From 9ebd1972ebfee6abe21275738c927865a00ddaf2 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Wed, 30 Oct 2019 13:42:29 +0100
Subject: [PATCH] stuff

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 src/reactor.rs | 28 +++++++++++++---------------
 src/tools.rs   | 14 ++++++++++++++
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/src/reactor.rs b/src/reactor.rs
index a20807f..2bb5b60 100644
--- a/src/reactor.rs
+++ b/src/reactor.rs
@@ -1,6 +1,7 @@
 use std::convert::TryFrom;
 use std::io;
 use std::os::unix::io::{AsRawFd, RawFd};
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::task::{Context, Poll, Waker};
 use std::thread::JoinHandle;
@@ -12,7 +13,7 @@ use crate::tools::Fd;
 
 pub struct Reactor {
     epoll: Arc<Epoll>,
-    removed: Mutex<Vec<(RawFd, Box<RegistrationInner>)>>,
+    removed: Mutex<Vec<Box<RegistrationInner>>>,
     thread: Mutex<Option<JoinHandle<()>>>,
 }
 
@@ -49,16 +50,16 @@ impl Reactor {
             for i in 0..count {
                 self.handle_event(&buf[i]);
             }
+            // After going through the events we can release memory associated with already closed
+            // file descriptors:
+            self.removed.lock().unwrap().clear();
         }
     }
 
     fn handle_event(&self, event: &EpollEvent) {
         let registration = unsafe { &mut *(event.r#u64 as *mut RegistrationInner) };
-        for (fd, _) in self.removed.lock().unwrap().iter() {
-            // This fd is already being dropped, don't touch it!
-            if *fd == registration.fd {
-                return;
-            }
+        if registration.gone.load(Ordering::Acquire) {
+            return;
         }
 
         if 0 != (event.events & EPOLLIN) {
@@ -88,8 +89,7 @@ impl Reactor {
 
     pub fn register(self: Arc<Self>, fd: RawFd) -> io::Result<Registration> {
         let mut inner = Box::new(RegistrationInner {
-            fd,
-            //ready: AtomicU32::new(0),
+            gone: AtomicBool::new(false),
             reactor: Arc::clone(&self),
             read_waker: Mutex::new(None),
             write_waker: Mutex::new(None),
@@ -109,10 +109,7 @@ impl Reactor {
     }
 
     fn deregister(&self, registration: Box<RegistrationInner>) {
-        self.removed
-            .lock()
-            .unwrap()
-            .push((registration.fd, registration));
+        self.removed.lock().unwrap().push(registration);
     }
 }
 
@@ -124,15 +121,16 @@ pub struct Registration {
 
 impl Drop for Registration {
     fn drop(&mut self) {
-        let reactor = Arc::clone(&self.inner.as_ref().unwrap().reactor);
+        let inner = self.inner.as_ref().unwrap();
+        let reactor = Arc::clone(&inner.reactor);
+        inner.gone.store(true, Ordering::Release);
         reactor.deregister(self.inner.take().unwrap());
     }
 }
 
 // This is accessed by the reactor
 struct RegistrationInner {
-    fd: RawFd,
-    //ready: AtomicU32,
+    gone: AtomicBool,
     reactor: Arc<Reactor>,
     read_waker: Mutex<Option<Waker>>,
     write_waker: Mutex<Option<Waker>>,
diff --git a/src/tools.rs b/src/tools.rs
index 1ae193a..3d88335 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -21,6 +21,20 @@ impl FromRawFd for Fd {
     }
 }
 
+impl Fd {
+    pub fn set_nonblocking(&self, nb: bool) -> std::io::Result<()> {
+        let fd = self.as_raw_fd();
+        let flags = c_try!(unsafe { libc::fcntl(fd, libc::F_GETFL) });
+        let flags = if nb {
+            flags | libc::O_NONBLOCK
+        } else {
+            flags & !libc::O_NONBLOCK
+        };
+        c_try!(unsafe { libc::fcntl(fd, libc::F_SETFL, flags) });
+        Ok(())
+    }
+}
+
 /// Byte vector utilities.
 pub mod vec {
     /// Create an uninitialized byte vector of a specific size.
-- 
2.39.5