rclcpp::TimerBase Class Reference

Inheritance diagram for rclcpp::TimerBase:

Public Member Functions
RCLCPP_PUBLIC	TimerBase (Clock::SharedPtr clock, std::chrono::nanoseconds period, rclcpp::Context::SharedPtr context)
	TimerBase constructor. More...
virtual RCLCPP_PUBLIC	~TimerBase ()
	TimerBase destructor.
RCLCPP_PUBLIC void	cancel ()
	Cancel the timer. More...
RCLCPP_PUBLIC bool	is_canceled ()
	Return the timer cancellation state. More...
RCLCPP_PUBLIC void	reset ()
	Reset the timer. More...
virtual RCLCPP_PUBLIC bool	call ()=0
	Indicate that we're about to execute the callback. More...
virtual RCLCPP_PUBLIC void	execute_callback ()=0
	Call the callback function when the timer signal is emitted.
RCLCPP_PUBLIC std::shared_ptr< const rcl_timer_t >	get_timer_handle ()
RCLCPP_PUBLIC std::chrono::nanoseconds	time_until_trigger ()
	Check how long the timer has until its next scheduled callback. More...
virtual bool	is_steady ()=0
	Is the clock steady (i.e. is the time between ticks constant?) More...
RCLCPP_PUBLIC bool	is_ready ()
	Check if the timer is ready to trigger the callback. More...
RCLCPP_PUBLIC bool	exchange_in_use_by_wait_set_state (bool in_use_state)
	Exchange the "in use by wait set" state for this timer. More...

Protected Attributes
Clock::SharedPtr	clock_
std::shared_ptr< rcl_timer_t >	timer_handle_
std::atomic< bool >	in_use_by_wait_set_ {false}

Detailed Description

Definition at line 46 of file timer.hpp.

Constructor & Destructor Documentation

TimerBase()

TimerBase::TimerBase ( Clock::SharedPtr  clock, std::chrono::nanoseconds  period, rclcpp::Context::SharedPtr  context  )

explicit

TimerBase constructor.

Parameters

clock	A clock to use for time and sleeping
period	The interval at which the timer fires
context	node context

Definition at line 29 of file timer.cpp.

References rcl_get_default_allocator, rcl_get_zero_initialized_timer(), RCL_RET_OK, rcl_timer_fini(), and rcl_timer_init().

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Member Function Documentation

call()

virtual RCLCPP_PUBLIC bool rclcpp::TimerBase::call ( )

pure virtual

Indicate that we're about to execute the callback.

The multithreaded executor takes advantage of this to avoid scheduling the callback multiple times.

Returns

true if the callback should be executed, false if the timer was canceled.

Implemented in rclcpp::GenericTimer< FunctorT, >.

cancel()

void TimerBase::cancel

(

)

Cancel the timer.

Exceptions

std::runtime_error

if the rcl_timer_cancel returns a failure

Definition at line 77 of file timer.cpp.

References RCL_RET_OK, and rcl_timer_cancel().

Referenced by rclcpp::GenericTimer< FunctorT, >::~GenericTimer().

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exchange_in_use_by_wait_set_state()

bool TimerBase::exchange_in_use_by_wait_set_state

(

bool

in_use_state

)

Exchange the "in use by wait set" state for this timer.

This is used to ensure this timer is not used by multiple wait sets at the same time.

Parameters

[in]

in_use_state

the new state to exchange into the state, true indicates it is now in use by a wait set, and false is that it is no longer in use by a wait set.

Returns

the previous state.

Definition at line 137 of file timer.cpp.

is_canceled()

bool TimerBase::is_canceled

(

)

Return the timer cancellation state.

Returns

true if the timer has been cancelled, false otherwise

Exceptions

std::runtime_error	if the rcl_get_error_state returns 0
rclcpp::exceptions::RCLError	some child class exception based on ret

Definition at line 86 of file timer.cpp.

References RCL_RET_OK, and rcl_timer_is_canceled().

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is_ready()

bool TimerBase::is_ready

(

)

Check if the timer is ready to trigger the callback.

This function expects its caller to immediately trigger the callback after this function, since it maintains the last time the callback was triggered.

Returns

True if the timer needs to trigger.

Exceptions

std::runtime_error

if it failed to check timer

Definition at line 106 of file timer.cpp.

References RCL_RET_OK, and rcl_timer_is_ready().

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is_steady()

virtual bool rclcpp::TimerBase::is_steady ( )

pure virtual

Is the clock steady (i.e. is the time between ticks constant?)

Returns

True if the clock used by this timer is steady.

Implemented in rclcpp::GenericTimer< FunctorT, >.

reset()

void TimerBase::reset

(

)

Reset the timer.

Exceptions

std::runtime_error

if the rcl_timer_reset returns a failure

Definition at line 97 of file timer.cpp.

References RCL_RET_OK, and rcl_timer_reset().

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time_until_trigger()

std::chrono::nanoseconds TimerBase::time_until_trigger

(

)

Check how long the timer has until its next scheduled callback.

Returns

A std::chrono::duration representing the relative time until the next callback or std::chrono::nanoseconds::max() if the timer is canceled.

Exceptions

std::runtime_error

if the rcl_timer_get_time_until_next_call returns a failure

Definition at line 117 of file timer.cpp.

References RCL_RET_OK, RCL_RET_TIMER_CANCELED, and rcl_timer_get_time_until_next_call().

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The documentation for this class was generated from the following files:

• rclcpp/include/rclcpp/timer.hpp
• rclcpp/src/rclcpp/timer.cpp