qpcpp/qf/source/qa_lifo.cpp

96 lines
4.0 KiB
C++

//****************************************************************************
// Product: QF/C++
// Last Updated for Version: 5.1.1
// Date of the Last Update: Oct 08, 2013
//
// Q u a n t u m L e a P s
// ---------------------------
// innovating embedded systems
//
// Copyright (C) 2002-2013 Quantum Leaps, LLC. All rights reserved.
//
// This program is open source software: you can redistribute it and/or
// modify it under the terms of the GNU General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Alternatively, this program may be distributed and modified under the
// terms of Quantum Leaps commercial licenses, which expressly supersede
// the GNU General Public License and are specifically designed for
// licensees interested in retaining the proprietary status of their code.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Contact information:
// Quantum Leaps Web sites: http://www.quantum-leaps.com
// http://www.state-machine.com
// e-mail: info@quantum-leaps.com
//****************************************************************************
#include "qf_pkg.h"
#include "qassert.h"
/// \file
/// \ingroup qf
/// \brief QActive::postLIFO() implementation.
///
/// \note this source file is only included in the QF library when the native
/// QF active object queue is used (instead of a message queue of an RTOS).
namespace QP {
Q_DEFINE_THIS_MODULE("qa_lifo")
//............................................................................
void QActive::postLIFO(QEvt const * const e) {
QF_CRIT_STAT_
QF_CRIT_ENTRY_();
QEQueueCtr nFree = m_eQueue.m_nFree;// tmp to avoid UB for volatile access
// the queue must be able to accept the event (cannot overflow)
Q_ASSERT(nFree != static_cast<QEQueueCtr>(0));
QS_BEGIN_NOCRIT_(QS_QF_ACTIVE_POST_LIFO, QS::priv_.aoObjFilter, this)
QS_TIME_(); // timestamp
QS_SIG_(e->sig); // the signal of this event
QS_OBJ_(this); // this active object
QS_2U8_(e->poolId_, e->refCtr_); // pool Id & refCtr of the evt
QS_EQC_(nFree); // number of free entries
QS_EQC_(m_eQueue.m_nMin); // min number of free entries
QS_END_NOCRIT_()
if (e->poolId_ != u8_0) { // is it a dynamic event?
QF_EVT_REF_CTR_INC_(e); // increment the reference counter
}
--nFree; // one free entry just used up
m_eQueue.m_nFree = nFree; // update the volatile
if (m_eQueue.m_nMin > nFree) {
m_eQueue.m_nMin = nFree; // update minimum so far
}
QEvt const *frontEvt = m_eQueue.m_frontEvt;// read volatile into temporary
m_eQueue.m_frontEvt = e; // deliver the event directly to the front
if (frontEvt == null_evt) { // is the queue empty?
QACTIVE_EQUEUE_SIGNAL_(this); // signal the event queue
}
else { // queue is not empty, leave event in the ring-buffer
++m_eQueue.m_tail;
if (m_eQueue.m_tail == m_eQueue.m_end) { // need to wrap the tail?
m_eQueue.m_tail = static_cast<QEQueueCtr>(0); // wrap around
}
QF_PTR_AT_(m_eQueue.m_ring, m_eQueue.m_tail) = frontEvt;
}
QF_CRIT_EXIT_();
}
} // namespace QP