Extract Crystal::EventLoop#shutdown from #close

src/crystal/event_loop/file_descriptor.cr

@@ -46,7 +46,16 @@ abstract class Crystal::EventLoop
     # file descriptor.
     abstract def reopened(file_descriptor : Crystal::System::FileDescriptor) : Nil
 
-    # Closes the file descriptor resource.
+    # Hook to react on the file descriptor after the IO object has been marked
+    # closed but before calling `#close` to actually close the system fd or
+    # handle.
+    #
+    # On UNIX targets the event loop must resume pending waiters and let them
+    # fail because the IO object is closed.
+    def before_close(file_descriptor : Crystal::System::FileDescriptor) : Nil
+    end
+
+    # Closes the system fd or handle.
     abstract def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
   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 before_close(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 before_close(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 before_close(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 before_close(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.
+    # Hook to react on the socket after the IO object has been marked closed but
+    # before calling `#close` to actually close the system socket fd or handle.
+    #
+    # On UNIX targets the event loop must resume pending waiters and let them
+    # fail because the IO object is closed.
+    def before_close(socket : ::Socket) : Nil
+    end
+
+    # Closes the system socket fd or handle.
     abstract def close(socket : ::Socket) : Nil
   end
 

src/crystal/event_loop/wasi.cr

@@ -80,8 +80,11 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     raise NotImplementedError.new("Crystal::EventLoop#reopened(FileDescriptor)")
   end
 
-  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  def before_close(file_descriptor : Crystal::System::FileDescriptor) : Nil
     file_descriptor.evented_close
+  end
+
+  def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
     file_descriptor.file_descriptor_close
   end
 
@@ -133,8 +136,11 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     raise NotImplementedError.new "Crystal::Wasi::EventLoop#accept"
   end
 
-  def close(socket : ::Socket) : Nil
+  def before_close(socket : ::Socket) : Nil
     socket.evented_close
+  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.before_close(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.before_close(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.before_close(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.before_close(self)
     event_loop.close(self)
   end