我如何找出我的c ++应用程序在Mac上使用了多少内存 [英] How can I find out how much memory my c++ app is using on the Mac

问题描述

我的应用程序中的某些操作使用的内存比我想象的要多，我想记录当前的内存使用情况以帮助识别它们.

Certain operations in my app are using more memory than I think they should, and I would like to log the current memory usage to help identify which they are.

是否存在将返回当前正在使用的内存量的系统调用?

Is there a system call that will return the amount of memory currently in use?

推荐答案

以下C函数返回CPU时间和进程pid的驻留内存.要获取其他进程的资源，您需要root权限.您也可以尝试getrusage()，但我永远无法使它正常运行以用于内存使用.使用getrusage()获取CPU时间始终对我有用.

The following C function returns the CPU time and resident memory of process pid. To get the resources of other processes, you need root permission. You may also try getrusage(), but I never get it work properly for memory usage. Getting CPU time with getrusage() always works to me.

该功能根据ps和top命令的源代码改编而成.这是我的程序的一部分，用于监视其他进程的内存.

The function is adapted from the source codes of the ps and top commands. It is part of my program that monitors the memory of other processes.

#ifdef __APPLE__

#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <mach/mach_init.h>
#include <mach/mach_host.h>
#include <mach/mach_port.h>
#include <mach/mach_traps.h>
#include <mach/task_info.h>
#include <mach/thread_info.h>
#include <mach/thread_act.h>
#include <mach/vm_region.h>
#include <mach/vm_map.h>
#include <mach/task.h>
#include <mach/shared_memory_server.h>

typedef struct vmtotal vmtotal_t;

typedef struct { /* dynamic process information */
    size_t rss, vsize;
    double utime, stime;
} RunProcDyn;

/* On Mac OS X, the only way to get enough information is to become root. Pretty frustrating!*/
int run_get_dynamic_proc_info(pid_t pid, RunProcDyn *rpd)
{
    task_t task;
    kern_return_t error;
    mach_msg_type_number_t count;
    thread_array_t thread_table;
    thread_basic_info_t thi;
    thread_basic_info_data_t thi_data;
    unsigned table_size;
    struct task_basic_info ti;

    error = task_for_pid(mach_task_self(), pid, &task);
    if (error != KERN_SUCCESS) {
        /* fprintf(stderr, "++ Probably you have to set suid or become root.\n"); */
        rpd->rss = rpd->vsize = 0;
        rpd->utime = rpd->stime = 0;
        return 0;
    }
    count = TASK_BASIC_INFO_COUNT;
    error = task_info(task, TASK_BASIC_INFO, (task_info_t)&ti, &count);
    assert(error == KERN_SUCCESS);
    { /* adapted from ps/tasks.c */
        vm_region_basic_info_data_64_t b_info;
        vm_address_t address = GLOBAL_SHARED_TEXT_SEGMENT;
        vm_size_t size;
        mach_port_t object_name;
        count = VM_REGION_BASIC_INFO_COUNT_64;
        error = vm_region_64(task, &address, &size, VM_REGION_BASIC_INFO,
                             (vm_region_info_t)&b_info, &count, &object_name);
        if (error == KERN_SUCCESS) {
            if (b_info.reserved && size == (SHARED_TEXT_REGION_SIZE) &&
                ti.virtual_size > (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE))
            {
                ti.virtual_size -= (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE);
            }
        }
        rpd->rss = ti.resident_size;
        rpd->vsize = ti.virtual_size;
    }
    { /* calculate CPU times, adapted from top/libtop.c */
        unsigned i;
        rpd->utime = ti.user_time.seconds + ti.user_time.microseconds * 1e-6;
        rpd->stime = ti.system_time.seconds + ti.system_time.microseconds * 1e-6;
        error = task_threads(task, &thread_table, &table_size);
        assert(error == KERN_SUCCESS);
        thi = &thi_data;
        for (i = 0; i != table_size; ++i) {
            count = THREAD_BASIC_INFO_COUNT;
            error = thread_info(thread_table[i], THREAD_BASIC_INFO, (thread_info_t)thi, &count);
            assert(error == KERN_SUCCESS);
            if ((thi->flags & TH_FLAGS_IDLE) == 0) {
                rpd->utime += thi->user_time.seconds + thi->user_time.microseconds * 1e-6;
                rpd->stime += thi->system_time.seconds + thi->system_time.microseconds * 1e-6;
            }
            if (task != mach_task_self()) {
                error = mach_port_deallocate(mach_task_self(), thread_table[i]);
                assert(error == KERN_SUCCESS);
            }
        }
        error = vm_deallocate(mach_task_self(), (vm_offset_t)thread_table, table_size * sizeof(thread_array_t));
        assert(error == KERN_SUCCESS);
    }
    mach_port_deallocate(mach_task_self(), task);
    return 0;
}

#endif /* __APPLE__ */

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