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我有以下兩個文件recvfrom函數被阻止
Client.c
int main(void)
{
struct sockaddr_in si_other;
int s, i, slen=sizeof(si_other);
char buf[BUFLEN];
if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1)
exit(-1);
memset((char *) &si_other, 0, sizeof(si_other));
si_other.sin_family = AF_INET;
si_other.sin_port = htons(PORT);
if (inet_aton(SRV_IP, &si_other.sin_addr)==0) {
fprintf(stderr, "inet_aton() failed\n");
exit(1);
}
for (i=0; i<NPACK; i++) {
printf("Sending packet %d\n", i);
sprintf(buf, "This is packet %d\n", i);
if (sendto(s, buf, BUFLEN, 0, &si_other, slen)==-1)
exit(1);
}
sleep(10);
close(s);
return 0;
}
Server.c
int tries=0; /* Count of times sent - GLOBAL for signal-handler access */
void diep(char *s)
{
perror(s);
exit(1);
}
void CatchAlarm(int ignored) /* Handler for SIGALRM */
{
tries += 1;
}
void DieWithError(char *errorMessage)
{
}
/* Error handling function */
void *print_message_function(void *ptr)
{
char *message;
usleep(6200*1000);
message = (char *) ptr;
printf("%s \n", message);
sleep(20);
}
int main(void)
{
struct sockaddr_in si_me, si_other;
int s, i, slen=sizeof(si_other);
struct sigaction myAction; /* For setting signal handler */
const char *message1 = "Thread 1====================================";
char buf[BUFLEN];
pthread_t thread1, thread2;
pthread_create(&thread1, NULL, print_message_function, (void*) message1);
if ((s=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1)
diep("socket");
myAction.sa_handler = CatchAlarm;
if (sigfillset(&myAction.sa_mask) < 0) /* block everything in handler */
DieWithError("sigfillset() failed");
myAction.sa_flags = 0;
if (sigaction(SIGALRM, &myAction, 0) < 0)
DieWithError("sigaction() failed for SIGALRM");
memset((char *) &si_me, 0, sizeof(si_me));
si_me.sin_family = AF_INET;
si_me.sin_port = htons(PORT);
si_me.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(s, &si_me, sizeof(si_me))==-1)
diep("bind");
alarm(TIMEOUT_SECS);
for (i=0; i<NPACK; i++) {
if (recvfrom(s, buf, BUFLEN, 0, &si_other, &slen)==-1)
{
printf("Inside eagain %d\n",errno);
if(errno == EINTR)
{
alarm(TIMEOUT_SECS); /* Set the timeout */
}
else
exit(-1);
}
else
printf("Received packet from %s:%d\nData: %s\n\n",
inet_ntoa(si_other.sin_addr), ntohs(si_other.sin_port), buf);
}
alarm(0);
pthread_join(thread1, NULL);
close(s);
return 0;
}
我先運行服務器,然後客戶端。在某些情況下,服務器無法接收發送給我的客戶端的消息。儘管客戶端發送成功。即使EINTR錯誤,我也因爲報警,但仍recvfrom功能被阻止之間
在單獨的線程中運行'print_message_fundtion()'是完全沒有意義的。在收到消息後運行它。您的錯誤處理將在晚上離開。如果系統調用返回-1,你必須*打印錯誤,*通過'perror(),strerror()'等。 – EJP
可能應該標記這個問題C而不是C++。獲得更好的目標響應。 – user4581301
當您被告知您的代碼存在重大問題時,您需要修復它們,重新測試,重新發布並告知結果。至少我期望它。 – EJP