fix:(loader) avoid race on lastmoduledatap with go plugin (only eff…

…ects on byted-tango) (#707)

go.work.sum

@@ -1,3 +1,4 @@
 github.com/bytedance/sonic/loader v0.2.0/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU=
 github.com/bytedance/sonic/loader v0.2.2/go.mod h1:N8A3vUdtUebEY2/VQC0MyhYeKUFosQU6FxH2JmUe6VI=
 github.com/cloudwego/iasm v0.2.0 h1:1KNIy1I1H9hNNFEEH3DVnI4UujN+1zjpuk6gwHLTssg=
+

loader/register.go

@@ -0,0 +1,55 @@
+// +build !bytedance_tango
+
+/**
+ * Copyright 2024 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package loader
+
+import (
+	"sync/atomic"
+	"unsafe"
+)
+
+func registerModule(mod *moduledata) {
+    registerModuleLockFree(&lastmoduledatap, mod)
+}
+
+func registerModuleLockFree(tail **moduledata, mod *moduledata) {
+    for {
+        oldTail := loadModule(tail)
+        if casModule(tail, oldTail, mod) {
+            storeModule(&oldTail.next, mod)
+            break
+        }
+    }
+}
+
+func loadModule(p **moduledata) *moduledata {
+    return (*moduledata)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
+}
+
+func storeModule(p **moduledata, value *moduledata) {
+    atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(value))
+}
+
+func casModule(p **moduledata, oldValue *moduledata, newValue *moduledata) bool {
+    return atomic.CompareAndSwapPointer(
+        (*unsafe.Pointer)(unsafe.Pointer(p)),
+        unsafe.Pointer(oldValue),
+        unsafe.Pointer(newValue),
+    )
+}
+

loader/register_tango.go

@@ -0,0 +1,34 @@
+// +build bytedance_tango
+
+/**
+ * Copyright 2024 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package loader
+
+import (
+    "sync"
+	_ "unsafe"
+)
+
+//go:linkname pluginsMu plugin.pluginsMu
+var pluginsMu sync.Mutex
+
+func registerModule(mod *moduledata) {
+    pluginsMu.Lock()
+    defer pluginsMu.Unlock()
+    lastmoduledatap.next = mod
+    lastmoduledatap = mod
+}

loader/stubs_test.go → loader/register_test.go

@@ -21,25 +21,24 @@ import (
     "sync"
 )
 
-func Test_registerModuleLockFree(t *testing.T) {
-    n, parallel := 1000, 8
-    head := moduledata{}
-    tail := &head
+func Test_registerModuleRace(t *testing.T) {
+    n, parallel := 100, 8
+    s := &moduledata{}
+    registerModule(s)
     wg := sync.WaitGroup{}
     wg.Add(parallel)
     filler := func(n int) {
         defer wg.Done()
         for i := 0; i < n; i++ {
-            m := &moduledata{}
-            registerModuleLockFree(&tail, m)
+            registerModule(&moduledata{})
         }
     }
     for i := 0; i < parallel; i++ {
         go filler(n)
     }
     wg.Wait()
     i := 0
-    for p := head.next; p != nil; p = p.next {
+    for p := s.next; p != nil; p = p.next {
         i += 1
     }
     if i != parallel * n {

loader/stubs.go

@@ -17,44 +17,12 @@
 package loader
 
 import (
-    "sync/atomic"
-    "unsafe"
     _ `unsafe`
 )
 
 //go:linkname lastmoduledatap runtime.lastmoduledatap
 //goland:noinspection GoUnusedGlobalVariable
 var lastmoduledatap *moduledata
 
-func registerModule(mod *moduledata) {
-    registerModuleLockFree(&lastmoduledatap, mod)
-}
-
 //go:linkname moduledataverify1 runtime.moduledataverify1
 func moduledataverify1(_ *moduledata)
-
-func registerModuleLockFree(tail **moduledata, mod *moduledata) {
-    for {
-        oldTail := loadModule(tail)
-        if casModule(tail, oldTail, mod) {
-            storeModule(&oldTail.next, mod)
-            break
-        }
-    }
-}
-
-func loadModule(p **moduledata) *moduledata {
-    return (*moduledata)(atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(p))))
-}
-
-func storeModule(p **moduledata, value *moduledata) {
-    atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(p)), unsafe.Pointer(value))
-}
-
-func casModule(p **moduledata, oldValue *moduledata, newValue *moduledata) bool {
-    return atomic.CompareAndSwapPointer(
-        (*unsafe.Pointer)(unsafe.Pointer(p)),
-        unsafe.Pointer(oldValue),
-        unsafe.Pointer(newValue),
-    )
-}