v8/renderscript/RenderScript.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.support.v8.renderscript;

import java.io.File;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Process;
import android.util.Log;
import android.view.Surface;
import java.util.ArrayList;

/**
 * This class provides access to a RenderScript context, which controls RenderScript
 * initialization, resource management, and teardown. An instance of the RenderScript
 * class must be created before any other RS objects can be created.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about creating an application that uses RenderScript, read the
 * <a href="{@docRoot}guide/topics/renderscript/index.html">RenderScript</a> developer guide.</p>
 * </div>
 **/
public class RenderScript {
    static final String LOG_TAG = "RenderScript_jni";
    static final boolean DEBUG  = false;
    @SuppressWarnings({"UnusedDeclaration", "deprecation"})
    static final boolean LOG_ENABLED = false;

    static private ArrayList<RenderScript> mProcessContextList = new ArrayList<RenderScript>();
    private boolean mIsProcessContext = false;
    private int mContextFlags = 0;
    private int mContextSdkVersion = 0;


    private Context mApplicationContext;
    private String mNativeLibDir;

    /*
     * We use a class initializer to allow the native code to cache some
     * field offsets.
     */
    @SuppressWarnings({"FieldCanBeLocal", "UnusedDeclaration"})
    static boolean sInitialized;
    static boolean sUseGCHooks;
    static Object sRuntime;
    static Method registerNativeAllocation;
    static Method registerNativeFree;

    static Object lock = new Object();

    // Non-threadsafe functions.
    native boolean nLoadSO(boolean useNative, int deviceApi);
    native boolean nLoadIOSO();
    native long nDeviceCreate();
    native void nDeviceDestroy(long dev);
    native void nDeviceSetConfig(long dev, int param, int value);
    native int nContextGetUserMessage(long con, int[] data);
    native String nContextGetErrorMessage(long con);
    native int  nContextPeekMessage(long con, int[] subID);
    native void nContextInitToClient(long con);
    native void nContextDeinitToClient(long con);

    static private int sNative = -1;
    static private int sSdkVersion = -1;
    static private boolean useIOlib = false;
    static private boolean useNative;

    /*
     * Context creation flag that specifies a normal context.
     * RenderScript Support lib only support normal context.
     */
    public static final int CREATE_FLAG_NONE = 0x0000;


    boolean isUseNative() {
        return useNative;
    }
    /*
     * Detect the bitness of the VM to allow FieldPacker to do the right thing.
     */
    static native int rsnSystemGetPointerSize();
    static int sPointerSize;

    /**
     * Determines whether or not we should be thunking into the native
     * RenderScript layer or actually using the compatibility library.
     */
    static private boolean setupNative(int sdkVersion, Context ctx) {
        // if targetSdkVersion is higher than the device api version, always use compat mode.
        // Workaround for KK
        if (android.os.Build.VERSION.SDK_INT < sdkVersion &&
            android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.LOLLIPOP) {
            sNative = 0;
        }

        if (sNative == -1) {

            // get the value of the debug.rs.forcecompat property
            int forcecompat = 0;
            try {
                Class<?> sysprop = Class.forName("android.os.SystemProperties");
                Class[] signature = {String.class, Integer.TYPE};
                Method getint = sysprop.getDeclaredMethod("getInt", signature);
                Object[] args = {"debug.rs.forcecompat", new Integer(0)};
                forcecompat = ((java.lang.Integer)getint.invoke(null, args)).intValue();
            } catch (Exception e) {

            }

            if ((android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT)
                     && forcecompat == 0) {
                sNative = 1;
            } else {
                sNative = 0;
            }


            if (sNative == 1) {
                // Workarounds that may disable thunking go here
                ApplicationInfo info;
                try {
                    info = ctx.getPackageManager().getApplicationInfo(ctx.getPackageName(),
                                                                      PackageManager.GET_META_DATA);
                } catch (PackageManager.NameNotFoundException e) {
                    // assume no workarounds needed
                    return true;
                }
                long minorVersion = 0;

