[JNI Example] Call native in Java (#4657)

This PR serves as an example of how we should migrate Java native API to Chromium JNI standard. Local test: Simply ensure the native API is invoked. haozheng@haozheng:~/chromium/src$ adb logcat | grep JNI 01-08 14:56:20.158 13226 13226 I starboard: [dev.cobalt.coat/13226:0108/225620.158117(UTC):INFO:starboard_bridge.cc(93)] JNI: StartNativeStarboard: 0xec140a60 Explanation: Replace Java_dev_cobalt_coat_StarboardBridge_startNativeStarboard(JniEnvExt* env) with JNI_StarboardBridge_StartNativeStarboard(JNIEnv* env). Move implementation over to starboard_bridge.cc because we should only include the _jni header from a single .cc file as the header defines functions, to avoid duplicate symbols issue. b/372559388
youtube · Jan 9, 2025 · 632168a · 632168a
1 parent c99e348
commit 632168a
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diff --git a/cobalt/android/apk/app/src/main/java/dev/cobalt/coat/StarboardBridge.java b/cobalt/android/apk/app/src/main/java/dev/cobalt/coat/StarboardBridge.java
@@ -131,13 +131,11 @@ public StarboardBridge(
     this.volumeStateReceiver = new VolumeStateReceiver(appContext);
     this.isAmatiDevice = appContext.getPackageManager().hasSystemFeature(AMATI_EXPERIENCE_FEATURE);
 
-    nativeApp = startNativeStarboard();
+    nativeApp = StarboardBridgeJni.get().startNativeStarboard();
   }
 
   private native boolean initJNI();
 
-  private native long startNativeStarboard();
-
   private native void closeNativeStarboard(long nativeApp);
 
   @NativeMethods
@@ -146,11 +144,10 @@ interface Natives {
 
         long currentMonotonicTime();
 
+        long startNativeStarboard();
         // TODO(cobalt, b/372559388): move below native methods to the Natives interface.
         // boolean initJNI();
 
-        // long startNativeStarboard();
-
         // void closeNativeStarboard(long nativeApp);
     }
 

diff --git a/starboard/android/shared/android_main.cc b/starboard/android/shared/android_main.cc
@@ -30,7 +30,6 @@
 #include "starboard/event.h"
 #include "starboard/log.h"
 #include "starboard/shared/starboard/command_line.h"
-#include "starboard/shared/starboard/log_mutex.h"
 #include "starboard/thread.h"
 #if SB_IS(EVERGREEN_COMPATIBLE)
 #include "starboard/crashpad_wrapper/wrapper.h"  // nogncheck
@@ -59,17 +58,6 @@ Semaphore* g_app_created_semaphore = nullptr;
 std::atomic_bool g_app_running{false};
 #endif  // SB_IS(EVERGREEN_COMPATIBLE)
 
-std::vector<std::string> GetArgs() {
-  std::vector<std::string> args;
-  // Fake program name as args[0]
-  args.push_back("android_main");
-
-  JNIEnv* env = base::android::AttachCurrentThread();
-  StarboardBridge::GetInstance()->AppendArgs(env, &args);
-
-  return args;
-}
-
 #if SB_IS(EVERGREEN_COMPATIBLE)
 bool CopyDirContents(const std::string& src_dir_path,
                      const std::string& dst_dir_path) {
@@ -242,30 +230,6 @@ Java_dev_cobalt_coat_StarboardBridge_nativeIsReleaseBuild() {
 #endif
 }
 
-#if SB_IS(EVERGREEN_COMPATIBLE)
-void StarboardThreadLaunch() {
-  // Start the Starboard thread the first time an Activity is created.
-  if (g_starboard_thread == 0) {
-    Semaphore semaphore;
-
-    pthread_attr_t attributes;
-    pthread_attr_init(&attributes);
-    pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
-
-    pthread_create(&g_starboard_thread, &attributes, &ThreadEntryPoint,
-                   &semaphore);
-
-    pthread_attr_destroy(&attributes);
-
-    // Wait for the ApplicationAndroid to be created.
-    semaphore.Take();
-  }
-
-  // Ensure application init happens here
-  ApplicationAndroid::Get();
-}
-#endif  // SB_IS(EVERGREEN_COMPATIBLE)
-
 // TODO(cobalt, b/372559388): consolidate this function when fully deprecate
 // JniEnvExt.
 extern "C" SB_EXPORT_PLATFORM void Java_dev_cobalt_coat_StarboardBridge_initJNI(
@@ -278,21 +242,6 @@ extern "C" SB_EXPORT_PLATFORM void Java_dev_cobalt_coat_StarboardBridge_initJNI(
   StarboardBridge::GetInstance()->Initialize(jni_env, starboard_bridge);
 }
 
