所以我在c进程中进行编程，我需要创建一个计时器，当它通过我的代码中的某个点时，它会激活x秒，然后在倒数计时器达到0之后它会做一些事情。但在此期间，定时器之后的代码，需要继续做才能工作，遵循代码流程。 所以在简历中我想要实现的是c中的倒数计时器，当它被激活时，它会创建另一个进程，如果它计算时间并在之后做一些事情。
很抱歉，如果我没有解释得这么好。
提前致谢。
到目前为止，我的代码是以下内容，我想将计时器放在consumeTutuc方法的中间。
#include "sema.h"
#include <sys/shm.h>
//#include <sys/types.h>
#define MAX_CHILD 3 /* max. # of child processes */
#define LIFETIME 5 /* max. lifetime of a process */
#define MAX_NTIME 4 /* max. time for normal work */
#define MAX_CTIME 2 /* max. time for critical work */
#define N 10
#define SHMKEY (key_t) 0x10
#define SHMKEY2 (key_t) 0x11
#define SHMKEY3 (key_t) 0x12
#define SHMKEY4 (key_t) 0x13
//estruturas
typedef struct
{
int numeroPessoas;
char condicao;
}PESSOAS;
typedef struct
{
int id;
int espera;
}TUTUC;
int in, out, inP, outP, tt;
int *ptr; /*posicao do tuctuc*/
int *ptr2; /*numero disponiveis de tuctuc*/
PESSOAS *ptr3; /*fila de pessoas*/
int *ptr4; /*pessoas a espera*/
semaphore mutex, empty, full, emptyP, fullP, mutexP;
void produceTucTuc();
void consumeTucTuc();
void producePessoas();
void consumePessoas();
int main (void)
{
//MEMORIA
int shmid;
int shmid2;
int shmid3;
int shmid4;
char *addr;
char *addr2;
char *addr3;
char *addr4;
shmid = shmget(SHMKEY, N, 0777|IPC_CREAT);
shmid2 = shmget(SHMKEY2, N, 0777|IPC_CREAT);
shmid3 = shmget(SHMKEY3, N, 0777|IPC_CREAT);
shmid4 = shmget(SHMKEY4, N, 0777|IPC_CREAT);
addr=(char*)shmat(shmid,0,0);
addr2=(char*)shmat(shmid2,0,0);
addr3=(char*)shmat(shmid3,0,0);
addr4=(char*)shmat(shmid4,0,0);
ptr=(int*)addr;
ptr2=(int*)addr2;
ptr3=(PESSOAS*)addr3;
ptr4=(int*)addr4;
//MEMORIA
tt=1;
in=0;
out=0;
inP=0;
outP=0;
*ptr=0;
*ptr2=1;
//SEMAFOROS
full = init_sem(0);
empty = init_sem(N);
mutex = init_sem(1);
fullP = init_sem(0);
emptyP = init_sem(N);
mutexP = init_sem(1);
semaphore s;
//SEMAFOROS
int child_pid [MAX_CHILD], /* process ID's */
wait_pid;
int i, j,i2, /* loop variables */
child_stat; /* return status of child */
srand (time(NULL));
s = init_sem (1); /* create sem with value 1 */
for(i=0; i<10; i++){
produceTucTuc();
}
for (i = 0; i < MAX_CHILD; ++i)
{
child_pid [i] = fork ();
switch (child_pid [i])
{
case -1: /* error: no process created */
perror ("fork failed");
exit (1);
break;
case 0: /* child process */
/* up to Linux 2.0.x the process didn't terminate after
* LIFETIME seconds because "alarm()" and "sleep()" have
* used the same clock. This problem is solved in Linux 2.2.x
*/
if(i==0) produceTucTuc();
//if(i==1) consumeTucTuc();
if(i==1) producePessoas();
if(i==2) consumePessoas();
break;
default: /* parent process */
if (i == (MAX_CHILD - 1)) /* all childs created ? */
{ /* yes -> wait for termination */
