//
// part 1 of demo of Linux memory overcommit:
// allocate lots of memory, filling as we go
// should work
//
#include <cstdio>
#include <cstdlib>
// #include <unistd.h>
#include <vector>
#include <cstring>

int main(void) {
    int * space;
    const long incr = 1L << 29;
    std::vector<int *> allocated;

    // allocate memory until we can't get any more, filling as we go
    int count = 0;
    do {
        space = (int *) malloc(incr*sizeof(*space));
        printf("call #%d to malloc for 0x%lx bytes returns %p\n", 
                ++count, incr*sizeof(*space), (void *) space);
        if (space != NULL) {
            allocated.push_back(space);
            memset(space, 1, incr*sizeof(*space));
        }
        /* sleep(1); */
    } while (space != NULL);
    // re-fill allocated memory (just to check that all is well)
    for (auto s = allocated.begin(); s != allocated.end(); ++s) {
        printf("initializing space at %p\n", (void *) *s);
        memset(*s, 1, incr*sizeof(**s));
    }

    return 0;
}