Question

我如何确定有多少cpu在线？我有一个处理程序，每1000毫秒读取当前频率，我还想确定有多少内核在线。

我一直在浏览目录“/ sys / devices / system / cpu /”。我监控了“/ sys / devices / system / cpu / cpu1 / online”，它总是1，我已经监控/ cpu0 / online，这也是1。

此信息内核/设备是否具体？如何以适用于所有设备的方式查找有多少内核？

编辑： Runtime.availableProcessors（）似乎很好用，我仍然有兴趣知道是否有一个系统文件告诉你核心是否打开/关闭？

Answer 1

我在试用过的设备上取得了availableProcessors()的成功。 official Java doc中提供了该功能的更详细说明。此forum post中描述了另一种可能的解决方案。

Answer 2

 /**
 * 
 * @return integer Array with 4 elements: user, system, idle and other cpu
 * usage in percentage. You can handle from here what you want. 
 * For example if you only want active CPUs add simple if statement >0 for usage
 */

private int[] getCpuUsageStatistic() {

String tempString = executeTop();

tempString = tempString.replaceAll(",", "");
tempString = tempString.replaceAll("User", "");
tempString = tempString.replaceAll("System", "");
tempString = tempString.replaceAll("IOW", "");
tempString = tempString.replaceAll("IRQ", "");
tempString = tempString.replaceAll("%", "");
for (int i = 0; i < 10; i++) {
    tempString = tempString.replaceAll("  ", " ");
}
tempString = tempString.trim();
String[] myString = tempString.split(" ");
int[] cpuUsageAsInt = new int[myString.length];
for (int i = 0; i < myString.length; i++) {
    myString[i] = myString[i].trim();
    cpuUsageAsInt[i] = Integer.parseInt(myString[i]);
}
return cpuUsageAsInt;
}

private String executeTop() {
java.lang.Process p = null;
BufferedReader in = null;
String returnString = null;
try {
    p = Runtime.getRuntime().exec("top -n 1");
    in = new BufferedReader(new InputStreamReader(p.getInputStream()));
    while (returnString == null || returnString.contentEquals("")) {
        returnString = in.readLine();
    }
} catch (IOException e) {
    Log.e("executeTop", "error in getting first line of top");
    e.printStackTrace();
} finally {
    try {
        in.close();
        p.destroy();
    } catch (IOException e) {
        Log.e("executeTop",
                "error in closing and destroying top process");
        e.printStackTrace();
    }
}
return returnString;
}

Android计算有多少cpus在线？

2 个答案: