chore: add dexkit as demo for automated JNI registration

Author: cinit

demo-app/build.gradle.kts

@@ -29,6 +29,7 @@ android {
         implementation(libs.androidx.annotation)
         implementation(projects.coreSyscall)
         implementation(libs.tencent.mmkv)
+        implementation(libs.luckypray.dexkit)
     }
 
     // force Java 8

demo-app/src/main/java/com/example/test/app/StandaloneTest.java

@@ -135,7 +135,7 @@ public static void main(String[] args) {
         } catch (Exception e) {
             System.out.println("Can map memfd as executable: " + e);
         }
-        long handle = TestNativeLoader.load();
+        long handle = TestNativeLoader.load("libmmkv.so");
         System.out.println("Handle: " + handle);
     }
 

demo-app/src/main/java/com/example/test/app/TestMainActivity.java

@@ -22,7 +22,11 @@
 
 import com.tencent.mmkv.MMKV;
 
+import org.luckypray.dexkit.DexKitBridge;
+import org.luckypray.dexkit.query.FindClass;
+
 import java.io.FileInputStream;
+import java.util.List;
 
 import dev.tmpfs.libcoresyscall.core.IAllocatedMemory;
 import dev.tmpfs.libcoresyscall.core.MemoryAccess;
@@ -184,14 +188,27 @@ private String runTests() {
             sb.append("domainname = ").append(MemoryAccess.peekCString(utsAddress + domainnameOffset));
             sb.append("\n");
             sb.append("Native load test: \n");
-            sb.append("handle = ").append(TestNativeLoader.initialize(this));
+            Long handle = TestNativeLoader.load("libmmkv.so");
+            MMKV.initialize(this, ctx -> {
+            });
+            sb.append("mmkv handle = ").append(handle);
             sb.append("\n");
             sb.append("MMKV.version = ").append(MMKV.version());
+            sb.append("\n");
+            handle = TestNativeLoader.load("libdexkit.so");
+            sb.append("dexkit handle = ").append(handle);
+            sb.append("\n");
+            try (DexKitBridge bridge = DexKitBridge.create(this.getClassLoader(), false)) {
+                List<?> clsList = bridge.findClass(FindClass.create());
+                sb.append("dexkit search class count: ").append(clsList.size());
+            }
         } catch (Exception | LinkageError | AssertionError e) {
             sb.append('\n').append("FAIL: \n").append(Log.getStackTraceString(e));
             Log.e("TestMainActivity", "runTests", e);
         }
         sb.append("\n");
+        sb.append(TestNativeLoader.sLoadLog);
+        sb.append("\n");
         sb.append("cat /proc/self/maps | grep libmmkv.so\n");
         sb.append(catProcSelfMapsAndGrep("libmmkv.so"));
         return sb.toString();

demo-app/src/main/java/com/example/test/app/TestNativeLoader.java

@@ -4,29 +4,33 @@
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.OsConstants;
+import android.util.Log;
 
 import androidx.annotation.NonNull;
 
-import com.tencent.mmkv.MMKV;
-
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
 
 import dev.tmpfs.libcoresyscall.core.NativeAccess;
 import dev.tmpfs.libcoresyscall.core.NativeHelper;
 import dev.tmpfs.libcoresyscall.core.impl.ReflectHelper;
 import dev.tmpfs.libcoresyscall.elfloader.DlExtLibraryLoader;
+import dev.tmpfs.libcoresyscall.elfloader.NativeRegistrationHelper;
 
 public class TestNativeLoader {
 
     private TestNativeLoader() {
     }
 
-    private static long sHandle;
+    private static final Map<String, Long> sHandleMap = new HashMap<>();
+
+    public static String sLoadLog = "";
 
     public static String getNativeLibraryDirName(int isa) {
         switch (isa) {
@@ -101,28 +105,24 @@ private static FileDescriptor createTempReadOnlyFile(@NonNull Context ctx, @NonN
         return fd;
     }
 
-    public static long initialize(@NonNull Context ctx) {
-        load();
-        if (sHandle != 0) {
-            MMKV.initialize(ctx, libName -> {
-                // no-op
-            });
-            return sHandle;
-        }
-        return 0;
-    }
 
-    public static long load() {
-        if (sHandle != 0) {
-            return sHandle;
+    public static synchronized long load(String soname) {
+        if (sHandleMap.containsKey(soname)) {
+            return sHandleMap.get(soname);
         }
-        String soname = "libmmkv.so";
+
         byte[] elfData = getElfData(soname);
 
-        sHandle = DlExtLibraryLoader.dlopenExtFromMemory(elfData, soname, DlExtLibraryLoader.RTLD_NOW, 0, 0);
+        long handle = DlExtLibraryLoader.dlopenExtFromMemory(elfData, soname, DlExtLibraryLoader.RTLD_NOW, 0, 0);
+
+        if (handle != 0) {
+            NativeRegistrationHelper.RegistrationSummary summary =
+                    NativeRegistrationHelper.registerNativeMethodsForLibrary(handle, elfData);
+
+            Log.d("TestNativeLoader", soname + ": registerNativeMethodsForLibrary: " + summary);
+            sLoadLog += soname + ": registerNativeMethodsForLibrary: " + summary + "\n";
 
-        if (sHandle != 0) {
-            long jniOnLoad = DlExtLibraryLoader.dlsym(sHandle, "JNI_OnLoad");
+            long jniOnLoad = DlExtLibraryLoader.dlsym(handle, "JNI_OnLoad");
             if (jniOnLoad != 0) {
                 long javaVm = NativeAccess.getJavaVM();
                 long ret = NativeAccess.callPointerFunction(jniOnLoad, javaVm, 0);
@@ -131,7 +131,10 @@ public static long load() {
                 }
             }
         }
-        return sHandle;
+        sHandleMap.put(soname, handle);
+        Log.d("TestNativeLoader", soname + " -> " + handle);
+        sLoadLog += soname + " -> " + handle + "\n";
+        return handle;
     }
 
 }

gradle/libs.versions.toml

@@ -6,6 +6,7 @@ compileSdk = "35"
 androidx-annotation = { module = "androidx.annotation:annotation", version = "1.9.1" }
 # for test elf loader
 tencent-mmkv = { module = "com.tencent:mmkv-static", version = "1.3.11" }
+luckypray-dexkit = { module = "org.luckypray:dexkit", version = "2.0.3" }
 
 [plugins]
 android-library = { id = "com.android.library", version.ref = "agp" }