Javet v0.9.1

README.rst

@@ -40,22 +40,22 @@ Maven
     <dependency>
         <groupId>com.caoccao.javet</groupId>
         <artifactId>javet</artifactId>
-        <version>0.9.0</version>
+        <version>0.9.1</version>
     </dependency>
 
 Gradle Kotlin DSL
 ^^^^^^^^^^^^^^^^^
 
 .. code-block:: kotlin
 
-    implementation("com.caoccao.javet:javet:0.9.0")
+    implementation("com.caoccao.javet:javet:0.9.1")
 
 Gradle Groovy DSL
 ^^^^^^^^^^^^^^^^^
 
 .. code-block:: groovy
 
-    implementation 'com.caoccao.javet:javet:0.9.0'
+    implementation 'com.caoccao.javet:javet:0.9.1'
 
 Hello Javet
 -----------

build.gradle.kts

@@ -25,7 +25,7 @@ repositories {
 }
 
 group = "com.caoccao.javet"
-version = "0.9.0"
+version = "0.9.1"
 
 repositories {
     mavenCentral()

cpp/build.cmd

@@ -1,7 +1,7 @@
 @echo off
 REM Usage for V8: build -DV8_DIR=C:\v8 
 REM Usage for Node: build -DNODE_DIR=C:\node 
-SET JAVET_VERSION=0.9.0
+SET JAVET_VERSION=0.9.1
 rd /s/q build
 mkdir build
 cd build

cpp/build.sh

@@ -2,7 +2,7 @@
 
 # Usage for V8: build -DV8_DIR=~/v8
 # Usage for Node: build -DNODE_DIR=~/node
-JAVET_VERSION=0.9.0
+JAVET_VERSION=0.9.1
 rm -rf build
 mkdir build
 cd build

cpp/jni/com_caoccao_javet_interop_V8Native.cpp

@@ -43,14 +43,24 @@
 namespace Javet {
 #ifdef ENABLE_NODE
 	namespace NodeNative {
+		static jclass jclassV8Host;
+		static jmethodID jmethodIDV8HostIsLibraryReloadable;
+
 		static std::shared_ptr<node::ArrayBufferAllocator> GlobalNodeArrayBufferAllocator;
 
-		void Dispose() {
-			GlobalNodeArrayBufferAllocator.reset();
+		void Dispose(JNIEnv* jniEnv) {
+			if (!jniEnv->CallStaticBooleanMethod(jclassV8Host, jmethodIDV8HostIsLibraryReloadable)) {
+				GlobalNodeArrayBufferAllocator.reset();
+			}
 		}
 
 		void Initialize(JNIEnv* jniEnv) {
-			GlobalNodeArrayBufferAllocator = node::ArrayBufferAllocator::Create();
+			jclassV8Host = (jclass)jniEnv->NewGlobalRef(jniEnv->FindClass("com/caoccao/javet/interop/V8Host"));
+			jmethodIDV8HostIsLibraryReloadable = jniEnv->GetStaticMethodID(jclassV8Host, "isLibraryReloadable", "()Z");
+
+			if (!GlobalNodeArrayBufferAllocator) {
+				GlobalNodeArrayBufferAllocator = node::ArrayBufferAllocator::Create();
+			}
 		}
 	}
 #endif
@@ -62,15 +72,20 @@ namespace Javet {
 		static std::unique_ptr<V8Platform> GlobalV8Platform;
 #endif
 
+		static jclass jclassV8Host;
+		static jmethodID jmethodIDV8HostIsLibraryReloadable;
+
 		static jclass jclassV8ValueInteger;
 		static jmethodID jmethodIDV8ValueIntegerToPrimitive;
 
 		static jclass jclassV8ValueString;
 		static jmethodID jmethodIDV8ValueStringToPrimitive;
 
-		void Dispose() {
-			v8::V8::Dispose();
-			v8::V8::ShutdownPlatform();
+		void Dispose(JNIEnv* jniEnv) {
+			if (!jniEnv->CallStaticBooleanMethod(jclassV8Host, jmethodIDV8HostIsLibraryReloadable)) {
+				v8::V8::Dispose();
+				v8::V8::ShutdownPlatform();
+			}
 		}
 
 		/*
@@ -79,6 +94,8 @@ namespace Javet {
 		or runtime memory corruption will take place.
 		*/
 		void Initialize(JNIEnv* jniEnv) {
+			jclassV8Host = (jclass)jniEnv->NewGlobalRef(jniEnv->FindClass("com/caoccao/javet/interop/V8Host"));
+			jmethodIDV8HostIsLibraryReloadable = jniEnv->GetStaticMethodID(jclassV8Host, "isLibraryReloadable", "()Z");
 
