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上面的一些值很容易從適當(dāng)?shù)腤in 32 API中獲得，我只是在這里列出它們的完整性。然而，另一些則需要從性能數(shù)據(jù)幫助庫(PDH)中獲得，這有點(diǎn)“不直觀”，需要大量痛苦的嘗試和錯(cuò)誤才能開始工作。(至少花了我一段時(shí)間，也許我只是有點(diǎn)傻.)
注意：為了清楚起見，以下代碼省略了所有錯(cuò)誤檢查。檢查返回碼.！
總虛擬內(nèi)存：
#include "windows.h"MEMORYSTATUSEX memInfo;memInfo.dwLength = sizeof(MEMORYSTATUSEX);GlobalMemoryStatusEx(&memInfo);
DWORDLONG totalVirtualMem = memInfo.ullTotalPageFile;
注意：這里的名字“TotalPageFile”有點(diǎn)誤導(dǎo)。實(shí)際上，這個(gè)參數(shù)給出了“虛擬內(nèi)存大小”，即交換文件加上已安裝RAM的大小。
當(dāng)前使用的虛擬內(nèi)存：
與“總虛擬內(nèi)存”中的代碼相同，然后
DWORDLONG virtualMemUsed = memInfo.ullTotalPageFile - memInfo.ullAvailPageFile;
當(dāng)前進(jìn)程當(dāng)前使用的虛擬內(nèi)存：
#include "windows.h"#include "psapi.h"PROCESS_MEMORY_COUNTERS_EX pmc;GetProcessMemoryInfo(GetCurrentProcess(),
&pmc, sizeof(pmc));SIZE_T virtualMemUsedByMe = pmc.PrivateUsage;
總物理內(nèi)存(RAM)：
與“總虛擬內(nèi)存”中的代碼相同，然后
DWORDLONG totalPhysMem = memInfo.ullTotalPhys;
目前使用的物理內(nèi)存：
Same code as in "Total Virtual Memory" and thenDWORDLONG physMemUsed = memInfo.ullTotalPhys - memInfo.ullAvailPhys;
當(dāng)前進(jìn)程當(dāng)前使用的物理內(nèi)存：
與“當(dāng)前進(jìn)程當(dāng)前使用的虛擬內(nèi)存”中的代碼相同，然后
SIZE_T physMemUsedByMe = pmc.WorkingSetSize;
目前使用的CPU：
#include "TCHAR.h"#include "pdh.h"static PDH_HQUERY cpuQuery;static PDH_HCOUNTER cpuTotal;void init(){
PdhOpenQuery(NULL, NULL, &cpuQuery);
// You can also use L"\\Processor(*)\\% Processor Time" and get individual CPU values with
PdhGetFormattedCounterArray()
PdhAddEnglishCounter(cpuQuery, L"\\Processor(_Total)\\% Processor Time", NULL, &cpuTotal);
PdhCollectQueryData(cpuQuery);}double getCurrentValue(){
PDH_FMT_COUNTERVALUE counterVal;
PdhCollectQueryData(cpuQuery);
PdhGetFormattedCounterValue(cpuTotal, PDH_FMT_DOUBLE, NULL, &counterVal);
return counterVal.doubleValue;}當(dāng)前進(jìn)程當(dāng)前使用的CPU：
#include "windows.h"static ULARGE_INTEGER lastCPU, lastSysCPU, lastUserCPU;static int numProcessors;static
HANDLE self;void init(){
SYSTEM_INFO sysInfo;
FILETIME ftime, fsys, fuser;
GetSystemInfo(&sysInfo);
numProcessors = sysInfo.dwNumberOfProcessors;
GetSystemTimeAsFileTime(&ftime);
memcpy(&lastCPU, &ftime, sizeof(FILETIME));
self = GetCurrentProcess();
GetProcessTimes(self, &ftime, &ftime, &fsys, &fuser);
memcpy(&lastSysCPU, &fsys, sizeof(FILETIME));
memcpy(&lastUserCPU, &fuser, sizeof(FILETIME));}double getCurrentValue(){
FILETIME ftime, fsys, fuser;
ULARGE_INTEGER now, sys, user;
double percent;
GetSystemTimeAsFileTime(&ftime);
memcpy(&now, &ftime, sizeof(FILETIME));
GetProcessTimes(self, &ftime, &ftime, &fsys, &fuser);
memcpy(&sys, &fsys, sizeof(FILETIME));
memcpy(&user, &fuser, sizeof(FILETIME));
percent = (sys.QuadPart - lastSysCPU.QuadPart) +
(user.QuadPart - lastUserCPU.QuadPart);
percent /= (now.QuadPart - lastCPU.QuadPart);
percent /= numProcessors;
lastCPU = now;
lastUserCPU = user;
lastSysCPU = sys;
return percent * 100;}
linux
在linux上，一開始似乎很明顯的選擇是使用POSIX API，如getrusage()等。我花了一些時(shí)間試著讓它發(fā)揮作用，但卻沒有得到有意義的價(jià)值。當(dāng)我最終檢查內(nèi)核源代碼時(shí)，我發(fā)現(xiàn)這些API顯然還沒有在Linux2.6內(nèi)核中完全實(shí)現(xiàn)！
最后，我通過合并讀取偽文件系統(tǒng)獲得了所有的值。/proc和內(nèi)核調(diào)用。
總虛擬內(nèi)存：
#include "sys/types.h"#include "sys/sysinfo.h"struct sysinfo memInfo;sysinfo (&memInfo);long long totalVirtualMem
= memInfo.totalram;//Add other values in next statement to avoid int overflow on right hand
side...totalVirtualMem += memInfo.totalswap;totalVirtualMem *= memInfo.mem_unit;
當(dāng)前使用的虛擬內(nèi)存：
與“總虛擬內(nèi)存”中的代碼相同，然后
long long virtualMemUsed = memInfo.totalram - memInfo.freeram;//Add other values in next statement to avoid
int overflow on right hand side...virtualMemUsed += memInfo.totalswap - memInfo.freeswap;virtualMemUsed *= memInfo.mem_unit;
當(dāng)前進(jìn)程當(dāng)前使用的虛擬內(nèi)存：
#include "stdlib.h"#include "stdio.h"#include "string.h"int parseLine(char* line){
// This assumes that a digit will be found and the line ends in " Kb".
