diff --git a/esphome/core/application.cpp b/esphome/core/application.cpp index c390b26cd43..be076ee8021 100644 --- a/esphome/core/application.cpp +++ b/esphome/core/application.cpp @@ -25,6 +25,10 @@ namespace esphome { static const char *const TAG = "app"; +// Delay after setup() finishes before trimming the scheduler freelist of its post-boot peak. +// 10 s is well past the bulk of post-setup async work (Wi-Fi/MQTT connects, first-read latency). +static constexpr uint32_t SCHEDULER_FREELIST_TRIM_DELAY_MS = 10000; + // Helper function for insertion sort of components by priority // Using insertion sort instead of std::stable_sort saves ~1.3KB of flash // by avoiding template instantiations (std::rotate, std::stable_sort, lambdas) @@ -112,6 +116,9 @@ void Application::setup() { ESP_LOGI(TAG, "setup() finished successfully!"); + // Trim the scheduler freelist of its post-boot peak once startup churn settles. + this->scheduler.set_timeout(this, SCHEDULER_FREELIST_TRIM_DELAY_MS, [this]() { this->scheduler.trim_freelist(); }); + #ifdef USE_SETUP_PRIORITY_OVERRIDE // Clear setup priority overrides to free memory clear_setup_priority_overrides(); diff --git a/esphome/core/scheduler.cpp b/esphome/core/scheduler.cpp index a8d56edfba5..eb070522276 100644 --- a/esphome/core/scheduler.cpp +++ b/esphome/core/scheduler.cpp @@ -913,6 +913,38 @@ void Scheduler::recycle_item_main_loop_(SchedulerItem *item) { #endif } +void Scheduler::trim_freelist() { + LockGuard guard{this->lock_}; + SchedulerItem *item = this->scheduler_item_pool_head_; + size_t freed = 0; + while (item != nullptr) { + SchedulerItem *next = item->next_free; + delete item; +#ifdef ESPHOME_DEBUG_SCHEDULER + this->debug_live_items_--; +#endif + item = next; + freed++; + } + this->scheduler_item_pool_head_ = nullptr; + this->scheduler_item_pool_size_ = 0; + + // The vectors that back items_/to_add_/defer_queue_ also retain their boot-peak + // capacity (std::vector grows by doubling). Swap each with a same-content copy to + // reclaim the slack -- the new vector is sized exactly to its current contents. + std::vector(this->items_).swap(this->items_); + std::vector(this->to_add_).swap(this->to_add_); +#ifndef ESPHOME_THREAD_SINGLE + std::vector(this->defer_queue_).swap(this->defer_queue_); +#endif + +#ifdef ESPHOME_DEBUG_SCHEDULER + ESP_LOGD(TAG, "Freelist trimmed (%zu items freed)", freed); +#else + (void) freed; +#endif +} + #ifdef ESPHOME_DEBUG_SCHEDULER void Scheduler::debug_log_timer_(const SchedulerItem *item, NameType name_type, const char *static_name, uint32_t hash_or_id, SchedulerItem::Type type, uint32_t delay, uint64_t now) { diff --git a/esphome/core/scheduler.h b/esphome/core/scheduler.h index aa41a161be4..7cdb29aae0e 100644 --- a/esphome/core/scheduler.h +++ b/esphome/core/scheduler.h @@ -132,6 +132,12 @@ class Scheduler { // @return Timestamp of the last item that ran, or `now` unchanged if none ran. uint32_t call(uint32_t now); + // Reclaim memory held by the post-boot peak. Frees every SchedulerItem in the + // recycle freelist and shrinks items_/to_add_/defer_queue_ vector capacity to + // their current sizes (std::vector grows by doubling and otherwise retains the + // peak). Live items in those vectors are preserved. + void trim_freelist(); + // Move items from to_add_ into the main heap. // IMPORTANT: This method should only be called from the main thread (loop task). // Inlined: the fast path (nothing to add) is just an atomic load / empty check.