 			jclassV8ValueInteger = (jclass)jniEnv->NewGlobalRef(jniEnv->FindClass("com/caoccao/javet/values/primitive/V8ValueInteger"));
 			jmethodIDV8ValueIntegerToPrimitive = jniEnv->GetMethodID(jclassV8ValueInteger, JAVA_METHOD_TO_PRIMITIVE, "()I");
@@ -90,21 +107,26 @@ namespace Javet {
 #ifdef ENABLE_I18N
 			v8::V8::InitializeICU();
 #endif
-#ifdef ENABLE_NODE
-			uv_setup_args(0, nullptr);
-			std::vector<std::string> args{ "" };
-			std::vector<std::string> execArgs{ "" };
-			std::vector<std::string> errors;
-			int errorCode = node::InitializeNodeWithArgs(&args, &execArgs, &errors);
-			if (errorCode != 0) {
-				LOG_ERROR("Failed to call node::InitializeNodeWithArgs().");
+			if (Javet::V8Native::GlobalV8Platform) {
+				LOG_INFO("V8::Initialize() is skipped.");
 			}
-			Javet::V8Native::GlobalV8Platform = node::MultiIsolatePlatform::Create(4);
+			else {
+#ifdef ENABLE_NODE
+				uv_setup_args(0, nullptr);
+				std::vector<std::string> args{ "" };
+				std::vector<std::string> execArgs{ "" };
+				std::vector<std::string> errors;
+				int errorCode = node::InitializeNodeWithArgs(&args, &execArgs, &errors);
+				if (errorCode != 0) {
+					LOG_ERROR("Failed to call node::InitializeNodeWithArgs().");
+				}
+				Javet::V8Native::GlobalV8Platform = node::MultiIsolatePlatform::Create(4);
 #else
-			Javet::V8Native::GlobalV8Platform = v8::platform::NewDefaultPlatform();
+				Javet::V8Native::GlobalV8Platform = v8::platform::NewDefaultPlatform();
 #endif
-			v8::V8::InitializePlatform(Javet::V8Native::GlobalV8Platform.get());
-			v8::V8::Initialize();
+				v8::V8::InitializePlatform(Javet::V8Native::GlobalV8Platform.get());
+				v8::V8::Initialize();
+			}
 			LOG_INFO("V8::Initialize() ends.");
 		}
 	}

cpp/jni/javet_native.cpp

@@ -51,10 +51,19 @@ jint JNI_OnLoad(JavaVM* javaVM, void* reserved) {
 
 void JNI_OnUnload(JavaVM* javaVM, void* reserved) {
 	LOG_INFO("JNI_OnUnload() begins.");
+	JNIEnv* jniEnv;
+	if (javaVM->GetEnv((void**)&jniEnv, JNI_VERSION_1_8) != JNI_OK) {
+		LOG_ERROR("Failed to call JavaVM.GetEnv().");
+	}
+	if (jniEnv == nullptr) {
+		LOG_ERROR("Failed to get JNIEnv.");
+	}
+	else {
 #ifdef ENABLE_NODE
-	Javet::NodeNative::Dispose();
+		Javet::NodeNative::Dispose(jniEnv);
 #endif
-	Javet::V8Native::Dispose();
+		Javet::V8Native::Dispose(jniEnv);
+	}
 	LOG_INFO("JNI_OnUnload() ends.");
 }
 

cpp/jni/javet_native.h

@@ -92,13 +92,13 @@ namespace Javet {
 
 #ifdef ENABLE_NODE
 	namespace NodeNative {
-		void Dispose();
+		void Dispose(JNIEnv* jniEnv);
 		void Initialize(JNIEnv* jniEnv);
 	}
 #endif
 
 	namespace V8Native {
-		void Dispose();
+		void Dispose(JNIEnv* jniEnv);
 		void Initialize(JNIEnv* jniEnv);
 	}
 }

cpp/jni/javet_node.h

@@ -21,6 +21,8 @@
 
 #pragma warning(disable: 4275)
 #pragma warning(disable: 4251)
+// #define NODE_WANT_INTERNALS 1
+// #include <node_binding.h>
 #include <node.h>
 #include <uv.h>
 #pragma warning(default: 4275)

cpp/jni/javet_resource_node.rc

@@ -61,8 +61,8 @@ LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 0,9,0,0
- PRODUCTVERSION 0,9,0,0
+ FILEVERSION 0,9,1,0
+ PRODUCTVERSION 0,9,1,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -79,12 +79,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "caoccao.com"
             VALUE "FileDescription", "caoccao.com"
-            VALUE "FileVersion", "0.9.0.0"
-            VALUE "InternalName", "libjavet-node-windows-x86_64.v.0.9.0.dll"
+            VALUE "FileVersion", "0.9.1.0"
+            VALUE "InternalName", "libjavet-node-windows-x86_64.v.0.9.1.dll"
             VALUE "LegalCopyright", "Copyright (C) 2021"
-            VALUE "OriginalFilename", "libjavet-node-windows-x86_64.v.0.9.0.dll"
+            VALUE "OriginalFilename", "libjavet-node-windows-x86_64.v.0.9.1.dll"
             VALUE "ProductName", "Javet Windows"
-            VALUE "ProductVersion", "0.9.0.0"
+            VALUE "ProductVersion", "0.9.1.0"
         END
     END
     BLOCK "VarFileInfo"

