improve profiler command output, doc, timeout. #2961

core/src/main/java/com/taobao/arthas/core/command/monitor200/ProfilerCommand.java

@@ -51,6 +51,9 @@ import one.profiler.Counter;
         + "  profiler list                # list all supported events\n"
         + "  profiler actions             # list all supported actions\n"
         + "  profiler start --event alloc\n"
+        + "  profiler start --timeout 300s"
+        + "  profiler start --loop 300s -f /tmp/result-%t.html"
+        + "  profiler start --duration 300"
         + "  profiler stop --format html   # output file format, support flat[=N]|traces[=N]|collapsed|flamegraph|tree|jfr\n"
         + "  profiler stop --file /tmp/result.html\n"
         + "  profiler stop --threads \n"
@@ -66,7 +69,10 @@ import one.profiler.Counter;
 //@formatter:on
 public class ProfilerCommand extends AnnotatedCommand {
     private static final Logger logger = LoggerFactory.getLogger(ProfilerCommand.class);
+    // Track if a file was specified during profiler start
+    private static String fileSpecifiedAtStart = null;
 
+    // TODO start 时，没指定 file， 是否在  stop 时，能生成 html 或者 jfr 不？ 
     private String action;
     private String actionArg;
 
@@ -743,10 +749,36 @@ public class ProfilerCommand extends AnnotatedCommand {
                 String result = execute(asyncProfiler, this.actionArg);
                 appendExecuteResult(process, result);
             } else if (ProfilerAction.start.equals(profilerAction)) {
+                // Track if file parameter was specified during start
+                boolean autoGeneratedFile = false;
+                if (this.file != null) {
+                    fileSpecifiedAtStart = this.file;
+                    logger.debug("File specified during profiler start: {}", fileSpecifiedAtStart);
+                } else if (this.timeout != null) {
+                    // Auto-generate file if timeout is specified but file is not
+                    try {
+                        this.file = outputFile();
+                        logger.debug("Auto-generated file for timeout: {}", this.file);
+                        fileSpecifiedAtStart = this.file;
+                        autoGeneratedFile = true;
+                    } catch (IOException e) {
+                        logger.warn("Failed to auto-generate file for timeout", e);
+                    }
+                }
+
                 if (this.duration == null) {
                     String executeArgs = executeArgs(ProfilerAction.start);
                     String result = execute(asyncProfiler, executeArgs);
-                    appendExecuteResult(process, result);
+                    ProfilerModel profilerModel = createProfilerModel(result);
+
+                    // Add information about auto-generated file for timeout
+                    if (autoGeneratedFile && this.file != null) {
+                        profilerModel.setOutputFile(this.file);
+                        profilerModel.setExecuteResult(profilerModel.getExecuteResult()
+                                + "\nAuto-generated output file will be: " + this.file + "\n");
+                    }
+
+                    process.appendResult(profilerModel);
                 } else { // 设置延时执行 stop
                     final String outputFile = outputFile();
                     String executeArgs = executeArgs(ProfilerAction.start);
@@ -833,12 +865,27 @@ public class ProfilerCommand extends AnnotatedCommand {
     }
 
     private ProfilerModel processStop(AsyncProfiler asyncProfiler, ProfilerAction profilerAction) throws IOException {
-        String outputFile = outputFile();
+        String outputFile = null;
+
+        // If we're stopping and a file was specified during start, don't generate a new
+        // output file
+        if (profilerAction == ProfilerAction.stop && fileSpecifiedAtStart != null) {
+            outputFile = fileSpecifiedAtStart;
+            // Reset the tracking variable after stop
+            logger.debug("Using file specified during start: {}", fileSpecifiedAtStart);
+            fileSpecifiedAtStart = null;
+        } else {
+            // Otherwise generate or use the specified output file
+            outputFile = outputFile();
+        }
+
         String executeArgs = executeArgs(profilerAction);
         String result = execute(asyncProfiler, executeArgs);
 
         ProfilerModel profilerModel = createProfilerModel(result);
-        profilerModel.setOutputFile(outputFile);
+        if (outputFile != null) {
+            profilerModel.setOutputFile(outputFile);
+        }
         return profilerModel;
     }
 

site/docs/doc/profiler.md

@@ -377,12 +377,18 @@ profiler start -e cpu --jfrsync +jdk.YoungGarbageCollection+jdk.OldGarbageCollec
 
 使用 `--loop TIME` 可以持续运行 profiler 并周期性保存结果。选项格式可以是具体时间 hh:mm:ss 或以秒、分钟、小时或天计算的时间间隔。需要确保指定的输出文件名中包含时间戳，否则每次输出的结果都会覆盖上次保存的结果。以下命令持续执行 profiling 并将每个小时内的记录保存到一个 jfr 文件中。
 
+> 如果没有指定 `-f` 参数，则不会保存任何内容。如果 `-f` 参数里没有 `%t`，则会循环保存到同一个文件里。
+
 ```bash
 profiler start --loop 1h -f /var/log/profile-%t.jfr
 ```
 
 ## `--timeout` 选项
 
+```bash
+profiler start --timeout 300s
+```
+
 这个选项指定 profiling 自动在多久后停止。该选项和 `--loop` 选项的格式一致，可以是时间点，也可以是一个时间间隔。这两个选项都是用于 `start` action。可参考 [async-profiler docs](https://github.com/async-profiler/async-profiler/blob/master/docs/ProfilerOptions.md) 了解更多信息。
 
 ## `--wall` 选项

site/docs/en/doc/profiler.md

@@ -379,12 +379,18 @@ profiler start -e cpu --jfrsync +jdk.YoungGarbageCollection+jdk.OldGarbageCollec
 
 Use `--loop TIME` to run profiler in a loop (continuous profiling). The argument is either a clock time (hh:mm:ss) or a loop duration in seconds, minutes, hours, or days. Make sure the filename includes a timestamp pattern, or the output will be overwritten on each iteration. The command below will run profiling endlessly and save records of each hour to a jfr file.
 
+> If the `-f` parameter is not specified, nothing will be saved. If the `-f` parameter does not contain `%t`, it will overwrite the same file repeatedly.
+
 ```bash
 profiler start --loop 1h -f /var/log/profile-%t.jfr
 ```
 
 ## `--timeout` option
 
+```bash
+profiler start --timeout 300s
+```
+
 This option specifies the time when profiling will automatically stop. The format is the same as in loop: it is either a wall clock time (12:34:56) or a relative time interval (2h).
 
 Both `--loop` and `--timeout` are used for `start` action, for further information refer to [async-profiler docs](https://github.com/async-profiler/async-profiler/blob/master/docs/ProfilerOptions.md).