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QP/C++
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00001 00002 // Product: QK/C++ 00003 // Last Updated for Version: 4.3.00 00004 // Date of the Last Update: Nov 02, 2011 00005 // 00006 // Q u a n t u m L e a P s 00007 // --------------------------- 00008 // innovating embedded systems 00009 // 00010 // Copyright (C) 2002-2011 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 00028 #include "qk_pkg.h" 00029 //#include "qassert.h" 00030 00034 00035 #ifdef Q_USE_NAMESPACE 00036 namespace QP { 00037 #endif 00038 00039 //Q_DEFINE_THIS_MODULE(qk_sched) 00040 00041 #ifdef Q_USE_NAMESPACE 00042 } // namespace QP 00043 #endif 00044 00045 //............................................................................ 00046 // NOTE: the QK scheduler is entered and exited with interrupts DISABLED. 00047 // QK_sched_() is extern "C", so it does not belong to the QP namespace. 00048 // 00049 extern "C" { 00050 00051 void QK_sched_(uint8_t p) { 00052 00053 #ifdef Q_USE_NAMESPACE 00054 using namespace QP; 00055 #endif 00056 00057 uint8_t pin = QK_currPrio_; // save the initial priority 00058 QActive *a; 00059 #ifdef QK_TLS // thread-local storage used? 00060 uint8_t pprev = pin; 00061 #endif 00062 do { 00063 a = QF::active_[p]; // obtain the pointer to the AO 00064 QK_currPrio_ = p; // this becomes the current task priority 00065 00066 #ifdef QK_TLS // thread-local storage used? 00067 if (p != pprev) { // are we changing threads? 00068 QK_TLS(a); // switch new thread-local storage 00069 pprev = p; 00070 } 00071 #endif 00072 QS_BEGIN_NOCRIT_(QS_QK_SCHEDULE, QS::aoObj_, a) 00073 QS_TIME_(); // timestamp 00074 QS_U8_(p); // the priority of the active object 00075 QS_U8_(pin); // the preempted priority 00076 QS_END_NOCRIT_() 00077 00078 QF_INT_ENABLE(); // unconditionally enable interrupts 00079 00080 QEvent const *e = a->get_(); // get the next event for this AO 00081 a->dispatch(e); // dispatch e to this AO 00082 QF::gc(e); // garbage collect the event, if necessary 00083 00084 // determine the next highest-priority AO ready to run 00085 QF_INT_DISABLE(); // disable interrupts 00086 p = QK_readySet_.findMax(); 00087 00088 #ifdef QK_NO_MUTEX 00089 } while (p > pin); // is the new priority higher than initial? 00090 #else // QK priority-ceiling mutexes allowed 00091 } while ((p > pin) && (p > QK_ceilingPrio_)); 00092 #endif 00093 00094 QK_currPrio_ = pin; // restore the initial priority 00095 00096 #ifdef QK_TLS // thread-local storage used? 00097 if (pin != (uint8_t)0) { // no extended context for the idle loop 00098 a = QF::active_[pin]; // the pointer to the preempted AO 00099 QK_TLS(a); // restore the original TLS 00100 } 00101 #endif 00102 } 00103 00104 } // extern "C"
1.7.5.1