lua: introduce vim.loop (expose libuv event-loop) #10123

Co-authored-by: Andrey Popp <8mayday@gmail.com>

closes #9546
closes #10084

8 files changed, 129 insertions, 6 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 43281dee2c..7d2314a418 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -385,6 +385,9 @@ include_directories(SYSTEM ${LIBUV_INCLUDE_DIRS})
 find_package(Msgpack 1.0.0 REQUIRED)
 include_directories(SYSTEM ${MSGPACK_INCLUDE_DIRS})
 
+find_package(LibLUV 1.29.1 REQUIRED)
+include_directories(SYSTEM ${LIBLUV_INCLUDE_DIRS})
+
 # Note: The test lib requires LuaJIT; it will be skipped if LuaJIT is missing.
 option(PREFER_LUA "Prefer Lua over LuaJIT in the nvim executable." OFF)
 
diff --git a/cmake/FindLibLUV.cmake b/cmake/FindLibLUV.cmake
new file mode 100644
index 0000000000..d8ce9264c3
--- /dev/null
+++ b/cmake/FindLibLUV.cmake
@@ -0,0 +1,32 @@
+# - Try to find luv
+# Once done this will define
+#  LIBLUV_FOUND - System has libluv
+#  LIBLUV_INCLUDE_DIRS - The libluv include directories
+#  LIBLUV_LIBRARIES - The libraries needed to use libluv
+
+find_path(LIBLUV_INCLUDE_DIR luv/luv.h
+          PATHS ${PC_LIBLUV_INCLUDEDIR} ${PC_LIBLUV_INCLUDE_DIRS}
+          ${LIMIT_SEARCH})
+
+# If we're asked to use static linkage, add libluv.a as a preferred library name.
+if(LIBLUV_USE_STATIC)
+  list(APPEND LIBLUV_NAMES
+    "${CMAKE_STATIC_LIBRARY_PREFIX}luv${CMAKE_STATIC_LIBRARY_SUFFIX}")
+endif()
+
+list(APPEND LIBLUV_NAMES luv)
+
+find_library(LIBLUV_LIBRARY NAMES ${LIBLUV_NAMES}
+  HINTS ${PC_LIBLUV_LIBDIR} ${PC_LIBLUV_LIBRARY_DIRS}
+  ${LIMIT_SEARCH})
+
+set(LIBLUV_LIBRARIES ${LIBLUV_LIBRARY})
+set(LIBLUV_INCLUDE_DIRS ${LIBLUV_INCLUDE_DIR})
+
+include(FindPackageHandleStandardArgs)
+# handle the QUIETLY and REQUIRED arguments and set LIBLUV_FOUND to TRUE
+# if all listed variables are TRUE
+find_package_handle_standard_args(libluv DEFAULT_MSG
+  LIBLUV_LIBRARY LIBLUV_INCLUDE_DIR)
+
+mark_as_advanced(LIBLUV_INCLUDE_DIR LIBLUV_LIBRARY)
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 8abc43c2aa..77c5bf59e4 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -383,6 +383,7 @@ endif()
 
 # Put these last on the link line, since multiple things may depend on them.
 list(APPEND NVIM_LINK_LIBRARIES
+  ${LIBLUV_LIBRARIES}
   ${LIBUV_LIBRARIES}
   ${MSGPACK_LIBRARIES}
   ${LIBVTERM_LIBRARIES}
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index df08a9dd87..8cb282356a 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -31,6 +31,8 @@
 #include "nvim/lua/executor.h"
 #include "nvim/lua/converter.h"
 
+#include "luv/luv.h"
+
 typedef struct {
   Error err;
   String lua_err_str;
@@ -176,6 +178,11 @@ static int nlua_state_init(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL
   lua_pushcfunction(lstate, &nlua_schedule);
   lua_setfield(lstate, -2, "schedule");
 