-extern "C" SB_EXPORT_PLATFORM jlong
-Java_dev_cobalt_coat_StarboardBridge_startNativeStarboard(JniEnvExt* env) {
-#if SB_IS(EVERGREEN_COMPATIBLE)
-  StarboardThreadLaunch();
-#else
-  starboard::shared::starboard::GetLoggingMutex();
-  auto command_line = std::make_unique<CommandLine>(GetArgs());
-  LogInit(*command_line);
-  auto* nativeApp = new ApplicationAndroid(std::move(command_line));
-  // Ensure application init happens here
-  ApplicationAndroid::Get();
-  return reinterpret_cast<jlong>(nativeApp);
-#endif  // SB_IS(EVERGREEN_COMPATIBLE)
-}
-
 extern "C" SB_EXPORT_PLATFORM void
 Java_dev_cobalt_coat_StarboardBridge_closeNativeStarboard(JniEnvExt* env,
                                                           jlong nativeApp) {

diff --git a/starboard/android/shared/starboard_bridge.cc b/starboard/android/shared/starboard_bridge.cc
@@ -16,11 +16,15 @@
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "starboard/android/shared/application_android.h"
 #include "starboard/android/shared/file_internal.h"
+#include "starboard/android/shared/log_internal.h"
 #include "starboard/common/log.h"
 #include "starboard/common/time.h"
 #include "starboard/media.h"
 #include "starboard/shared/starboard/audio_sink/audio_sink_internal.h"
+#include "starboard/shared/starboard/command_line.h"
+#include "starboard/shared/starboard/log_mutex.h"
 
 // Must come after all headers that specialize FromJniType() / ToJniType().
 #include "cobalt/android/jni_headers/StarboardBridge_jni.h"
@@ -29,6 +33,43 @@ namespace starboard {
 namespace android {
 namespace shared {
 
+namespace {
+#if SB_IS(EVERGREEN_COMPATIBLE)
+void StarboardThreadLaunch() {
+  // Start the Starboard thread the first time an Activity is created.
+  if (g_starboard_thread == 0) {
+    Semaphore semaphore;
+
+    pthread_attr_t attributes;
+    pthread_attr_init(&attributes);
+    pthread_attr_setdetachstate(&attributes, PTHREAD_CREATE_DETACHED);
+
+    pthread_create(&g_starboard_thread, &attributes, &ThreadEntryPoint,
+                   &semaphore);
+
+    pthread_attr_destroy(&attributes);
+
+    // Wait for the ApplicationAndroid to be created.
+    semaphore.Take();
+  }
+
+  // Ensure application init happens here
+  ApplicationAndroid::Get();
+}
+#endif  // SB_IS(EVERGREEN_COMPATIBLE)
+}  // namespace
+
+std::vector<std::string> GetArgs() {
+  std::vector<std::string> args;
+  // Fake program name as args[0]
+  args.push_back("android_main");
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  StarboardBridge::GetInstance()->AppendArgs(env, &args);
+
+  return args;
+}
+
 extern "C" SB_EXPORT_PLATFORM void JNI_StarboardBridge_OnStop(JNIEnv* env) {
   ::starboard::shared::starboard::audio_sink::SbAudioSinkImpl::TearDown();
   SbFileAndroidTeardown();
@@ -39,6 +80,21 @@ JNI_StarboardBridge_CurrentMonotonicTime(JNIEnv* env) {
   return CurrentMonotonicTime();
 }
 
+extern "C" SB_EXPORT_PLATFORM jlong
+JNI_StarboardBridge_StartNativeStarboard(JNIEnv* env) {
+#if SB_IS(EVERGREEN_COMPATIBLE)
+  StarboardThreadLaunch();
+#else
+  starboard::shared::starboard::GetLoggingMutex();
+  auto command_line = std::make_unique<CommandLine>(GetArgs());
+  LogInit(*command_line);
+  auto* nativeApp = new ApplicationAndroid(std::move(command_line));
+  // Ensure application init happens here
+  ApplicationAndroid::Get();
+  return reinterpret_cast<jlong>(nativeApp);
+#endif  // SB_IS(EVERGREEN_COMPATIBLE)
+}
+
 // StarboardBridge::GetInstance() should not be inlined in the
 // header. This makes sure that when source files from multiple targets include
 // this header they don't end up with different copies of the inlined code