for (j = 0; j < MAX_CHILD; ++j)
{
wait_pid = wait (&child_stat);
if (wait_pid == -1)
{
perror ("wait failed");
};
};
printf ("All child processes have terminated.\n");
//LIBERTA MEMORIA
rel_sem (s);
rel_sem (mutex);
rel_sem (empty);
rel_sem (full);
rel_sem (mutexP);
rel_sem (emptyP);
rel_sem (fullP);
shmdt(addr);
shmctl(shmid, IPC_RMID,NULL);
shmdt(addr2);
shmctl(shmid2, IPC_RMID,NULL);
shmdt(addr3);
shmctl(shmid3, IPC_RMID,NULL);
shmdt(addr4);
shmctl(shmid4, IPC_RMID,NULL);
//LIBERTA MEMORIA
};
}; /* end switch */
}; /* end for */
return 0;
}
void produceTucTuc(){
int ntuctuc;
alarm(LIFETIME);
//for(;;){
P(empty);
P(mutex);
*(ptr+in)=tt;
ntuctuc=*ptr2;
printf("------------------------------------\n");
printf("Produzi na pos %d o tuctuc %d\n",in,tt);
printf("Numero de TucTucs disponiveis:%d\n",ntuctuc);
in=(in+1)%N;
ntuctuc++;
*ptr2=ntuctuc;
tt=(tt+1)%N;
V(mutex);
V(full);
//}
}
void consumeTucTuc(){
int tuctuc;
int ntuctuc;
alarm(LIFETIME);
P(full);
P(mutex);
tuctuc=*(ptr+out);
ntuctuc=*ptr2;
ntuctuc--;
//printf("------------------------------------\n");
printf("Consumi na pos %d o tuctuc %d\n",out,tuctuc);
printf("Numero de TucTucs disponiveis:%d\n",ntuctuc);
out=(out+1)%N;
*ptr2=ntuctuc;
V(mutex);
V(empty);
}
void producePessoas(){
PESSOAS pessoa;
int espera =0;
alarm(LIFETIME);
for(;;){
P(emptyP);
P(mutexP);
if(rand()%5 == 0){
pessoa.numeroPessoas = 5;
}
else {
pessoa.numeroPessoas=rand()%5;
}
if(rand()%10<3){
pessoa.condicao = 'E';
}
else {
pessoa.condicao = 'N';
}
*(ptr3+inP)=pessoa;
espera=*ptr4;
espera=espera+pessoa.numeroPessoas;
*ptr4=espera;
printf("------------------------------------\n");
printf("Na pos %d entraram %d pessoas com %c condicao\n",inP,pessoa.numeroPessoas, pessoa.condicao);
printf("Estao %d pessoas à espera\n",*ptr4);
inP=(inP+1)%N;
V(mutexP);
V(fullP);
}
}
void consumePessoas(){
int pessoa;
int espera;
int p;
int aux;
alarm(LIFETIME);
while((*(ptr3 + outP)).numeroPessoas<(*ptr2)){
P(fullP);
P(mutexP);
pessoa=(*(ptr3+outP)).numeroPessoas;
espera=*ptr4;
espera=espera-pessoa;
*ptr4=espera;
printf("------------------------------------\n");
printf("Na pos %d sairam %d pessoas\n",inP,pessoa);
printf("Estao %d pessoas à espera\n",espera);
if(pessoa%2==1){
aux=(pessoa/2) + 1;
}else{
aux=pessoa/2;
}
for(p=0; p<aux; p++){
printf("%d\n",pessoa);
consumeTucTuc();
}
outP=(outP+1)%N;
V(mutexP);
V(emptyP);
}
}
答案 0 :(得分：0)
此功能可以作为线程调用，它是一个计数器：
（你可以在while循环中构建一个条件并杀死线程！）
void counter( void *dummy ){
time_t start;
int weiter = 1,count = 0;
while (weiter) {
time(&start);
printf("\b\b\b\b%3i:",count);
while(difftime(time(NULL),start)<1);
count++;
//if condition kill thread
}
}