p1: support custom promise API

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

Author: skyzh

src/include/storage/disk/disk_scheduler.h

@@ -73,6 +73,16 @@ class DiskScheduler {
    */
   void StartWorkerThread();
 
+  using DiskSchedulerPromise = std::promise<bool>;
+
+  /**
+   * @brief Create a Promise object. If you want to implement your own version of promise, you can change this function
+   * so that our test cases can use your promise implementation.
+   *
+   * @return std::promise<bool>
+   */
+  auto CreatePromise() -> DiskSchedulerPromise { return {}; };
+
  private:
   /** Pointer to the disk manager. */
   DiskManager *disk_manager_ __attribute__((__unused__));

test/storage/disk_scheduler_test.cpp

@@ -33,9 +33,9 @@ TEST(DiskSchedulerTest, DISABLED_ScheduleWriteReadPageTest) {
 
   std::strncpy(data, "A test string.", sizeof(data));
 
-  std::promise<bool> promise1;
+  auto promise1 = disk_scheduler->CreatePromise();
   auto future1 = promise1.get_future();
-  std::promise<bool> promise2;
+  auto promise2 = disk_scheduler->CreatePromise();
   auto future2 = promise2.get_future();
 
   disk_scheduler->Schedule({/*is_write=*/true, reinterpret_cast<char *>(&data), /*page_id=*/0, promise1});