                // load minorID from reflection
                try {
                    Class<?> javaRS = Class.forName("android.renderscript.RenderScript");
                    Method getMinorID = javaRS.getDeclaredMethod("getMinorID");
                    minorVersion = ((java.lang.Long)getMinorID.invoke(null)).longValue();
                } catch (Exception e) {
                    // minor version remains 0 on devices with no possible WARs
                }

                if (info.metaData != null) {
                    // asynchronous teardown: minor version 1+
                    if (info.metaData.getBoolean("com.android.support.v8.renderscript.EnableAsyncTeardown") == true) {
                        if (minorVersion == 0) {
                            sNative = 0;
                        }
                    }

                    // blur issues on some drivers with 4.4
                    if (info.metaData.getBoolean("com.android.support.v8.renderscript.EnableBlurWorkaround") == true) {
                        if (android.os.Build.VERSION.SDK_INT <= 19) {
                            //android.util.Log.e("rs", "war on");
                            sNative = 0;
                        }
                    }
                }
                // end of workarounds
            }
        }

        if (sNative == 1) {
            return true;
        }
        return false;
    }

    /**
     * Name of the file that holds the object cache.
     */
    private static final String CACHE_PATH = "com.android.renderscript.cache";
    static String mCachePath;

     /**
     * Sets the directory to use as a persistent storage for the
     * renderscript object file cache.
     *
     * @hide
     * @param cacheDir A directory the current process can write to
     */
    public static void setupDiskCache(File cacheDir) {
        File f = new File(cacheDir, CACHE_PATH);
        mCachePath = f.getAbsolutePath();
        f.mkdirs();
    }

    /**
     * ContextType specifies the specific type of context to be created.
     *
     */
    public enum ContextType {
        /**
         * NORMAL context, this is the default and what shipping apps should
         * use.
         */
        NORMAL (0),

        /**
         * DEBUG context, perform extra runtime checks to validate the
         * kernels and APIs are being used as intended.  Get and SetElementAt
         * will be bounds checked in this mode.
         */
        DEBUG (1),

        /**
         * PROFILE context, Intended to be used once the first time an
         * application is run on a new device.  This mode allows the runtime to
         * do additional testing and performance tuning.
         */
        PROFILE (2);

        int mID;
        ContextType(int id) {
            mID = id;
        }
    }

    ContextType mContextType;
    // Methods below are wrapped to protect the non-threadsafe
    // lockless fifo.

    native long  rsnContextCreate(long dev, int ver, int sdkVer, int contextType, String nativeLibDir);
    synchronized long nContextCreate(long dev, int ver, int sdkVer, int contextType, String nativeLibDir) {
        return rsnContextCreate(dev, ver, sdkVer, contextType, nativeLibDir);
    }
    native void rsnContextDestroy(long con);
    synchronized void nContextDestroy() {
        validate();

        // take teardown lock
        // teardown lock can only be taken when no objects are being destroyed
        ReentrantReadWriteLock.WriteLock wlock = mRWLock.writeLock();
        wlock.lock();

        long curCon = mContext;
        // context is considered dead as of this point
        mContext = 0;

        wlock.unlock();
        rsnContextDestroy(curCon);
    }
    native void rsnContextSetPriority(long con, int p);
    synchronized void nContextSetPriority(int p) {
        validate();
        rsnContextSetPriority(mContext, p);
    }
    native void rsnContextDump(long con, int bits);
    synchronized void nContextDump(int bits) {
        validate();
        rsnContextDump(mContext, bits);
    }
    native void rsnContextFinish(long con);
    synchronized void nContextFinish() {
        validate();
        rsnContextFinish(mContext);
    }

    native void rsnContextSendMessage(long con, int id, int[] data);
    synchronized void nContextSendMessage(int id, int[] data) {
        validate();
        rsnContextSendMessage(mContext, id, data);
    }

