Valentin V. Bartenev
482b31bc19
Previously _onSample() computed and stored a volatile float _sma_avg
on every sample (64 times/minute on core 0). The getter simply returned
that pre-computed value.
This commit inverts the responsibility:
- _sma_sum is now volatile uint16_t — the raw integer sum is the
cross-core shared state, written atomically by core 0 (single S16I
instruction on Xtensa LX7) and read by core 1.
- The float conversion (uint16_t → float multiply) is moved into
getCore0Util(), which is called rarely (once/minute for history,
on-demand for web requests). The multiply now happens on the core
that actually needs the result.
- _sma_avg is removed entirely, saving 4 bytes and one volatile float
store per sample from the hot path.
- The SMA update is rewritten as a single combined expression:
const uint16_t last = _sma_buf[_sma_idx];
_sma_buf[_sma_idx] = s8;
_sma_sum = (_sma_sum - last) + s8;
This produces a single write to _sma_sum instead of two (decrement
then increment), which is cleaner when _sma_sum is volatile.
The cross-core contract is unchanged: core 0 writes _sma_sum once per
sample; core 1 reads it in getCore0Util(). A 16-bit aligned store on
Xtensa LX7 is a single instruction, so no spinlock is needed.
42 خطوط
823 B
C++
42 خطوط
823 B
C++
#pragma once
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#ifdef ESP32
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#include <stdint.h>
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#include "esp_attr.h"
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#include "esp_timer.h"
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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class CPUUsageTracker {
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public:
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void begin();
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float getCore0Util() const {
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return (float)_sma_sum * (1.0f / (SMA_WINDOW * 255.0f));
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}
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private:
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static constexpr uint8_t SMA_WINDOW = 64; // power of 2 — enables & mask
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static volatile uint32_t s_idle_ticks;
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static volatile uint32_t s_busy_ticks;
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static TaskHandle_t s_idle_handle;
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static void IRAM_ATTR s_tick_hook();
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static void s_sample_cb(void* arg);
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uint32_t _last_idle = 0;
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uint32_t _last_busy = 0;
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uint8_t _sma_buf[SMA_WINDOW] = {};
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uint8_t _sma_idx = 0;
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volatile uint16_t _sma_sum = 0;
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esp_timer_handle_t _timer = nullptr;
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void _onSample();
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};
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#endif
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