fa597148b1f8 ·

native函数没有指针数组哦，我看了一下android Q里边的实现，在注册native函数的时候，通过反射获取到java方法地址后，直接将native 函数的地址，写入到 对应java 方法地址开始往后的4个字节或8个字节的内存空间里边。
具体实现在： android/art/runtime/art_method.h
template<typename T>
ALWAYS_INLINE void SetNativePointer(MemberOffset offset, T new_value, PointerSize pointer_size) {
static_assert(std::is_pointer<T>::value, "T must be a pointer type");
const auto addr = reinterpret_cast<uintptr_t>(this) + offset.Uint32Value();
///这边将native函数地址进行写入哦
if (pointer_size == PointerSize::k32) {
uintptr_t ptr = reinterpret_cast<uintptr_t>(new_value);
*reinterpret_cast<uint32_t*>(addr) = dchecked_integral_cast<uint32_t>(ptr);
} else {
*reinterpret_cast<uint64_t*>(addr) = reinterpret_cast<uintptr_t>(new_value);
}
}

大致调用栈为：
SetNativePointer()
SetDataPtrSize()
SetEntryPointFromJniPtrSize()
SetEntryPointFromJni()
RegisterNative()
RegisterNatives()
jniRegisterNativeMethods()
registerNativeMethods()
RegisterMethodsOrDie()

1d9a81351590 评论自Android JNI(一)——NDK与JNI基础