malloc/free test

gistfile1.c

#include <Arduino.h>
#include "memdebug.h"
 
 
void shuffle(void **array, int n);
void showmem();
void dotest(bool shuffle);
 
 
// Compatibility stub for undefined pure virtual
 
extern "C" void __cxa_pure_virtual() { for(;;); }
 
 
int main(void)
{
  init();
 
  Serial.begin(115200);
 
  dotest(false);
  dotest(true);
 
// freeze the mcu until reset
  delay(1000);
  exit(0);
}
 
 
void dotest(bool shuffle_)
{
  void *ptrs[50];
  uint16_t i;
 
  Serial.println("allocating");
  showmem();
  for(i=0;i<sizeof(ptrs)/sizeof(ptrs[0]);i++)
  {
    ptrs[i]=malloc(640);
    showmem();
  }
 
  if(shuffle_)
    shuffle(ptrs,sizeof(ptrs)/sizeof(ptrs[0]));
 
  Serial.println("freeing");
  for(i=0;i<sizeof(ptrs)/sizeof(ptrs[0]);i++)
  {
    free(ptrs[i]);
    showmem();
  }
}
 
 
void showmem()
{
  char buffer[100];
 
  sprintf(buffer,"%04u %04u %04u : used/free/large",
      getMemoryUsed(),
      getFreeMemory(),
      getLargestAvailableMemoryBlock()
    );
 
  Serial.println(buffer);
}
 
int rand_int(int n)
{
  int limit = RAND_MAX - RAND_MAX % n;
  int rnd;
 
  do
  {
    rnd = rand();
  } while (rnd >= limit);
  return rnd % n;
}
 
void shuffle(void **array, int n)
{
  int i, j;
  void *tmp;
 
  for (i = n - 1; i > 0; i--)
  {
    j = rand_int(i + 1);
    tmp = array[j];
    array[j] = array[i];
    array[i] = tmp;
  }
}