跟踪可用和已用的内存

#import <mach/mach.h>

1、获取已用内存大小

vm_size_t getUsedMemory() {
    task_basic_info_data_t info;
    mach_msg_type_number_t size = sizeof(info);
    kern_return_t kerr = task_info(mach_task_self(),TASK_BASIC_INFO,(task_info_t) &info, &size);
    if(kerr == KERN_SUCCESS) { 
        return info.resident_size;
    } else {
        return 0;
    }
}

2、获取可用内存的大小

vm_size_t getFreeMemory() {
    mach_port_t host = mach_host_self();
    mach_msg_type_number_t size = sizeof(vm_statistics_data_t) / sizeof(integer_t); 
    vm_size_t pagesize;
    vm_statistics_data_t vmstat;
    host_page_size(host, &pagesize);
    host_statistics(host, HOST_VM_INFO, (host_info_t) &vmstat, &size);
    return vmstat.free_count * pagesize;
 }