int i = strlen(line);
const char* p = line;
while (*p <'0' || *p > '9') p++;
line[i-3] = '\0';
i = atoi(p);
return i;}int getValue(){ //Note: this value is in KB!
FILE* file = fopen("/proc/self/status", "r");
int result = -1;
char line[128];
while (fgets(line, 128, file) != NULL){
if (strncmp(line, "VmSize:", 7) == 0){
result = parseLine(line);
break;
}
}
fclose(file);
return result;}
總物理內(nèi)存(RAM)：
與“總虛擬內(nèi)存”中的代碼相同，然后
long long totalPhysMem = memInfo.totalram;//Multiply in next statement to avoid int overflow on right hand
side...totalPhysMem *= memInfo.mem_unit;
目前使用的物理內(nèi)存：
與“總虛擬內(nèi)存”中的代碼相同，然后
long long physMemUsed = memInfo.totalram - memInfo.freeram;//Multiply in next statement to avoid int overflow
on right hand side...physMemUsed *= memInfo.mem_unit;
當(dāng)前進(jìn)程當(dāng)前使用的物理內(nèi)存：
在“當(dāng)前進(jìn)程當(dāng)前使用的虛擬內(nèi)存”中更改getValue()如下：
int getValue(){ //Note: this value is in KB!
FILE* file = fopen("/proc/self/status", "r");
int result = -1;
char line[128];
while (fgets(line, 128, file) != NULL){
if (strncmp(line, "VmRSS:", 6) == 0){
result = parseLine(line);
break;
}
}
fclose(file);
return result;}
目前使用的CPU：
#include "stdlib.h"#include "stdio.h"#include "string.h"static unsigned long long lastTotalUser, lastTotalUserLow,
lastTotalSys, lastTotalIdle;void init(){
FILE* file = fopen("/proc/stat", "r");
fscanf(file, "cpu %llu %llu %llu %llu", &lastTotalUser, &lastTotalUserLow,
&lastTotalSys, &lastTotalIdle);
fclose(file);}double getCurrentValue(){
double percent;
FILE* file;
unsigned long long totalUser, totalUserLow, totalSys, totalIdle, total;
file = fopen("/proc/stat", "r");
fscanf(file, "cpu %llu %llu %llu %llu", &totalUser, &totalUserLow,
&totalSys, &totalIdle);
fclose(file);
if (totalUser < lastTotalUser || totalUserLow < lastTotalUserLow ||
totalSys < lastTotalSys || totalIdle < lastTotalIdle){
//Overflow detection. Just skip this value.
percent = -1.0;
}
else{
total = (totalUser - lastTotalUser) + (totalUserLow - lastTotalUserLow) +
(totalSys - lastTotalSys);
percent = total;
total += (totalIdle - lastTotalIdle);
percent /= total;
percent *= 100;
}
lastTotalUser = totalUser;
lastTotalUserLow = totalUserLow;
lastTotalSys = totalSys;
lastTotalIdle = totalIdle;
return percent;}當(dāng)前進(jìn)程當(dāng)前使用的CPU：
#include "stdlib.h"#include "stdio.h"#include "string.h"#include "sys/times.h"#include "sys/vtimes.h"static clock_t lastCPU,
lastSysCPU, lastUserCPU;static int numProcessors;void init(){
FILE* file;
struct tms timeSample;
char line[128];
lastCPU = times(&timeSample);
lastSysCPU = timeSample.tms_stime;
lastUserCPU = timeSample.tms_utime;
file = fopen("/proc/cpuinfo", "r");
numProcessors = 0;
while(fgets(line, 128, file) != NULL){
if (strncmp(line, "processor", 9) == 0) numProcessors++;
}
fclose(file);}double getCurrentValue(){
struct tms timeSample;
clock_t now;
double percent;
now = times(&timeSample);
if (now <= lastCPU || timeSample.tms_stime < lastSysCPU ||
timeSample.tms_utime < lastUserCPU){
//Overflow detection. Just skip this value.
percent = -1.0;
}
else{
percent = (timeSample.tms_stime - lastSysCPU) +
(timeSample.tms_utime - lastUserCPU);
percent /= (now - lastCPU);
percent /= numProcessors;
percent *= 100;
}
lastCPU = now;
lastSysCPU = timeSample.tms_stime;
lastUserCPU = timeSample.tms_utime;
return percent;}
Todo：其他平臺(tái)
我假設(shè)，除了讀取/proc偽文件系統(tǒng)的部分之外，一些Linux代碼也適用于unix。也許在unix上，這些部件可以由getrusage()還有類似的功能？如果有Unix技術(shù)的人可以編輯這個(gè)答案并填寫詳細(xì)信息？！
