From d15b2e02c8a1fbfdac4b8a1ee6b7f9809eb0abdd Mon Sep 17 00:00:00 2001
From: guosheng <guosheng@baidu.com>
Date: Wed, 27 Jun 2018 02:25:42 +0800
Subject: [PATCH] Fix copying empty tensor in beam_search_decode_op

---
 paddle/fluid/operators/beam_search_decode_op.cc | 17 +++++++++++------
 paddle/fluid/operators/beam_search_decode_op.h  |  3 +--
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/paddle/fluid/operators/beam_search_decode_op.cc b/paddle/fluid/operators/beam_search_decode_op.cc
index 57496dd2b..10d678111 100644
--- a/paddle/fluid/operators/beam_search_decode_op.cc
+++ b/paddle/fluid/operators/beam_search_decode_op.cc
@@ -42,9 +42,11 @@ struct BeamSearchDecodeFunctor {
       // Copy all tensors in the input tensor array
       for (auto& step_id : step_ids_origin_) {
         framework::LoDTensor out;
-        dev_ctx->Wait();
-        framework::TensorCopy(step_id, platform::CPUPlace(), *dev_ctx, &out);
-        dev_ctx->Wait();
+        if (step_id.numel() > 0) {
+          dev_ctx->Wait();
+          framework::TensorCopy(step_id, platform::CPUPlace(), *dev_ctx, &out);
+          dev_ctx->Wait();
+        }
 
         out.set_lod(step_id.lod());
         step_ids_.push_back(out);
@@ -58,9 +60,12 @@ struct BeamSearchDecodeFunctor {
       // Copy all tensors in the input tensor array
       for (auto& step_score : step_scores_origin_) {
         framework::LoDTensor out;
-        dev_ctx->Wait();
-        framework::TensorCopy(step_score, platform::CPUPlace(), *dev_ctx, &out);
-        dev_ctx->Wait();
+        if (step_score.numel() > 0) {
+          dev_ctx->Wait();
+          framework::TensorCopy(step_score, platform::CPUPlace(), *dev_ctx,
+                                &out);
+          dev_ctx->Wait();
+        }
 
         out.set_lod(step_score.lod());
         step_scores_.push_back(out);
diff --git a/paddle/fluid/operators/beam_search_decode_op.h b/paddle/fluid/operators/beam_search_decode_op.h
index bb5936a09..6aefc5446 100644
--- a/paddle/fluid/operators/beam_search_decode_op.h
+++ b/paddle/fluid/operators/beam_search_decode_op.h
@@ -151,8 +151,7 @@ void BeamSearchDecoder<T>::Backtrace(const LoDTensorArray& step_ids,
   const size_t src_num = step_ids.at(0).lod().at(kSourceLevel).size() - 1;
   std::vector<SentenceVector<T>> sentence_vector_list(
       src_num, SentenceVector<T>(beam_size_));
-  std::vector<std::vector<size_t>> prefix_idx_vector_list(
-      src_num, std::vector<size_t>());
+  std::vector<std::vector<size_t>> prefix_idx_vector_list(src_num);
   for (int step_id = step_num - 1; step_id >= 0; --step_id) {
     auto& cur_ids = step_ids.at(step_id);
     auto& cur_scores = step_scores.at(step_id);
-- 
GitLab