How can I discover the amount of free memory in iOS?

Question

What do you hope to accomplish? And how exactly do you define "free" memory? Since the OS can evict other processes at will, depending on what is needed, the right answer depends on your use case. — StilesCrisis, Feb 27 '12 at 06:14
Possible duplication http://stackoverflow.com/questions/1020327/how-to-find-available-memory-in-iphone-programmatically — 0xDE4E15B, Feb 27 '12 at 08:55
possible duplicate of [Available memory for iPhone OS app](http://stackoverflow.com/questions/2798638/available-memory-for-iphone-os-app) — dirkgently, Jun 22 '12 at 06:31

score 1 · Answer 1 · edited May 23 '17 at 10:24

Use this code:

natural_t  freeMemory(void) {
    mach_port_t           host_port = mach_host_self();
    mach_msg_type_number_t   host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
    vm_size_t               pagesize;
    vm_statistics_data_t     vm_stat;

    host_page_size(host_port, &pagesize);

    if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) NSLog(@"Failed to fetch vm statistics");

    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;

    return mem_free;
}

I'm not claiming credit for this code; I got it from here.

Hope this helps!

score 1 · Accepted Answer · answered Feb 05 '13 at 05:19

- (uint64_t)getFreeDiskspace
{
uint64_t totalSpace = 0;
uint64_t totalFreeSpace = 0;

__autoreleasing error = nil;  
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
NSDictionary *dictionary = [[NSFileManager defaultManager] attributesOfFileSystemForPath:[paths lastObject] error: &error];  

if (dictionary) {  
    NSNumber *fileSystemSizeInBytes = [dictionary objectForKey: NSFileSystemSize];  
    NSNumber *freeFileSystemSizeInBytes = [dictionary objectForKey:NSFileSystemFreeSize];
    totalSpace = [fileSystemSizeInBytes unsignedLongLongValue];
    totalFreeSpace = [freeFileSystemSizeInBytes unsignedLongLongValue];
    NSLog(@"Memory Capacity of %llu MiB with %llu MiB Free memory available.", ((totalSpace/1024ll)/1024ll), ((totalFreeSpace/1024ll)/1024ll));
} else {  
    NSLog(@"Error Obtaining System Memory Info: Domain = %@, Code = %d", [error domain], [error code]);  
}  

return totalFreeSpace;
}

This is working

How can I discover the amount of free memory in iOS?

2 Answers2