:github_url: https://github.com/pytorch/pytorch


.. _program_listing_file_torch_csrc_api_include_torch_data_detail_queue.h:

Program Listing for File queue.h
================================

|exhale_lsh| :ref:`Return to documentation for file <file_torch_csrc_api_include_torch_data_detail_queue.h>` (``torch/csrc/api/include/torch/data/detail/queue.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include <torch/types.h>
   
   #include <c10/util/Exception.h>
   
   #include <chrono>
   #include <condition_variable>
   #include <cstddef>
   #include <mutex>
   #include <queue>
   
   namespace torch::data::detail {
   
   template <typename T>
   class Queue {
    public:
     void push(T value) {
       {
         std::lock_guard<std::mutex> lock(mutex_);
         queue_.push(std::move(value));
       }
       cv_.notify_one();
     }
   
     T pop(std::optional<std::chrono::milliseconds> timeout = std::nullopt) {
       std::unique_lock<std::mutex> lock(mutex_);
       if (timeout) {
         if (!cv_.wait_for(
                 lock, *timeout, [this] { return !this->queue_.empty(); })) {
           // clang-format off
           TORCH_CHECK(false,
               "Timeout in DataLoader queue while waiting for next batch"
               " (timeout was ", timeout->count(), " ms)");
           // clang-format on
         }
       } else {
         cv_.wait(lock, [this] { return !this->queue_.empty(); });
       }
       AT_ASSERT(!queue_.empty());
       T value = queue_.front();
       queue_.pop();
       lock.unlock();
       return value;
     }
   
     size_t clear() {
       std::lock_guard<std::mutex> lock(this->mutex_);
       const auto size = queue_.size();
       while (!queue_.empty()) {
         queue_.pop();
       }
       return size;
     }
   
    private:
     std::queue<T> queue_;
     std::mutex mutex_;
     std::condition_variable cv_;
   };
   } // namespace torch::data::detail