printf.cpp

#include <Arduino.h>
#include <FreeRTOS.h>
#include <sstream>
#include <mutex>

//static std::mutex m;

template <typename T>
void testPrintf(void *fmt)
{
  const auto s1 = uxTaskGetStackHighWaterMark(NULL);
  {
    char buf[16];
    snprintf(buf, sizeof(buf), (const char *)fmt, (T)xTaskGetTickCount());
  }
  const auto s2 = uxTaskGetStackHighWaterMark(NULL);
  printf("printf %s: %d B\n", (const char *)fmt, s1 - s2);

  while (1)
  {
    sleep(1);
  }

  vTaskDelete(NULL);
}

template <typename T>
void testStringStream(void *fmt)
{
  const auto s1 = uxTaskGetStackHighWaterMark(NULL);
  {
    //m.lock();
    std::ostringstream ss;
    //m.unlock();
    ss << (T)xTaskGetTickCount();
  }
  const auto s2 = uxTaskGetStackHighWaterMark(NULL);

  printf("sstream %s: %d B\n", (const char *)fmt, s1 - s2);

  vTaskDelete(NULL);
}

void setup()
{
  // put your setup code here, to run once:
  sleep(1);

  xTaskCreate(testPrintf<int>, "", 4096, (void *)"%d", 1, NULL);
  xTaskCreate(testPrintf<long long>, "", 4096, (void *)"%lld", 1, NULL);
  xTaskCreate(testPrintf<double>, "", 4096, (void *)"%f", 1, NULL);
  xTaskCreate(testPrintf<double>, "", 4096, (void *)"%.4f", 1, NULL);

  xTaskCreate(testStringStream<int>, "", 4096, (void *)"%d", 1, NULL);
  usleep(100000);
  xTaskCreate(testStringStream<long long>, "", 4096, (void *)"%lld", 1, NULL);
  usleep(100000);
  xTaskCreate(testStringStream<double>, "", 4096, (void *)"%f", 1, NULL);

  while (1)
    sleep(1);
}

void loop()
{
  // put your main code here, to run repeatedly:
}

/*
printf %d: 1072 B
printf %.4f: 1332 B
printf %lld: 928 B
printf %f: 1332 B
sstream %d: 948 B
sstream %lld: 1012 B
sstream %f: 2052 B
*/