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/* $Id: smpfork.c,v 1.1.1.1 2006/09/14 01:59:08 root Exp $ */
/*
* Copyright (c) 2002 Opsycon AB (www.opsycon.se)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Opsycon AB, Sweden.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*
* This is a simple program that demonstrate the SMP fork
* functionality for the purpose of starting up additional CPUs.
* The semaphore locking around the cpu2done variable access
* is not really necessary since only one thread modifies it.
* Instead it's there to show how access to shared variables
* can be protected withing the realm of PMON2000. Once CPU 2
* has been scheduled the client program can take full control
* of the system.
*/
typedef long long off_t;
struct callvectors {
int (*open) (char *, int, int);
int (*close) (int);
int (*read) (int, void *, int);
int (*write) (int, void *, int);
off_t (*lseek) (int, off_t, int);
int (*printf) (const char *, ...);
void (*cacheflush) (void);
char *(*gets) (char *);
int *(*smpfork) (int, char *);
int *(*semlock) (int);
int *(*semunlock) (int);
};
struct callvectors *callvec;
#define printf (*callvec->printf)
#define gets (*callvec->gets)
#define smpfork (*callvec->smpfork)
#define semlock (*callvec->semlock)
#define semunlock (*callvec->semunlock)
volatile int cpu2done;
char str[256];
int
main(int argc, char **argv, char **env, struct callvectors *cv)
{
char **ev;
int i;
callvec = cv;
printf("\n\nSimple SMP FORK demo program!\n\n");
printf("It was invoked with:\n");
for (i = 0; i < argc; i++) {
printf("Arg %2d: %s\n", i, argv[i]);
}
printf("\nCPU 1 is running\n");
printf("\nScheduling CPU 2\n");
if (smpfork(1024, (char *)&argc - 16384) == 0) {
printf("This is CPU 2!\n");
printf("Type someting\n");
gets(str);
printf("Telling CPU 1 that input is done\n");
while(!semlock(0));
cpu2done = 1;
semunlock(0);
return(0);
}
printf("This is CPU 1 waiting for CPU 2!\n");
do {
while(!semlock(0));
i = cpu2done;
semunlock(0);
} while (!i);
printf("CPU 1 recognized that CPU 2 is done.\n");
printf("You typed '%s'\n", str);
return(0);
}