add Tensor::IsSharedBufferWith method, test=develop (#23175)

paddle/fluid/framework/details/share_tensor_buffer_functor.cc

@@ -104,7 +104,7 @@ void ShareTensorBufferFunctor::operator()(Scope *exec_scope) {
       // If in_var is inplaced in the previous batch and we want to fetch
       // in_var in the current batch, we have to reset memory of out_var
       // to avoid wrong calculation result.
-      if (in_tensor.Holder() == out_tensor->Holder()) {
+      if (out_tensor->IsSharedBufferWith(in_tensor)) {
         VLOG(1) << "Clear " << out_var_names_[i]
                 << " because you may want to fetch an inplaced variable "
                 << in_var_info->Name()

paddle/fluid/framework/tensor.h

@@ -160,6 +160,10 @@ class Tensor {
     offset_ = tensor.offset_;
   }
 
+  bool IsSharedBufferWith(const Tensor& src) const {
+    return holder_ && holder_ == src.Holder();
+  }
+
   const std::shared_ptr<memory::Allocation>& Holder() const { return holder_; }
   size_t offset() const { return offset_; }
 

paddle/fluid/operators/elementwise/elementwise_op_function.h

@@ -1100,7 +1100,7 @@ void CommonElementwiseBroadcastBackward(
 
   // for inplace strategy. memset will make dx and dout clear and get wrong
   // result.
-  if (dx && dout.Holder() == dx->Holder()) {
+  if (dx && dx->IsSharedBufferWith(dout)) {
     dx->clear();
     dx->mutable_data<T>(x_dims, ctx.GetPlace());
   }