#include <malloc.h>
#include <stdio.h>

 /*
Program to request megs of RAM to demo malloc
=============================================
Compile with no flags to allow up to 900 megs.

     cc -Ae -o mallocmax mallomax.c

Compile with -Wl -N to allow up to 1700 megs. 

     cc -Ae -Wl -N -o mallocmax mallocmax.c

Use "chatr +q3p enable" to increase to about 2700 megs:

     chatr +q3p enable mallocmax 

and chatr +q4p enable mallocmax to reach 3700 megs.

    The chatr option works with 11.11 and with several patches,
    with 11.0. Does not apply to anything earlier.

Compile with +DA2.0W or +DD64 to create a 64bit program.
With a 64-bit program, only the kernel parameter maxdsiz_64 
(and swap) will limit the total malloc area:

    cc -Ae +DD64 -o mallocmax mallocmax.c
 
 */

main(int argc, char **argv)
{
  pid_t mypid;
  char *m;
  int i,j,chunk;
 
  for(i=1; i<=4096; i++) {
    chunk=100*1024*1024;
    m=malloc(chunk);
    if(m) { 
       printf("Malloc of %d Meg succeeded.  Address %P. \n",100*i,m);
    } else {
       for(j=0;j<5;j++) { 
          sleep(1);
          if( (m=malloc(chunk)) != 0) break;
       }
       if(m == 0){
          printf("malloc of %d Meg failed.\n",i*100);
          break;
       } else {
    printf("malloc of %d Meg succeeded after %d sec sleep.\n",i*100,j+1);
       }
    }
  }
  mypid = getpid();
  fprintf(stdout, "PID = %d, press <Enter> to continue...",mypid);
  getchar();
}