- don't repeatedly attach / detach worker pool threads

inolen · inolen · commit 3add52931d32 · 2013-11-08T09:03:10.000-08:00
diff --git a/src/methodCallBaton.cpp b/src/methodCallBaton.cpp
@@ -43,13 +43,9 @@ v8::Handle<v8::Value> MethodCallBaton::runSync() {
 
 /*static*/ void MethodCallBaton::EIO_MethodCall(uv_work_t* req) {
   MethodCallBaton* self = static_cast<MethodCallBaton*>(req->data);
-  JNIEnv *env = javaAttachCurrentThread(self->m_java->getJvm(), self->m_java->getClassLoader());
-  // scope the java scope to after/before attaching to thread.
-  {
-    JavaScope javaScope(env);
-    self->execute(env);
-  }
-  javaDetachCurrentThread(self->m_java->getJvm());
+  JNIEnv *env = javaGetEnv(self->m_java->getJvm(), self->m_java->getClassLoader());
+  JavaScope javaScope(env);
+  self->execute(env);
 }
 
 #if NODE_MINOR_VERSION >= 10
diff --git a/src/utils.cpp b/src/utils.cpp
@@ -120,19 +120,26 @@ std::string javaMethodCallToString(JNIEnv *env, jobject obj, jmethodID methodId,
   return result.str();
 }
 
-JNIEnv* javaAttachCurrentThread(JavaVM* jvm, jobject classLoader) {
-  JNIEnv* env;
-  JavaVMAttachArgs attachArgs;
-  attachArgs.version = JNI_VERSION_1_4;
-  attachArgs.name = NULL;
-  attachArgs.group = NULL;
-  jvm->AttachCurrentThread((void**)&env, &attachArgs);
-
-  jclass threadClazz = env->FindClass("java/lang/Thread");
-  jmethodID thread_currentThread = env->GetStaticMethodID(threadClazz, "currentThread", "()Ljava/lang/Thread;");
-  jmethodID thread_setContextClassLoader = env->GetMethodID(threadClazz, "setContextClassLoader", "(Ljava/lang/ClassLoader;)V");
-  jobject currentThread = env->CallStaticObjectMethod(threadClazz, thread_currentThread);
-  env->CallObjectMethod(currentThread, thread_setContextClassLoader, classLoader);
+JNIEnv* javaGetEnv(JavaVM* jvm, jobject classLoader) {
+  JNIEnv *env = NULL;
+  int ret = jvm->GetEnv((void**)&env, JNI_VERSION_1_6);
+
+  if (ret == JNI_EDETACHED) {
+    JavaVMAttachArgs attachArgs;
+    attachArgs.version = JNI_VERSION_1_6;
+    attachArgs.name = NULL;
+    attachArgs.group = NULL;
+    jvm->AttachCurrentThread((void**)&env, &attachArgs);
+
+    jclass threadClazz = env->FindClass("java/lang/Thread");
+    jmethodID thread_currentThread = env->GetStaticMethodID(threadClazz, "currentThread", "()Ljava/lang/Thread;");
+    jmethodID thread_setContextClassLoader = env->GetMethodID(threadClazz, "setContextClassLoader", "(Ljava/lang/ClassLoader;)V");
+    jobject currentThread = env->CallStaticObjectMethod(threadClazz, thread_currentThread);
+    env->CallObjectMethod(currentThread, thread_setContextClassLoader, classLoader);
+
+    env->DeleteLocalRef(threadClazz);
+    env->DeleteLocalRef(currentThread);
+  }
 
   return env;
 }
@@ -145,10 +152,6 @@ jobject getSystemClassLoader(JNIEnv *env) {
   return env->CallObjectMethod(currentThread, thread_getContextClassLoader);
 }
 
-void javaDetachCurrentThread(JavaVM* jvm) {
-  jvm->DetachCurrentThread();
-}
-
 jvalueType javaGetType(JNIEnv *env, jclass type) {
   jclass clazzClazz = env->FindClass("java/lang/Class");
   jmethodID class_isArray = env->GetMethodID(clazzClazz, "isArray", "()Z");
@@ -704,4 +707,4 @@ std::string methodNotFoundToString(JNIEnv *env, jclass clazz, std::string method
   }
 
   return msg.str();
-}
+}
diff --git a/src/utils.h b/src/utils.h
@@ -55,8 +55,7 @@ std::string javaToString(JNIEnv *env, jstring str);
 std::string javaObjectToString(JNIEnv *env, jobject obj);
 std::string javaArrayToString(JNIEnv *env, jobjectArray arr);
 std::string javaMethodCallToString(JNIEnv *env, jobject obj, jmethodID methodId, jarray args);
-JNIEnv* javaAttachCurrentThread(JavaVM* jvm, jobject classLoader);
-void javaDetachCurrentThread(JavaVM* jvm);
+JNIEnv* javaGetEnv(JavaVM* jvm, jobject classLoader);
 jobject getSystemClassLoader(JNIEnv *env);
 jvalueType javaGetArrayComponentType(JNIEnv *env, jobjectArray array);
 jvalueType javaGetType(JNIEnv *env, jclass type);
