refactor sys_close_internal to SocketWrapper::drop

kernel/src/syscall/fs.rs

@@ -326,15 +326,8 @@ pub fn sys_open(path: *const u8, flags: usize, mode: usize) -> SysResult {
 pub fn sys_close(fd: usize) -> SysResult {
     info!("close: fd: {:?}", fd);
     let mut proc = process();
-    sys_close_internal(&mut proc, fd)
+    proc.files.remove(&fd).ok_or(SysError::EBADF)?;
-}
+    Ok(0)
-
-pub fn sys_close_internal(proc: &mut Process, fd: usize) -> SysResult {
-    match proc.files.remove(&fd) {
-        Some(FileLike::File(_)) => Ok(0),
-        Some(FileLike::Socket(wrapper)) => sys_close_socket(proc, fd, wrapper.handle),
-        None => Err(SysError::EINVAL),
-    }
 }
 
 pub fn sys_access(path: *const u8, mode: usize) -> SysResult {
@@ -450,10 +443,8 @@ pub fn sys_getdents64(fd: usize, buf: *mut LinuxDirent64, buf_size: usize) -> Sy
 pub fn sys_dup2(fd1: usize, fd2: usize) -> SysResult {
     info!("dup2: from {} to {}", fd1, fd2);
     let mut proc = process();
-    if proc.files.contains_key(&fd2) {
     // close fd2 first if it is opened
-        sys_close_internal(&mut proc, fd2)?;
+    proc.files.remove(&fd2);
-    }
 
     match proc.files.get(&fd1) {
         Some(FileLike::File(file)) => {

kernel/src/syscall/net.rs

@@ -484,16 +484,17 @@ pub fn sys_recvfrom(
     }
 }
 
-pub fn sys_close_socket(proc: &mut Process, fd: usize, handle: SocketHandle) -> SysResult {
+impl Drop for SocketWrapper {
+    fn drop(&mut self) {
         let iface = &*(NET_DRIVERS.read()[0]);
         let mut sockets = iface.sockets();
-    sockets.release(handle);
+        sockets.release(self.handle);
         sockets.prune();
 
         // send FIN immediately when applicable
         drop(sockets);
         iface.poll();
-    Ok(0)
+    }
 }
 
 pub fn sys_bind(fd: usize, addr: *const SockaddrIn, len: usize) -> SysResult {

kernel/src/syscall/proc.rs

@@ -179,20 +179,11 @@ pub fn sys_getppid() -> SysResult {
     Ok(ppid)
 }
 
-/// Exit the current process
+/// Exit the current thread
 pub fn sys_exit(exit_code: isize) -> ! {
     let pid = thread::current().id();
     info!("exit: {}, code: {}", pid, exit_code);
 
-    // close all files.
-    // TODO: close them in all possible ways a process can exit
-    let mut proc = process();
-    let fds: Vec<usize> = proc.files.keys().cloned().collect();
-    for fd in fds.into_iter() {
-        sys_close_internal(&mut proc, fd).unwrap();
-    }
-    drop(proc);
-
     processor().manager().exit(pid, exit_code as usize);
     processor().yield_now();
     unreachable!();