[WIP/RFC] session: store exitcode/exitsignal from child

nvim/child_process_stream.lua

@@ -19,7 +19,9 @@ function ChildProcessStream.spawn(argv, env)
     stdio = {self._child_stdin, self._child_stdout, 2},
     args = args,
     env = env,
-  }, function()
+  }, function(code, signal)
+    self.exitcode = code
+    self.exitsignal = signal
     self:close()
   end)
 
@@ -59,8 +61,11 @@ function ChildProcessStream:close(signal)
   if type(signal) == 'string' then
     self._proc:kill('sig'..signal)
   end
-  self._proc:close()
-  uv.run('nowait')
+
+  while not self.exitcode do
+    uv.run('once')
+  end
+  assert(self.exitcode)
   native.pid_wait(self._pid)
 end
 

nvim/session.lua

@@ -135,6 +135,12 @@ function Session:close(signal)
   if not self._timer:is_closing() then self._timer:close() end
   if not self._prepare:is_closing() then self._prepare:close() end
   self._msgpack_rpc_stream:close(signal)
+
+  if not self.child_exit then
+    uv.run('nowait')  -- run the loop to get exitcode from child process.
+    self.child_exit = self._msgpack_rpc_stream._stream.exitcode
+    self.child_signal = self._msgpack_rpc_stream._stream.exitsignal
+  end
 end
 
 function Session:_yielding_request(method, args)
@@ -175,7 +181,12 @@ function Session:_run(request_cb, notification_cb, timeout)
       self._prepare:stop()
     end)
   end
-  self._msgpack_rpc_stream:read_start(request_cb, notification_cb, uv.stop)
+  self._msgpack_rpc_stream:read_start(request_cb, notification_cb, function()
+    uv.run()  -- run the loop to get exitcode from child process.
+    self.child_exit = self._msgpack_rpc_stream._stream.exitcode
+    self.child_signal = self._msgpack_rpc_stream._stream.exitsignal
+    uv.stop()
+  end)
   uv.run()
   self._prepare:stop()
   self._timer:stop()

test/session_spec.lua

@@ -153,6 +153,8 @@ local function test_session(description, session_factory, session_destroy)
         session_destroy()
       else
         session:close()
+        assert.are.equal(0, session.child_exit)
+        assert.are.equal(0, session.child_signal)
       end
       closed = true
     end)
@@ -179,6 +181,8 @@ test_session(string.format("Session using SocketStream [%s]", socket_file), func
   return socket_session
 end, function ()
   child_session:close()
+  assert.are.equal(0, child_session.child_exit)
+  assert.are.equal(0, child_session.child_signal)
   socket_session:close()
   -- clean up leftovers if something goes wrong
   local fd = io.open(socket_file)
@@ -218,6 +222,8 @@ test_session("Session using TcpStream", function ()
   return tcp_session
 end, function ()
   child_session:close()
+  assert.are.equal(0, child_session.child_exit)
+  assert.are.equal(0, child_session.child_signal)
   tcp_session:close()
 end)
 
@@ -257,3 +263,11 @@ describe('stdio', function()
     assert.are.same({'notification', 'd', {6, 7}}, session:next_message())
   end)
 end)
+
+it('closing session does not hang with active loop', function()
+  local cmd = {nvim_prog, '-u', 'NONE', '--embed', '--headless'}
+  local session1 = Session.new(ChildProcessStream.spawn(cmd))
+  local session2 = Session.new(ChildProcessStream.spawn(cmd))
+  session1:close()
+  session2:close()
+end)