Examples with VMRuntime dalvik.system.VMRuntime used on opensource projects

Example 31 with VMRuntime

use of dalvik.system.VMRuntime in project android_frameworks_base by crdroidandroid.

the class ZygoteInit method gcAndFinalize.

/**
     * Runs several special GCs to try to clean up a few generations of
     * softly- and final-reachable objects, along with any other garbage.
     * This is only useful just before a fork().
     */
/*package*/
static void gcAndFinalize() {
    final VMRuntime runtime = VMRuntime.getRuntime();
    /* runFinalizationSync() lets finalizers be called in Zygote,
         * which doesn't have a HeapWorker thread.
         */
    System.gc();
    runtime.runFinalizationSync();
    System.gc();
}

Example 32 with VMRuntime

use of dalvik.system.VMRuntime in project android_frameworks_base by crdroidandroid.

the class ZygoteInit method preloadResources.

/**
     * Load in commonly used resources, so they can be shared across
     * processes.
     *
     * These tend to be a few Kbytes, but are frequently in the 20-40K
     * range, and occasionally even larger.
     */
private static void preloadResources() {
    final VMRuntime runtime = VMRuntime.getRuntime();
    try {
        mResources = Resources.getSystem();
        mResources.startPreloading();
        if (PRELOAD_RESOURCES) {
            Log.i(TAG, "Preloading resources...");
            long startTime = SystemClock.uptimeMillis();
            TypedArray ar = mResources.obtainTypedArray(com.android.internal.R.array.preloaded_drawables);
            int N = preloadDrawables(ar);
            ar.recycle();
            Log.i(TAG, "...preloaded " + N + " resources in " + (SystemClock.uptimeMillis() - startTime) + "ms.");
            startTime = SystemClock.uptimeMillis();
            ar = mResources.obtainTypedArray(com.android.internal.R.array.preloaded_color_state_lists);
            N = preloadColorStateLists(ar);
            ar.recycle();
            Log.i(TAG, "...preloaded " + N + " resources in " + (SystemClock.uptimeMillis() - startTime) + "ms.");
            if (mResources.getBoolean(com.android.internal.R.bool.config_freeformWindowManagement)) {
                startTime = SystemClock.uptimeMillis();
                ar = mResources.obtainTypedArray(com.android.internal.R.array.preloaded_freeform_multi_window_drawables);
                N = preloadDrawables(ar);
                ar.recycle();
                Log.i(TAG, "...preloaded " + N + " resource in " + (SystemClock.uptimeMillis() - startTime) + "ms.");
            }
        } else {
            Log.i(TAG, "Preload resources disabled, skipped.");
        }
        mResources.finishPreloading();
    } catch (RuntimeException e) {
        Log.w(TAG, "Failure preloading resources", e);
    }
}

Example 33 with VMRuntime

use of dalvik.system.VMRuntime in project android_frameworks_base by crdroidandroid.

the class ZygoteInit method preloadClasses.

/**
     * Performs Zygote process initialization. Loads and initializes
     * commonly used classes.
     *
     * Most classes only cause a few hundred bytes to be allocated, but
     * a few will allocate a dozen Kbytes (in one case, 500+K).
     */
private static void preloadClasses() {
    final VMRuntime runtime = VMRuntime.getRuntime();
    InputStream is;
    try {
        is = new FileInputStream(PRELOADED_CLASSES);
    } catch (FileNotFoundException e) {
        Log.e(TAG, "Couldn't find " + PRELOADED_CLASSES + ".");
        return;
    }
    Log.i(TAG, "Preloading classes...");
    long startTime = SystemClock.uptimeMillis();
    // Drop root perms while running static initializers.
    final int reuid = Os.getuid();
    final int regid = Os.getgid();
    // We need to drop root perms only if we're already root. In the case of "wrapped"
    // processes (see WrapperInit), this function is called from an unprivileged uid
    // and gid.
    boolean droppedPriviliges = false;
    if (reuid == ROOT_UID && regid == ROOT_GID) {
        try {
            Os.setregid(ROOT_GID, UNPRIVILEGED_GID);
            Os.setreuid(ROOT_UID, UNPRIVILEGED_UID);
        } catch (ErrnoException ex) {
            throw new RuntimeException("Failed to drop root", ex);
        }
        droppedPriviliges = true;
    }
    // Alter the target heap utilization.  With explicit GCs this
    // is not likely to have any effect.
    float defaultUtilization = runtime.getTargetHeapUtilization();
    runtime.setTargetHeapUtilization(0.8f);
    try {
        BufferedReader br = new BufferedReader(new InputStreamReader(is), 256);
        int count = 0;
        String line;
        while ((line = br.readLine()) != null) {
            // Skip comments and blank lines.
            line = line.trim();
            if (line.startsWith("#") || line.equals("")) {
                continue;
            }
            Trace.traceBegin(Trace.TRACE_TAG_DALVIK, line);
            try {
                if (false) {
                    Log.v(TAG, "Preloading " + line + "...");
                }
                // Load and explicitly initialize the given class. Use
                // Class.forName(String, boolean, ClassLoader) to avoid repeated stack lookups
                // (to derive the caller's class-loader). Use true to force initialization, and
                // null for the boot classpath class-loader (could as well cache the
                // class-loader of this class in a variable).
                Class.forName(line, true, null);
                count++;
            } catch (ClassNotFoundException e) {
                Log.w(TAG, "Class not found for preloading: " + line);
            } catch (UnsatisfiedLinkError e) {
                Log.w(TAG, "Problem preloading " + line + ": " + e);
            } catch (Throwable t) {
                Log.e(TAG, "Error preloading " + line + ".", t);
                if (t instanceof Error) {
                    throw (Error) t;
                }
                if (t instanceof RuntimeException) {
                    throw (RuntimeException) t;
                }
                throw new RuntimeException(t);
            }
            Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
        }
        Log.i(TAG, "...preloaded " + count + " classes in " + (SystemClock.uptimeMillis() - startTime) + "ms.");
    } catch (IOException e) {
        Log.e(TAG, "Error reading " + PRELOADED_CLASSES + ".", e);
    } finally {
        IoUtils.closeQuietly(is);
        // Restore default.
        runtime.setTargetHeapUtilization(defaultUtilization);
        // Fill in dex caches with classes, fields, and methods brought in by preloading.
        Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "PreloadDexCaches");
        runtime.preloadDexCaches();
        Trace.traceEnd(Trace.TRACE_TAG_DALVIK);
        // Bring back root. We'll need it later if we're in the zygote.
        if (droppedPriviliges) {
            try {
                Os.setreuid(ROOT_UID, ROOT_UID);
                Os.setregid(ROOT_GID, ROOT_GID);
            } catch (ErrnoException ex) {
                throw new RuntimeException("Failed to restore root", ex);
            }
        }
    }
}