Don't use local ref for cached jclass reference in JNI code

Change-Id: Id45b2acb358a819f2fd332e99f3a095f6fc7299b
related-to-bug: 4241138

8 files changed, 38 insertions, 52 deletions

diff --git a/core/jni/android/graphics/Movie.cpp b/core/jni/android/graphics/Movie.cpp
index de18f9f..b319a74 100644
--- a/core/jni/android/graphics/Movie.cpp
+++ b/core/jni/android/graphics/Movie.cpp
@@ -137,7 +137,6 @@ static JNINativeMethod gMethods[] = {
 
 #define RETURN_ERR_IF_NULL(value)   do { if (!(value)) { assert(0); return -1; } } while (false)
 
-int register_android_graphics_Movie(JNIEnv* env);
 int register_android_graphics_Movie(JNIEnv* env)
 {
     gMovie_class = env->FindClass(kClassPathName);
diff --git a/core/jni/android_media_AudioRecord.cpp b/core/jni/android_media_AudioRecord.cpp
index b6619ab..1b6b24f 100644
--- a/core/jni/android_media_AudioRecord.cpp
+++ b/core/jni/android_media_AudioRecord.cpp
@@ -41,7 +41,6 @@ static const char* const kClassPathName = "android/media/AudioRecord";
 
 struct fields_t {
     // these fields provide access from C++ to the...
-    jclass    audioRecordClass;      //... AudioRecord class
     jmethodID postNativeEventInJava; //... event post callback method
     int       PCM16;                 //...  format constants
     int       PCM8;                  //...  format constants
@@ -520,22 +519,20 @@ extern bool android_media_getIntConstantFromClass(JNIEnv* pEnv,
 // ----------------------------------------------------------------------------
 int register_android_media_AudioRecord(JNIEnv *env)
 {
-    javaAudioRecordFields.audioRecordClass = NULL;
     javaAudioRecordFields.postNativeEventInJava = NULL;
     javaAudioRecordFields.nativeRecorderInJavaObj = NULL;
     javaAudioRecordFields.nativeCallbackCookie = NULL;
     
 
     // Get the AudioRecord class
-    javaAudioRecordFields.audioRecordClass = env->FindClass(kClassPathName);
-    if (javaAudioRecordFields.audioRecordClass == NULL) {
+    jclass audioRecordClass = env->FindClass(kClassPathName);
+    if (audioRecordClass == NULL) {
         LOGE("Can't find %s", kClassPathName);
         return -1;
     }
-    
     // Get the postEvent method
     javaAudioRecordFields.postNativeEventInJava = env->GetStaticMethodID(
-            javaAudioRecordFields.audioRecordClass,
+            audioRecordClass,
             JAVA_POSTEVENT_CALLBACK_NAME, "(Ljava/lang/Object;IIILjava/lang/Object;)V");
     if (javaAudioRecordFields.postNativeEventInJava == NULL) {
         LOGE("Can't find AudioRecord.%s", JAVA_POSTEVENT_CALLBACK_NAME);
@@ -545,7 +542,7 @@ int register_android_media_AudioRecord(JNIEnv *env)
     // Get the variables
     //    mNativeRecorderInJavaObj
     javaAudioRecordFields.nativeRecorderInJavaObj = 
-        env->GetFieldID(javaAudioRecordFields.audioRecordClass,
+        env->GetFieldID(audioRecordClass,
                         JAVA_NATIVERECORDERINJAVAOBJ_FIELD_NAME, "I");
     if (javaAudioRecordFields.nativeRecorderInJavaObj == NULL) {
         LOGE("Can't find AudioRecord.%s", JAVA_NATIVERECORDERINJAVAOBJ_FIELD_NAME);
@@ -553,7 +550,7 @@ int register_android_media_AudioRecord(JNIEnv *env)
     }
     //     mNativeCallbackCookie
     javaAudioRecordFields.nativeCallbackCookie = env->GetFieldID(
-            javaAudioRecordFields.audioRecordClass,
+            audioRecordClass,
             JAVA_NATIVECALLBACKINFO_FIELD_NAME, "I");
     if (javaAudioRecordFields.nativeCallbackCookie == NULL) {
         LOGE("Can't find AudioRecord.%s", JAVA_NATIVECALLBACKINFO_FIELD_NAME);
diff --git a/core/jni/android_media_AudioTrack.cpp b/core/jni/android_media_AudioTrack.cpp
index 44d2a52..587a16c 100644
--- a/core/jni/android_media_AudioTrack.cpp
+++ b/core/jni/android_media_AudioTrack.cpp
@@ -43,7 +43,6 @@ static const char* const kClassPathName = "android/media/AudioTrack";
 
 struct fields_t {
     // these fields provide access from C++ to the...
-    jclass    audioTrackClass;       //... AudioTrack class
     jmethodID postNativeEventInJava; //... event post callback method
     int       PCM16;                 //...  format constants
     int       PCM8;                  //...  format constants
@@ -915,20 +914,19 @@ bool android_media_getIntConstantFromClass(JNIEnv* pEnv, jclass theClass, const
 // ----------------------------------------------------------------------------
 int register_android_media_AudioTrack(JNIEnv *env)
 {
-    javaAudioTrackFields.audioTrackClass = NULL;
     javaAudioTrackFields.nativeTrackInJavaObj = NULL;
     javaAudioTrackFields.postNativeEventInJava = NULL;
 
