QP/C: qeq_fifo.c Source File

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00001 /*****************************************************************************
00002 * Product: QF/C
00003 * Last Updated for Version: 4.4.00
00004 * Date of the Last Update:  Jan 14, 2012
00005 *
00006 *                    Q u a n t u m     L e a P s
00007 *                    ---------------------------
00008 *                    innovating embedded systems
00009 *
00010 * Copyright (C) 2002-2012 Quantum Leaps, LLC. All rights reserved.
00011 *
00012 * This software may be distributed and modified under the terms of the GNU
00013 * General Public License version 2 (GPL) as published by the Free Software
00014 * Foundation and appearing in the file GPL.TXT included in the packaging of
00015 * this file. Please note that GPL Section 2[b] requires that all works based
00016 * on this software must also be made publicly available under the terms of
00017 * the GPL ("Copyleft").
00018 *
00019 * Alternatively, this software may be distributed and modified under the
00020 * terms of Quantum Leaps commercial licenses, which expressly supersede
00021 * the GPL and are specifically designed for licensees interested in
00022 * retaining the proprietary status of their code.
00023 *
00024 * Contact information:
00025 * Quantum Leaps Web site:  http://www.quantum-leaps.com
00026 * e-mail:                  info@quantum-leaps.com
00027 *****************************************************************************/
00028 #include "qf_pkg.h"
00029 #include "qassert.h"
00030 
00031 Q_DEFINE_THIS_MODULE("qeq_fifo")
00032 
00033 
00040 /*..........................................................................*/
00041 void QEQueue_postFIFO(QEQueue *me, QEvent const *e) {
00042     QF_CRIT_STAT_
00043     QF_CRIT_ENTRY_();
00044 
00045     QS_BEGIN_NOCRIT_(QS_QF_EQUEUE_POST_FIFO, QS_eqObj_, me)
00046         QS_TIME_();                                            /* timestamp */
00047         QS_SIG_(e->sig);                        /* the signal of this event */
00048         QS_OBJ_(me);                                   /* this queue object */
00049         QS_U8_(QF_EVT_POOL_ID_(e));             /* the pool Id of the event */
00050         QS_U8_(QF_EVT_REF_CTR_(e));           /* the ref count of the event */
00051         QS_EQC_(me->nFree);                       /* number of free entries */
00052         QS_EQC_(me->nMin);                    /* min number of free entries */
00053     QS_END_NOCRIT_()
00054 
00055     if (QF_EVT_POOL_ID_(e) != (uint8_t)0) {          /* is it a pool event? */
00056         QF_EVT_REF_CTR_INC_(e);          /* increment the reference counter */
00057     }
00058 
00059     if (me->frontEvt == (QEvent *)0) {               /* is the queue empty? */
00060         me->frontEvt = e;                         /* deliver event directly */
00061     }
00062     else {            /* queue is not empty, leave event in the ring-buffer */
00063             /* the queue must be able to accept the event (cannot overflow) */
00064         Q_ASSERT(me->nFree != (QEQueueCtr)0);
00065 
00066         QF_PTR_AT_(me->ring, me->head) = e;  /* insert e into buffer (FIFO) */
00067         if (me->head == (QEQueueCtr)0) {          /* need to wrap the head? */
00068             me->head = me->end;                              /* wrap around */
00069         }
00070         --me->head;
00071 
00072         --me->nFree;                        /* update number of free events */
00073         if (me->nMin > me->nFree) {
00074             me->nMin = me->nFree;                  /* update minimum so far */
00075         }
00076     }
00077     QF_CRIT_EXIT_();
00078 }