+  // vim.loop
+  luv_set_loop(lstate, &main_loop.uv);
+  luaopen_luv(lstate);
+  lua_setfield(lstate, -2, "loop");
+
   lua_setglobal(lstate, "vim");
   return 0;
 }
diff --git a/test/functional/lua/loop_spec.lua b/test/functional/lua/loop_spec.lua
new file mode 100644
index 0000000000..8cc54e8c13
--- /dev/null
+++ b/test/functional/lua/loop_spec.lua
@@ -0,0 +1,55 @@
+-- Test suite for testing interactions with API bindings
+local helpers = require('test.functional.helpers')(after_each)
+local funcs = helpers.funcs
+local meths = helpers.meths
+local clear = helpers.clear
+local sleep = helpers.sleep
+local eq = helpers.eq
+local matches = helpers.matches
+
+before_each(clear)
+
+describe('vim.loop', function()
+
+  it('version', function()
+    assert(funcs.luaeval('vim.loop.version()')>=72961, "libuv version too old")
+    matches("(%d+)%.(%d+)%.(%d+)", funcs.luaeval('vim.loop.version_string()'))
+  end)
+
+  it('timer', function()
+    meths.execute_lua('vim.api.nvim_set_var("coroutine_cnt", 0)', {})
+
+    local code=[[
+      local loop = vim.loop
+
+      local touch = 0
+      local function wait(ms)
+        local this = coroutine.running()
+        assert(this)
+        local timer = loop.new_timer()
+        timer:start(ms, 0, 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)
+        coroutine.yield()
+        touch = touch + 1
+        return touch
+      end
+      coroutine.wrap(function()
+        local touched = wait(10)
+        assert(touched==touch)
+        vim.api.nvim_set_var("coroutine_cnt", touched)
+      end)()
+    ]]
+
+    eq(0, meths.get_var('coroutine_cnt'))
+    meths.execute_lua(code, {})
+    sleep(20)
+    eq(2, meths.get_var('coroutine_cnt'))
+    eq(3, meths.get_var('coroutine_cnt_1'))
+  end)
+end)
diff --git a/third-party/CMakeLists.txt b/third-party/CMakeLists.txt
index db4dae4b39..21a1752054 100644
--- a/third-party/CMakeLists.txt
+++ b/third-party/CMakeLists.txt
@@ -154,8 +154,11 @@ set(LIBTERMKEY_SHA256 cecbf737f35d18f433c8d7864f63c0f878af41f8bd0255a3ebb16010dc
 set(LIBVTERM_URL https://github.com/neovim/libvterm/archive/b45b648cab73f9667bde7c0c6045b285e22b3ecd.tar.gz)
 set(LIBVTERM_SHA256 37cc123deff29327efa654358c2ebaaf8589da03754ca5adb8ec47be386a0433)
 
-set(LUV_URL https://github.com/luvit/luv/archive/1.9.1-1.tar.gz)
-set(LUV_SHA256 562b9efaad30aa051a40eac9ade0c3df48bb8186763769abe47ec3fb3edb1268)
+set(LUV_URL https://github.com/luvit/luv/archive/1.29.1-2.tar.gz)
+set(LUV_SHA256 e75d8fd2a14433bb798900a71e45318b3c0b8c2ef2c1c43593482ce95b4999e2)
+
+set(LUA_COMPAT53_URL https://github.com/keplerproject/lua-compat-5.3/archive/v0.7.tar.gz)
+set(LUA_COMPAT53_SHA256 bec3a23114a3d9b3218038309657f0f506ad10dfbc03bb54e91da7e5ffdba0a2)
 
 set(GPERF_URL https://github.com/neovim/deps/raw/ff5b4b18a87397a8564016071ae64f64bcd8c635/opt/gperf-3.1.tar.gz)
 set(GPERF_SHA256 588546b945bba4b70b6a3a616e80b4ab466e3f33024a352fc2198112cdbb3ae2)
diff --git a/third-party/cmake/BuildLuarocks.cmake b/third-party/cmake/BuildLuarocks.cmake
index de4db35bfd..3ef7c6300e 100644
--- a/third-party/cmake/BuildLuarocks.cmake
+++ b/third-party/cmake/BuildLuarocks.cmake
@@ -182,7 +182,7 @@ if(USE_BUNDLED_BUSTED)
   add_custom_target(luacheck
     DEPENDS ${LUACHECK_EXE})
 
