获取系统CPU、内存和IO信息

process_stat.h的内容如下：

/** @file
* @brief 进程统计信息函数的声明
* @author 张亚霏
* @date 2009/05/03
* @version 0.1
*
*/
#ifndef PROCESS_STAT_H
#define PROCESS_STAT_H

#ifdef __cplusplus
extern "C" {
#endif

typedef long long           int64_t;
typedef unsigned long long  uint64_t;

/// 获取当前进程的cpu使用率，返回-1失败
int get_cpu_usage();

/// 获取当前进程内存和虚拟内存使用量，返回-1失败，0成功
int get_memory_usage(uint64_t* mem, uint64_t* vmem);

/// 获取当前进程总共读和写的IO字节数，返回-1失败，0成功
int get_io_bytes(uint64_t* read_bytes, uint64_t* write_bytes);

#ifdef  __cplusplus
}
#endif

#endif/*PROCESS_STAT_H*/

process_stat_win.c的内容如下：
/** @file
* @brief 进程统计信息函数的实现
* @author 张亚霏
* @date 2009/05/03
* @version 0.1
*
* 部分代码来自MSDN的例子
* 部分代码来自google chromium项目
*
* 需要连接到psapi.lib
*/

#include <windows.h>
#include <psapi.h>
#include <assert.h>
#include "process_stat.h"

/// 时间转换
static uint64_t file_time_2_utc(const FILETIME* ftime)
{
LARGE_INTEGER li;

assert(ftime);
li.LowPart = ftime->dwLowDateTime;
li.HighPart = ftime->dwHighDateTime;
return li.QuadPart;
}

/// 获得CPU的核数
static int get_processor_number()
{
SYSTEM_INFO info;
GetSystemInfo(&info);
return (int)info.dwNumberOfProcessors;
}

int get_cpu_usage()
{
//cpu数量
static int processor_count_ = -1;
//上一次的时间
static int64_t last_time_ = 0;
static int64_t last_system_time_ = 0;

FILETIME now;
FILETIME creation_time;
FILETIME exit_time;
FILETIME kernel_time;
FILETIME user_time;
int64_t system_time;
int64_t time;
int64_t system_time_delta;
int64_t time_delta;

int cpu = -1;

if(processor_count_ == -1)
{
processor_count_ = get_processor_number();
}

GetSystemTimeAsFileTime(&now);

if (!GetProcessTimes(GetCurrentProcess(), &creation_time, &exit_time,
&kernel_time, &user_time))
{
// We don't assert here because in some cases (such as in the Task

Manager)
// we may call this function on a process that has just exited but

we have
// not yet received the notification.
return -1;
}
system_time = (file_time_2_utc(&kernel_time) + file_time_2_utc(&user_time)) /   processor_count_;
time = file_time_2_utc(&now);

if ((last_system_time_ == 0) || (last_time_ == 0))
{
// First call, just set the last values.
last_system_time_ = system_time;
last_time_ = time;
return -1;
}

system_time_delta = system_time - last_system_time_;
time_delta = time - last_time_;

assert(time_delta != 0);

if (time_delta == 0)
return -1;

// We add time_delta / 2 so the result is rounded.
cpu = (int)((system_time_delta * 100 + time_delta / 2) / time_delta);
last_system_time_ = system_time;
last_time_ = time;
return cpu;
}

int get_memory_usage(uint64_t* mem, uint64_t* vmem)
{
PROCESS_MEMORY_COUNTERS pmc;
if(GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc)))
{
if(mem) *mem = pmc.WorkingSetSize;
if(vmem) *vmem = pmc.PagefileUsage;
return 0;
}
return -1;
}

int get_io_bytes(uint64_t* read_bytes, uint64_t* write_bytes)
{
IO_COUNTERS io_counter;
if(GetProcessIoCounters(GetCurrentProcess(), &io_counter))
{
if(read_bytes) *read_bytes = io_counter.ReadTransferCount;
if(write_bytes) *write_bytes = io_counter.WriteTransferCount;
return 0;
}
return -1;
}

可以这样使用：
/** @file
* @brief 进程统计信息函数的测试
* @author 张亚霏
* @date 2009/05/03
* @version 0.1
*
*/
#include "process_stat.h"
#include <stdio.h>
#include <Windows.h>

int main()
{
while(1)
{
int cpu;
uint64_t mem, vmem, r, w;

cpu = get_cpu_usage();
get_memory_usage(&mem, &vmem);
get_io_bytes(&r, &w);

printf("CPU使用率: %u\n",cpu);
printf("内存使用: %u 字节\n", mem);
printf("虚拟内存使用: %u 字节\n", vmem);
printf("总共读: %u 字节\n", r);
printf("总共写: %u 字节\n", w);

Sleep(1000);
}
return 0;
}