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 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /*

 ** File:            switch.cpp

 ** Description:     trying to time context switches

 */

 #include "rccv.h"

 #include "rcinrval.h"

 #include "rclock.h"

 #include "rcthread.h"

 #include <prio.h>

 #include <prlog.h>

 #include <prprf.h>

 #include <plerror.h>

 #include <plgetopt.h>

 #include <stdlib.h>

 #define INNER_LOOPS 100

 #define DEFAULT_LOOPS 100

 #define DEFAULT_THREADS 10

 static PRFileDesc *debug_out = NULL;

 static PRBool debug_mode = PR_FALSE, verbosity = PR_FALSE, failed = PR_FALSE;

 class Home: public RCCondition

 {

 public:

     virtual ~Home();

     Home(Home *link, RCLock* ml);

 public:

     Home *next;

     RCLock* ml;

     PRBool twiddle;

 };  /* Home */

 Home::~Home() { }

 Home::Home(Home *link, RCLock* lock): RCCondition(lock)

 {

     ml = lock;

     next = link;

     twiddle = PR_FALSE;

 }  /* Home::Home */

 class Shared: public Home, public RCThread

 {

 public:

     Shared(RCThread::Scope scope, Home* link, RCLock* ml);

 private:

     ~Shared();

     void RootFunction();

 };  /* Shared */

 Shared::Shared(RCThread::Scope scope, Home* link, RCLock* lock):

     Home(link, lock), RCThread(scope, RCThread::joinable) { }

 Shared::~Shared() { }

 void Shared::RootFunction()

 {

     PRStatus status = PR_SUCCESS;

     while (PR_SUCCESS == status)

     {

         RCEnter entry(ml);

         while (twiddle && (PR_SUCCESS == status)) status = Wait();

 		if (verbosity) PR_fprintf(debug_out, "+");

         twiddle = PR_TRUE;

         next->twiddle = PR_FALSE;

         next->Notify();

     }

 }  /* Shared::RootFunction */

 static void Help(void)

 {

     debug_out = PR_STDOUT;

     PR_fprintf(

 		debug_out, "Usage: >./switch [-d] [-c n] [-t n] [-T n] [-G]\n");

     PR_fprintf(

 		debug_out, "-c n\tloops at thread level (default: %d)\n", DEFAULT_LOOPS);

     PR_fprintf(

 		debug_out, "-t n\tnumber of threads (default: %d)\n", DEFAULT_THREADS);

     PR_fprintf(debug_out, "-d\tturn on debugging output (default: FALSE)\n");

     PR_fprintf(debug_out, "-v\tturn on verbose output (default: FALSE)\n");

     PR_fprintf(debug_out, "-G n\tglobal threads only (default: FALSE)\n");

     PR_fprintf(debug_out, "-C n\tconcurrency setting (default: 1)\n");

 }  /* Help */

 PRIntn main(PRIntn argc, char **argv)

 {

 	PLOptStatus os;

     PRStatus status;

     PRBool help = PR_FALSE;

     PRUintn concurrency = 1;

     RCThread::Scope thread_scope = RCThread::local;

     PRUintn thread_count, inner_count, loop_count, average;

     PRUintn thread_limit = DEFAULT_THREADS, loop_limit = DEFAULT_LOOPS;

 	PLOptState *opt = PL_CreateOptState(argc, argv, "hdvc:t:C:G");

 	while (PL_OPT_EOL != (os = PL_GetNextOpt(opt)))

     {

 		if (PL_OPT_BAD == os) continue;

         switch (opt->option)

         {

         case 'v':  /* verbose mode */

 			verbosity = PR_TRUE;

         case 'd':  /* debug mode */

 			debug_mode = PR_TRUE;

             break;

         case 'c':  /* loop counter */

 			loop_limit = atoi(opt->value);

             break;

         case 't':  /* thread limit */

 			thread_limit = atoi(opt->value);

             break;

         case 'C':  /* Concurrency limit */

 			concurrency = atoi(opt->value);

             break;

         case 'G':  /* global threads only */

 			thread_scope = RCThread::global;

             break;

         case 'h':  /* help message */

 			Help();

 			help = PR_TRUE;

             break;

          default:

             break;

         }

     }

 	PL_DestroyOptState(opt);

     if (help) return -1;

 	if (PR_TRUE == debug_mode)

 	{

 		debug_out = PR_STDOUT;

 		PR_fprintf(debug_out, "Test parameters\n");

 		PR_fprintf(debug_out, "\tThreads involved: %d\n", thread_limit);

 		PR_fprintf(debug_out, "\tIteration limit: %d\n", loop_limit);

 		PR_fprintf(debug_out, "\tConcurrency: %d\n", concurrency);

 		PR_fprintf(

 			debug_out, "\tThread type: %s\n",

 			(PR_GLOBAL_THREAD == thread_scope) ? "GLOBAL" : "LOCAL");

 	}

     /*

     ** The interesting part starts here

     */

     RCLock lock;

     Shared* shared;

     Home home(NULL, &lock);

     Home* link = &home;

     RCInterval timein, timeout = 0;

     /* Build up the string of objects */

     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)

     {

         shared = new Shared(thread_scope, link, &lock);

         shared->Start();  /* make it run */

         link = (Home*)shared;

 	}

     /* Pass the message around the horn a few times */

     for (loop_count = 1; loop_count <= loop_limit; ++loop_count)

     {

 		timein.SetToNow();

 		for (inner_count = 0; inner_count < INNER_LOOPS; ++inner_count)

 		{

 			RCEnter entry(&lock);

 			home.twiddle = PR_TRUE;

 			shared->twiddle = PR_FALSE;

 			shared->Notify();

 			while (home.twiddle)

             {

 				failed = (PR_FAILURE == home.Wait()) ? PR_TRUE : PR_FALSE;

             }

 		}

 		timeout += (RCInterval(RCInterval::now) - timein);

 	}

     /* Figure out how well we did */

 	if (debug_mode)

 	{

 		average = timeout.ToMicroseconds()

 			/ (INNER_LOOPS * loop_limit * thread_count);

 		PR_fprintf(

 			debug_out, "Average switch times %d usecs for %d threads\n",

             average, thread_limit);

 	}

     /* Start reclamation process */

     link = shared;

     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)

     {

         if (&home == link) break;

         status = ((Shared*)link)->Interrupt();

 		if (PR_SUCCESS != status)

         {

             failed = PR_TRUE;

             if (debug_mode)

 			    PL_FPrintError(debug_out, "Failed to interrupt");

         }

 		link = link->next; 

     }

     for (thread_count = 1; thread_count <= thread_limit; ++thread_count)

     {

         link = shared->next;

         status = shared->Join();

 		if (PR_SUCCESS != status)

 		{

             failed = PR_TRUE;

             if (debug_mode)

 			    PL_FPrintError(debug_out, "Failed to join");

         }

         if (&home == link) break;

         shared = (Shared*)link;

     }

     PR_fprintf(PR_STDOUT, ((failed) ? "FAILED\n" : "PASSED\n"));

     failed |= (PR_SUCCESS == RCPrimordialThread::Cleanup());

     return ((failed) ? 1 : 0);

 }  /* main */

 /* switch.c */