98 lines
4.1 KiB
Markdown
98 lines
4.1 KiB
Markdown
#安卓
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#unity/日常积累
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移动端，存在几个不同的内存获取方式：USS、PSS、RSS，他们之间的区别：
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对于USS（Unique Set Size），计算了TotalPrivateDirty和TotalPrivateClean的总和，再转换为MB。USS指的是进程独占的物理内存，不包含共享库的部分，这部分是正确的。
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PSS（Proportional Set Size）是共享内存按比例分配后的值，比如三个进程共享一个库，每个进程的PSS会加上该库大小的1/3。这也是正确的实现。
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RSS，实际物理内存占用，通过读取/proc/self/status中的VmRSS来获取，这是更直接且准确的方式，因为系统提供的这个值直接反映了RSS的大小。
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![[Pasted image 20250407142019.png]]
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逻辑参考：
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（目前采用，最真实的内存获取接口：getRSSMemoryMBProc）
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``` java
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//获取USS
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public static int getUSSMemoryMB()
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{
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try {
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// if (!hasUsageStatsPermission()) {
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// return -2;
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// }
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int pid = android.os.Process.myPid();
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Activity activity = UnityActivity.getActivity();
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ActivityManager am = (ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE);
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Debug.MemoryInfo[] memInfoArray = am.getProcessMemoryInfo(new int[]{pid});
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if (memInfoArray != null && memInfoArray.length > 0)
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{
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Debug.MemoryInfo mi = memInfoArray[0];
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int ussKb = mi.getTotalPrivateDirty() + mi.getTotalPrivateClean();
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return ussKb / 1024; //转MB
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}
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}
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catch (Exception e) {
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e.printStackTrace();
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}
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return -1;
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}
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// 获取 PSS（MB）
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public static int getPSSMemoryMB() {
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try {
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// if (!hasUsageStatsPermission()) {
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// return -2;
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// }
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int pid = android.os.Process.myPid();
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Activity activity = UnityActivity.getActivity();
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ActivityManager am = (ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE);
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Debug.MemoryInfo[] memInfoArray = am.getProcessMemoryInfo(new int[]{pid});
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if (memInfoArray != null && memInfoArray.length > 0) {
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return memInfoArray[0].getTotalPss() / 1024; // 转换为MB
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}
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} catch (Exception e) {
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e.printStackTrace();
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}
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return -1;
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}
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// 获取 RSS（MB）
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public static int getRSSMemoryMBProc() {
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// long startTime = System.nanoTime(); // 记录开始时间
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try (BufferedReader br = new BufferedReader(new FileReader("/proc/self/status"))) {
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String line;
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while ((line = br.readLine()) != null) {
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if (line.startsWith("VmRSS:")) {
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String[] parts = line.split("\\s+");
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int kb = Integer.parseInt(parts[1]);
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// long duration = (System.nanoTime() - startTime) / 1000; // 微秒耗时
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// Log.d("PerfMonitor", "getRSSMemoryMBProc took " + duration + "μs");
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return kb / 1024;
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}
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}
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// 如果没有找到VmRSS行也记录耗时
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// long duration = (System.nanoTime() - startTime) / 1000;
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// Log.d("PerfMonitor", "getRSSMemoryMBProc (no data) took " + duration + "μs");
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} catch (Exception e) {
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// long duration = (System.nanoTime() - startTime) / 1000;
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// Log.e("PerfMonitor", "getRSSMemoryMBProc failed after " + duration + "μs", e);
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e.printStackTrace();
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}
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return -1;
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}
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// 获取系统可用内存百分比
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public float getAvailableMemoryPercent() {
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ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
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Activity activity = UnityActivity.getActivity();
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ActivityManager am = (ActivityManager) activity.getSystemService(Context.ACTIVITY_SERVICE);
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am.getMemoryInfo(mi);
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return (float)mi.availMem / mi.totalMem * 100;
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}
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```
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安卓相关的Manifest.xml文件，也添加一下，权限申请
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![[Pasted image 20250407143343.png]] |