The Thread class allow defining, creating, and controlling thread functions in the system. More...

#include <Thread.h>

Inheritance diagram for Thread:

Public Types
enum	State { Inactive , Ready , Running , WaitingDelay , WaitingJoin , WaitingThreadFlag , WaitingEventFlag , WaitingMutex , WaitingSemaphore , WaitingMemoryPool , WaitingMessageGet , WaitingMessagePut , WaitingInterval , WaitingOr , WaitingAnd , WaitingMailbox , Deleted }
	State of the Thread. More...

Public Member Functions
	Thread (osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char stack_mem=nullptr, const char name=nullptr)
	Allocate a new thread without starting execution. More...

	Thread (uint32_t tz_module, osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char stack_mem=nullptr, const char name=nullptr)
	Allocate a new thread without starting execution. More...

osStatus	start (mbed::Callback< void()> task)
	Starts a thread executing the specified function. More...

osStatus	join ()
	Wait for thread to terminate. More...

osStatus	terminate ()
	Terminate execution of a thread and remove it from Active Threads. More...

osStatus	set_priority (osPriority priority)
	Set priority of an active thread. More...

osPriority	get_priority () const
	Get priority of an active thread. More...

uint32_t	flags_set (uint32_t flags)
	Set the specified Thread Flags for the thread. More...

State	get_state () const
	State of this Thread. More...

uint32_t	stack_size () const
	Get the total stack memory size for this Thread. More...

uint32_t	free_stack () const
	Get the currently unused stack memory for this Thread. More...

uint32_t	used_stack () const
	Get the currently used stack memory for this Thread. More...

uint32_t	max_stack () const
	Get the maximum stack memory usage to date for this Thread. More...

const char *	get_name () const
	Get thread name. More...

osThreadId_t	get_id () const
	Get thread id. More...

virtual	~Thread ()
	Thread destructor. More...

Detailed Description

The Thread class allow defining, creating, and controlling thread functions in the system.

Example:

#include "mbed.h"
#include "rtos.h"
 
Thread thread;
DigitalOut led1(LED1);
volatile bool running = true;
 
// Blink function toggles the led in a long running loop
void blink(DigitalOut *led) {
    while (running) {
        *led = !*led;
        ThisThread::sleep_for(1000);
    }
}
 
// Spawns a thread to run blink for 5 seconds
int main() {
    thread.start(callback(blink, &led1));
    ThisThread::sleep_for(5000);
    running = false;
    thread.join();
}

Note: Memory considerations: The thread control structures will be created on current thread's stack, both for the mbed OS and underlying RTOS objects (static or dynamic RTOS memory pools are not being used). Additionally the stack memory for this thread will be allocated on the heap, if it wasn't supplied to the constructor.; MBED_TZ_DEFAULT_ACCESS (default:0) flag can be used to change the default access of all user threads in non-secure mode. MBED_TZ_DEFAULT_ACCESS set to 1, means all non-secure user threads have access to call secure functions. MBED_TZ_DEFAULT_ACCESS set to 0, means none of the non-secure user thread have access to call secure functions, to give access to particular thread used overloaded constructor with tz_module as argument during thread creation.

MBED_TZ_DEFAULT_ACCESS is target specific define, should be set in targets.json file for Cortex-M23/M33 devices.

Note: Bare metal profile: This class is not supported.

Definition at line 92 of file Thread.h.

Member Enumeration Documentation

◆ State

enum State

State of the Thread.

Enumerator
Inactive	NOT USED.
Ready	Ready to run.
Running	Running.
WaitingDelay	Waiting for a delay to occur.
WaitingJoin	Waiting for thread to join. Only happens when using RTX directly.
WaitingThreadFlag	Waiting for a thread flag to be set.
WaitingEventFlag	Waiting for a event flag to be set.
WaitingMutex	Waiting for a mutex event to occur.
WaitingSemaphore	Waiting for a semaphore event to occur.
WaitingMemoryPool	Waiting for a memory pool.
WaitingMessageGet	Waiting for message to arrive.
WaitingMessagePut	Waiting for message to be send.
WaitingInterval	NOT USED.
WaitingOr	NOT USED.
WaitingAnd	NOT USED.
WaitingMailbox	NOT USED (Mail is implemented as MemoryPool and Queue)
Deleted	The task has been deleted or not started.

Definition at line 180 of file Thread.h.

Constructor & Destructor Documentation

◆ Thread() [1/2]

Thread	(	osPriority	priority = `osPriorityNormal`,
		uint32_t	stack_size = `OS_STACK_SIZE`,
		unsigned char *	stack_mem = `nullptr`,
		const char *	name = `nullptr`
	)

Allocate a new thread without starting execution.

