feat: introduce thread {set,get}priority api

docs.md

@@ -3407,6 +3407,43 @@ the number to correspond with the table keys used in `uv.thread_getaffinity` and
 
 **Returns:** `integer` or `fail`
 
+### `uv.thread_setpriority(thread, priority)`
+
+> method form `thread:setpriority(priority)`
+
+**Parameters:**
+- `thread`: `luv_thread_t userdata`
+- `priority`: ``number`
+
+Sets the specified thread's scheduling priority setting. It requires elevated
+privilege to set specific priorities on some platforms.
+
+The priority can be set to the following constants.
+
+- uv.constants.THREAD_PRIORITY_HIGHEST
+- uv.constants.THREAD_PRIORITY_ABOVE_NORMAL
+- uv.constants.THREAD_PRIORITY_NORMAL
+- uv.constants.THREAD_PRIORITY_BELOW_NORMAL
+- uv.constants.THREAD_PRIORITY_LOWEST
+
+**Returns:** `boolean` or `fail`
+
+### `uv.thread_getpriority(thread)
+
+> method form `thread:getpriority()`
+
+**Parameters:**
+- `thread`: `luv_thread_t userdata`
+
+Gets the  thread's priority setting.
+
+Retrieves the scheduling priority of the specified thread. The returned priority
+value is platform dependent.
+
+For Linux, when schedule policy is SCHED_OTHER (default), priority is 0.
+
+**Returns:** `number` or `fail`
+
 ### `uv.thread_self()`
 
 Returns the handle for the thread in which this is called.

src/constants.c

@@ -355,6 +355,19 @@ static int luv_constants(lua_State* L) {
   lua_setfield(L, -2, "TTY_MODE_IO");
 #endif
 
+#if LUV_UV_VERSION_GEQ(1, 48, 0)
+  lua_pushinteger(L, UV_THREAD_PRIORITY_HIGHEST);
+  lua_setfield(L, -2, "THREAD_PRIORITY_HIGHEST");
+  lua_pushinteger(L, UV_THREAD_PRIORITY_ABOVE_NORMAL);
+  lua_setfield(L, -2, "THREAD_PRIORITY_ABOVE_NORMAL");
+  lua_pushinteger(L, UV_THREAD_PRIORITY_NORMAL);
+  lua_setfield(L, -2, "THREAD_PRIORITY_NORMAL");
+  lua_pushinteger(L, UV_THREAD_PRIORITY_BELOW_NORMAL);
+  lua_setfield(L, -2, "THREAD_PRIORITY_BELOW_NORMAL");
+  lua_pushinteger(L, UV_THREAD_PRIORITY_LOWEST);
+  lua_setfield(L, -2, "THREAD_PRIORITY_LOWEST");
+#endif
+
   return 1;
 }
 

src/luv.c

@@ -392,6 +392,10 @@ static const luaL_Reg luv_functions[] = {
   {"thread_setaffinity", luv_thread_setaffinity},
   {"thread_getcpu", luv_thread_getcpu},
 #endif
+#if LUV_UV_VERSION_GEQ(1, 48, 0)
+  {"thread_getpriority", luv_thread_getpriority},
+  {"thread_setpriority", luv_thread_setpriority},
+#endif
 
   // work.c
   {"new_work", luv_new_work},

src/thread.c

@@ -463,6 +463,26 @@ static int luv_thread_getcpu(lua_State* L) {
 }
 #endif
 
+#if LUV_UV_VERSION_GEQ(1, 48, 0)
+static int luv_thread_getpriority(lua_State* L) {
+  int priority;
+  luv_thread_t* tid = luv_check_thread(L, 1);
+  int ret = uv_thread_getpriority(tid->handle, &priority);
+  if (ret < 0) return luv_error(L, ret);
+  lua_pushinteger(L, priority);
+  return 1;
+}
+
+static int luv_thread_setpriority(lua_State* L) {
+  luv_thread_t* tid = luv_check_thread(L, 1);
+  int priority = luaL_checkinteger(L, 2);
+  int ret = uv_thread_setpriority(tid->handle, priority);
+  if (ret < 0) return luv_error(L, ret);
+  lua_pushboolean(L, 1);
+  return 1;
+}
+#endif
+
 static int luv_thread_join(lua_State* L) {
   luv_thread_t* tid = luv_check_thread(L, 1);
   int ret = uv_thread_join(&tid->handle);
@@ -498,6 +518,11 @@ static const luaL_Reg luv_thread_methods[] = {
 #if LUV_UV_VERSION_GEQ(1, 45, 0)
   {"getaffinity", luv_thread_getaffinity},
   {"setaffinity", luv_thread_setaffinity},
+  {"getcpu", luv_thread_getcpu},
+#endif
+#if LUV_UV_VERSION_GEQ(1, 48, 0)
+  {"getpriority", luv_thread_getpriority},
+  {"setpriority", luv_thread_setpriority},
 #endif
   {NULL, NULL}
 };

tests/test-thread.lua

@@ -154,4 +154,27 @@ return require('lib/tap')(function (test)
       end
     end, mask_size):join()
   end, "1.45.0")
+
+  test("getpriority, setpriority", function(_, p, _, uv)
+    assert(type(uv.constants.THREAD_PRIORITY_HIGHEST)=='number')
+    assert(type(uv.constants.THREAD_PRIORITY_ABOVE_NORMAL)=='number')
+    assert(type(uv.constants.THREAD_PRIORITY_NORMAL)=='number')
+    assert(type(uv.constants.THREAD_PRIORITY_BELOW_NORMAL)=='number')
+    assert(type(uv.constants.THREAD_PRIORITY_LOWEST)=='number')
+
+    local thread = uv.new_thread(function()
+      local _uv = require('luv')
+      local self = _uv.thread_self()
+      local priority = assert(self:getpriority())
+      print('priority in thread', priority)
+    end)
+
+    local priority = assert(thread:getpriority())
+    print('default priority', priority)
+
+    assert(thread:setpriority(uv.constants.THREAD_PRIORITY_LOWEST))
+    priority = assert(thread:getpriority())
+    print('priority after change', priority)
+    thread:join()
+  end, "1.48.0")
 end)