选择并接受Linux中的延迟

我使用python脚本来测试它.它按顺序打开100个连接.即：

for i in range(100):
    s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    print s.connect((IP,PORT))
    s.send("Testrn")

我观察到的是我的应用程序在第一个X连接之后被卡在select()中2秒钟.
strace的输出：

1344391414.452208 select(30,[3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29],NULL,NULL) = 1 (in [3])
1344391416.742843 accept(3,NULL)    = 30

我的代码如下.知道我做错了什么吗？

#include <assert.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/select.h>

int
fd_create (void)
{
    int fd;
    int set = true;
    struct sockaddr_in addr;

    fd = socket(AF_INET,SOCK_STREAM,0);

    setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&set,sizeof(set));

    memset(&addr,sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(1999);
    addr.sin_addr.s_addr = INADDR_ANY;

    bind(fd,(struct sockaddr *)&addr,sizeof(addr));

    listen(fd,1024);

    return (fd);
}

int
fd_echo (int fd)
{
    int n;
    char buffer[128 + 1];

    while ((n = recv(fd,buffer,128,0)) > 0);

    return (n);
}

int
main (void)
{
    int listen_fd;
    fd_set working;
    fd_set master;
    int max_fd;
    int i;
    int new_fd;
    int rc;
    int con;

    FD_ZERO(&master);
    listen_fd = fd_create();
    fcntl(listen_fd,F_SETFL,fcntl(listen_fd,F_GETFL) | O_NONBLOCK);

    max_fd = listen_fd;
    printf("%dn",listen_fd);
    FD_SET(listen_fd,&master);
    con = 0;
    for (;;) {
    memcpy(&working,&master,sizeof(fd_set));
    select(max_fd + 1,&working,NULL);

    for (i = 0; i <= max_fd; i++) {
        if (FD_ISSET(i,&working)) {
        if (i == listen_fd) {
            while ((new_fd = accept(i,NULL)) >= 0) {
            fcntl(new_fd,fcntl(new_fd,F_GETFL) | O_NONBLOCK);
            FD_SET(new_fd,&master);
            if (max_fd < new_fd) {
                max_fd = new_fd;
            }
            printf("New connection %d (%d)n",new_fd,++con);
            }
            if ((new_fd == -1) && (errno != EAGAIN && errno != EWOULDBLOCK)) {
            return(0);
            }
        } else {
            rc = fd_echo(i);
            if ((rc == 0) ||
            ((rc == -1) && ((errno != EAGAIN && errno != EWOULDBLOCK)))) {
            close(i);
            FD_CLR(i,&master);
            }
        }
        }
    }
    }
    return (0);
}