Signal Class Reference

Overview

A wrapper class for the EtcPal signal type.

Example usage:

etcpal::Signal sig;
std::string data;
 
void worker_thread()
{
  // Wait until main() sends data
  sig.Wait();
 
  std::cout << "Worker thread is processing data\n";
  data += " after processing";
 
  // Send data back to main()
  std::cout << "Worker thread signals data processing completed\n";
  sig.Notify();
}
 
int main()
{
  etcpal::Thread worker(worker_thread);
 
  data = "Example data";
  // send data to the worker thread
  std::cout << "main() signals data ready for processing\n";
  sig.Notify();
 
  // wait for the worker
  sig.Wait();
  std::cout << "Back in main(), data = " << data << '\n';
 
  worker.Join();
  return 0;
}

The output of the above would be:

main() signals data ready for processing
Worker thread is processing data
Worker thread signals data processing completed
Back in main(), data = Example data after processing

See signal (Signals) for more information.

Public Member Functions
	Signal ()
	Create a new signal.
	~Signal ()
	Destroy the signal.
	Signal (const Signal &other)=delete
Signal &	operator= (const Signal &other)=delete
	Signal (Signal &&other)=delete
Signal &	operator= (Signal &&other)=delete
bool	Wait ()
	Wait for the signal. More...
bool	TryWait (int timeout_ms=0)
	Wait for the signal until either it is received or a timeout expires. More...
void	Notify ()
	Notify those waiting on the signal. More...
void	NotifyFromIsr ()
	Notify those waiting on the signal from an interrupt context. More...
etcpal_signal_t &	get ()
	Get a reference to the underlying etcpal_signal_t type.

Member Function Documentation

Notify()

void Notify ( )

inline

Notify those waiting on the signal.

See etcpal_signal_post().

NotifyFromIsr()

void NotifyFromIsr ( )

inline

Notify those waiting on the signal from an interrupt context.

NOTE: Only meaningful on some platforms. See the table in signal (Signals) and etcpal_signal_post_from_isr() for more information. On platforms on which it is not meaningful, executes the equivalent of Notify().

TryWait()

bool TryWait ( int  timeout_ms = 0 )

inline

Wait for the signal until either it is received or a timeout expires.

NOTE: Timeouts other than 0 or ETCPAL_WAIT_FOREVER are typically only honored on real-time platforms. See the table in signal (Signals) for more information. On platforms where timeouts are not honored, passing 0 for timeout_ms returns immediately whether the signal is in the signaled or unsignaled state, while any other value executes the equivalent of Wait().

Parameters

timeout_ms

How long to wait for the signal, in milliseconds.

Returns

The result of etcpal_signal_timed_wait() on the underlying signal.

Wait()

bool Wait ( )

inline

Wait for the signal.

Returns

The result of etcpal_signal_wait() on the underlying signal.

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

• include/etcpal/cpp/signal.h