From 1866d2dbefbaa630eac57da6838b8423d1074dd8 Mon Sep 17 00:00:00 2001
From: Qiao Longfei <qiaolongfei@baidu.com>
Date: Thu, 24 Jan 2019 17:16:32 +0800
Subject: [PATCH] parameter send support selected_rows

---
 .../operators/distributed/parameter_send.cc   | 84 +++++++++++++++++--
 .../operators/distributed/parameter_send.h    |  1 +
 2 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/paddle/fluid/operators/distributed/parameter_send.cc b/paddle/fluid/operators/distributed/parameter_send.cc
index 01e7341f15f..d79ea8cdb98 100644
--- a/paddle/fluid/operators/distributed/parameter_send.cc
+++ b/paddle/fluid/operators/distributed/parameter_send.cc
@@ -47,6 +47,15 @@ static size_t GetSectionIndex(int64_t id,
   return abs_sections.size() - 1;
 }
 
+static int FindOutIdx(int row, const std::vector<int64_t>& abs_sections) {
+  for (size_t i = 1; i < abs_sections.size(); ++i) {
+    if (row < abs_sections[i]) {
+      return i - 1;
+    }
+  }
+  return abs_sections.size() - 1;
+}
+
 static std::vector<int64_t> ToAbsoluteSection(
     const std::vector<int>& height_sections) {
   std::vector<int64_t> abs_sections;
@@ -97,21 +106,22 @@ static void SplitIdsIntoMultipleVarsBySection(
   }
 }
 
+template <typename T>
 void send(const std::string& var_name,
           const std::vector<std::string>& send_varnames,
           const std::vector<std::string>& epmap,
           const std::vector<int>& height_sections,
-          const framework::ExecutionContext& context,
-          const framework::Scope& scope, bool sync) {
+          const framework::ExecutionContext& ctx, const framework::Scope& scope,
+          bool sync) {
   framework::Scope* local_scope = scope.NewTmpScope();
 
   platform::DeviceContextPool& pool = platform::DeviceContextPool::Instance();
   auto& cpu_ctx = *pool.Get(platform::CPUPlace());
-  auto& actual_ctx = *pool.Get(context.GetPlace());
+  auto& actual_ctx = *pool.Get(ctx.GetPlace());
 
   distributed::RPCClient* rpc_client =
       distributed::RPCClient::GetInstance<RPCCLIENT_T>(
-          context.Attr<int>("trainer_id"));
+          ctx.Attr<int>("trainer_id"));
 
   auto* send_var = scope.FindVar(var_name);
   size_t out_num = send_varnames.size();
@@ -122,7 +132,7 @@ void send(const std::string& var_name,
     outs_dims.reserve(out_num);
 
     // infer output shape
-    int num = context.Attr<int>("num");
+    int num = ctx.Attr<int>("num");
     if (num > 0) {
       int64_t in_axis_dim = send_tensor_dims[0];
       PADDLE_ENFORCE_EQ(in_axis_dim % num, 0,
@@ -153,13 +163,71 @@ void send(const std::string& var_name,
       *out = send_tensor.Slice(row_offset, row_offset + outs_dims[i][0]);
       row_offset += outs_dims[i][0];
     }
-  } else if (send_var->IsType<framework::LoDTensor>()) {
+  } else if (send_var->IsType<framework::SelectedRows>()) {
+    auto& send_slr = send_var->Get<framework::SelectedRows>();
+    auto abs_sections = ToAbsoluteSection(height_sections);
+
+    auto send_rows = send_slr.rows();
+    std::vector<std::vector<int>> outs_rows_idx;
+    std::vector<std::vector<int>> outs_dense_idx;
+
+    outs_rows_idx.resize(out_num);
+    outs_dense_idx.resize(out_num);
+
+    auto row_numel = send_slr.value().numel() / send_slr.value().dims()[0];
+    auto src = send_slr.value().data<T>();
+
     // create output var in local scope
+    std::vector<framework::SelectedRows*> outs;
     for (auto& name : send_varnames) {
-      local_scope->Var(name)->GetMutable<framework::SelectedRows>();
+      auto* out = local_scope->Var(name)->GetMutable<framework::SelectedRows>();
+      outs.push_back(out);
+    }
+
+    // split rows index into output sparse vars
+    for (size_t i = 0; i < send_rows.size(); ++i) {
+      int out_idx = FindOutIdx(send_rows[i], abs_sections);
+      outs_rows_idx[out_idx].push_back(send_rows[i]);
+      outs_dense_idx[out_idx].push_back(i);
     }
+    auto place = ctx.GetPlace();
+
+    for (size_t i = 0; i < outs_rows_idx.size(); ++i) {
+      auto rows_idx = outs_rows_idx[i];
+      outs[i]->set_height(height_sections[i]);
+      auto dims = send_slr.GetCompleteDims();
+      dims[0] = rows_idx.size();
+      outs[i]->mutable_value()->mutable_data<T>(dims, send_slr.place());
+      outs[i]->mutable_rows()->clear();
+      if (rows_idx.size() > 0) {
+        for (auto idx : rows_idx) {
+          outs[i]->mutable_rows()->push_back(idx - abs_sections[i]);
+        }
+        auto dst = outs[i]->mutable_value()->mutable_data<T>(ctx.GetPlace());
+        for (size_t j = 0; j < rows_idx.size(); j++) {
+          if (platform::is_cpu_place(place)) {
+            memory::Copy(
+                platform::CPUPlace(), dst + j * row_numel, platform::CPUPlace(),
+                src + outs_dense_idx[i][j] * row_numel, sizeof(T) * row_numel);
+          } else {
+#ifdef PADDLE_WITH_CUDA
+            auto stream = ctx.cuda_device_context().stream();
+            memory::Copy(platform::CUDAPlace(), dst + j * row_numel,
+                         platform::CUDAPlace(),
+                         src + outs_dense_idx[i][j] * row_numel,
+                         sizeof(T) * row_numel, stream);
+#else
+            PADDLE_THROW("Paddle is not compiled with GPU");
+#endif
+          }
+        }
+      }
+      PADDLE_ENFORCE_EQ(rows_idx.size(), outs[i]->rows().size(),
+                        "rows should has the same size with tensor dim 0");
+    }
+
   } else {
-    PADDLE_THROW("unsupported var type");
+    PADDLE_THROW("unsupported var type to send!");
   }
 
   std::vector<distributed::VarHandlePtr> rets;
diff --git a/paddle/fluid/operators/distributed/parameter_send.h b/paddle/fluid/operators/distributed/parameter_send.h
index ee4da997b73..e337649cf23 100644
--- a/paddle/fluid/operators/distributed/parameter_send.h
+++ b/paddle/fluid/operators/distributed/parameter_send.h
@@ -23,6 +23,7 @@ namespace paddle {
 namespace operators {
 namespace distributed {
 
+template <typename T>
 void send(const std::string& var_name,
           const std::vector<std::string>& send_varnames,
           const std::vector<std::string>& epmap,
-- 
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