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

#include <Thread.h>

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=NULL, const char name=NULL)
	Allocate a new thread without starting execution.
	MBED_DEPRECATED_SINCE ("mbed-os-5.1","Thread-spawning constructors hide errors. ""Replaced by thread.start(task).") Thread(mbed
	Create a new thread, and start it executing the specified function.
template<typename T >
	MBED_DEPRECATED_SINCE ("mbed-os-5.1","Thread-spawning constructors hide errors. ""Replaced by thread.start(callback(task, argument)).") Thread(T *argument
	Create a new thread, and start it executing the specified function.
template<typename T , typename M >
	MBED_DEPRECATED_SINCE ("mbed-os-5.1","The start function does not support cv-qualifiers. ""Replaced by thread.start(callback(obj, method)).") osStatus start(T *obj
	Starts a thread executing the specified function.
osStatus	join ()
	Wait for thread to terminate.
osStatus	terminate ()
	Terminate execution of a thread and remove it from Active Threads.
osStatus	set_priority (osPriority priority)
	Set priority of an active thread.
osPriority	get_priority ()
	Get priority of an active thread.
int32_t	signal_set (int32_t signals)
	Set the specified Thread Flags for the thread.
State	get_state ()
	State of this Thread.
uint32_t	stack_size ()
	Get the total stack memory size for this Thread.
uint32_t	free_stack ()
	Get the currently unused stack memory for this Thread.
uint32_t	used_stack ()
	Get the currently used stack memory for this Thread.
uint32_t	max_stack ()
	Get the maximum stack memory usage to date for this Thread.
const char *	get_name ()
	Get thread name.
virtual	~Thread ()
	Thread destructor.
Static Public Member Functions
static int32_t	signal_clr (int32_t signals)
	Clears the specified Thread Flags of the currently running thread.
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.
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.
static osStatus	wait_until (uint64_t millisec)
	Wait until a specified time in millisec The specified time is according to Kernel::get_ms_count().
static osStatus	yield ()
	Pass control to next thread that is in state READY.
static osThreadId	gettid ()
	Get the thread id of the current running thread.
static void	attach_idle_hook (void(*fptr)(void))
	Attach a function to be called by the RTOS idle task.
static void	attach_terminate_hook (void(*fptr)(osThreadId id))
	Attach a function to be called when a task is killed.
Private Member Functions
	MBED_DEPRECATED ("Invalid copy construction of a NonCopyable resource.") NonCopyable(const NonCopyable &)
	NonCopyable copy constructor.
	MBED_DEPRECATED ("Invalid copy assignment of a NonCopyable resource.") NonCopyable &operator
	NonCopyable copy assignment operator.

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.

Definition at line 76 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 282 of file Thread.h.

Constructor & Destructor Documentation

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

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: NULL).
name	name to be used for this thread. It has to stay allocated for the lifetime of the thread (default: NULL)

Note:: You cannot call this function from ISR context.

Definition at line 86 of file Thread.h.

~Thread ( ) [virtual]

Thread destructor.

Note:: You cannot call this function from ISR context.

Definition at line 401 of file Thread.cpp.

Member Function Documentation

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.

Definition at line 393 of file Thread.cpp.

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.

uint32_t free_stack ( )

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.

Definition at line 261 of file Thread.cpp.

const char * get_name ( )

Get thread name.

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

Note:: You may call this function from ISR context.

Definition at line 311 of file Thread.cpp.

osPriority get_priority ( )

Get priority of an active thread.

Returns:: current priority value of the thread function.

Note:: You cannot call this function from ISR context.

Definition at line 170 of file Thread.cpp.

Thread::State get_state ( )

State of this Thread.

Returns:: the State of this Thread

Note:: You cannot call this function from ISR context.

Definition at line 184 of file Thread.cpp.

osThreadId gettid ( ) [static]

Get the thread id of the current running thread.

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

Note:: You may call this function from ISR context.

Definition at line 389 of file Thread.cpp.

osStatus join ( )

Wait for thread to terminate.

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

Note:: not callable from interrupt; You cannot call this function from ISR context.

Definition at line 142 of file Thread.cpp.

uint32_t max_stack ( )

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.

Definition at line 291 of file Thread.cpp.

MBED_DEPRECATED_SINCE	(	"mbed-os-5.1"	,
		"Thread-spawning constructors hide errors. ""Replaced by thread.start(task)."
	)

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: NULL).

        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 111 of file Thread.h.

MBED_DEPRECATED_SINCE	(	"mbed-os-5.1"	,
		"The start function does not support cv-qualifiers. ""Replaced by thread.start(callback(obj, 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.

Note:: You cannot call this function from ISR context.

MBED_DEPRECATED_SINCE	(	"mbed-os-5.1"	,
		"Thread-spawning constructors hide errors. ""Replaced by thread.start(callback(task, argument))."
	)

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: NULL).
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: NULL).

        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.

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.

Definition at line 160 of file Thread.cpp.

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.

Definition at line 315 of file Thread.cpp.

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.

Definition at line 180 of file Thread.cpp.

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 or 0 in case of no time-out. (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.

Definition at line 319 of file Thread.cpp.

uint32_t stack_size ( )

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 terminate ( void )

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.

Definition at line 120 of file Thread.cpp.

uint32_t used_stack ( )

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.

Definition at line 276 of file Thread.cpp.

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.

Definition at line 352 of file Thread.cpp.

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.

Definition at line 356 of file Thread.cpp.

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.

Definition at line 385 of file Thread.cpp.

Type:	Program
Mbed OS support:	Mbed OS
Created:	13 Apr 2018
Imports:	1
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	1

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Thread Class Reference
[Thread class]

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

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Important changes to repositories hosted on mbed.com

Thread Class Reference [Thread class]

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

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Thread Class Reference
[Thread class]