cpp/jni/javet_resource_v8.rc

@@ -61,8 +61,8 @@ LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 0,9,0,0
- PRODUCTVERSION 0,9,0,0
+ FILEVERSION 0,9,1,0
+ PRODUCTVERSION 0,9,1,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -79,12 +79,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "caoccao.com"
             VALUE "FileDescription", "caoccao.com"
-            VALUE "FileVersion", "0.9.0.0"
-            VALUE "InternalName", "libjavet-v8-windows-x86_64.v.0.9.0.dll"
+            VALUE "FileVersion", "0.9.1.0"
+            VALUE "InternalName", "libjavet-v8-windows-x86_64.v.0.9.1.dll"
             VALUE "LegalCopyright", "Copyright (C) 2021"
-            VALUE "OriginalFilename", "libjavet-v8-windows-x86_64.v.0.9.0.dll"
+            VALUE "OriginalFilename", "libjavet-v8-windows-x86_64.v.0.9.1.dll"
             VALUE "ProductName", "Javet Windows"
-            VALUE "ProductVersion", "0.9.0.0"
+            VALUE "ProductVersion", "0.9.1.0"
         END
     END
     BLOCK "VarFileInfo"

docs/development/design.rst

@@ -34,16 +34,16 @@ Javet supports both Node.js mode and V8 mode both of which can co-exist in one J
 .. image:: ../resources/images/javet_modes.png?raw=true
     :alt: Javet Modes
 
-As the diagram shows, Javet loads V8 v8.9+ in the default classloader as an out-of-box solution. Node.js is lazy loaded in a custom classloader. Detailed comparisons are as following.
+As the diagram shows, both Node.js and V8 are lazy loaded in dedicated custom classloaders. Detailed comparisons are as following.
 
 =========================== ======================= ==============================
 Feature                     Node.js Mode            V8 Mode
 =========================== ======================= ==============================
-Built-in                    No                      **Yes**
+Lazy Loadable               **Yes**                 **Yes**
 Customization               **High**                **High**
 Node.js Ecosystem           **Complete**            No
 Security                    Low                     **High**
-Unload                      Potentially Yes         No
+Unload                      **Yes**                 **Yes**
 V8 Ecosystem                **Complete**            **Complete**
 V8 Version                  Low                     **High**
 =========================== ======================= ==============================

docs/development/tools.rst

@@ -20,7 +20,7 @@ For now, Gradle v6.7 + Kotlin DSL constructs the build system.
 Node.js
 =================
 
-Node.js 14.16.1+ is supported.
+Node.js 14.17.0+ is supported.
 
 Maven (Optional)
 ================

docs/reference/index.rst

@@ -9,6 +9,7 @@ Javet Reference
 * `Lock <lock.rst>`_
 * `Termination <termination.rst>`_
 * `Logging <logging.rst>`_
+* `Load and Unload <load_and_unload.rst>`_
 * `Best Practices <best_practices.rst>`_
 * `Performance <performance.rst>`_
 * `Error Codes <error_codes.rst>`_

docs/reference/load_and_unload.rst

@@ -0,0 +1,47 @@
+===============
+Load and Unload
+===============
+
+As documented in `design <../development/design.rst>`_, Javet supports loading and unloading the JNI libraries during runtime in both Node.js and V8 modes.
+
+How?
+====
+
+Unload
+------
+
+Assuming the JNI library per mode is already loaded, here are the step-by-step on how to unload it.
+
+.. code-block:: java
+
+    // Step 1: Set library reloadable. Why? Because Javet defaults that switch to false.
+    V8Host.setLibraryReloadable(true);
+    // Step 2: Get V8Host per JS runtime type.
+    V8Host v8Host = V8Host.getInstance(jsRuntimeType);
+    // Step 3: Unload the library.
+    v8Host.unloadLibrary();
+    // Step 4: Restore the switch.
+    V8Host.setLibraryReloadable(false);
+
+How does ``unloadLibrary()`` work? There is no API that allows unloading a JNI library explicitly. The only way is GC will automatically unload the library if all references to that library are garbage collectable. So, application is supposed to close all V8 values, V8 runtimes prior to calling ``unloadLibrary()``. 
+
+Load
+----
+
+Assuming the JNI library per mode is already unloaded, here are the step-by-step on how to load it again.
+
+.. code-block:: java
+
+    // Step 1: Get V8Host per JS runtime type.
+    V8Host v8Host = V8Host.getInstance(jsRuntimeType);
+    // Step 2: Load the library.
+    v8Host.loadLibrary();
+
+Notes
+=====
+
+* ``unloadLibrary()`` can only take effect after all references are garbage collectable.
+* ``loadLibrary()`` is internally called by Javet in the first time and only takes effect after ``unloadLibrary()`` is called.
+* ``loadLibrary()`` and ``unloadLibrary()`` are for experiment only. **They may be unstable and crash JVM. Please use this feature at your own risk.**
+
+[`Home <../../README.rst>`_] [`Javet Reference <index.rst>`_]

docs/release_notes.rst

@@ -2,6 +2,12 @@
 Release Notes
 =============
 
+0.9.1
+-----
+
+* Moved V8 to a custom classloader
+* Enabled ``unloadLibrary()`` and ``loadLibrary()`` in ``V8Host``
+
 0.9.0
 -----