log is as follows

I/user.SYS test running...
I/user.SYS test running...
I/user.SYS test running...
I/user.SYS test running...
I/user.SYS test running...
...
...

Start a single timer or cycle timer

The code is as follows

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

function test1(arg)
    log.info(PROJECT, "test1 running...")
    log.info("TEST1-ARG", arg)

end

function test2(arg)
    log.info(PROJECT, "test2 running...")
    log.info("TEST2-ARG", arg)
end

-- Create a one-shot timer
sys.timerStart(test1, 2000, "TEST1")

-- Create a loop timer
sys.timerLoopStart(test2, 2000, "TEST2")

sys.run()

The log is as follows

I/user.SYS test1 running...
I/user.TEST1-ARG TEST1
I/user.SYS test2 running...
I/user.TEST2-ARG TEST2
I/user.SYS test2 running...
I/user.TEST2-ARG TEST2
I/user.SYS test2 running...
I/user.TEST2-ARG TEST2
...
...

Stop a timer

The code is as follows

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

function test(arg)
    log.info(PROJECT, "test running...")
    log.info("TEST-ARG", arg)
end

sys.taskInit(function()
    -- Create a loop timer
    local tid = sys.timerLoopStart(test, 1000, "TEST_DATA")
    log.info(PROJECT, "5S The post cycle timer will stop running")
    sys.wait(5000)
    -- Stop Cycle Timer
    log.info(PROJECT, "Stop Cycle Timer")
    sys.timerStop(tid)
end)

sys.run()

The log is as follows

I/user.SYS 5S The post cycle timer will stop running
I/user.SYS test running...
I/user.TEST-ARG TEST_DATA
I/user.SYS test running...
I/user.TEST-ARG TEST_DATA
I/user.SYS test running...
I/user.TEST-ARG TEST_DATA
I/user.SYS test running...
I/user.TEST-ARG TEST_DATA
I/user.SYS test running...
I/user.TEST-ARG TEST_DATA
I/user.SYS Stop Cycle Timer

Sending and subscribing to user messages

The code is as follows

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

local count = 1

sys.subscribe("USER_MSG", function(arg)
    log.info(PROJECT, "receive data : " .. arg)
end)

sys.timerLoopStart(function()
    sys.publish("USER_MSG", "DATA" .. count)
    count = count + 1
end, 3000)

sys.run()

The log is as follows

I/user.SYS receive data : DATA1
I/user.SYS receive data : DATA2
I/user.SYS receive data : DATA3
I/user.SYS receive data : DATA4
I/user.SYS receive data : DATA5
...
...

Wait for a message in a task

PROJECT = "SYS"
VERSION = "1.0.0"

-- Introducing the sys library
sys = require("sys")

local count = 1

sys.taskInit(function()
    local res, data
    while true do
        res, data = sys.waitUntil("USER_MSG")
        log.info(PROJECT, res, data)
    end
end)

sys.timerLoopStart(function()
    sys.publish("USER_MSG", "DATA" .. count)
    count = count + 1
end, 3000)

sys.run()

The log is as follows

I/user.SYS true DATA1
I/user.SYS true DATA2
I/user.SYS true DATA3
I/user.SYS true DATA4
I/user.SYS true DATA5
...
...