     // Get the AudioTrack class
-    javaAudioTrackFields.audioTrackClass = env->FindClass(kClassPathName);
-    if (javaAudioTrackFields.audioTrackClass == NULL) {
+    jclass audioTrackClass = env->FindClass(kClassPathName);
+    if (audioTrackClass == NULL) {
         LOGE("Can't find %s", kClassPathName);
         return -1;
     }
 
     // Get the postEvent method
     javaAudioTrackFields.postNativeEventInJava = env->GetStaticMethodID(
-            javaAudioTrackFields.audioTrackClass,
+            audioTrackClass,
             JAVA_POSTEVENT_CALLBACK_NAME, "(Ljava/lang/Object;IIILjava/lang/Object;)V");
     if (javaAudioTrackFields.postNativeEventInJava == NULL) {
         LOGE("Can't find AudioTrack.%s", JAVA_POSTEVENT_CALLBACK_NAME);
@@ -938,7 +936,7 @@ int register_android_media_AudioTrack(JNIEnv *env)
     // Get the variables fields
     //      nativeTrackInJavaObj
     javaAudioTrackFields.nativeTrackInJavaObj = env->GetFieldID(
-            javaAudioTrackFields.audioTrackClass,
+            audioTrackClass,
             JAVA_NATIVETRACKINJAVAOBJ_FIELD_NAME, "I");
     if (javaAudioTrackFields.nativeTrackInJavaObj == NULL) {
         LOGE("Can't find AudioTrack.%s", JAVA_NATIVETRACKINJAVAOBJ_FIELD_NAME);
@@ -946,7 +944,7 @@ int register_android_media_AudioTrack(JNIEnv *env)
     }
     //      jniData;
     javaAudioTrackFields.jniData = env->GetFieldID(
-            javaAudioTrackFields.audioTrackClass,
+            audioTrackClass,
             JAVA_JNIDATA_FIELD_NAME, "I");
     if (javaAudioTrackFields.jniData == NULL) {
         LOGE("Can't find AudioTrack.%s", JAVA_JNIDATA_FIELD_NAME);
@@ -954,10 +952,10 @@ int register_android_media_AudioTrack(JNIEnv *env)
     }
 
     // Get the memory mode constants
-    if ( !android_media_getIntConstantFromClass(env, javaAudioTrackFields.audioTrackClass,
+    if ( !android_media_getIntConstantFromClass(env, audioTrackClass,
                kClassPathName, 
                JAVA_CONST_MODE_STATIC_NAME, &(javaAudioTrackFields.MODE_STATIC))
-         || !android_media_getIntConstantFromClass(env, javaAudioTrackFields.audioTrackClass,
+         || !android_media_getIntConstantFromClass(env, audioTrackClass,
                kClassPathName, 
                JAVA_CONST_MODE_STREAM_NAME, &(javaAudioTrackFields.MODE_STREAM)) ) {
         // error log performed in android_media_getIntConstantFromClass() 
diff --git a/core/jni/android_net_NetUtils.cpp b/core/jni/android_net_NetUtils.cpp
index 3adf770..db132ec 100644
--- a/core/jni/android_net_NetUtils.cpp
+++ b/core/jni/android_net_NetUtils.cpp
@@ -55,7 +55,6 @@ namespace android {
  * to look them up every time.
  */
 static struct fieldIds {
-    jclass dhcpInfoInternalClass;
     jmethodID constructorId;
     jfieldID ipaddress;
     jfieldID gateway;
@@ -163,7 +162,7 @@ static jboolean android_net_utils_runDhcp(JNIEnv* env, jobject clazz, jstring if
     result = ::dhcp_do_request(nameStr, ipaddr, gateway, &prefixLength,
                                         dns1, dns2, server, &lease);
     env->ReleaseStringUTFChars(ifname, nameStr);
-    if (result == 0 && dhcpInfoInternalFieldIds.dhcpInfoInternalClass != NULL) {
+    if (result == 0) {
         env->SetObjectField(info, dhcpInfoInternalFieldIds.ipaddress, env->NewStringUTF(ipaddr));
         env->SetObjectField(info, dhcpInfoInternalFieldIds.gateway, env->NewStringUTF(gateway));
         env->SetIntField(info, dhcpInfoInternalFieldIds.prefixLength, prefixLength);
@@ -229,17 +228,16 @@ int register_android_net_NetworkUtils(JNIEnv* env)
     jclass netutils = env->FindClass(NETUTILS_PKG_NAME);
     LOG_FATAL_IF(netutils == NULL, "Unable to find class " NETUTILS_PKG_NAME);
 
