[promises] Make Sleep promise movable (#33997)
I have a cool optimization in mind for promises - but it requires that
we can move them after polling, which is a contract change. I'm going to
work through the set of primitives we have in the coming weeks and
change that contract to enable the optimization.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
diff --git a/src/core/lib/promise/sleep.h b/src/core/lib/promise/sleep.h
index 5fe735f..7f3a968 100644
--- a/src/core/lib/promise/sleep.h
+++ b/src/core/lib/promise/sleep.h
@@ -18,11 +18,11 @@
#include <grpc/support/port_platform.h>
#include <atomic>
+#include <utility>
#include "absl/status/status.h"
#include <grpc/event_engine/event_engine.h>
-#include <grpc/support/log.h>
#include "src/core/lib/gprpp/time.h"
#include "src/core/lib/promise/activity.h"
@@ -38,17 +38,12 @@
Sleep(const Sleep&) = delete;
Sleep& operator=(const Sleep&) = delete;
- Sleep(Sleep&& other) noexcept : deadline_(other.deadline_) {
- // Promises can be moved only until they're polled, and since we only create
- // the closure when first polled we can assume it's nullptr here.
- GPR_DEBUG_ASSERT(other.closure_ == nullptr);
- };
+ Sleep(Sleep&& other) noexcept
+ : deadline_(other.deadline_),
+ closure_(std::exchange(other.closure_, nullptr)) {}
Sleep& operator=(Sleep&& other) noexcept {
- // Promises can be moved only until they're polled, and since we only create
- // the closure when first polled we can assume it's nullptr here.
- GPR_DEBUG_ASSERT(closure_ == nullptr);
- GPR_DEBUG_ASSERT(other.closure_ == nullptr);
deadline_ = other.deadline_;
+ std::swap(closure_, other.closure_);
return *this;
};
diff --git a/test/core/promise/BUILD b/test/core/promise/BUILD
index f34b1d6..620c40a 100644
--- a/test/core/promise/BUILD
+++ b/test/core/promise/BUILD
@@ -501,6 +501,7 @@
deps = [
"test_wakeup_schedulers",
"//:exec_ctx",
+ "//:gpr",
"//:grpc",
"//src/core:default_event_engine",
"//src/core:exec_ctx_wakeup_scheduler",
diff --git a/test/core/promise/sleep_test.cc b/test/core/promise/sleep_test.cc
index 197f596..ac8abce 100644
--- a/test/core/promise/sleep_test.cc
+++ b/test/core/promise/sleep_test.cc
@@ -24,6 +24,7 @@
#include "gtest/gtest.h"
#include <grpc/grpc.h>
+#include <grpc/support/log.h>
#include "src/core/lib/event_engine/default_event_engine.h"
#include "src/core/lib/gprpp/notification.h"
