From 0de2c758aa1c42d6b9734fb410244c18bf7156f7 Mon Sep 17 00:00:00 2001 From: "J. Nick Koston" Date: Sun, 22 Mar 2026 17:31:27 -1000 Subject: [PATCH] [scheduler] Use placement-new for std::function move in set_timer_common_ (#14757) --- esphome/core/scheduler.cpp | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/esphome/core/scheduler.cpp b/esphome/core/scheduler.cpp index 51cbfb208ea..9ee3b2fdd2a 100644 --- a/esphome/core/scheduler.cpp +++ b/esphome/core/scheduler.cpp @@ -166,7 +166,13 @@ void HOT Scheduler::set_timer_common_(Component *component, SchedulerItem::Type item->component = component; item->set_name(name_type, static_name, hash_or_id); item->type = type; - item->callback = std::move(func); + // Use destroy + placement-new instead of move-assignment. + // GCC's std::function::operator=(function&&) does a full swap dance even when the + // target is empty. Since recycled/new items always have an empty callback, we can + // destroy the empty one (no-op) and move-construct directly, saving ~40 bytes of + // swap/destructor code on Xtensa. + item->callback.~function(); + new (&item->callback) std::function(std::move(func)); // Reset remove flag - recycled items may have been cancelled (remove=true) in previous use this->set_item_removed_(item, false); item->is_retry = is_retry;