-    dhcpInfoInternalFieldIds.dhcpInfoInternalClass = env->FindClass("android/net/DhcpInfoInternal");
-    if (dhcpInfoInternalFieldIds.dhcpInfoInternalClass != NULL) {
-        dhcpInfoInternalFieldIds.constructorId = env->GetMethodID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "<init>", "()V");
-        dhcpInfoInternalFieldIds.ipaddress = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "ipAddress", "Ljava/lang/String;");
-        dhcpInfoInternalFieldIds.gateway = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "gateway", "Ljava/lang/String;");
-        dhcpInfoInternalFieldIds.prefixLength = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "prefixLength", "I");
-        dhcpInfoInternalFieldIds.dns1 = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "dns1", "Ljava/lang/String;");
-        dhcpInfoInternalFieldIds.dns2 = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "dns2", "Ljava/lang/String;");
-        dhcpInfoInternalFieldIds.serverAddress = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "serverAddress", "Ljava/lang/String;");
-        dhcpInfoInternalFieldIds.leaseDuration = env->GetFieldID(dhcpInfoInternalFieldIds.dhcpInfoInternalClass, "leaseDuration", "I");
-    }
+    jclass dhcpInfoInternalClass = env->FindClass("android/net/DhcpInfoInternal");
+    LOG_FATAL_IF(dhcpInfoInternalClass == NULL, "Unable to find class android/net/DhcpInfoInternal");
+    dhcpInfoInternalFieldIds.constructorId = env->GetMethodID(dhcpInfoInternalClass, "<init>", "()V");
+    dhcpInfoInternalFieldIds.ipaddress = env->GetFieldID(dhcpInfoInternalClass, "ipAddress", "Ljava/lang/String;");
+    dhcpInfoInternalFieldIds.gateway = env->GetFieldID(dhcpInfoInternalClass, "gateway", "Ljava/lang/String;");
+    dhcpInfoInternalFieldIds.prefixLength = env->GetFieldID(dhcpInfoInternalClass, "prefixLength", "I");
+    dhcpInfoInternalFieldIds.dns1 = env->GetFieldID(dhcpInfoInternalClass, "dns1", "Ljava/lang/String;");
+    dhcpInfoInternalFieldIds.dns2 = env->GetFieldID(dhcpInfoInternalClass, "dns2", "Ljava/lang/String;");
+    dhcpInfoInternalFieldIds.serverAddress = env->GetFieldID(dhcpInfoInternalClass, "serverAddress", "Ljava/lang/String;");
+    dhcpInfoInternalFieldIds.leaseDuration = env->GetFieldID(dhcpInfoInternalClass, "leaseDuration", "I");
 
     return AndroidRuntime::registerNativeMethods(env,
             NETUTILS_PKG_NAME, gNetworkUtilMethods, NELEM(gNetworkUtilMethods));
diff --git a/core/jni/android_view_GLES20Canvas.cpp b/core/jni/android_view_GLES20Canvas.cpp
index 9a727a7..f31bba9 100644
--- a/core/jni/android_view_GLES20Canvas.cpp
+++ b/core/jni/android_view_GLES20Canvas.cpp
@@ -736,9 +736,9 @@ const char* const kActivityThreadPathName = "android/app/ActivityThread";
 
 int register_android_app_ActivityThread(JNIEnv* env)
 {
-    jclass gFileDescriptorClass = env->FindClass("java/io/FileDescriptor");
+    jclass fileDescriptorClass = env->FindClass("java/io/FileDescriptor");
     LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
-    gFileDescriptorField = env->GetFieldID(gFileDescriptorClass, "descriptor", "I");
+    gFileDescriptorField = env->GetFieldID(fileDescriptorClass, "descriptor", "I");
     LOG_FATAL_IF(gFileDescriptorField == NULL,
                  "Unable to find descriptor field in java.io.FileDescriptor");
 
diff --git a/media/jni/android_media_MediaMetadataRetriever.cpp b/media/jni/android_media_MediaMetadataRetriever.cpp
index 5d9a3c5..27b37b7 100644
--- a/media/jni/android_media_MediaMetadataRetriever.cpp
+++ b/media/jni/android_media_MediaMetadataRetriever.cpp
@@ -441,19 +441,20 @@ static void android_media_MediaMetadataRetriever_native_init(JNIEnv *env)
 {
     jclass clazz = env->FindClass(kClassPathName);
     if (clazz == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/media/MediaMetadataRetriever");
         return;
     }
 
     fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
     if (fields.context == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaMetadataRetriever.mNativeContext");
         return;
     }
 
