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

#include <Thread.h>

Inheritance diagram for Thread:

Public Types

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...

	Thread (mbed::Callback< void()> task, osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char *stack_mem=nullptr)
	Create a new thread, and start it executing the specified function. More...

template<typename T >
	Thread (T argument, void(T::task)(), osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char *stack_mem=nullptr)
	Create a new thread, and start it executing the specified function. More...

template<typename T >
	Thread (T argument, void(task)(T ), osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char stack_mem=nullptr)
	Create a new thread, and start it executing the specified function. More...

	Thread (void(task)(void const argument), void argument=nullptr, osPriority priority=osPriorityNormal, uint32_t stack_size=OS_STACK_SIZE, unsigned char stack_mem=nullptr)
	Create a new thread, and start it executing the specified function. More...

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

template<typename T , typename M >
osStatus	start (T *obj, M method)
	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...

int32_t	signal_set (int32_t signals)
	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...

Static Public Member Functions
static int32_t	signal_clr (int32_t signals)
	Clears the specified Thread Flags of the currently running thread. More...

static osEvent	signal_wait (int32_t signals, uint32_t millisec=osWaitForever)
	Wait for one or more Thread Flags to become signaled for the current RUNNING thread. More...

static osStatus	wait (uint32_t millisec)
	Wait for a specified time period in milliseconds Being tick-based, the delay will be up to the specified time - eg for a value of 1 the system waits until the next millisecond tick occurs, leading to a delay of 0-1 milliseconds. More...

static osStatus	wait_until (uint64_t millisec)
	Wait until a specified time in millisec The specified time is according to Kernel::get_ms_count(). More...

static osStatus	yield ()
	Pass control to next thread that is in state READY. More...

static osThreadId	gettid ()
	Get the thread id of the current running thread. More...

static void	attach_idle_hook (void(*fptr)(void))
	Attach a function to be called by the RTOS idle task. More...

static void	attach_terminate_hook (void(*fptr)(osThreadId id))
	Attach a function to be called when a task is killed. 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;
        wait(1);
    }
}
// Spawns a thread to run blink for 5 seconds
int main() {
    thread.start(callback(blink, &led1));
    wait(5);
    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.

Definition at line 88 of file Thread.h.

Member Enumeration Documentation

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 335 of file Thread.h.

Constructor & Destructor Documentation

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 100 of file Thread.h.

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 120 of file Thread.h.

Thread	(	mbed::Callback< void()>	task,
		osPriority	priority = `osPriorityNormal`,
		uint32_t	stack_size = `OS_STACK_SIZE`,
		unsigned char *	stack_mem = `nullptr`
	)

Create a new thread, and start it executing the specified function.

Parameters

task	function to be executed by this thread.
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).

Deprecated:: Thread-spawning constructors hide errors. Replaced by thread.start(task).

Thread thread(priority, stack_size, stack_mem);
osStatus status = thread.start(task);
if (status != osOK) {
    error("oh no!");
}

Note: You cannot call this function from ISR context.

Definition at line 150 of file Thread.h.

Thread	(	T *	argument,
		void(T::*)()	task,
		osPriority	priority = `osPriorityNormal`,
		uint32_t	stack_size = `OS_STACK_SIZE`,
		unsigned char *	stack_mem = `nullptr`
	)

Create a new thread, and start it executing the specified function.

Parameters

argument	pointer that is passed to the thread function as start argument. (default: nullptr).
task	argument to task.
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).

Deprecated:: Thread-spawning constructors hide errors. Replaced by thread.start(callback(task, argument)).

Thread thread(priority, stack_size, stack_mem);
osStatus status = thread.start(callback(task, argument));
if (status != osOK) {
    error("oh no!");
}

Note: You cannot call this function from ISR context.

Definition at line 182 of file Thread.h.

Thread	(	T *	argument,
		void()(T )	task,
		osPriority	priority = `osPriorityNormal`,
		uint32_t	stack_size = `OS_STACK_SIZE`,
		unsigned char *	stack_mem = `nullptr`
	)

Create a new thread, and start it executing the specified function.

Parameters

argument	pointer that is passed to the thread function as start argument. (default: nullptr).
task	argument to task.
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).

Deprecated:: Thread-spawning constructors hide errors. Replaced by thread.start(callback(task, argument)).

Thread thread(priority, stack_size, stack_mem);
osStatus status = thread.start(callback(task, argument));
if (status != osOK) {
    error("oh no!");
}

Note: You cannot call this function from ISR context.

