Extract Crystal::EventLoop#shutdown from #close

src/crystal/event_loop/file_descriptor.cr

@@ -46,7 +46,15 @@ abstract class Crystal::EventLoop
     # file descriptor.
     abstract def reopened(file_descriptor : Crystal::System::FileDescriptor) : Nil
 
-    # Closes the file descriptor resource.
+    # Internal shutdown of the file descriptor. Called after the
+    # `IO::FileDescriptor` has been marked closed but before calling `#close` to
+    # actually close the system fd or handle.
+    #
+    # Implementations shall resume all pending waiters and let them fail because
+    # the IO has been closed.
+    abstract def shutdown(file_descriptor : Crystal::System::FileDescriptor) : Nil
+
+    # Closes the system fd or handle.
     abstract def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
   end
 

src/crystal/event_loop/iocp.cr

@@ -307,6 +307,9 @@ class Crystal::EventLoop::IOCP < Crystal::EventLoop
     raise NotImplementedError.new("Crystal::System::IOCP#reopened(FileDescriptor)")
   end
 
+  def shutdown(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  end
+
   def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
     LibC.CancelIoEx(file_descriptor.windows_handle, nil) unless file_descriptor.system_blocking?
     file_descriptor.file_descriptor_close
@@ -445,6 +448,9 @@ class Crystal::EventLoop::IOCP < Crystal::EventLoop
     end
   end
 
+  def shutdown(socket : ::Socket) : Nil
+  end
+
   def close(socket : ::Socket) : Nil
     raise NotImplementedError.new("Crystal::System::IOCP#close(Socket)")
   end

src/crystal/event_loop/libevent.cr

@@ -178,10 +178,13 @@ class Crystal::EventLoop::LibEvent < Crystal::EventLoop
     file_descriptor.evented_close
   end
 
-  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  def shutdown(file_descriptor : Crystal::System::FileDescriptor) : Nil
     # perform cleanup before LibC.close. Using a file descriptor after it has
     # been closed is never defined and can always lead to undefined results
     file_descriptor.evented_close
+  end
+
+  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
     file_descriptor.file_descriptor_close
   end
 
@@ -299,10 +302,13 @@ class Crystal::EventLoop::LibEvent < Crystal::EventLoop
     end
   end
 
-  def close(socket : ::Socket) : Nil
+  def shutdown(socket : ::Socket) : Nil
     # perform cleanup before LibC.close. Using a file descriptor after it has
     # been closed is never defined and can always lead to undefined results
     socket.evented_close
+  end
+
+  def close(socket : ::Socket) : Nil
     socket.socket_close
   end
 

src/crystal/event_loop/polling.cr

@@ -232,10 +232,13 @@ abstract class Crystal::EventLoop::Polling < Crystal::EventLoop
     resume_all(file_descriptor)
   end
 
-  def close(file_descriptor : System::FileDescriptor) : Nil
+  def shutdown(file_descriptor : System::FileDescriptor) : Nil
     # perform cleanup before LibC.close. Using a file descriptor after it has
     # been closed is never defined and can always lead to undefined results
     resume_all(file_descriptor)
+  end
+
+  def close(file_descriptor : System::FileDescriptor) : Nil
     file_descriptor.file_descriptor_close
   end
 
@@ -363,10 +366,13 @@ abstract class Crystal::EventLoop::Polling < Crystal::EventLoop
     end
   end
 
-  def close(socket : ::Socket) : Nil
+  def shutdown(socket : ::Socket) : Nil
     # perform cleanup before LibC.close. Using a file descriptor after it has
     # been closed is never defined and can always lead to undefined results
     resume_all(socket)
+  end
+
+  def close(socket : ::Socket) : Nil
     socket.socket_close
   end
 

src/crystal/event_loop/socket.cr

@@ -74,7 +74,15 @@ abstract class Crystal::EventLoop
     # and the source address.
     abstract def receive_from(socket : ::Socket, slice : Bytes) : Tuple(Int32, ::Socket::Address)
 
-    # Closes the socket.
+    # Internal shutdown of the socket. Called after the `Socket` has been marked
+    # closed but before calling `#close` to actually close the system socket fd
+    # or handle.
+    #
+    # Implementations shall resume all pending waiters and let them fail because
+    # the IO has been closed. They don't have to call the `shutdown` syscall.
+    abstract def shutdown(socket : ::Socket) : Nil
+
+    # Closes the system socket fd or handle.
     abstract def close(socket : ::Socket) : Nil
   end
 

src/crystal/event_loop/wasi.cr

@@ -80,8 +80,14 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     raise NotImplementedError.new("Crystal::EventLoop#reopened(FileDescriptor)")
   end
 
-  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  def shutdown(file_descriptor : Crystal::System::FileDescriptor) : Nil
     file_descriptor.evented_close
+  end
+
+  def shutdown(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  end
+
+  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
     file_descriptor.file_descriptor_close
   end
 
@@ -133,8 +139,14 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     raise NotImplementedError.new "Crystal::Wasi::EventLoop#accept"
   end
 
-  def close(socket : ::Socket) : Nil
+  def shutdown(socket : ::Socket) : Nil
     socket.evented_close
+  end
+
+  def shutdown(socket : ::Socket) : Nil
+  end
+
+  def close(socket : ::Socket) : Nil
     socket.socket_close
   end
 

src/crystal/system/unix/file_descriptor.cr

@@ -134,6 +134,7 @@ module Crystal::System::FileDescriptor
   end
 
   private def system_close
+    event_loop.shutdown(self)
     event_loop.close(self)
   end
 

src/crystal/system/unix/socket.cr

@@ -224,6 +224,7 @@ module Crystal::System::Socket
   end
 
   private def system_close
+    event_loop.shutdown(self)
     event_loop.close(self)
   end
 

src/crystal/system/wasi/socket.cr

@@ -152,6 +152,7 @@ module Crystal::System::Socket
   end
 
   private def system_close
+    event_loop.shutdown(self)
     event_loop.close(self)
   end
 

src/crystal/system/win32/file_descriptor.cr

@@ -216,6 +216,7 @@ module Crystal::System::FileDescriptor
   end
 
   private def system_close
+    event_loop.shutdown(self)
     event_loop.close(self)
   end