    // nObjDestroy is explicitly _not_ synchronous to prevent crashes in finalizers
    native void rsnObjDestroy(long con, long id);
    void nObjDestroy(long id) {
        // There is a race condition here.  The calling code may be run
        // by the gc while teardown is occuring.  This protects againts
        // deleting dead objects.
        if (mContext != 0) {
            rsnObjDestroy(mContext, id);
        }
    }

    native long  rsnElementCreate(long con, long type, int kind, boolean norm, int vecSize);
    synchronized long nElementCreate(long type, int kind, boolean norm, int vecSize) {
        validate();
        return rsnElementCreate(mContext, type, kind, norm, vecSize);
    }
    native long  rsnElementCreate2(long con, long[] elements, String[] names, int[] arraySizes);
    synchronized long nElementCreate2(long[] elements, String[] names, int[] arraySizes) {
        validate();
        return rsnElementCreate2(mContext, elements, names, arraySizes);
    }
    native void rsnElementGetNativeData(long con, long id, int[] elementData);
    synchronized void nElementGetNativeData(long id, int[] elementData) {
        validate();
        rsnElementGetNativeData(mContext, id, elementData);
    }
    native void rsnElementGetSubElements(long con, long id,
                                         long[] IDs, String[] names, int[] arraySizes);
    synchronized void nElementGetSubElements(long id, long[] IDs, String[] names, int[] arraySizes) {
        validate();
        rsnElementGetSubElements(mContext, id, IDs, names, arraySizes);
    }

    native long rsnTypeCreate(long con, long eid, int x, int y, int z, boolean mips, boolean faces, int yuv);
    synchronized long nTypeCreate(long eid, int x, int y, int z, boolean mips, boolean faces, int yuv) {
        validate();
        return rsnTypeCreate(mContext, eid, x, y, z, mips, faces, yuv);
    }

    native void rsnTypeGetNativeData(long con, long id, long[] typeData);
    synchronized void nTypeGetNativeData(long id, long[] typeData) {
        validate();
        rsnTypeGetNativeData(mContext, id, typeData);
    }

    native long  rsnAllocationCreateTyped(long con, long type, int mip, int usage, long pointer);
    synchronized long nAllocationCreateTyped(long type, int mip, int usage, long pointer) {
        validate();
        return rsnAllocationCreateTyped(mContext, type, mip, usage, pointer);
    }
    native long  rsnAllocationCreateFromBitmap(long con, long type, int mip, Bitmap bmp, int usage);
    synchronized long nAllocationCreateFromBitmap(long type, int mip, Bitmap bmp, int usage) {
        validate();
        return rsnAllocationCreateFromBitmap(mContext, type, mip, bmp, usage);
    }

    native long  rsnAllocationCreateBitmapBackedAllocation(long con, long type, int mip, Bitmap bmp, int usage);
    synchronized long nAllocationCreateBitmapBackedAllocation(long type, int mip, Bitmap bmp, int usage) {
        validate();
        return rsnAllocationCreateBitmapBackedAllocation(mContext, type, mip, bmp, usage);
    }


    native long  rsnAllocationCubeCreateFromBitmap(long con, long type, int mip, Bitmap bmp, int usage);
    synchronized long nAllocationCubeCreateFromBitmap(long type, int mip, Bitmap bmp, int usage) {
        validate();
        return rsnAllocationCubeCreateFromBitmap(mContext, type, mip, bmp, usage);
    }
    native long  rsnAllocationCreateBitmapRef(long con, long type, Bitmap bmp);
    synchronized long nAllocationCreateBitmapRef(long type, Bitmap bmp) {
        validate();
        return rsnAllocationCreateBitmapRef(mContext, type, bmp);
    }
    native long  rsnAllocationCreateFromAssetStream(long con, int mips, int assetStream, int usage);
    synchronized long nAllocationCreateFromAssetStream(int mips, int assetStream, int usage) {
        validate();
        return rsnAllocationCreateFromAssetStream(mContext, mips, assetStream, usage);
    }

