Starts monitoring a signal, notifying about its reception. More...

#include <Async.h>

Inheritance diagram for SC::AsyncSignal:

Classes
struct	CompletionData

struct	Result

Public Member Functions
SC::Result	start (AsyncEventLoop &eventLoop, int num, AsyncSignalOptions options={})
	Sets async request members and calls AsyncEventLoop::start.

Result	start (AsyncEventLoop &eventLoop)
	Shortcut for AsyncEventLoop::start.

Public Member Functions inherited from SC::AsyncRequest
void	setDebugName (const char *newDebugName)

void	executeOn (AsyncSequence &sequence)
	Adds the request to be executed on a specific AsyncSequence.

Result	executeOn (AsyncTaskSequence &task, ThreadPool &pool, AsyncThreadPoolMode mode=AsyncThreadPoolMode::NativePreferred)
	Adds the request to be executed on a specific AsyncTaskSequence.

void	disableThreadPool ()
	Disables the thread-pool usage for this request.

	AsyncRequest (Type type)
	Constructs a free async request of given type.

Result	stop (AsyncEventLoop &eventLoop, Function< void(AsyncResult &)> *afterStopped=nullptr)
	Ask to stop current async operation.

bool	isFree () const
	Returns `true` if this request is free.

bool	isCancelling () const
	Returns `true` if this request is being cancelled.

bool	isActive () const
	Returns `true` if this request is active or being reactivated.

Type	getType () const
	Returns request type.

Result	start (AsyncEventLoop &eventLoop)
	Shortcut for AsyncEventLoop::start.

void	setUserFlags (uint16_t externalFlags)
	Sets user flags, holding some meaningful data for the caller.

uint16_t	getUserFlags () const
	Gets user flags, holding some meaningful data for the caller.

Function< void(AsyncResult &)> *	getCloseCallback ()
	Returns currently set close callback (if any) passed to AsyncRequest::stop.

const Function< void(AsyncResult &)> *	getCloseCallback () const

Public Attributes
Function< void(Result &)>	callback
	Called when the signal is raised.

Public Attributes inherited from SC::AsyncRequest
AsyncRequest *	next = nullptr

AsyncRequest *	prev = nullptr

Friends
struct	AsyncEventLoop

Additional Inherited Members
Public Types inherited from SC::AsyncRequest
enum class	Type : uint8_t { LoopTimeout , LoopWakeUp , LoopWork , ProcessExit , Signal , SocketAccept , SocketConnect , SocketSend , SocketSendTo , SocketReceive , SocketReceiveFrom , FileRead , FileWrite , FileSend , FileReadiness , ExternalCompletion , FileSystemOperation }
	Type of async request. More...

Protected Member Functions inherited from SC::AsyncRequest
Result	checkState ()

void	queueSubmission (AsyncEventLoop &eventLoop)

AsyncTaskSequence *	getTask ()

bool	isThreadPoolForced () const

Protected Attributes inherited from SC::AsyncRequest
AsyncSequence *	sequence = nullptr

Detailed Description

Starts monitoring a signal, notifying about its reception.

AsyncSignal follows the base AsyncRequest lifecycle: after a delivered signal, the request is completed unless the callback calls Result::reactivateRequest(true). AsyncSignalOptions::mode and coalesce are kept as explicit policy fields for future backend-parity work, but portable code should not rely on them for automatic reactivation.

On POSIX systems, signals like SIGINT, SIGTERM, SIGHUP are supported. On Windows, console control signals CTRL_C_EVENT, CTRL_BREAK_EVENT, and CTRL_CLOSE_EVENT are mapped to SIGINT (2), signal 21, and SIGTERM (15) respectively.

Signal watcher capabilities:

one watcher for a given signal is supported on all backends.
multiple different signals on the same loop are supported on all backends.
multiple watchers for the same signal on Windows are supported through the process-wide console signal registry.
multiple POSIX watchers for the same signal are backend-dependent and should not be used as a portable fanout mechanism. Prefer one AsyncSignal per process signal and fan out from that callback when portable behavior matters.

// Assuming an already created (and running) AsyncEventLoop named eventLoop
// ...
AsyncSignal asyncSignal;
asyncSignal.callback = [&](AsyncSignal::Result& res)
{
    console.print("Signal {} received {} times", res.completionData.signalNumber, res.completionData.deliveryCount);
};
// On Windows, SIGINT (2) -> CTRL_C_EVENT, 21 -> CTRL_BREAK_EVENT, SIGTERM (15) -> CTRL_CLOSE_EVENT
SC_TRY(asyncSignal.start(eventLoop, SIGINT));

Member Function Documentation

◆ start() [1/2]

Result SC::AsyncRequest::start ( AsyncEventLoop & eventLoop )

Shortcut for AsyncEventLoop::start.

◆ start() [2/2]

SC::Result SC::AsyncSignal::start	(	AsyncEventLoop &	eventLoop,
		int	num,
		AsyncSignalOptions	options = {} )

Sets async request members and calls AsyncEventLoop::start.

Member Data Documentation

◆ callback

Function<void(Result&)> SC::AsyncSignal::callback

Called when the signal is raised.

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

Async.h

Classes

Public Member Functions

Public Attributes