-  set(LUV_DEPS luacheck luv-static)
+  set(LUV_DEPS luacheck luv-static lua-compat-5.3)
   if(MINGW AND CMAKE_CROSSCOMPILING)
     set(LUV_DEPS ${LUV_DEPS} libuv_host)
   endif()
@@ -191,9 +191,10 @@ if(USE_BUNDLED_BUSTED)
     list(APPEND LUV_ARGS LIBUV_DIR=${HOSTDEPS_INSTALL_DIR})
   endif()
   # DEPENDS on the previous module, because Luarocks breaks if parallel.
+  SET(LUV_PRIVATE_ARGS LUA_COMPAT53_INCDIR=${DEPS_BUILD_DIR}/src/lua-compat-5.3)
   add_custom_command(OUTPUT ${HOSTDEPS_LIB_DIR}/luarocks/rocks/luv
     COMMAND ${LUAROCKS_BINARY}
-    ARGS make ${LUAROCKS_BUILDARGS} ${LUV_ARGS}
+    ARGS make ${LUAROCKS_BUILDARGS} ${LUV_ARGS} ${LUV_PRIVATE_ARGS}
     WORKING_DIRECTORY ${DEPS_BUILD_DIR}/src/luv
     DEPENDS ${LUV_DEPS})
   add_custom_target(luv
diff --git a/third-party/cmake/BuildLuv.cmake b/third-party/cmake/BuildLuv.cmake
index a62ee72f91..5de5ddbf9c 100644
--- a/third-party/cmake/BuildLuv.cmake
+++ b/third-party/cmake/BuildLuv.cmake
@@ -15,8 +15,26 @@ function(BuildLuv)
     message(FATAL_ERROR "Must pass at least one of CONFIGURE_COMMAND, BUILD_COMMAND, INSTALL_COMMAND")
   endif()
 
+  ExternalProject_Add(lua-compat-5.3
+    PREFIX ${DEPS_BUILD_DIR}
+    URL ${LUA_COMPAT53_URL}
+    DOWNLOAD_DIR ${DEPS_DOWNLOAD_DIR}/lua-compat-5.3
+    DOWNLOAD_COMMAND ${CMAKE_COMMAND}
+      -DPREFIX=${DEPS_BUILD_DIR}
+      -DDOWNLOAD_DIR=${DEPS_DOWNLOAD_DIR}/lua-compat-5.3
+      -DURL=${LUA_COMPAT53_URL}
+      -DEXPECTED_SHA256=${LUA_COMPAT53_SHA256}
+      -DTARGET=lua-compat-5.3
+      -DUSE_EXISTING_SRC_DIR=${USE_EXISTING_SRC_DIR}
+      -P ${CMAKE_CURRENT_SOURCE_DIR}/cmake/DownloadAndExtractFile.cmake
+    PATCH_COMMAND ""
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND ""
+    INSTALL_COMMAND "")
+
   ExternalProject_Add(luv-static
     PREFIX ${DEPS_BUILD_DIR}
+    DEPENDS lua-compat-5.3
     URL ${LUV_URL}
     DOWNLOAD_DIR ${DEPS_DOWNLOAD_DIR}/luv
     DOWNLOAD_COMMAND ${CMAKE_COMMAND}
@@ -94,9 +112,12 @@ endif()
 
 if(CMAKE_GENERATOR MATCHES "Unix Makefiles" AND
         (CMAKE_SYSTEM_NAME MATCHES ".*BSD" OR CMAKE_SYSTEM_NAME MATCHES "DragonFly"))
-  set(LUV_BUILD_COMMAND ${CMAKE_COMMAND} "-DCMAKE_MAKE_PROGRAM=gmake" --build .)
+        set(LUV_BUILD_COMMAND ${CMAKE_COMMAND}
+          "-DLUA_COMPAT53_DIR=${DEPS_BUILD_DIR}/src/lua-compat-5.3"
+          "-DCMAKE_MAKE_PROGRAM=gmake" --build .)
 else()
-  set(LUV_BUILD_COMMAND ${CMAKE_COMMAND} --build .)
+  set(LUV_BUILD_COMMAND ${CMAKE_COMMAND}
+    "-DLUA_COMPAT53_DIR=${DEPS_BUILD_DIR}/src/lua-compat-5.3" --build .)
 endif()
 set(LUV_INSTALL_COMMAND ${CMAKE_COMMAND} --build . --target install)