Parameters

priority	initial priority of the thread function. (default: osPriorityNormal).
stack_size	stack size (in bytes) requirements for the thread function. (default: OS_STACK_SIZE).
stack_mem	pointer to the stack area to be used by this thread (default: nullptr).
name	name to be used for this thread. It has to stay allocated for the lifetime of the thread (default: nullptr)

Note: Default value of tz_module will be MBED_TZ_DEFAULT_ACCESS; You cannot call this function from ISR context.

Definition at line 104 of file Thread.h.

◆ Thread() [2/2]

Thread	(	uint32_t	tz_module,
		osPriority	priority = `osPriorityNormal`,
		uint32_t	stack_size = `OS_STACK_SIZE`,
		unsigned char *	stack_mem = `nullptr`,
		const char *	name = `nullptr`
	)

Allocate a new thread without starting execution.

Parameters

tz_module	trustzone thread identifier (osThreadAttr_t::tz_module) Context of RTOS threads in non-secure state must be saved when calling secure functions. tz_module ID is used to allocate context memory for threads, and it can be safely set to zero for threads not using secure calls at all. See "TrustZone RTOS Context Management" for more details.
priority	initial priority of the thread function. (default: osPriorityNormal).
stack_size	stack size (in bytes) requirements for the thread function. (default: OS_STACK_SIZE).
stack_mem	pointer to the stack area to be used by this thread (default: nullptr).
name	name to be used for this thread. It has to stay allocated for the lifetime of the thread (default: nullptr)

Note: You cannot call this function from ISR context.

Definition at line 124 of file Thread.h.

◆ ~Thread()

virtual ~Thread ( )

virtual

Thread destructor.

Note: You cannot call this function from ISR context.

Member Function Documentation

◆ start()

osStatus start ( mbed::Callback< void()> task )

Starts a thread executing the specified function.

Parameters

task	function to be executed by this thread.

Returns: status code that indicates the execution status of the function, or osErrorNoMemory if stack allocation failed.

Note: a thread can only be started once; You cannot call this function ISR context.

◆ join()

osStatus join ( )

Wait for thread to terminate.

Returns: status code that indicates the execution status of the function.

Note: You cannot call this function from ISR context.

◆ terminate()

osStatus terminate ( )

Terminate execution of a thread and remove it from Active Threads.

Returns: status code that indicates the execution status of the function.

Note: You cannot call this function from ISR context.

◆ set_priority()

osStatus set_priority ( osPriority priority )

Set priority of an active thread.

Parameters

priority new priority value for the thread function.

Returns: status code that indicates the execution status of the function.

Note: You cannot call this function from ISR context.

◆ get_priority()

osPriority get_priority ( ) const

Get priority of an active thread.

Returns: current priority value of the thread function.

Note: You cannot call this function from ISR context.

◆ flags_set()

uint32_t flags_set ( uint32_t flags )

Set the specified Thread Flags for the thread.

Parameters

flags specifies the flags of the thread that should be set.

Returns: thread flags after setting or osFlagsError in case of incorrect parameters.

Note: You may call this function from ISR context.

◆ get_state()

State get_state ( ) const

State of this Thread.

Returns: the State of this Thread

Note: You cannot call this function from ISR context.

◆ stack_size()

uint32_t stack_size ( ) const

Get the total stack memory size for this Thread.

Returns: the total stack memory size in bytes

Note: You cannot call this function from ISR context.

◆ free_stack()

uint32_t free_stack ( ) const

Get the currently unused stack memory for this Thread.

Returns: the currently unused stack memory in bytes

Note: You cannot call this function from ISR context.

◆ used_stack()

uint32_t used_stack ( ) const

Get the currently used stack memory for this Thread.

Returns: the currently used stack memory in bytes

Note: You cannot call this function from ISR context.

◆ max_stack()

uint32_t max_stack ( ) const

Get the maximum stack memory usage to date for this Thread.

Returns: the maximum stack memory usage to date in bytes

Note: You cannot call this function from ISR context.

◆ get_name()

const char * get_name ( ) const

Get thread name.

Returns: thread name or nullptr if the name was not set.

Note: You may call this function from ISR context.

◆ get_id()

osThreadId_t get_id ( ) const

Get thread id.

Returns: thread ID for reference by other functions.

Note: You may call this function from ISR context.

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ State

Constructor & Destructor Documentation

◆ Thread() [1/2]

◆ Thread() [2/2]

◆ ~Thread()

Member Function Documentation

◆ start()

◆ join()

◆ terminate()

◆ set_priority()

◆ get_priority()

◆ flags_set()

◆ get_state()

◆ stack_size()

◆ free_stack()

◆ used_stack()

◆ max_stack()

◆ get_name()

◆ get_id()