Lua (#225)

* Add periodic pruning of the lua state pool

cmd/tile38-benchmark/main.go

@@ -319,30 +319,6 @@ func main() {
 					fmt.Println("SET SCRIPT: " + set_script)
 				}
 
-				redbench.Bench("EVALRO (get point)", addr, opts, prepFn,
-					func(buf []byte) []byte {
-						i := atomic.AddInt64(&i, 1)
-						return redbench.AppendCommand(buf, "EVALRO", get_script, "1", "key:bench", "id:"+strconv.FormatInt(i, 10))
-					},
-				)
-				redbench.Bench("EVALRO (get 4 points)", addr, opts, prepFn,
-					func(buf []byte) []byte {
-						i := atomic.AddInt64(&i, 1)
-						return redbench.AppendCommand(buf, "EVALRO", get4_script, "1",
-							"key:bench",
-							"id:"+strconv.FormatInt(i, 10),
-							"id:"+strconv.FormatInt(i+1, 10),
-							"id:"+strconv.FormatInt(i+2, 10),
-							"id:"+strconv.FormatInt(i+3, 10),
-						)
-					},
-				)
-				redbench.Bench("EVALNA (get point)", addr, opts, prepFn,
-					func(buf []byte) []byte {
-						i := atomic.AddInt64(&i, 1)
-						return redbench.AppendCommand(buf, "EVALNA", get_script, "1", "key:bench", "id:"+strconv.FormatInt(i, 10))
-					},
-				)
 				redbench.Bench("EVAL (set point)", addr, opts, prepFn,
 					func(buf []byte) []byte {
 						i := atomic.AddInt64(&i, 1)
@@ -367,6 +343,30 @@ func main() {
 						)
 					},
 				)
+				redbench.Bench("EVALRO (get point)", addr, opts, prepFn,
+					func(buf []byte) []byte {
+						i := atomic.AddInt64(&i, 1)
+						return redbench.AppendCommand(buf, "EVALRO", get_script, "1", "key:bench", "id:"+strconv.FormatInt(i, 10))
+					},
+				)
+				redbench.Bench("EVALRO (get 4 points)", addr, opts, prepFn,
+					func(buf []byte) []byte {
+						i := atomic.AddInt64(&i, 1)
+						return redbench.AppendCommand(buf, "EVALRO", get4_script, "1",
+							"key:bench",
+							"id:"+strconv.FormatInt(i, 10),
+							"id:"+strconv.FormatInt(i+1, 10),
+							"id:"+strconv.FormatInt(i+2, 10),
+							"id:"+strconv.FormatInt(i+3, 10),
+						)
+					},
+				)
+				redbench.Bench("EVALNA (get point)", addr, opts, prepFn,
+					func(buf []byte) []byte {
+						i := atomic.AddInt64(&i, 1)
+						return redbench.AppendCommand(buf, "EVALNA", get_script, "1", "key:bench", "id:"+strconv.FormatInt(i, 10))
+					},
+				)
 			}
 		}
 	}

controller/controller.go

@@ -194,6 +194,7 @@ func ListenAndServeEx(host string, port int, dir string, ln *net.Listener, http
 	}()
 	go c.processLives()
 	go c.watchOutOfMemory()
+	go c.watchLuaStatePool()
 	go c.watchAutoGC()
 	go c.backgroundExpiring()
 	defer func() {
@@ -318,6 +319,16 @@ func (c *Controller) watchOutOfMemory() {
 	}
 }
 
+func (c *Controller) watchLuaStatePool() {
+	t := time.NewTicker(time.Second * 10)
+	defer t.Stop()
+	for range t.C {
+		func() {
+			c.luapool.Prune()
+		}()
+	}
+}
+
 func (c *Controller) setCol(key string, col *collection.Collection) {
 	c.cols.ReplaceOrInsert(&collectionT{Key: key, Collection: col})
 }

controller/scripts.go

@@ -41,12 +41,12 @@ type lStatePool struct {
 // NewPool returns a new pool of lua states
 func (c *Controller) NewPool() *lStatePool {
 	pl := &lStatePool{
-		saved: make([]*lua.LState, 0),
+		saved: make([]*lua.LState, iniLuaPoolSize),
 		c:     c,
 	}
 	// Fill the pool with some ready handlers
 	for i := 0; i < iniLuaPoolSize; i++ {
-		pl.Put(pl.New())
+		pl.saved[i] = pl.New()
 		pl.total++
 	}
 	return pl
@@ -68,6 +68,23 @@ func (pl *lStatePool) Get() (*lua.LState, error) {
 	return x, nil
 }
 
+// Prune removes some of the idle lua states from the pool
+func (pl *lStatePool) Prune() {
+	pl.m.Lock()
+	n := len(pl.saved)
+	if n > iniLuaPoolSize {
+		// drop half of the idle states that is above the minimum
+		dropNum := (n - iniLuaPoolSize) / 2
+		if dropNum < 1 {
+			dropNum = 1
+		}
+		newSaved := make([]*lua.LState, n - dropNum)
+		copy(newSaved, pl.saved[dropNum:])
+		pl.saved = newSaved
+	}
+	pl.m.Unlock()
+}
+
 func (pl *lStatePool) New() *lua.LState {
 	L := lua.NewState()
 

core/commands.json

@@ -1332,7 +1332,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "EVALSHA":{
@@ -1360,7 +1360,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "EVALRO":{
@@ -1388,7 +1388,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "EVALROSHA":{
@@ -1416,7 +1416,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "EVALNA":{
@@ -1444,7 +1444,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "EVALNASHA":{
@@ -1472,7 +1472,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "SCRIPT EXISTS":{
@@ -1485,7 +1485,7 @@
         "multiple": true
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "SCRIPT LOAD":{
@@ -1497,13 +1497,13 @@
         "type": "string"
       }
     ],
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   },
   "SCRIPT FLUSH":{
     "summary": "Flushes the server cache of Lua scripts",
     "complexity": "O(1)",
-    "since": "1.9.2",
+    "since": "1.10.0",
     "group": "scripting"
   }
 }