Get free memory

gistfile1.m

+(natural_t) getFreeMemory
{
    mach_port_t host_port;
    mach_msg_type_number_t host_size;
    vm_size_t pagesize;
    host_port = mach_host_self();
    host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
    host_page_size(host_port, &pagesize);
    vm_statistics_data_t vm_stat;
    if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {
        T21Log(@"Failed to fetch vm statistics");
        return 0;
    }
    /* Stats in bytes */
    natural_t mem_free = vm_stat.free_count * pagesize;
    return mem_free;
}