user: 请从给定的汇编指令推导出C源代码:

```asm
<main>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x70,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  movl   $0x7,-0x5c(%rbp)
  movl   $0x23,-0x58(%rbp)
  movl   $0x0,-0x54(%rbp)
  movl   $0xbebc200,-0x64(%rbp)
  movl   $0x0,-0x60(%rbp)
  lea    -0x6c(%rbp),%rax
  mov    %rax,%rdi
  call   <sigemptyset@plt>
  mov    D5(%rip),%rax
  mov    (%rax),%edx
  lea    -0x6c(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <sigaddset@plt>
  mov    $0x20,%edi
  call   <epoll_create@plt>
  mov    %eax,-0x68(%rbp)
  mov    $0xffffffff,%edi
  call   <epoll_create@plt>
  mov    D46(%rip),%rax
  mov    (%rax),%esi
  lea    -0x70(%rbp),%rdx
  mov    -0x68(%rbp),%eax
  mov    %rdx,%rcx
  mov    $0xd,%edx
  mov    %eax,%edi
  call   <epoll_ctl@plt>
  mov    D46(%rip),%rax
  mov    (%rax),%eax
  lea    -0x70(%rbp),%rdx
  mov    %rdx,%rcx
  mov    $0xd,%edx
  mov    %eax,%esi
  mov    $0xffffffff,%edi
  call   <epoll_ctl@plt>
  lea    -0x70(%rbp),%rdx
  mov    -0x68(%rbp),%eax
  mov    %rdx,%rcx
  mov    $0xd,%edx
  mov    $0xffffffff,%esi
  mov    %eax,%edi
  call   <epoll_ctl@plt>
  mov    D46(%rip),%rax
  mov    (%rax),%esi
  lea    -0x70(%rbp),%rdx
  mov    -0x68(%rbp),%eax
  mov    %rdx,%rcx
  mov    $0xffffffff,%edx
  mov    %eax,%edi
  call   <epoll_ctl@plt>
  mov    D46(%rip),%rax
  mov    (%rax),%esi
  mov    -0x68(%rbp),%eax
  mov    $0xffffffffffffffff,%rcx
  mov    $0xd,%edx
  mov    %eax,%edi
  call   <epoll_ctl@plt>
  lea    -0x50(%rbp),%rsi
  mov    -0x68(%rbp),%eax
  mov    $0x0,%ecx
  mov    $0x11,%edx
  mov    %eax,%edi
  call   <epoll_wait@plt>
  lea    -0x50(%rbp),%rax
  mov    $0x0,%ecx
  mov    $0x11,%edx
  mov    %rax,%rsi
  mov    $0xffffffff,%edi
  call   <epoll_wait@plt>
  mov    -0x68(%rbp),%eax
  mov    $0x0,%ecx
  mov    $0x11,%edx
  mov    $0xffffffffffffffff,%rsi
  mov    %eax,%edi
  call   <epoll_wait@plt>
  lea    -0x50(%rbp),%rsi
  mov    -0x68(%rbp),%eax
  mov    $0x0,%ecx
  mov    $0xffffffff,%edx
  mov    %eax,%edi
  call   <epoll_wait@plt>
  lea    -0x50(%rbp),%rax
  mov    $0xffffffff,%ecx
  mov    $0x11,%edx
  mov    %rax,%rsi
  mov    $0xffffffff,%edi
  call   <epoll_wait@plt>
  mov    -0x68(%rbp),%eax
  mov    %eax,%edi
  call   <close@plt>
  lea    -0x5c(%rbp),%rax
  mov    $0x0,%edx
  mov    $0x1,%esi
  mov    %rax,%rdi
  call   <poll@plt>
  mov    $0x0,%edx
  mov    $0x1,%esi
  mov    $0xffffffffffffffff,%rdi
  call   <poll@plt>
  lea    -0x5c(%rbp),%rax
  mov    $0x0,%edx
  mov    $0xffffffff,%esi
  mov    %rax,%rdi
  call   <poll@plt>
  mov    $0xffffffff,%edx
  mov    $0x1,%esi
  mov    $0x0,%edi
  call   <poll@plt>
  mov    $0x0,%eax
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L7
  call   <__stack_chk_fail@plt>
L7:
  leave
  ret
```

assistant: ```c
int main() {
  struct epoll_event ev, events[17];
  struct pollfd pfd = {7, 0x23, 0};
  int fd;
  struct timespec tim = {.tv_sec = 0, .tv_nsec = 200000000};
  sigset_t sigs;
  sigemptyset(&sigs);
  sigaddset(&sigs, SIGUSR2);
  fd = epoll_create(32);
  epoll_create(-1);
  epoll_ctl(fd, EPOLL_CTL_ADD, 13, &ev);
  epoll_ctl(-1, EPOLL_CTL_ADD, 13, &ev);
  epoll_ctl(fd, -1, 13, &ev);
  epoll_ctl(fd, EPOLL_CTL_ADD, -1, &ev);
  epoll_ctl(fd, EPOLL_CTL_ADD, 13, (struct epoll_event *)-1);
  epoll_wait(fd, events, 17, 0);
  epoll_wait(-1, events, 17, 0);
  epoll_wait(fd, (struct epoll_event *)-1, 17, 0);
  epoll_wait(fd, events, -1, 0);
  epoll_wait(-1, events, 17, -1);
  close(fd);
  poll(&pfd, 1, 0);
  poll((struct pollfd *)-1, 1, 0);
  poll(&pfd, -1, 0);
  poll(NULL, 1, -1);
  return 0;
}
```