Attachment 591717 Details for Bug 831900 – calls semget 1 millions times

calls semget 1 millions times

a.c (text/x-csrc), 1.32 KB, created by slh on 2012-06-14 03:16:23 UTC

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Creator: slh

Created: 2012-06-14 03:16:23 UTC

Size: 1.32 KB

patch

obsolete

>#include <stdio.h>
>#include <stdlib.h>
>#include <errno.h>
>#include <sys/ipc.h>
>#include <sys/sem.h>
>#include <sys/time.h>
>
>
>
>int InitSem(const key_t key, const int nsems)
>{
>        int i = 0;
>	if( (key <= 0) || (nsems <= 0) )
>	{
>		return (-1);
>	}
>	
>	int sem_id = semget(key, 0, 0);
>	if( sem_id < 0 )
>	{
>		sem_id = semget(key, nsems, IPC_CREAT|IPC_EXCL|0666);
>		if ( sem_id < 0)
>		{
>			if( errno == EEXIST )
>			{
>				sem_id = semget(key, 0, 0);
>				return (sem_id);
>			}
>			else
>			{
>				return (-1);
>			}
>		}
>		else
>		{
>			for(i = 0; i < nsems; ++i )
>			{
>				int status = semctl(sem_id, i, SETVAL);
>				if( status < 0 )
>				{
>					return (-1);
>				}
>			}
>			
>			return (sem_id);
>		}
>	}
>	return (sem_id);
>}
>
>int main(int argc ,char ** argv)
>{
>
>	
>	key_t key = 6228;
>	int nsems = 2;
>	int sem_id = 0;
>        int i = 0;
>	sem_id = InitSem(key, nsems);
>	
>	
>        struct timeval tstartall, tendall;
>        float timeuseall;
>	gettimeofday(&tstartall, NULL);
>	int j = 0;
>	for(j = 0; j < 100; ++j)
>	{
>		for(i = 0; i < 10000; ++i)
>		{
>
>			sem_id = semget(key, 0, 0);
>		}
>	}
>	 gettimeofday(&tendall, NULL);
>	 timeuseall = (1000000 * (tendall.tv_sec - tstartall.tv_sec) + (tendall.tv_usec - tstartall.tv_usec))/1000000.000000;
>	 printf("timeuseall: %f seconds\n", timeuseall);
>		
>}

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Attachments on bug 831900: 591717 | 591718