使用c++使用accept(）和文件描述符会导致错误加重

我已经使用该网站一段时间了，(在本学期结束后)期待着做出贡献！然而，我最后一次希望得到你的帮助，似乎没有其他答案能带来任何帮助。

背景：使用c++、套接字和客户端/服务器架构设计一个基本的聊天室，其中最多有十个客户端与服务器对话。一个客户端所说的任何话都会在所有客户端和服务器之间得到响应(发送客户端除外)。

问题：错误发生在recv调用上，作为clientTalk函数中的while循环条件。我得到了一个"Receive failed:Bad file descriptor"，但服务器和客户端都没有完全"崩溃"，也没有发生明显的行为变化，尽管接收完全崩溃了。

尝试解决：

• 谷歌和SOf。两个小时。。。

• 移动变量，玩插座设置和打开/关闭

Valgrind：

==773== Warning: invalid file descriptor 96600128 in syscall read()
Recieve failed: Bad file descriptor
==773== Thread 2:
==773== Conditional jump or move depends on uninitialised value(s)
==773==    at 0x4015A0: ??? (in /nethome/users/ghm455/CS284/ChatServer/server)
==773==    by 0x4E39E99: start_thread (pthread_create.c:308)
==773==    by 0x5442CBC: clone (clone.S:112)
==773==
==773== Conditional jump or move depends on uninitialised value(s)
==773==    at 0x401614: ??? (in /nethome/users/ghm455/CS284/ChatServer/server)
==773==    by 0x4E39E99: start_thread (pthread_create.c:308)
==773==    by 0x5442CBC: clone (clone.S:112)
==773==
==773== Warning: invalid file descriptor 96600128 in syscall close()

第一个警告出现在我的accept语句中。接收失败发生在recv，最后一个警告发生在尝试关闭时。这是由散布在整个代码中的cout语句决定的。

代码：如下。如果你认为错误就在那里，我会发布客户端，但一切都表明这是服务器端的问题。

`#define SERVER_PORT 9999        /* define a server port number */
using std::cout;
using std::endl;
using std::string;
//Globals - descriptorArray holds client FDs.  arraySize is its size.
//soc holds the information on the server's socket.
//m is the global mutex shared among the server and all clients
const int MAX_CLIENT = 10;
int descriptorArray[MAX_CLIENT];
int arraySize = 0;
int soc;
pthread_mutex_t m;
struct thread_info
{
pthread_t threadID; //Stores the ID number returned by pthread_create
int threadNumber;   //We have to number incoming threads correctly
char *messageSent;  //Message taken in from command line
};
int main()
{
void exitHandler(int sig); // Function that handles the control-C
void* clientTalk(void *arg); // Reads and writes with clients
struct sockaddr_in server_addr, client_addr;
int option = 1;
unsigned int clientCount;
uint8_t *new_socket;
//Initialize the socket
soc = socket(AF_INET, SOCK_STREAM, 0);
if (soc < 0)
{
cout << "ERROR : problem opening socket" <<endl;
return 1;
}
//Create socket structure
bzero((char *) &server_addr, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(SERVER_PORT);
//Binding host address
if (bind(soc, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0)
{
cout << "ERROR : problem occured while binding" <<endl;
close(soc);
exit(1);
}
if(setsockopt(soc, SOL_SOCKET, SO_REUSEADDR, (char*) &option, sizeof(option)) < 0)
{
printf("setsockopt failedn");
close(soc);
exit(1);
} 
signal(SIGINT, exitHandler);
listen(soc, MAX_CLIENT);
clientCount = sizeof(struct sockaddr_in);
int clientID;
//cout << "Z " <<endl;
while(clientID = accept(soc, (struct sockaddr *) &client_addr, (socklen_t*)&clientCount))
{
//printf( "A");
if (clientID < 0 )  
{   
perror("ERROR ON ACCEPT");
exit(1);
}
else
{
pthread_t newClient;
new_socket = (uint8_t*)malloc(1);
*new_socket = clientID;
pthread_mutex_lock(&m);
if (arraySize < 10)
{
descriptorArray[arraySize++] = newClient;
}
else
{
cout << "There are already 10 clients connected!" << endl;
}
pthread_mutex_unlock(&m);
if( pthread_create(&newClient, NULL, clientTalk, &new_socket) < 0)
{
perror("ERROR Creating thread");
return 1;
}
cout << "Assigned!" <<endl;
pthread_join(newClient, NULL);
}
}
close(soc);
return 0;
}
void exitHandler(int sig)
{
sig = sig + 0; //Removing the warning. A clean compile looks a lot nicer.
for (int i = 0; i < arraySize; i++)
{
write(descriptorArray[i], "WARNING: Server exiting in ten seconds. End your conversation!", 1000);
}
cout << "WARNING: Server exiting in ten seconds.  ";
cout << "End your conversation!" << endl;
sleep(10f); 
for (int i = 0; i < arraySize; i++)
{
close(descriptorArray[i]);
}
close(soc);
exit(1);
}

void* clientTalk(void* arg)
{
int* myFD = (int*) arg;
char buffer[2000];
read(*myFD, buffer, 20);
char username[20];
//strcpy(username, buffer); // Takes in the username and stores it
char movableString[2000];
int amount_read;
// for (int i = 0; i < arraySize; i++)
// {
//strcpy(movableString, username);
//  strcat(movableString, " has joined the room!");
//if (descriptorArray[0] != *myFD)
//{
//  write(descriptorArray[0], movableString, 2000);
//}
//}
cout << "x" << endl;
int arrayLocation;  
while ( (amount_read = recv(*myFD, buffer, 2000, MSG_WAITALL)) > 0)
{
cout << " Um" << endl;
pthread_mutex_lock(&m);
for (int i = 0; i < arraySize; i++)
{
if (descriptorArray[i] == *myFD)
{
arrayLocation = i;
break;
}
}
strcpy(movableString, username);
strcat(movableString, ": ");
strcat(movableString, buffer);
for (int i = 0; i < arraySize; i++)
{
//if (i != arrayLocation)
//{
write(*myFD, movableString, 2000); 
//}
}
pthread_mutex_unlock(&m);
}
if (amount_read == 0)
{
cout << username << "disconnected unexpectedly" <<endl;
fflush(stdout);
}
if (amount_read == -1)
{
perror("Recieve failed");
}

pthread_mutex_lock(&m);
for (int i = 0; i < arraySize; i++)
{
if (descriptorArray[i] == *myFD)
{
arrayLocation = i;
break;
}
}
for (int i = arrayLocation; i < arraySize - 1; i++)
{
descriptorArray[i] = descriptorArray[i + 1];
}
arraySize--;
pthread_mutex_unlock(&m);
close(*myFD);
pthread_exit(NULL);
free(arg);
}

`

我将监控此网站，以回答您可能存在的任何问题。我提前为新手在提问时犯下的任何错误道歉。

谢谢你的帮助！