file-descriptor starvation when using epoll edge-triggered notification

epoll-starvation.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/epoll.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <strings.h>
#include <errno.h>
#include <netinet/in.h>

#define MAX_EVENTS 10
#define BUF_SIZE 100

void onError(const char *why)
{
    perror(why);
    exit(EXIT_FAILURE);
}

void handle_conn(int epollfd, int fd)
{
    struct sockaddr_in addr = {0};

    int socket = accept(fd, NULL, NULL);
    if (socket == -1)
        onError("accpet");

    struct epoll_event epollev;
    epollev.events = EPOLLIN | EPOLLET;
    epollev.data.fd = socket;

    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, socket, &epollev) == -1)
        onError("epoll_ctl add fd");

    printf("%d added\n", socket);
}

int initServSocket(int port)
{
    struct sockaddr_in sin;
    int servsock = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
    if (servsock == -1)
        onError("socket()");

    bzero(&sin, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = INADDR_ANY;
    sin.sin_port = htons(port);

    if (bind(servsock, (struct sockaddr *)&sin, sizeof(sin)) == -1)
        onError("bind()");

    listen(servsock, SOMAXCONN);

    return servsock;
}

void handle_read(int epollfd,int fd)
{
    while (1)
    {
        char buf[BUF_SIZE];
        bzero(buf, BUF_SIZE);
        int ret = read(fd, buf, BUF_SIZE);
        if (ret == -1)
        {
            if (errno == EAGAIN)
                break;
        }
        if (ret <= 0)
        {
            epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL);
            close(fd);
            break;
        }
        
        printf("%s \n", buf);
    }
}

int main()
{

    struct epoll_event ev, events[MAX_EVENTS];
    int nfds, epollfd, n, ret;

    int servsock = initServSocket(9999);

    epollfd = epoll_create1(0);
    if (epollfd == -1)
        onError("epoll_create1");

    ev.events = EPOLLIN | EPOLLET;
    ev.data.fd = servsock;
    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, servsock, &ev) == -1)
        onError("epoll_ctl");

    for (;;)
    {
        int n = 0;
        nfds = epoll_wait(epollfd, events, MAX_EVENTS, -1);
        if (nfds == -1)
        {
            perror("epoll_wait");
            exit(EXIT_FAILURE);
        }

        for (n = 0; n < nfds; ++n)
        {
            if (events[n].data.fd == servsock)
            {
                handle_conn(epollfd, servsock);
            }
            else
            {
                handle_read(epollfd,events[n].data.fd);
            }
        }
    }
}