process.c

这是一个模拟调度程序

#include <sys/types.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int COLOR[] = { 31, 32, 33, 34, 35, 36 };
const int COLOR_NUM = sizeof( COLOR ) / sizeof( COLOR[0] );

pid_t pid;
unsigned int t;
int color;

void term_handler( int sig )
{
	printf( "\033[;;%dmPid %d terminated, time runned: %u sec.\033[m\n", color, pid, t );
	signal( sig, SIG_DFL );
	raise( sig );
}//end term_handler

void susp_handler( int sig )
{
	printf( "\033[;;%dmPid %d suspended.\033[m\n", color, pid );
	signal( sig, SIG_DFL );
	raise( sig );
}//end susp_handler

void resu_handler( int sig )
{
	signal( SIGTSTP, susp_handler );
	printf( "\033[;;%dmPid %d resumed.\033[m\n", color, pid );
}//end resu_handler

int main(void)
{
	struct timespec ts, tr;

	nice( 10 );
	pid = getpid();

	srand( time(NULL) * pid );
	color = COLOR[ rand() % COLOR_NUM ];

	signal( SIGINT, term_handler );
	signal( SIGTSTP, susp_handler );
	signal( SIGCONT, resu_handler );

	printf( "\033[;;%dmPid %d starts.\033[m\n", color, pid );

	ts.tv_sec = 0;
	ts.tv_nsec = 500000000;
	for( t = 0; t < 19; )
		{
		nanosleep( &ts, &tr );
		++t;
		printf( "\033[;;%dmTime running: %d\033[m\n", color, t );
		nanosleep( &ts, &tr );
		}//end for

	sleep( 1 );
	++t;
	printf( "\033[;;%dmPid %d exited, time runned: %u sec.\033[m\n", color, pid, t );

	return 0;
}