register_android_os_Parcel

register_jni_procs(gRegJNI, NELEM(gRegJNI), env)开始注册jni方法。下面重点查看一下gRegJNI数组的register_android_os_Parcel类型。

int register_android_os_Parcel(JNIEnv* env) {
    jclass clazz;
    clazz = env->FindClass(kParcelPathName);
    gParcelOffsets.clazz = (jclass) env->NewGlobalRef(clazz);
    gParcelOffsets.mNativePtr = env->GetFieldID(clazz, "mNativePtr", "I");
    gParcelOffsets.obtain = env->GetStaticMethodID(clazz, "obtain", "()Landroid/os/Parcel;");
    gParcelOffsets.recycle = env->GetMethodID(clazz, "recycle", "()V");
    return AndroidRuntime::registerNativeMethods(env, kParcelPathName,
        gParcelMethods, NELEM(gParcelMethods));
}

const char* const kParcelPathName = "android/os/Parcel";

上述方法在保存了Parcel类的相关信息后，注册了其相关的jni映射。

static const JNINativeMethod gParcelMethods[] = {
    {"nativeDataSize",            "(I)I", (void*)android_os_Parcel_dataSize},
    {"nativeDataAvail",           "(I)I", (void*)android_os_Parcel_dataAvail},
    {"nativeDataPosition",        "(I)I", (void*)android_os_Parcel_dataPosition},
    {"nativeDataCapacity",        "(I)I", (void*)android_os_Parcel_dataCapacity},
    {"nativeSetDataSize",         "(II)V", (void*)android_os_Parcel_setDataSize},
    {"nativeSetDataPosition",     "(II)V", (void*)android_os_Parcel_setDataPosition},
    {"nativeSetDataCapacity",     "(II)V", (void*)android_os_Parcel_setDataCapacity},

    {"nativePushAllowFds",        "(IZ)Z", (void*)android_os_Parcel_pushAllowFds},
    {"nativeRestoreAllowFds",     "(IZ)V", (void*)android_os_Parcel_restoreAllowFds},

    {"nativeWriteByteArray",      "(I[BII)V", (void*)android_os_Parcel_writeNative},
    {"nativeWriteInt",            "(II)V", (void*)android_os_Parcel_writeInt},
    {"nativeWriteLong",           "(IJ)V", (void*)android_os_Parcel_writeLong},
    {"nativeWriteFloat",          "(IF)V", (void*)android_os_Parcel_writeFloat},
    {"nativeWriteDouble",         "(ID)V", (void*)android_os_Parcel_writeDouble},
    {"nativeWriteString",         "(ILjava/lang/String;)V", (void*)android_os_Parcel_writeString},
    {"nativeWriteStrongBinder",   "(ILandroid/os/IBinder;)V", (void*)android_os_Parcel_writeStrongBinder},
    {"nativeWriteFileDescriptor", "(ILjava/io/FileDescriptor;)V", (void*)android_os_Parcel_writeFileDescriptor},

    {"nativeCreateByteArray",     "(I)[B", (void*)android_os_Parcel_createByteArray},
    {"nativeReadInt",             "(I)I", (void*)android_os_Parcel_readInt},
    {"nativeReadLong",            "(I)J", (void*)android_os_Parcel_readLong},
    {"nativeReadFloat",           "(I)F", (void*)android_os_Parcel_readFloat},
    {"nativeReadDouble",          "(I)D", (void*)android_os_Parcel_readDouble},
    {"nativeReadString",          "(I)Ljava/lang/String;", (void*)android_os_Parcel_readString},
    {"nativeReadStrongBinder",    "(I)Landroid/os/IBinder;", (void*)android_os_Parcel_readStrongBinder},
    {"nativeReadFileDescriptor",  "(I)Ljava/io/FileDescriptor;", (void*)android_os_Parcel_readFileDescriptor},

    {"openFileDescriptor",        "(Ljava/lang/String;I)Ljava/io/FileDescriptor;", (void*)android_os_Parcel_openFileDescriptor},
    {"dupFileDescriptor",         "(Ljava/io/FileDescriptor;)Ljava/io/FileDescriptor;", (void*)android_os_Parcel_dupFileDescriptor},
    {"closeFileDescriptor",       "(Ljava/io/FileDescriptor;)V", (void*)android_os_Parcel_closeFileDescriptor},
    {"clearFileDescriptor",       "(Ljava/io/FileDescriptor;)V", (void*)android_os_Parcel_clearFileDescriptor},

    {"nativeCreate",              "()I", (void*)android_os_Parcel_create},
    {"nativeFreeBuffer",          "(I)V", (void*)android_os_Parcel_freeBuffer},
    {"nativeDestroy",             "(I)V", (void*)android_os_Parcel_destroy},

    {"nativeMarshall",            "(I)[B", (void*)android_os_Parcel_marshall},
    {"nativeUnmarshall",          "(I[BII)V", (void*)android_os_Parcel_unmarshall},
    {"nativeAppendFrom",          "(IIII)V", (void*)android_os_Parcel_appendFrom},
    {"nativeHasFileDescriptors",  "(I)Z", (void*)android_os_Parcel_hasFileDescriptors},
    {"nativeWriteInterfaceToken", "(ILjava/lang/String;)V", (void*)android_os_Parcel_writeInterfaceToken},
    {"nativeEnforceInterface",    "(ILjava/lang/String;)V", (void*)android_os_Parcel_enforceInterface},
};

在后续的Java层的调用native方法时需要跳转到对应的C/C++代码中。