[완료]multi thread 사용시 thread create시 마다 VSZ 증가 이유가 궁금합니다.

/*
 * HTTPServer.c
 *
 *  Created on: 2008. 11. 27
 *      Author: 조태문
 */
 
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <pthread.h>
 
#define BUFSIZE 1024
#define LINESIZE 100
#define _REENTRANT // 확인차
 
void * clnt_connection(void *arg); // HTTP처리 thread
char* strtrim(char *str); // string trimer
void send_data(FILE* fp, char* ct, char* file_name); // response 전송
char* content_type(char * file); // content_type 협상
void send_error(FILE* fp); // error 전송
void error_handling(char *message); // error 메세지 출력 후 종료
 
//pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 
int main(int argc, char **argv)
{
  int serv_sock;
  int clnt_sock;
  int stat;
 
  struct sockaddr_in serv_addr;
  struct sockaddr_in clnt_addr;
  int clnt_addr_size;
  char buf[BUFSIZE];
  pthread_t thread;
 
  signal(SIGPIPE, SIG_IGN); // client에서 connection
 
  if(argc!=2){
    printf("Usage : %s <port>\n", argv[0]);
    exit(1);
  }
  signal(SIGPIPE, SIG_IGN);
  // create sock
  serv_sock=socket(PF_INET, SOCK_STREAM, 0);
  if(serv_sock==-1)
    error_handling("socket() error");
 
  // bind
  memset(&serv_addr, 0, sizeof(serv_addr));
  serv_addr.sin_family = AF_INET;
  serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
  serv_addr.sin_port = htons(atoi(argv[1]));
  if(bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr))==-1)
    error_handling("bind() error");
  // listen
  if(listen(serv_sock, 5)==-1)
    error_handling("listen() error");
 
  while (1) {
    clnt_addr_size=sizeof(clnt_addr);
    //accept
    //pthread_mutex_lock(&mutex);
    clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);
    printf("연결요청 : %s:%d\n", inet_ntoa(clnt_addr.sin_addr), ntohs(clnt_addr.sin_port));
    if ( pthread_create(&thread, NULL, clnt_connection, &clnt_sock) != 0 ){
    	perror("쓰레드 생성 실패 : ");
    }
    //else pthread_detach(thread);
    pthread_join(thread,(void **)stat);
    //pthread_mutex_unlock(&mutex);
  }
  return 0;
}
 
/* 쓰레드 영역 */
void * clnt_connection(void *arg)
{
  int clnt_sock=*((int*)arg);
  char req_line[LINESIZE];
  FILE* clnt_read;
  FILE* clnt_write;
 
  char method[10];
  char ct[15];
  char file_name[30];
 
 
  printf("thread ID[%d]\n", pthread_self());
 
  clnt_read = fdopen(clnt_sock, "r");
  clnt_write = fdopen(dup(clnt_sock), "w");
 
  fgets(req_line, LINESIZE, clnt_read);
  fputs(req_line, stdout);
 
  if(strstr(req_line, "HTTP/")==NULL){
    send_error(clnt_write);
    fclose(clnt_read);
    fclose(clnt_write);
    return;
  }
  strcpy(method, strtok_r(req_line, " /"));
  strcpy(file_name, strtok_r(NULL, " /"));
  strcpy(ct, content_type(file_name));
 
  if(strcmp(method, "GET")!=0){
    send_error(clnt_write);
    fclose(clnt_read);
    fclose(clnt_write);
    return;
  }
 
  while(1){
    fgets(req_line, LINESIZE, clnt_read);
    fputs(req_line, stdout);
    if(strcmp(strtrim(req_line),"")==0)
      break;
  }
  fclose(clnt_read);
  send_data(clnt_write, ct, file_name);
  close(clnt_sock);
 
  //pthread_exit(0);
}
/* 쓰레드 영역 */
 
char* strtrim(char *str)
{
  int end=strlen(str);
  while(str[end]<=' ' && end>0)  end--;
  str[end+1]=0;
  while(*str<=' ' && *str!=0) str++;
 
  return str;
}
 
void send_data(FILE* fp, char* ct, char* file_name)
{
  	char protocol[]="HTTP/1.0 200 OK\r\n";
	char server[]="Server:Best Http Server \r\n";
	char cnt_len[]="Content-length:2048\r\n";
	char cnt_type[LINESIZE];
	char buf[BUFSIZE];
	FILE* send_file;
	int len;
 
	sprintf(cnt_type, "Content-type:%s\r\n\r\n", ct);
 
	send_file = fopen(file_name, "r");
	if(send_file == NULL){
		send_error(fp);
		return;
	}
 
	/* 헤더 정보 전송 */
	fputs(protocol, fp);
	fputs(server, fp);
	fputs(cnt_len, fp);
	fputs(cnt_type, fp);
 
	/* 요청 데이터 전송 */
	while( len=fgets(buf, BUFSIZE, send_file ) != 0) {
		fputs(buf, fp);
		fflush(fp);
	}
	fflush(fp);
	fclose(fp);
}
 
char* content_type(char* file){
  char extension[LINESIZE];
  char file_name[LINESIZE];
  strcpy(file_name, file);
  strtok(file_name, ".");
  strcpy(extension, strtok(NULL, "."));
 
  if(!strcmp(extension, "html")||!strcmp(extension, "htm")) return "text/html";
  if(!strcmp(extension, "txt")||!strcmp(extension, "c")) return "text/plain";
 
  return "text/plain";
}
 
void send_error(FILE* fp)
{
	char protocol[]="HTTP/1.0 400 Bad Request\r\n";
	char server[]="Server:Best Http Server \r\n";
	char cnt_len[]="Content-length:2048\r\n";
	char cnt_type[]="Content-type:text/html\r\n\r\n";
	char content[]="[geshifilter-html]&lt;head&gt;&lt;title&gt;NETWORK&lt;/title&gt;&lt;/head&gt;&quot;&#10;	       &quot;&lt;body&gt;&lt;font size=+5&gt;&lt;br&gt;오류 발생! 요청 파일명 및 요청 방식 확인!&quot;&#10;		   &quot;&lt;/font&gt;&lt;/body&gt;[/geshifilter-html]";
 
	fputs(protocol, fp);
	fputs(server, fp);
	fputs(cnt_len, fp);
	fputs(cnt_type, fp);
	fflush(fp);
}
 
void error_handling(char *message)
{
  fputs(message, stderr);
  fputc('\n', stderr);
  exit(1);
}