Definition at line 215 of file Thread.h.

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

Create a new thread, and start it executing the specified function.

Provided for backwards compatibility

Parameters

task	function to be executed by this thread.
argument	pointer that is passed to the thread function as start argument. (default: nullptr).
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).

Deprecated:: Thread-spawning constructors hide errors. Replaced by thread.start(callback(task, argument)).

Thread thread(priority, stack_size, stack_mem);
osStatus status = thread.start(callback(task, argument));
if (status != osOK) {
    error("oh no!");
}

Note: You cannot call this function from ISR context.

Definition at line 248 of file Thread.h.

virtual ~Thread ( )

virtual

Thread destructor.

Note: You cannot call this function from ISR context.

Member Function Documentation

static void attach_idle_hook ( void(*)(void) fptr )

static

Attach a function to be called by the RTOS idle task.

Parameters

fptr	pointer to the function to be called

Note: You may call this function from ISR context.

Deprecated:: Static methods affecting system cause confusion. Replaced by Kernel::attach_idle_hook.

static void attach_terminate_hook ( void(*)(osThreadId id) fptr )

static

Attach a function to be called when a task is killed.

Parameters

fptr	pointer to the function to be called

Note: You may call this function from ISR context.

Deprecated:: Static methods affecting system cause confusion. Replaced by Kernel::attach_thread_terminate_hook.

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.

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.

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.

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.

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.

State get_state ( ) const

State of this Thread.

Returns: the State of this Thread

Note: You cannot call this function from ISR context.

static osThreadId gettid ( )

static

Get the thread id of the current running thread.

Returns: thread ID for reference by other functions or nullptr in case of error.

Note: You may call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::get_id. Use Thread::get_id for the ID of a specific Thread.

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.

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.

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.

static int32_t signal_clr ( int32_t signals )

static

Clears the specified Thread Flags of the currently running thread.

Parameters

signals specifies the signal flags of the thread that should be cleared.

Returns: signal flags before clearing or osFlagsError in case of incorrect parameters.

Note: You cannot call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::flags_clear.

int32_t signal_set ( int32_t signals )

Set the specified Thread Flags for the thread.

Parameters

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

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

Note: You may call this function from ISR context.

Deprecated:: Other signal_xxx methods have been deprecated in favour of ThisThread::flags functions. To match this naming scheme, derived from CMSIS-RTOS2, Thread::flags_set is now provided.

static osEvent signal_wait	(	int32_t	signals,
		uint32_t	millisec = `osWaitForever`
	)

static

Wait for one or more Thread Flags to become signaled for the current RUNNING thread.

Parameters

signals	wait until all specified signal flags are set or 0 for any single signal flag.
millisec	timeout value. (default: osWaitForever).

Returns: event flag information or error code.

Note: if millisec is set to 0 and flag is no set the event carries osOK value.; You cannot call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::flags_wait_all, ThisThread::flags_wait_all_for, ThisThread::flags_wait_any and ThisThread:wait_any_for.

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.

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.

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

osStatus start	(	T *	obj,
		M	method
	)

Starts a thread executing the specified function.

Parameters

obj	argument to task
method	function to be executed by this thread.

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

Deprecated:: The start function does not support cv-qualifiers. Replaced by start(callback(obj, method)).

Note: You cannot call this function from ISR context.

Definition at line 279 of file Thread.h.

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.

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.

static osStatus wait ( uint32_t millisec )

static

Wait for a specified time period in milliseconds Being tick-based, the delay will be up to the specified time - eg for a value of 1 the system waits until the next millisecond tick occurs, leading to a delay of 0-1 milliseconds.

Parameters

millisec time delay value

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

Note: You cannot call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::sleep_for.

static osStatus wait_until ( uint64_t millisec )

static

Wait until a specified time in millisec The specified time is according to Kernel::get_ms_count().

Parameters

millisec absolute time in millisec

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

Note: not callable from interrupt; if millisec is equal to or lower than the current tick count, this returns immediately, either with an error or "osOK".; the underlying RTOS may have a limit to the maximum wait time due to internal 32-bit computations, but this is guaranteed to work if the delay is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded, it may return with an immediate error, or wait for the maximum delay.; You cannot call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::sleep_until.

static osStatus yield ( )

static

Pass control to next thread that is in state READY.

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

Note: You cannot call this function from ISR context.

Deprecated:: Static methods only affecting current thread cause confusion. Replaced by ThisThread::sleep_until.

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

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