p1: use more efficient implementation of channel

Signed-off-by: Alex Chi <[email protected]>

Author: skyzh

src/include/common/channel.h

@@ -16,6 +16,7 @@
 #include <mutex>               // NOLINT
 #include <queue>
 #include <utility>
+#include "readerwriterqueue/readerwriterqueue.h"
 
 namespace bustub {
 
@@ -33,27 +34,18 @@ class Channel {
    *
    * @param element The element to be inserted.
    */
-  void Put(T element) {
-    std::unique_lock<std::mutex> lk(m_);
-    q_.push(std::move(element));
-    lk.unlock();
-    cv_.notify_all();
-  }
+  void Put(T element) { q_.enqueue(std::move(element)); }
 
   /**
    * @brief Gets an element from the shared queue. If the queue is empty, blocks until an element is available.
    */
   auto Get() -> T {
-    std::unique_lock<std::mutex> lk(m_);
-    cv_.wait(lk, [&]() { return !q_.empty(); });
-    T element = std::move(q_.front());
-    q_.pop();
-    return element;
+    T x;
+    q_.wait_dequeue(x);
+    return x;
   }
 
  private:
-  std::mutex m_;
-  std::condition_variable cv_;
-  std::queue<T> q_;
+  moodycamel::BlockingReaderWriterQueue<T> q_;
 };
 }  // namespace bustub

third_party/CMakeLists.txt

@@ -15,3 +15,5 @@ add_subdirectory(argparse)
 add_subdirectory(utf8proc)
 
 add_subdirectory(backward-cpp)
+
+add_subdirectory(readerwriterqueue)

third_party/versions.txt

@@ -64,3 +64,9 @@
 # tag: v2.7.0
 # commit hash: 8ca6144c85c165987cb1c5d8395c7314e13d4cd7
 # commit hash date: Dec 16 2021
+
+# readerwriterqueue
+# url: https://github.com/cameron314/readerwriterqueue
+# branch: master
+# commit hash: 2dee33ae3edd1e454ac34fea0a27017613355eff
+# commit hash date: Mar 5 2023