From 47bbf61bff38b9cc3fc1e4305f1e00c34147f34b Mon Sep 17 00:00:00 2001
From: Martin Chang <marty1885@users.noreply.github.com>
Date: Fri, 2 Feb 2024 22:43:07 +0800
Subject: [PATCH] add option to when_all to switch thread

---
 lib/inc/drogon/utils/coroutine.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/inc/drogon/utils/coroutine.h b/lib/inc/drogon/utils/coroutine.h
index 04fe71b3..272c45e5 100644
--- a/lib/inc/drogon/utils/coroutine.h
+++ b/lib/inc/drogon/utils/coroutine.h
@@ -21,7 +21,6 @@
 #include <cassert>
 #include <condition_variable>
 #include <coroutine>
-#include <cstddef>
 #include <exception>
 #include <future>
 #include <mutex>
@@ -850,7 +849,7 @@ inline internal::EventLoopAwaiter<T> queueInLoopCoro(trantor::EventLoop *loop,
  * @brief Waits for all tasks to complete. Throws exception if any of the tasks
  * throws. In such cases, all tasks are still waited for completion.
  */
-inline Task<> when_all(std::vector<Task<>> tasks)
+inline Task<> when_all(std::vector<Task<>> tasks, trantor::EventLoop* loop = nullptr)
 {
     std::exception_ptr eptr;
     std::atomic_size_t counter = tasks.size();
@@ -878,11 +877,11 @@ inline Task<> when_all(std::vector<Task<>> tasks)
         }(eptr, counter, waiter, std::move(task));
     }
     co_await waiter;
+    if(loop)
+        co_await switchThreadCoro(loop);
 
     if (eptr)
-    {
         std::rethrow_exception(eptr);
-    }
 }
 
 }  // namespace drogon