📄 bbpc_sem.c
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<HTML><HEAD><TITLE>/home/asysweb/public_html/cortex/examples/exmpl1/src/bbpc_sem.c</TITLE></HEAD><BODY><pre><font color="#6920ac">/*************************************************************************/</font><font color="#6920ac">/* */</font><font color="#6920ac">/* Copyright (c) 1997-1999 Australian Real Time Embedded Systems */</font><font color="#6920ac">/* */</font><font color="#6920ac">/* PROPRIETARY RIGHTS of Australian Real Time Embedded Systems */</font><font color="#6920ac">/* are involved in the subject matter of this material. All reproduction,*/</font><font color="#6920ac">/* manufacturing, use, and sales rights pertaining to this subject matter*/</font><font color="#6920ac">/* are governed by the license agreement. The recipient of this software */</font><font color="#6920ac">/* implicitly accepts the terms of the license. */</font><font color="#6920ac">/* */</font><font color="#6920ac">/*************************************************************************/</font><font color="#6920ac">/* * The Bounded Buffer Consumers and Producers problem * (semaphore implementation) * -------------------------------------------------- * * This program solves the bounded buffer producers and consumers * problem with semaphores. This implementation is direct translation * into CORTEX environment of the classical semaphore solution presented * in operation systems textbooks. * * In this program, the semaphore Mutex is used to synchronize access to the * shared variable Count in critical section of code where Count is updated. * This semaphore is used for mutual exclusion synchronisation. The other two * semaphores, Elements and Spaces, are used to synchronize the producer and * consumer process so the producer doesn't try to put something into a full * buffer and the consumer doesn't try to take something from an empty * buffer. These semaphores are used for conditional synchronisation, also * called event synchronisation. */</font><b><font color='DarkGreen'>#include</font></b> <a href="bbpc_sem.h.FIND-INC"><font color="blue">"bbpc_sem.h"</font></a><b><font color='DarkGreen'>#include</font></b> <a href="plt_defs.h.FIND-INC"><font color="blue">"plt_defs.h"</font></a><b><font color='DarkGreen'>#include</font></b> <a href="prn_defs.h.FIND-INC"><font color="blue">"prn_defs.h"</font></a><font size="+1"><i>crtx_Void_t</i> <b><font color="azure1"><a name="crtx_Main">crtx_Main</a></font></b>( <i>crtx_Int_t</i> ArgC_a, <i>crtx_Void_t</i> *pArgV_a, <i>crtx_Void_t</i> *pEnvV_a){</font><font color="#6920ac">/********************* * LOCAL VARIABLES * *********************/</font> <i>crtx_Int_t</i> ArgC; <i>crtx_Void_t</i> *pArgV; <i>crtx_Void_t</i> *pEnvV; <i>sema_Attr_t</i> sema_Attr; <font color="#6920ac">/* semaphore attributes */</font> <i>task_Attr_t</i> task_Attr; <font color="#6920ac">/* task attributes */</font> <font color="#6920ac">/* task name buffer */</font> <i>crtx_Char_t</i> TaskName[<a href="TASK_MAX_NAME_LEN.FIND-DEF">TASK_MAX_NAME_LEN</a>]; <i>crtx_Int_t</i> i; <i>crtx_Status_t</i> Status;<font color="#6920ac">/********************* * PROCEDURE LOGIC * *********************/</font> <a href="pltf_Init.FIND-FUNC">pltf_Init</a>(ArgC_a, pArgV_a, pEnvV_a); ArgC = ArgC_a; <font color="#6920ac">/* to avoid compiler's warning */</font> pArgV = pArgV_a; <font color="#6920ac">/* ... */</font> pEnvV = pEnvV_a; <font color="#6920ac">/* ... */</font> <font color="#6920ac">/* startup message */</font> <a href="printf.FIND-FUNC">printf</a>(<font color="DarkGreen">"\n%s (Version: %s)\n\n"</font>, <a href="syst_Copyright.FIND-FUNC">syst_Copyright</a>(), <a href="syst_VersionStr.FIND-FUNC">syst_VersionStr</a>()); <a href="printf.FIND-FUNC">printf</a>(<font color="DarkGreen">"%s[%d]:Example: The Bounded Buffer Producers and Consumers "</font> <font color="DarkGreen">"(semaphore implementation) (%d ticks/sec) ...