-    fields.bitmapClazz = env->FindClass("android/graphics/Bitmap");
+    jclass bitmapClazz = env->FindClass("android/graphics/Bitmap");
+    if (bitmapClazz == NULL) {
+        return;
+    }
+    fields.bitmapClazz = (jclass) env->NewGlobalRef(bitmapClazz);
     if (fields.bitmapClazz == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/graphics/Bitmap");
         return;
     }
     fields.createBitmapMethod =
@@ -461,8 +462,6 @@ static void android_media_MediaMetadataRetriever_native_init(JNIEnv *env)
                     "(IILandroid/graphics/Bitmap$Config;)"
                     "Landroid/graphics/Bitmap;");
     if (fields.createBitmapMethod == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException",
-                "Can't find Bitmap.createBitmap(int, int, Config)  method");
         return;
     }
     fields.createScaledBitmapMethod =
@@ -470,28 +469,25 @@ static void android_media_MediaMetadataRetriever_native_init(JNIEnv *env)
                     "(Landroid/graphics/Bitmap;IIZ)"
                     "Landroid/graphics/Bitmap;");
     if (fields.createScaledBitmapMethod == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException",
-                "Can't find Bitmap.createScaledBitmap(Bitmap, int, int, boolean)  method");
         return;
     }
     fields.nativeBitmap = env->GetFieldID(fields.bitmapClazz, "mNativeBitmap", "I");
     if (fields.nativeBitmap == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException",
-                "Can't find Bitmap.mNativeBitmap field");
+        return;
     }
 
-    fields.configClazz = env->FindClass("android/graphics/Bitmap$Config");
+    jclass configClazz = env->FindClass("android/graphics/Bitmap$Config");
+    if (configClazz == NULL) {
+        return;
+    }
+    fields.configClazz = (jclass) env->NewGlobalRef(configClazz);
     if (fields.configClazz == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException",
-                               "Can't find Bitmap$Config class");
         return;
     }
     fields.createConfigMethod =
             env->GetStaticMethodID(fields.configClazz, "nativeToConfig",
                     "(I)Landroid/graphics/Bitmap$Config;");
     if (fields.createConfigMethod == NULL) {
-        jniThrowException(env, "java/lang/RuntimeException",
-                "Can't find Bitmap$Config.nativeToConfig(int)  method");
         return;
     }
 }
diff --git a/packages/TtsService/jni/android_tts_SynthProxy.cpp b/packages/TtsService/jni/android_tts_SynthProxy.cpp
index 27d1fc0..e00fa85 100644
--- a/packages/TtsService/jni/android_tts_SynthProxy.cpp
+++ b/packages/TtsService/jni/android_tts_SynthProxy.cpp
@@ -53,7 +53,6 @@ using namespace android;
 // ----------------------------------------------------------------------------
 struct fields_t {
     jfieldID    synthProxyFieldJniData;
-    jclass      synthProxyClass;
     jmethodID   synthProxyMethodPost;
 };
 
@@ -1043,7 +1042,6 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved)
         goto bail;
     }
 
-    javaTTSFields.synthProxyClass = clazz;
     javaTTSFields.synthProxyFieldJniData = NULL;
     javaTTSFields.synthProxyMethodPost = NULL;
 
diff --git a/services/jni/com_android_server_UsbService.cpp b/services/jni/com_android_server_UsbService.cpp
index 6aeede2..00ee7e3 100644
--- a/services/jni/com_android_server_UsbService.cpp
+++ b/services/jni/com_android_server_UsbService.cpp
@@ -260,7 +260,7 @@ int register_android_server_UsbService(JNIEnv *env)
         return -1;
     }
 
-   clazz = env->FindClass("java/io/FileDescriptor");
+    clazz = env->FindClass("java/io/FileDescriptor");
     LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
     gFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
     gFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "()V");
@@ -268,7 +268,7 @@ int register_android_server_UsbService(JNIEnv *env)
     LOG_FATAL_IF(gFileDescriptorOffsets.mDescriptor == NULL,
                  "Unable to find descriptor field in java.io.FileDescriptor");
 
-   clazz = env->FindClass("android/os/ParcelFileDescriptor");
+    clazz = env->FindClass("android/os/ParcelFileDescriptor");
     LOG_FATAL_IF(clazz == NULL, "Unable to find class android.os.ParcelFileDescriptor");
     gParcelFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
     gParcelFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "(Ljava/io/FileDescriptor;)V");