linux 管道 线程同步
各位，最近想使用管道来实现线程同步，出现一个问题，百思不得其解，望各位大侠指点一二...
先贴上代码：
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/time.h>
#include <sys/types.h>
#include <signal.h>
int pip[] = {-1, -1};
void sleep_select(int i)
{
struct timeval timeout;
timeout.tv_sec = i;
timeout.tv_usec = 0;
select(0, NULL, NULL, NULL, &timeout);
}
static void *threadFunction(void* userdata)
{
char data[5] = {0};
fd_set fds;
struct timeval timeout = {1,0};
int ret;
FD_ZERO(&fds);
FD_SET(pip[0], &fds);
printf("p0: %d\n", pip[0]);
printf("p1: %d\n", pip[1]);
while (1)
{
ret = select(pip[0] + 1, &fds, NULL, NULL, &timeout);
if (ret < 0)
{
printf("select error\n");
break;
}
else if (ret == 0)
{
//printf("no fd ready\n");
continue;
}
else
{
if (FD_ISSET(pip[0], &fds) > 0)
{
read(pip[0], data, 5);
printf("data: %s\n", data);
}
}
}
}
void *mysignal()
{
printf("signal\n");
char data[] = "data";
while (1)
{
sleep_select(2);
//printf("sowelflsdfsldfsdlfsdl\n");
write(pip[1], data, 5);
}
}
int main(int argc, char* argv[])
{
char data[] = "data";
pthread_t id;
if (pipe(pip)) {
printf("pipe error\n");
exit(-1);
}
printf("p0: %d\n", pip[0]);
printf("p1: %d\n", pip[1]);
if (pthread_create(&id, NULL, threadFunction, NULL))
{
printf("create thread error\n");
exit(-1);
}
printf("pthread id = %u\n", id);
pthread_create(&id, NULL, mysignal, NULL);
//signal(SIGUSR1, mysignal);
while (1)
{
sleep_select(2);
//sleep(2);
//write(pip[1], data, 5);
}
pthread_join(id, NULL);
}
#include <unistd.h>
#include <sys/time.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <pthread.h>
#include <string.h>
#include <errno.h>
//#include <fcntl.h>
int pip[2] = {-1, -1};
void sleep_select(int i)
{
struct timeval timeout;
timeout.tv_sec = i;
timeout.tv_usec = 0;
select(0, NULL, NULL, NULL, &timeout);
}
static void *threadFunction(void* userdata)
{
char data[6] = {0};
fd_set fds;
struct timeval timeout;
int ret;
FD_ZERO(&fds);
FD_SET(pip[0], &fds);
printf("p0: %d\n", pip[0]);
printf("p1: %d\n", pip[1]);
int counter = 0;
while (1)
{
timeout.tv_sec = 5;
timeout.tv_usec = 0;
//FD_ZERO(&fds);
FD_SET(pip[0], &fds);
ret = select(pip[0]+1, &fds, NULL, NULL, &timeout);
if (ret == -1)
{
printf("select error\n");
break;
}
else if (ret > 0)
{
if (FD_ISSET(pip[0], &fds))
{
read(pip[0], data, 5);
printf("data: %s\n", data);
printf("%s: %d, [%s]\n", __FUNCTION__, counter++, strerror(errno));
}
}
else
{
printf("no fd ready\n");
}
}
return NULL;
}
void *mysignal()
{
printf("signal\n");
char data[] = "data";
int counter = 0;
while (1)
{
sleep_select(2);
//sleep(2);
//printf("sowelflsdfsldfsdlfsdl\n");
write(pip[1], data, 5);
printf("time:%lu,%s: %d, [%s]\n", time(NULL), __FUNCTION__, counter++, strerror(errno));
}
}
int main(int argc, char* argv[])
{
pthread_t id;
if (pipe(pip))
{
printf("pipe error\n");
exit(-1);
}
printf("p0: %d\n", pip[0]);
printf("p1: %d\n", pip[1]);
//fcntl(pip[0], F_SETFL, fcntl(pip[0], F_GETFL, 0)
[解决办法]
O_NONBLOCK);
//fcntl(pip[1], F_SETFL, fcntl(pip[1], F_GETFL, 0)
[解决办法]
O_NONBLOCK);
if (pthread_create(&id, NULL, threadFunction, NULL))
{
printf("create thread error\n");
exit(-1);
}
printf("pthread id = %lu\n", id);
pthread_create(&id, NULL, mysignal, NULL);
//signal(SIGUSR1, mysignal);
while (1)
{
sleep_select(2);
//sleep(2);
//write(pip[1], data, 5);
}
pthread_join(id, NULL);
}
