Add Crystal::EventLoop#delete to clean up on finalize

Author: ysbaddaden

src/crystal/system/event_loop/file_descriptor.cr

@@ -19,5 +19,13 @@ abstract class Crystal::EventLoop
 
     # Closes the file descriptor resource.
     abstract def close(file_descriptor : Crystal::System::FileDescriptor) : Nil
+
+    # Removes the file descriptor from the event loop. Can be used to free up
+    # memory resources associated with the file descriptor, as well as removing
+    # the file descriptor from kernel data structures.
+    #
+    # Called by `::IO::FileDescriptor#finalize` before closing the file
+    # descriptor. Errors shall be silently ignored.
+    abstract def delete(file_descriptor : Crystal::System::FileDescriptor) : Nil
   end
 end

src/crystal/system/event_loop/socket.cr

@@ -62,5 +62,13 @@ abstract class Crystal::EventLoop
 
     # Closes the socket.
     abstract def close(socket : ::Socket) : Nil
+
+    # Removes the socket from the event loop. Can be used to free up memory
+    # resources associated with the socket, as well as removing the socket from
+    # kernel data structures.
+    #
+    # Called by `::Socket#finalize` before closing the socket. Errors shall be
+    # silently ignored.
+    abstract def delete(socket : ::Socket) : Nil
   end
 end

src/crystal/system/unix/event_loop_libevent.cr

@@ -94,6 +94,9 @@ class Crystal::LibEvent::EventLoop < Crystal::EventLoop
     file_descriptor.evented_close
   end
 
+  def delete(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  end
+
   def read(socket : ::Socket, slice : Bytes) : Int32
     evented_read(socket, "Error reading socket") do
       LibC.recv(socket.fd, slice, slice.size, 0).to_i32
@@ -187,6 +190,9 @@ class Crystal::LibEvent::EventLoop < Crystal::EventLoop
     socket.evented_close
   end
 
+  def delete(socket : ::Socket) : Nil
+  end
+
   def evented_read(target, errno_msg : String, &) : Int32
     loop do
       bytes_read = yield

src/crystal/system/wasi/event_loop.cr

@@ -53,6 +53,9 @@ class Crystal::Wasi::EventLoop < Crystal::EventLoop
     file_descriptor.evented_close
   end
 
+  def delete(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  end
+
   def read(socket : ::Socket, slice : Bytes) : Int32
     evented_read(socket, "Error reading socket") do
       LibC.recv(socket.fd, slice, slice.size, 0).to_i32
@@ -85,6 +88,9 @@ class Crystal::Wasi::EventLoop < Crystal::EventLoop
     socket.evented_close
   end
 
+  def delete(socket : ::Socket) : Nil
+  end
+
   def evented_read(target, errno_msg : String, &) : Int32
     loop do
       bytes_read = yield

src/crystal/system/win32/event_loop_iocp.cr

@@ -164,6 +164,9 @@ class Crystal::IOCP::EventLoop < Crystal::EventLoop
     LibC.CancelIoEx(file_descriptor.windows_handle, nil) unless file_descriptor.system_blocking?
   end
 
+  def delete(file_descriptor : Crystal::System::FileDescriptor) : Nil
+  end
+
   private def wsa_buffer(bytes)
     wsabuf = LibC::WSABUF.new
     wsabuf.len = bytes.size
@@ -274,6 +277,9 @@ class Crystal::IOCP::EventLoop < Crystal::EventLoop
 
   def close(socket : ::Socket) : Nil
   end
+
+  def delete(socket : ::Socket) : Nil
+  end
 end
 
 class Crystal::IOCP::Event

src/io/file_descriptor.cr

@@ -247,10 +247,7 @@ class IO::FileDescriptor < IO
   def finalize
     return if closed? || !close_on_finalize?
 
-    if event_loop.responds_to?(:delete)
-      event_loop.delete(self)
-    end
-
+    event_loop.delete(self)
     file_descriptor_close { } # ignore error
   end
 

src/socket.cr

@@ -430,10 +430,7 @@ class Socket < IO
   def finalize
     return if closed?
 
-    if event_loop.responds_to?(:delete)
-      event_loop.delete(self)
-    end
-
+    event_loop.delete(self)
     socket_close { } # ignore error
   end