Knowing Memory Usage in iOS

This task is quite straightforward. First, import the following headers:

[cc lang=”objc”]#import
#import [/cc]

Now what?. Simple… use this method:

[cc lang=”objc”]
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)
NSLog(@”Failed to fetch vm statistics”);

/* Stats in bytes */
natural_t mem_used = (vm_stat.active_count +
vm_stat.inactive_count +
vm_stat.wire_count) * pagesize;
natural_t mem_free = vm_stat.free_count * pagesize;
natural_t mem_total = mem_used + mem_free;

NSLog(@”used: %u free: %u total: %u”, mem_used, mem_free, mem_total);

Credits: This is a snippet taken from this Stackoverflow question.