From 31f39d767b225acd7db44bd76296450f08430afc Mon Sep 17 00:00:00 2001
From: Julien Portalier <julien@portalier.com>
Date: Mon, 16 Dec 2024 11:09:04 +0100
Subject: [PATCH] Fix: make Crystal::EventLoop#remove(io) a class method

The method is called from IO::FileDescriptor and Socket finalizers,
which means they can be run from any thread during GC collections, yet
calling an instance method means accessing the current event loop, which
may have not been instantiated yet for the thread.
---
 src/crystal/event_loop/file_descriptor.cr | 3 ++-
 src/crystal/event_loop/iocp.cr            | 6 ------
 src/crystal/event_loop/libevent.cr        | 6 ------
 src/crystal/event_loop/polling.cr         | 6 +++---
 src/crystal/event_loop/socket.cr          | 3 ++-
 src/crystal/event_loop/wasi.cr            | 6 ------
 src/crystal/system/unix/process.cr        | 2 +-
 src/crystal/system/unix/signal.cr         | 2 +-
 src/io/file_descriptor.cr                 | 2 +-
 src/socket.cr                             | 2 +-
 10 files changed, 11 insertions(+), 27 deletions(-)

diff --git a/src/crystal/event_loop/file_descriptor.cr b/src/crystal/event_loop/file_descriptor.cr
index 5fb6cbb95cb0..c0df2e5aefff 100644
--- a/src/crystal/event_loop/file_descriptor.cr
+++ b/src/crystal/event_loop/file_descriptor.cr
@@ -26,6 +26,7 @@ abstract class Crystal::EventLoop
     #
     # Called by `::IO::FileDescriptor#finalize` before closing the file
     # descriptor. Errors shall be silently ignored.
-    abstract def remove(file_descriptor : Crystal::System::FileDescriptor) : Nil
+    def self.remove(file_descriptor : Crystal::System::FileDescriptor) : Nil
+    end
   end
 end
diff --git a/src/crystal/event_loop/iocp.cr b/src/crystal/event_loop/iocp.cr
index 5628e99121b1..6e4175e3daee 100644
--- a/src/crystal/event_loop/iocp.cr
+++ b/src/crystal/event_loop/iocp.cr
@@ -201,9 +201,6 @@ class Crystal::EventLoop::IOCP < Crystal::EventLoop
     LibC.CancelIoEx(file_descriptor.windows_handle, nil) unless file_descriptor.system_blocking?
   end
 
-  def remove(file_descriptor : Crystal::System::FileDescriptor) : Nil
-  end
-
   private def wsa_buffer(bytes)
     wsabuf = LibC::WSABUF.new
     wsabuf.len = bytes.size
@@ -314,7 +311,4 @@ class Crystal::EventLoop::IOCP < Crystal::EventLoop
 
   def close(socket : ::Socket) : Nil
   end
-
-  def remove(socket : ::Socket) : Nil
-  end
 end
diff --git a/src/crystal/event_loop/libevent.cr b/src/crystal/event_loop/libevent.cr
index 7b45939bd537..9c0b3d33b15c 100644
--- a/src/crystal/event_loop/libevent.cr
+++ b/src/crystal/event_loop/libevent.cr
@@ -98,9 +98,6 @@ class Crystal::EventLoop::LibEvent < Crystal::EventLoop
     file_descriptor.evented_close
   end
 
-  def remove(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
@@ -194,9 +191,6 @@ class Crystal::EventLoop::LibEvent < Crystal::EventLoop
     socket.evented_close
   end
 
-  def remove(socket : ::Socket) : Nil
-  end
-
   def evented_read(target, errno_msg : String, &) : Int32
     loop do
       bytes_read = yield
diff --git a/src/crystal/event_loop/polling.cr b/src/crystal/event_loop/polling.cr
index 774cc7060715..510b45909b04 100644
--- a/src/crystal/event_loop/polling.cr
+++ b/src/crystal/event_loop/polling.cr
@@ -164,7 +164,7 @@ abstract class Crystal::EventLoop::Polling < Crystal::EventLoop
     evented_close(file_descriptor)
   end
 
-  def remove(file_descriptor : System::FileDescriptor) : Nil
+  def self.remove(file_descriptor : System::FileDescriptor) : Nil
     internal_remove(file_descriptor)
   end
 
@@ -267,7 +267,7 @@ abstract class Crystal::EventLoop::Polling < Crystal::EventLoop
     evented_close(socket)
   end
 
-  def remove(socket : ::Socket) : Nil
+  def self.remove(socket : ::Socket) : Nil
     internal_remove(socket)
   end
 
@@ -317,7 +317,7 @@ abstract class Crystal::EventLoop::Polling < Crystal::EventLoop
     end
   end
 
-  private def internal_remove(io)
+  private def self.internal_remove(io)
     return unless (index = io.__evloop_data).valid?
 
