libluv: use luv_set_callback to control callback execution

Disable the use of deferred API functions in a fast lua callback
Correctly display error messages from a fast lua callback

1 files changed, 95 insertions, 5 deletions

diff --git a/test/functional/lua/loop_spec.lua b/test/functional/lua/loop_spec.lua
index 8cc54e8c13..3b3b81f886 100644
--- a/test/functional/lua/loop_spec.lua
+++ b/test/functional/lua/loop_spec.lua
@@ -1,11 +1,15 @@
 -- Test suite for testing interactions with API bindings
 local helpers = require('test.functional.helpers')(after_each)
+local Screen = require('test.functional.ui.screen')
 local funcs = helpers.funcs
 local meths = helpers.meths
 local clear = helpers.clear
 local sleep = helpers.sleep
+local feed = helpers.feed
 local eq = helpers.eq
+local eval = helpers.eval
 local matches = helpers.matches
+local exec_lua = helpers.exec_lua
 
 before_each(clear)
 
@@ -17,7 +21,7 @@ describe('vim.loop', function()
   end)
 
   it('timer', function()
-    meths.execute_lua('vim.api.nvim_set_var("coroutine_cnt", 0)', {})
+    exec_lua('vim.api.nvim_set_var("coroutine_cnt", 0)', {})
 
     local code=[[
       local loop = vim.loop
@@ -27,14 +31,14 @@ describe('vim.loop', function()
         local this = coroutine.running()
         assert(this)
         local timer = loop.new_timer()
-        timer:start(ms, 0, function ()
+        timer:start(ms, 0, vim.schedule_wrap(function ()
           timer:close()
           touch = touch + 1
           coroutine.resume(this)
           touch = touch + 1
           assert(touch==3)
           vim.api.nvim_set_var("coroutine_cnt_1", touch)
-        end)
+        end))
         coroutine.yield()
         touch = touch + 1
         return touch
@@ -47,9 +51,95 @@ describe('vim.loop', function()
     ]]
 
     eq(0, meths.get_var('coroutine_cnt'))
-    meths.execute_lua(code, {})
-    sleep(20)
+    exec_lua(code)
+    sleep(50)
     eq(2, meths.get_var('coroutine_cnt'))
     eq(3, meths.get_var('coroutine_cnt_1'))
   end)
+
+  it('is API safe', function()
+    local screen = Screen.new(50,10)
+    screen:attach()
+    screen:set_default_attr_ids({
+      [1] = {bold = true, foreground = Screen.colors.Blue1},
+      [2] = {bold = true, reverse = true},
+      [3] = {foreground = Screen.colors.Grey100, background = Screen.colors.Red},
+      [4] = {bold = true, foreground = Screen.colors.SeaGreen4},
+      [5] = {bold = true},
+    })
+
+    -- deferred API functions are disabled, as their safety can't be guaranteed
+    exec_lua([[
+      local timer = vim.loop.new_timer()
+      timer:start(20, 0, function ()
+        timer:close()
+        vim.api.nvim_set_var("valid", true)
+        vim.api.nvim_command("echomsg 'howdy'")
+      end)
+    ]])
+
+    screen:expect([[
+                                                        |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {2:                                                  }|
+      {3:Error executing luv callback:}                     |
+      {3:[string "<nvim>"]:4: E5560: nvim_set_var must not }|
+      {3:be called in a lua loop callback}                  |
+      {4:Press ENTER or type command to continue}^           |
+    ]])
+    feed('<cr>')
+    eq(false, eval("get(g:, 'valid', v:false)"))
+
+    -- callbacks can be scheduled to be executed in the main event loop
+    -- where the entire API is available
+    exec_lua([[
+      local timer = vim.loop.new_timer()
+      timer:start(20, 0, vim.schedule_wrap(function ()
+        timer:close()
+        vim.api.nvim_set_var("valid", true)
+        vim.api.nvim_command("echomsg 'howdy'")
+      end))
+    ]])
+
+    screen:expect([[
+      ^                                                  |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      howdy                                             |
+    ]])
+    eq(true, eval("get(g:, 'valid', v:false)"))
+
+    -- fast (not deferred) API functions are allowed to be called directly
+    exec_lua([[
+      local timer = vim.loop.new_timer()
+      timer:start(20, 0, function ()
+        timer:close()
+        -- input is queued for processing after the callback returns
+        vim.api.nvim_input("isneaky")
+        _G.mode = vim.api.nvim_get_mode()
+      end)
+    ]])
+    screen:expect([[
+      sneaky^                                            |
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {1:~                                                 }|
+      {5:-- INSERT --}                                      |
+    ]])
+    eq({blocking=false, mode='n'}, exec_lua("return _G.mode"))
+  end)
 end)