Merge "Remove the watchdog's fd tracker." am: 4a724fc1

import android.content.IntentFilter;

import android.hidl.manager.V1_0.IServiceManager;

import android.os.Binder;

import android.os.Build;

import android.os.Debug;

import android.os.Handler;

import android.os.IPowerManager;

import android.os.RemoteException;

import android.os.ServiceManager;

import android.os.SystemClock;

import android.system.ErrnoException;

import android.system.Os;

import android.system.OsConstants;

import android.system.StructRlimit;

import android.util.EventLog;

import android.util.Log;

import android.util.Slog;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.nio.charset.StandardCharsets;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.List;

    int mPhonePid;

    IActivityController mController;

    boolean mAllowRestart = true;

    final OpenFdMonitor mOpenFdMonitor;

    /**

     * Used for checking status of handle threads and scheduling monitor callbacks.

        // Initialize monitor for Binder threads.

        addMonitor(new BinderThreadMonitor());

        mOpenFdMonitor = OpenFdMonitor.create();

        // See the notes on DEFAULT_TIMEOUT.

        assert DB ||

                DEFAULT_TIMEOUT > ZygoteConnectionConstants.WRAPPED_PID_TIMEOUT_MILLIS;

                    timeout = CHECK_INTERVAL - (SystemClock.uptimeMillis() - start);

                }

                boolean fdLimitTriggered = false;

                if (mOpenFdMonitor != null) {

                    fdLimitTriggered = mOpenFdMonitor.monitor();

                }

                if (!fdLimitTriggered) {

                final int waitState = evaluateCheckerCompletionLocked();

                if (waitState == COMPLETED) {

                    // The monitors have returned; reset

                // something is overdue!

                blockedCheckers = getBlockedCheckersLocked();

                subject = describeCheckersLocked(blockedCheckers);

                } else {

                    blockedCheckers = Collections.emptyList();

                    subject = "Open FD high water mark reached";

                }

                allowRestart = mAllowRestart;

            }

            Slog.w(TAG, "Failed to write to /proc/sysrq-trigger", e);

        }

    }

    public static final class OpenFdMonitor {

        /**

         * Number of FDs below the soft limit that we trigger a runtime restart at. This was

         * chosen arbitrarily, but will need to be at least 6 in order to have a sufficient number

         * of FDs in reserve to complete a dump.

         */

        private static final int FD_HIGH_WATER_MARK = 12;

        private final File mDumpDir;

        private final File mFdHighWaterMark;

        public static OpenFdMonitor create() {

            // Only run the FD monitor on debuggable builds (such as userdebug and eng builds).

            if (!Build.IS_DEBUGGABLE) {

                return null;

            }

            final StructRlimit rlimit;

            try {

                rlimit = android.system.Os.getrlimit(OsConstants.RLIMIT_NOFILE);

            } catch (ErrnoException errno) {

                Slog.w(TAG, "Error thrown from getrlimit(RLIMIT_NOFILE)", errno);

                return null;

            }

            // The assumption we're making here is that FD numbers are allocated (more or less)

            // sequentially, which is currently (and historically) true since open is currently

            // specified to always return the lowest-numbered non-open file descriptor for the

            // current process.

            //

            // We do this to avoid having to enumerate the contents of /proc/self/fd in order to

            // count the number of descriptors open in the process.

            final File fdThreshold = new File("/proc/self/fd/" + (rlimit.rlim_cur - FD_HIGH_WATER_MARK));

            return new OpenFdMonitor(new File("/data/anr"), fdThreshold);

        }

        OpenFdMonitor(File dumpDir, File fdThreshold) {

            mDumpDir = dumpDir;

            mFdHighWaterMark = fdThreshold;

        }

        /**

         * Dumps open file descriptors and their full paths to a temporary file in {@code mDumpDir}.

         */

        private void dumpOpenDescriptors() {

            // We cannot exec lsof to get more info about open file descriptors because a newly

            // forked process will not have the permissions to readlink. Instead list all open

            // descriptors from /proc/pid/fd and resolve them.

            List<String> dumpInfo = new ArrayList<>();

            String fdDirPath = String.format("/proc/%d/fd/", Process.myPid());

            File[] fds = new File(fdDirPath).listFiles();

            if (fds == null) {

                dumpInfo.add("Unable to list " + fdDirPath);

            } else {

                for (File f : fds) {

                    String fdSymLink = f.getAbsolutePath();

                    String resolvedPath = "";

                    try {

                        resolvedPath = Os.readlink(fdSymLink);

                    } catch (ErrnoException ex) {

                        resolvedPath = ex.getMessage();

                    }

                    dumpInfo.add(fdSymLink + "\t" + resolvedPath);

                }

            }

            // Dump the fds & paths to a temp file.

            try {

                File dumpFile = File.createTempFile("anr_fd_", "", mDumpDir);

                Path out = Paths.get(dumpFile.getAbsolutePath());

                Files.write(out, dumpInfo, StandardCharsets.UTF_8);

            } catch (IOException ex) {

                Slog.w(TAG, "Unable to write open descriptors to file: " + ex);

            }

        }

        /**

         * @return {@code true} if the high water mark was breached and a dump was written,

         *     {@code false} otherwise.

         */

        public boolean monitor() {

            if (mFdHighWaterMark.exists()) {

                dumpOpenDescriptors();

                return true;

            }

            return false;

        }

    }

}