qa_sub.c File Reference

QActive_subscribe() definition. More...

#include "qf_pkg.h"
#include "qassert.h"

Go to the source code of this file.

Functions
void	QActive_subscribe (QActive const *me, QSignal sig)
	Subscribes for delivery of signal sig to the active object me.

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Detailed Description

QActive_subscribe() definition.

Definition in file qa_sub.c.

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Function Documentation

void QActive_subscribe	(	QActive const *	me,
		QSignal	sig
	)

Subscribes for delivery of signal sig to the active object me.

This function is part of the Publish-Subscribe event delivery mechanism available in QF. Subscribing to an event means that the framework will start posting all published events with a given signal sig to the event queue of the active object me.

The following example shows how the Table active object subscribes to three signals in the initial transition:

QState Table_initial(Table *me, QEvent const *e) {
    uint8_t n;
    (void)e;                               /* suppress the compiler warning */

    QActive_subscribe((QActive *)me, HUNGRY_SIG);   /* subscribe to HUNGRY */
    QActive_subscribe((QActive *)me, DONE_SIG);              /*... to DONE */
    QActive_subscribe((QActive *)me, TERMINATE_SIG); /*...and to TERMINATE */
    for (n = 0; n < N; ++n) {
        me->fork[n] = FREE;
        me->isHungry[n] = 0;
    }
    return Q_TRAN(&Table_serving);
}

See also:

QF_publish(), QActive_unsubscribe(), and QActive_unsubscribeAll()

Definition at line 40 of file qa_sub.c.

References Q_REQUIRE, Q_USER_SIG, QF_active_, QF_div8Lkup, QF_MAX_ACTIVE, QF_maxSignal_, QF_PTR_AT_, QF_pwr2Lkup, QF_subscrList_, QS_aoObj_, QS_BEGIN_NOCRIT_, QS_END_NOCRIT_, QS_OBJ_, QS_QF_ACTIVE_SUBSCRIBE, and QS_TIME_.