android线程监测，排查性能问题

java

    static class ThreadMonitor {
        private void startThreadMonitor() {
            final Thread mainThread = Thread.currentThread();
            ThreadGroup threadGroup = mainThread.getThreadGroup();
            final Thread[] allThread = new Thread[threadGroup.activeCount()];
            threadGroup.enumerate(allThread);
            final Map<Thread, ThreadStateTimeLine> timeLineMap = new HashMap<>(allThread.length);
            for (Thread thread : allThread) {
                timeLineMap.put(thread, new ThreadStateTimeLine(thread));
            }

            new Thread(new Runnable() {
                @Override
                public void run() {
                    Process.setThreadPriority(Process.THREAD_PRIORITY_FOREGROUND);

                    long time0 = SystemClock.uptimeMillis();
                    long time;
                    while ((time = SystemClock.uptimeMillis() - time0) < 3000) {
//                    for (Thread thread : allThread) {
                        Thread thread = mainThread;
                        Thread.State currState = thread.getState();
                        ThreadStateTimeLine timeLine = timeLineMap.get(thread);
                        ThreadStage threadStage;
                        if (timeLine.stateTimeLine.size() == 0) {
                            threadStage = new ThreadStage(currState);
                            threadStage.startUpMillis = time;
                            timeLine.stateTimeLine.add(threadStage);
                        } else {
                            threadStage = timeLine.stateTimeLine.get(
                                    timeLine.stateTimeLine.size() - 1);
                            if (currState == threadStage.state) {
                                threadStage.endMillis = time;
                                threadStage.time = threadStage.endMillis - threadStage.startUpMillis;
                            } else {
                                threadStage.endMillis = time;
                                threadStage.time = threadStage.endMillis - threadStage.startUpMillis;
                                threadStage = new ThreadStage(currState);
                                threadStage.startUpMillis = time;
                                timeLine.stateTimeLine.add(threadStage);
                            }

                            if (currState == Thread.State.BLOCKED || currState == Thread.State.WAITING) {
                                StackTraceElement[] elements = mainThread.getStackTrace();
                                if (threadStage.stackTraceElements == null) {
                                    threadStage.stackTraceElements = elements;
                                } else {
                                    if (threadStage.stackTraceElements.length != elements.length) {
                                        threadStage = new ThreadStage(currState);
                                        threadStage.startUpMillis = time;
                                        threadStage.stackTraceElements = elements;
                                        timeLine.stateTimeLine.add(threadStage);
                                    }
                                }
                            }

                        }

//                    }
                    }
                    Object[] threadStages = null;
                    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
                        threadStages = timeLineMap.get(mainThread).stateTimeLine
                                .stream()
                                .filter(new Predicate<ThreadStage>() {
                                    @Override
                                    public boolean test(ThreadStage threadStage) {
                                        return threadStage.state == Thread.State.BLOCKED;
                                    }
                                })
                                .toArray();
                    }
                    String result = JSON.toJSONString(threadStages);
                    File file = new File("/sdcard/result.json");
                    file.setWritable(true);
                    try {
                        new FileOutputStream(file).write(result.getBytes());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    Log.e(TAG, "main thread:"
                            + result);
                }
            }).start();
        }

        static class ThreadStateTimeLine {
            Thread thread;
            List<ThreadStage> stateTimeLine = new ArrayList<>(1000);

            public ThreadStateTimeLine(Thread thread) {
                this.thread = thread;
            }
        }

        static class ThreadStage {
            public long startUpMillis;
            public long endMillis;
            public Thread.State state;
            public long time;
            public StackTraceElement[] stackTraceElements;

            public ThreadStage(Thread.State currState) {
                this.state = currState;
            }
        }
    }