IOS内存等信息

1. 获取IOS APP占用的内存

#import <mach/mach.h>

// ...

void report_memory(void) {
  struct task_basic_info 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 ) {
    NSLog(@"Memory in use (in bytes): %u", info.resident_size);
  } else {
    NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
  }
}

void report_memory(void) {
    static unsigned last_resident_size=0;
    static unsigned greatest = 0;
    static unsigned last_greatest = 0;

    struct task_basic_info 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 ) {
        int diff = (int)info.resident_size - (int)last_resident_size;
        unsigned latest = info.resident_size;
        if( latest > greatest   )   greatest = latest;  // track greatest mem usage
        int greatest_diff = greatest - last_greatest;
        int latest_greatest_diff = latest - greatest;
        NSLog(@"Mem: %10u (%10d) : %10d :   greatest: %10u (%d)", info.resident_size, diff,
          latest_greatest_diff,
          greatest, greatest_diff  );
    } else {
        NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
    }
    last_resident_size = info.resident_size;
    last_greatest = greatest;
}

void report_memory(void)
{
    struct mach_task_basic_info info;
    mach_msg_type_number_t size = MACH_TASK_BASIC_INFO_COUNT;
    kern_return_t kerr = task_info(mach_task_self(),
                                   MACH_TASK_BASIC_INFO,
                                   (task_info_t)&info,
                                   &size);
    if( kerr == KERN_SUCCESS ) {
        NSLog(@"Memory in use (in bytes): %u", info.resident_size);
    } else {
        NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
    }
}

//test 1
    struct mach_task_basic_info info;
    mach_msg_type_number_t size = MACH_TASK_BASIC_INFO_COUNT;
    kern_return_t kerr = task_info(mach_task_self(),
                                   MACH_TASK_BASIC_INFO,
                                   (task_info_t)&info,
                                   &size);
    if( kerr == KERN_SUCCESS ) {
        CCLOG("Memory in use (in bytes): %llu", info.resident_size);
    } else {
        CCLOG("Error with task_info()");
    }
    
    //test 2
    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);
//    host_statistics(host_t host_priv, host_flavor_t flavor, host_info_t host_info_out, <#mach_msg_type_number_t *host_info_outCnt#>)
//    host_statistics64(host_t host_priv, host_flavor_t flavor, host_info64_t host_info64_out, mach_msg_type_number_t *host_info64_outCnt)
    int r = host_statistics(host_port, HOST_VM_INFO, (host_info64_t)&vm_stat, &host_size);
    if (r != KERN_SUCCESS)
        CCLOG("Failed to fetch vm statistics");
    float active = (float)(vm_stat.active_count * pagesize) / 1048576.0f;
    float inactive = (float)(vm_stat.inactive_count * pagesize)/1048576.0f;
    float wire = (float)(vm_stat.wire_count * pagesize)/1048576.0f;
    
    unsigned long int  mem_used = (vm_stat.active_count + vm_stat.inactive_count + vm_stat.wire_count) * pagesize;
    unsigned long int  mem_free = vm_stat.free_count * pagesize;
    unsigned long int  mem_total = mem_used + mem_free;
    CCLOG("page size: %u", pagesize);
    CCLOG("memory active: %f, memory inactive: %f, memory wire: %f", active, inactive, wire);
    CCLOG("memory used: %lu, memory free: %lu, memory total: %lu", mem_used, mem_free, mem_total);

 Resident memory is a measurement of the memory that has been allocated to your application and has not yet been reclaimed by the system, but some/most of the resident memory could be reclaimed by the system.

http://stackoverflow.com/questions/18642421/understanding-task-basic-info-task-resident-size

http://stackoverflow.com/questions/787160/programmatically-retrieve-memory-usage-on-iphone

C/C++ tip: How to get the process resident set size (physical memory use)

http://nadeausoftware.com/articles/2012/07/c_c_tip_how_get_process_resident_set_size_physical_memory_use#taskinfoforcurrentresidentsetsize

这篇文章救了我一天：

http://gamesfromwithin.com/whered-that-memory-go