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Valentin V. Bartenev 72fc497980 Slightly optimize CPU util tracking by branchless tick hook
Replace the two separate volatile counters (s_idle_ticks, s_busy_ticks)
with a two-element array s_ticks[2]:

  [0] = idle ticks   (xTaskGetCurrentTaskHandle() != s_idle_handle → false → 0)
  [1] = busy ticks   (xTaskGetCurrentTaskHandle() != s_idle_handle → true  → 1)

The tick hook becomes a single branchless statement:

  s_ticks[xTaskGetCurrentTaskHandle() != s_idle_handle]++;

This eliminates the conditional branch from the tick ISR at the cost
of a few additional instructions in IRAM.  On Xtensa LX7 the branch
is somewhat unpredictable — the system alternates between idle and
busy — so removing the misprediction penalty (~5–10 cycles/call)
outweighs the slightly larger code size.

_onSample() is updated to read s_ticks[0] (idle) and s_ticks[1]
(busy) accordingly. All other logic is unchanged.
2026-05-10 10:02:21 +03:00

41 строка
819 B
C++

#pragma once
#ifdef ESP32
#include <stdint.h>
#include "esp_attr.h"
#include "esp_timer.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
class CPUUsageTracker {
public:
void begin();
float getCore0Util() const {
return (float)_sma_sum * (1.0f / (SMA_WINDOW * 255.0f));
}
private:
static constexpr uint8_t SMA_WINDOW = 64; // power of 2 — enables & mask
static volatile uint32_t s_ticks[2]; // [0] = idle ticks, [1] = busy ticks
static TaskHandle_t s_idle_handle;
static void IRAM_ATTR s_tick_hook();
static void s_sample_cb(void* arg);
uint32_t _last_idle = 0;
uint32_t _last_busy = 0;
uint8_t _sma_buf[SMA_WINDOW] = {};
uint8_t _sma_idx = 0;
volatile uint16_t _sma_sum = 0;
esp_timer_handle_t _timer = nullptr;
void _onSample();
};
#endif