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ffi.rs (1227B)

      1 //! This contain the code related to the syscalls we need to communicate
      2 //! with the host operating system
      3 
      4 // This structure is used to communicate with the operating system in
      5 // epoll_ctl, and the operating system uses the same structure to communicate
      6 // with us in epoll_wait
      7 #[derive(Debug)]
      8 #[repr(C, packed)]
      9 pub struct Event {
     10     // Events are defined as a u32, but it’s more than just a number.
     11     // This field is what we call a bitmask.
     12     pub(crate) events: u32,
     13     // Token to identify event:
     14     // A union is much like an enum, but in contrast to Rust’s enums,
     15     // it doesn’t carry any information on what type it is, so it’s up
     16     // to us to make sure we know what type of data it holds.
     17     pub(crate) epoll_data: usize,
     18 }
     19 
     20 impl Event {
     21     pub fn token(&self) -> usize {
     22         self.epoll_data
     23     }
     24 }
     25 
     26 pub const EPOLL_CTL_ADD: i32 = 1;
     27 pub const EPOLLIN: i32 = 0x1;
     28 pub const EPOLLET: i32 = 1 << 31;
     29 
     30 #[link(name = "c")]
     31 unsafe extern "C" {
     32     pub fn epoll_create(size: i32) -> i32;
     33     pub fn close(fd: i32) -> i32;
     34     pub fn epoll_ctl(epfd: i32, op: i32, fd: i32, event: *mut Event) -> i32;
     35     pub fn epoll_wait(epfd: i32, events: *mut Event, maxevents: i32, timeout: i32) -> i32;
     36 }