\n"</font>, <a href="task_GetName.FIND-FUNC">task_GetName</a>(<a href="task_Self.FIND-FUNC">task_Self</a>()), <a href="task_Self.FIND-FUNC">task_Self</a>(), <a href="TICK_SYSTEM_TICKS_PER_SEC.FIND-DEF">TICK_SYSTEM_TICKS_PER_SEC</a>); <font color="#6920ac">/* initialise the counded buffer's variables */</font> Count = 0; <font color="#6920ac">/* buffer is empty */</font> PutIn = 0; <font color="#6920ac">/* where to put */</font> TakeOut = 0; <font color="#6920ac">/* where to take */</font> <font color="#6920ac">/* initialise the buffer access semaphores */</font> <font color="#6920ac">/* Note: sema_Create() wouldn't fail because preallocated * semaphore control blockes are used */</font> <font color="#6920ac">/* example of correct attribute initialisation */</font> sema_Attr = sema_AttrDefault_g; sema_Attr.SuspendPolicy = <a href="THRD_SUSPEND_FIFO.FIND-DEF">THRD_SUSPEND_FIFO</a>; <font color="#6920ac">/* First In First Out */</font> <font color="#6920ac">/* mutex here -- binary semaphore */</font> pMutex = <a href="sema_Create.FIND-FUNC">sema_Create</a>(&Mutex, 1, 1, &sema_Attr); <font color="#6920ac">/* used to count items in the buffer */</font> pElements = <a href="sema_Create.FIND-FUNC">sema_Create</a>(&Elements, 0, <a href="BOUNDED_BUFFER_SIZE.FIND-DEF">BOUNDED_BUFFER_SIZE</a>, &sema_Attr); <font color="#6920ac">/* used to count empty slots in the buffer */</font> pSpaces = <a href="sema_Create.FIND-FUNC">sema_Create</a>(&Spaces, <a href="BOUNDED_BUFFER_SIZE.FIND-DEF">BOUNDED_BUFFER_SIZE</a>, <a href="BOUNDED_BUFFER_SIZE.FIND-DEF">BOUNDED_BUFFER_SIZE</a>, &sema_Attr); <font color="#6920ac">/* create Producers */</font> <b>for</b> (i=0; i<<a href="NUM_PRODUCERS.FIND-DEF">NUM_PRODUCERS</a>; i++) { <font color="#6920ac">/* make a name for the current producer */</font> <a href="sprintf.FIND-FUNC">sprintf</a>(TaskName, <font color="DarkGreen">"Prod %d"</font>, i); task_Attr = task_AttrDefault_g; task_Attr.Priority = <a href="PRIORITY.FIND-DEF">PRIORITY</a>;<font color="#6920ac">#if 0 task_Attr.SchdPolicy = task_SchdTimeSharing; task_Attr.TimeSlice = TIMESLICE;#else task_Attr.SchdPolicy = thrd_SchdRoundRobin;#endif</font> task_Attr.State = <a href="TASK_READY.FIND-DEF">TASK_READY</a>; task_Attr.pName = TaskName; Producers[i] = <a href="task_Create1.FIND-FUNC">task_Create1</a>((<i>task_Entry1_t</i>)Producer, &task_Attr, &Status, 0, <a href="CRTX_NULL.FIND-DEF">CRTX_NULL</a>); <b>if</b> (Status != <a href="TASK_SUCCESS.FIND-DEF">TASK_SUCCESS</a>) { <a href="printf.FIND-FUNC">printf</a>(<font color="DarkGreen">"%s[%d]:ERROR: %s: %d: task_Create: P%d, E:%ld\n"</font>, <a href="task_GetName.FIND-FUNC">task_GetName</a>(<a href="task_Self.FIND-FUNC">task_Self</a>()), <a href="task_Self.FIND-FUNC">task_Self</a>(), <a href="__FILE__.FIND-DEF">__FILE__</a>, <a href="__LINE__.FIND-DEF">__LINE__</a>, i, Status); <a href="CRTX_EXCEPTION.FIND-DEF">CRTX_EXCEPTION</a> Error_Exc; } } <font color="#6920ac">/* create Consumers */</font> <b>for</b> (i=0; i<<a href="NUM_CONSUMERS.FIND-DEF">NUM_CONSUMERS</a>; i++) { <font color="#6920ac">/* make a name for the current consumer */</font> <a href="sprintf.FIND-FUNC">sprintf</a>(TaskName, <font color="DarkGreen">"Cons %d"</font>, i); task_Attr = task_AttrDefault_g; task_Attr.Priority = <a href="PRIORITY.FIND-DEF">PRIORITY</a>;<font color="#6920ac">#if 0 task_Attr.SchdPolicy = task_SchdTimeSharing; task_Attr.TimeSlice = TIMESLICE;#else task_Attr.SchdPolicy = thrd_SchdRoundRobin;#endif</font> task_Attr.State = <a href="TASK_READY.FIND-DEF">TASK_READY</a>; task_Attr.pName = TaskName; Consumers[i] = <a href="task_Create1.FIND-FUNC">task_Create1</a>((<i>task_Entry1_t</i>)Consumer, &task_Attr, &Status, 0, <a href="CRTX_NULL.FIND-DEF">CRTX_NULL</a>); <b>if</b> (Status != <a href="TASK_SUCCESS.FIND-DEF">TASK_SUCCESS</a>) { <a href="printf.FIND-FUNC">printf</a>(<font color="DarkGreen">"%s[%d]:ERROR: %s: %d: task_Create: C%d, E:%ld\n"</font>, <a href="task_GetName.FIND-FUNC">task_GetName</a>(<a href="task_Self.FIND-FUNC">task_Self</a>()), <a href="task_Self.FIND-FUNC">task_Self</a>(), <a href="__FILE__.FIND-DEF">__FILE__</a>, <a href="__LINE__.FIND-DEF">__LINE__</a>, i, Status); <a href="CRTX_EXCEPTION.FIND-DEF">CRTX_EXCEPTION</a> Error_Exc; } } <a href="task_Sleep.FIND-FUNC">task_Sleep</a>(<a href="TICK_SECS_TO_TICKS.FIND-DEF">TICK_SECS_TO_TICKS</a>(<a href="RUNTIME.FIND-DEF">RUNTIME</a>)); <a href="printf.FIND-FUNC">printf</a>(<font color="DarkGreen">"%s[%d]: must stop now\n"</font>, <a href="task_GetName.FIND-FUNC">task_GetName</a>(<a href="task_Self.FIND-FUNC">task_Self</a>()), <a href="task_Self.FIND-FUNC">task_Self</a>()); <font color="#6920ac">/* delete Consumers */</font> <b>for</b> (i=0; i<<a href="NUM_CONSUMERS.FIND-DEF">NUM_CONSUMERS</a>; i++) {⌨️ 快捷键说明
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