Merge "fdtrack: generate a heapdump when triggered." into sc-dev

import java.io.FileDescriptor;

import java.io.IOException;

import java.io.PrintWriter;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Date;

import java.util.LinkedList;

import java.util.List;

import java.util.Locale;

import java.util.Timer;

import java.util.TreeSet;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.Future;

    private static native void fdtrackAbort();

    private static final File HEAP_DUMP_PATH = new File("/data/system/heapdump/");

    private static final int MAX_HEAP_DUMPS = 2;

    /**

     * Dump system_server's heap.

     *

     * For privacy reasons, these aren't automatically pulled into bugreports:

     * they must be manually pulled by the user.

     */

    private static void dumpHprof() {

        // hprof dumps are rather large, so ensure we don't fill the disk by generating

        // hundreds of these that will live forever.

        TreeSet<File> existingTombstones = new TreeSet<>();

        for (File file : HEAP_DUMP_PATH.listFiles()) {

            if (!file.isFile()) {

                continue;

            }

            if (!file.getName().startsWith("fdtrack-")) {

                continue;

            }

            existingTombstones.add(file);

        }

        if (existingTombstones.size() >= MAX_HEAP_DUMPS) {

            for (int i = 0; i < MAX_HEAP_DUMPS - 1; ++i) {

                // Leave the newest `MAX_HEAP_DUMPS - 1` tombstones in place.

                existingTombstones.pollLast();

            }

            for (File file : existingTombstones) {

                if (!file.delete()) {

                    Slog.w("System", "Failed to clean up hprof " + file);

                }

            }

        }

        try {

            String date = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss").format(new Date());

            String filename = "/data/system/heapdump/fdtrack-" + date + ".hprof";

            Debug.dumpHprofData(filename);

        } catch (IOException ex) {

            Slog.e("System", "Failed to dump fdtrack hprof");

            ex.printStackTrace();

        }

    }

    /**

     * Spawn a thread that monitors for fd leaks.

     */

                    enabled = true;

                } else if (maxFd > abortThreshold) {

                    Slog.i("System", "fdtrack abort threshold reached, dumping and aborting");

                    dumpHprof();

                    fdtrackAbort();

                }