add reader thread status

Author: jacquesqiao

paddle/fluid/operators/reader/ctr_reader.cc

@@ -124,7 +124,10 @@ class MultiGzipReader : public Reader {
 
 void ReadThread(const std::vector<std::string>& file_list,
                 const std::vector<std::string>& slots, int batch_size,
+                int thread_id, std::vector<ReaderThreadStatus>* thread_status,
                 std::shared_ptr<LoDTensorBlockingQueue> queue) {
+  (*thread_status)[thread_id] = Running;
+
   std::string line;
 
   std::vector<std::unordered_map<std::string, std::vector<int64_t>>> batch_data;
@@ -181,6 +184,8 @@ void ReadThread(const std::vector<std::string>& file_list,
 
     queue->Push(lod_datas);
   }
+
+  (*thread_status)[thread_id] = Stopped;
 }
 
 }  // namespace reader

paddle/fluid/operators/reader/ctr_reader.h

@@ -30,8 +30,11 @@ namespace paddle {
 namespace operators {
 namespace reader {
 
+enum ReaderThreadStatus { Running, Stopped };
+
 void ReadThread(const std::vector<std::string>& file_list,
                 const std::vector<std::string>& slots, int batch_size,
+                int thread_id, std::vector<ReaderThreadStatus>* thread_status,
                 std::shared_ptr<LoDTensorBlockingQueue> queue);
 
 class CTRReader : public framework::FileReader {
@@ -40,13 +43,16 @@ class CTRReader : public framework::FileReader {
                      int batch_size, int thread_num,
                      const std::vector<std::string>& slots,
                      const std::vector<std::string>& file_list)
-      : thread_num_(thread_num),
-        batch_size_(batch_size),
-        slots_(slots),
-        file_list_(file_list) {
+      : batch_size_(batch_size), slots_(slots), file_list_(file_list) {
     PADDLE_ENFORCE(queue != nullptr, "LoDTensorBlockingQueue must not be null");
+    PADDLE_ENFORCE_GT(file_list.size(), 0, "file list should not be empty");
+    thread_num_ =
+        file_list_.size() > thread_num_ ? thread_num_ : file_list_.size();
     queue_ = queue;
     SplitFiles();
+    for (int i = 0; i < thread_num; ++i) {
+      read_thread_status_.push_back(Stopped);
+    }
   }
 
   ~CTRReader() { queue_->Close(); }
@@ -69,28 +75,29 @@ class CTRReader : public framework::FileReader {
   void Start() override {
     VLOG(3) << "Start reader";
     queue_->ReOpen();
-    for (int i = 0; i < file_groups_.size(); i++) {
-      read_threads_.emplace_back(new std::thread(std::bind(
-          &ReadThread, file_groups_[i], slots_, batch_size_, queue_)));
+    for (int thread_id = 0; thread_id < file_groups_.size(); thread_id++) {
+      read_threads_.emplace_back(new std::thread(
+          std::bind(&ReadThread, file_groups_[thread_id], slots_, batch_size_,
+                    thread_id, &read_thread_status_, queue_)));
     }
   }
 
  private:
   void SplitFiles() {
-    file_groups_.resize(file_list_.size() > thread_num_ ? thread_num_
-                                                        : file_list_.size());
+    file_groups_.resize(thread_num_);
     for (int i = 0; i < file_list_.size(); ++i) {
       file_groups_[i % thread_num_].push_back(file_list_[i]);
     }
   }
 
  private:
-  const int thread_num_;
+  int thread_num_;
   const int batch_size_;
   const std::vector<std::string> slots_;
   const std::vector<std::string> file_list_;
   std::shared_ptr<LoDTensorBlockingQueue> queue_;
   std::vector<std::unique_ptr<std::thread>> read_threads_;
+  std::vector<ReaderThreadStatus> read_thread_status_;
   std::vector<std::vector<std::string>> file_groups_;
 };