Current memory use of a simple Blink sketch

ESP8266

blink sketch

Executable segment sizes
IROM   *: 228440          - code in flash         (default or ICACHE_FLASH_ATTR)
IRAM   *: 26564   \ 32768 - code in IRAM          (ICACHE_RAM_ATTR, ISRs...)
DATA   *: 1236  )         - initialized variables (global, static) in RAM\HEAP
RODATA *: 1528  ) \ 81920 - constants             (global, static) in RAM\HEAP
BSS    *: 25208 )         - zeroed variables      (global, static) in RAM\HEAP
Program size: 257,768 bytes (used 25% of a 1,044,464 byte maximum) (2.45 secs)
Minimum Memory Usage: 27972 bytes (34% of a 81920 byte maximum)

using CoopTask

Executable segment sizes
IROM   *: 237996          - code in flash         (default or ICACHE_FLASH_ATTR)
IRAM   *: 26900   \ 32768 - code in IRAM          (ICACHE_RAM_ATTR, ISRs...)
DATA   *: 1244  )         - initialized variables (global, static) in RAM\HEAP
RODATA *: 1652  ) \ 81920 - constants             (global, static) in RAM\HEAP
BSS    *: 25504 )         - zeroed variables      (global, static) in RAM\HEAP
Program size: 267,792 bytes (used 26% of a 1,044,464 byte maximum) (5.27 secs)
Minimum Memory Usage: 28400 bytes (35% of a 81920 byte maximum) 

CoopTask adds:

IROM: 9556
IRAM: 336
DATA: 8
RODATA: 124
BSS: 296
Program size: 10,024
Minimum Memory Usage: 428

ATmega328P

blink sketch

Compiling 'CoopMemoryTest' for 'ATmega328P (3.3V, 8 MHz) (Arduino Pro or Pro Mini)'
Program size: 928 bytes (used 3% of a 30,720 byte maximum) (1.09 secs)
Minimum Memory Usage: 9 bytes (0% of a 2048 byte maximum)

using CoopTask

Compiling 'CoopMemoryTest' for 'ATmega328P (3.3V, 8 MHz) (Arduino Pro or Pro Mini)'
Program size: 5,510 bytes (used 18% of a 30,720 byte maximum) (0.97 secs)
Minimum Memory Usage: 161 bytes (8% of a 2048 byte maximum)

CoopTask adds:

Program size: 4582
Minimum Memory Usage: 152

ESP32

blink sketch

Program size: 259,145 bytes (used 20% of a 1,310,720 byte maximum) (5.01 secs)
Minimum Memory Usage: 15564 bytes (5% of a 327680 byte maximum)

using CoopTask

Program size: 263,105 bytes (used 20% of a 1,310,720 byte maximum) (5.81 secs)
Minimum Memory Usage: 15668 bytes (5% of a 327680 byte maximum)

CoopTask adds:

Program size: 3,960
Minimum Memory Usage: 104

The code

/*
    Created:	2019-11-12 13:14:04
*/

#define USECOOPTASK

#ifdef USECOOPTASK
#include <CoopTaskBase.h>
#include <CoopTask.h>
#include <CoopSemaphore.h>
#include <CoopMutex.h>
#include <BasicCoopTask.h>
#endif

#if defined(ESP32) || defined(ESP8266)
#include <functional>
#endif // defined(ESP32) || defined(ESP8266)

void blink()
{
    digitalWrite(LED_BUILTIN, LOW);
    delay(100);
    digitalWrite(LED_BUILTIN, HIGH);
    delay(100);
}

void setup()
{
    pinMode(LED_BUILTIN, OUTPUT);
#ifdef USECOOPTASK
#ifdef ESP8266
    CoopTaskBase::useBuiltinScheduler();
#endif
    createCoopTask("blink", []() { for (;;) blink(); return 0; });
#endif
}

// std::function on ESP32 needs over 50K program size alone - level playing field for the demonstration:
#if !defined(USECOOPTASK) && defined(ESP32)
std::function<void()> dummyFunction = []() {};
#endif // !defined(USECOOPTASK) && defined(ESP32)

#if defined(USECOOPTASK) && !defined(ESP8266)
auto reaper = [](const CoopTaskBase* const) {};
#endif // defined(USECOOPTASK) && !defined(ESP8266)

void loop()
{
#ifndef USECOOPTASK
    blink();
#ifdef ESP32
    dummyFunction();
#endif // ESP32
#elif !defined(ESP8266)
    runCoopTasks(reaper);
#endif
}