     Polling.arena.free(index) do |pd|
diff --git a/src/crystal/event_loop/socket.cr b/src/crystal/event_loop/socket.cr
index 03b556b3be96..cd9926bf6ee3 100644
--- a/src/crystal/event_loop/socket.cr
+++ b/src/crystal/event_loop/socket.cr
@@ -69,6 +69,7 @@ abstract class Crystal::EventLoop
     #
     # Called by `::Socket#finalize` before closing the socket. Errors shall be
     # silently ignored.
-    abstract def remove(socket : ::Socket) : Nil
+    def self.remove(socket : ::Socket) : Nil
+    end
   end
 end
diff --git a/src/crystal/event_loop/wasi.cr b/src/crystal/event_loop/wasi.cr
index a91c469f406c..08781b4fb950 100644
--- a/src/crystal/event_loop/wasi.cr
+++ b/src/crystal/event_loop/wasi.cr
@@ -53,9 +53,6 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     file_descriptor.evented_close
   end
 
-  def remove(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
@@ -88,9 +85,6 @@ class Crystal::EventLoop::Wasi < Crystal::EventLoop
     socket.evented_close
   end
 
-  def remove(socket : ::Socket) : Nil
-  end
-
   def evented_read(target, errno_msg : String, &) : Int32
     loop do
       bytes_read = yield
diff --git a/src/crystal/system/unix/process.cr b/src/crystal/system/unix/process.cr
index 875d834bb266..7330cb28b3c7 100644
--- a/src/crystal/system/unix/process.cr
+++ b/src/crystal/system/unix/process.cr
@@ -352,7 +352,7 @@ struct Crystal::System::Process
 
   private def self.reopen_io(src_io : IO::FileDescriptor, dst_io : IO::FileDescriptor)
     if src_io.closed?
-      Crystal::EventLoop.current.remove(dst_io)
+      typeof(Crystal::EventLoop.current).remove(dst_io)
       dst_io.file_descriptor_close
     else
       src_io = to_real_fd(src_io)
diff --git a/src/crystal/system/unix/signal.cr b/src/crystal/system/unix/signal.cr
index 802cb418db15..9eb3db7bfbda 100644
--- a/src/crystal/system/unix/signal.cr
+++ b/src/crystal/system/unix/signal.cr
@@ -111,7 +111,7 @@ module Crystal::System::Signal
   # descriptors of the parent process and send it received signals.
   def self.after_fork
     @@pipe.each do |pipe_io|
-      Crystal::EventLoop.current.remove(pipe_io)
+      typeof(Crystal::EventLoop.current).remove(pipe_io)
       pipe_io.file_descriptor_close { }
     end
   ensure
diff --git a/src/io/file_descriptor.cr b/src/io/file_descriptor.cr
index a9b303b4b58c..1689081e09c5 100644
--- a/src/io/file_descriptor.cr
+++ b/src/io/file_descriptor.cr
@@ -255,7 +255,7 @@ class IO::FileDescriptor < IO
   def finalize
     return if closed? || !close_on_finalize?
 
-    event_loop?.try(&.remove(self))
+    typeof(Crystal::EventLoop.current).remove(self)
     file_descriptor_close { } # ignore error
   end
 
diff --git a/src/socket.cr b/src/socket.cr
index e97deea9eb04..5801fc94db88 100644
--- a/src/socket.cr
+++ b/src/socket.cr
@@ -430,7 +430,7 @@ class Socket < IO
   def finalize
     return if closed?
 
-    event_loop?.try(&.remove(self))
+    typeof(Crystal::EventLoop.current).remove(self)
     socket_close { } # ignore error
   end