c언어 질문점요 머가 문제인지 모르겠어요,,pthread_create 이쪽 문제 같은데요,,

[root@localhost ~]# gcc -D_REENTRSNT chattingserver.c -o chattingserver -lpthread
chattingserver.c: In function ‘main’:
chattingserver.c:55: error: ‘broadcast’ undeclared (first use in this function)
chattingserver.c:55: error: (Each undeclared identifier is reported only once
chattingserver.c:55: error: for each function it appears in.)
[root@localhost ~]#

오류 메시지는 이렇게 나오구요,,,
while(1){
struct sockaddr_in clientaddress;
int clientaddressSize=sizeof(clientaddress);
int clientsocket = accept ( serversocket, ( struct sockaddr*)&clientaddress,&clientaddressSize);
pthread_mutex_lock(&mutex);
clientNumber++;
allclientsocket [clientNumber -1] = clientsocket;
pthread_mutex_unlock(&mutex);
char greetMessage[BUFFERSIZE];
sprintf(greetMessage,"[서버]환영합니다. 대화명을 입력해 주세요\n");
write(clientsocket,greetMessage,sizeof(greetMessage));
pthread_create(&thread,NULL,broadcast,(void*)clientsocket);<-- 여기서 에러가 나는데 왜 그런지 도저히 모르겠습니다,,
}
printf("채팅을 종료합니다\n");
return 0 ;
}
void *broadcast(void *arg){
char fromclient[NAMESIZE+BUFFERSIZE];
int myclientsocket=(int)arg;
int i = 0;
while(1){
int readlen=read(myclientsocket,fromclient,sizeof(fromclient));
if(readlen<=0) break;
printf("%s\n",fromclient);
pthread_mutex_lock(&mutex);
소스가 다 안올라 가네요 아 답답해 죽겠습니다 좀 도와주세요,,