    native void  rsnAllocationCopyToBitmap(long con, long alloc, Bitmap bmp);
    synchronized void nAllocationCopyToBitmap(long alloc, Bitmap bmp) {
        validate();
        rsnAllocationCopyToBitmap(mContext, alloc, bmp);
    }


    native void rsnAllocationSyncAll(long con, long alloc, int src);
    synchronized void nAllocationSyncAll(long alloc, int src) {
        validate();
        rsnAllocationSyncAll(mContext, alloc, src);
    }

    native void rsnAllocationSetSurface(long con, long alloc, Surface sur);
    synchronized void nAllocationSetSurface(long alloc, Surface sur) {
        validate();
        rsnAllocationSetSurface(mContext, alloc, sur);
    }

    native void rsnAllocationIoSend(long con, long alloc);
    synchronized void nAllocationIoSend(long alloc) {
        validate();
        rsnAllocationIoSend(mContext, alloc);
    }
    native void rsnAllocationIoReceive(long con, long alloc);
    synchronized void nAllocationIoReceive(long alloc) {
        validate();
        rsnAllocationIoReceive(mContext, alloc);
    }


    native void rsnAllocationGenerateMipmaps(long con, long alloc);
    synchronized void nAllocationGenerateMipmaps(long alloc) {
        validate();
        rsnAllocationGenerateMipmaps(mContext, alloc);
    }
    native void  rsnAllocationCopyFromBitmap(long con, long alloc, Bitmap bmp);
    synchronized void nAllocationCopyFromBitmap(long alloc, Bitmap bmp) {
        validate();
        rsnAllocationCopyFromBitmap(mContext, alloc, bmp);
    }


    native void rsnAllocationData1D(long con, long id, int off, int mip, int count, Object d, int sizeBytes, int dt,
                                    int mSize, boolean usePadding);
    synchronized void nAllocationData1D(long id, int off, int mip, int count, Object d, int sizeBytes, Element.DataType dt,
                                        int mSize, boolean usePadding) {
        validate();
        rsnAllocationData1D(mContext, id, off, mip, count, d, sizeBytes, dt.mID, mSize, usePadding);
    }

    native void rsnAllocationElementData1D(long con,long id, int xoff, int mip, int compIdx, byte[] d, int sizeBytes);
    synchronized void nAllocationElementData1D(long id, int xoff, int mip, int compIdx, byte[] d, int sizeBytes) {
        validate();
        rsnAllocationElementData1D(mContext, id, xoff, mip, compIdx, d, sizeBytes);
    }
    /*
    native void rsnAllocationElementData(long con,long id, int xoff, int yoff, int zoff, int mip, int compIdx, byte[] d, int sizeBytes);
    synchronized void nAllocationElementData(long id, int xoff, int yoff, int zoff, int mip, int compIdx, byte[] d, int sizeBytes) {
        validate();
        rsnAllocationElementData(mContext, id, xoff, yoff, zoff, mip, compIdx, d, sizeBytes);
    }
    */

    native void rsnAllocationData2D(long con,
                                    long dstAlloc, int dstXoff, int dstYoff,
                                    int dstMip, int dstFace,
                                    int width, int height,
                                    long srcAlloc, int srcXoff, int srcYoff,
                                    int srcMip, int srcFace);
    synchronized void nAllocationData2D(long dstAlloc, int dstXoff, int dstYoff,
                                        int dstMip, int dstFace,
                                        int width, int height,
                                        long srcAlloc, int srcXoff, int srcYoff,
                                        int srcMip, int srcFace) {
        validate();
        rsnAllocationData2D(mContext,
                            dstAlloc, dstXoff, dstYoff,
                            dstMip, dstFace,
                            width, height,
                            srcAlloc, srcXoff, srcYoff,
                            srcMip, srcFace);
    }

    native void rsnAllocationData2D(long con, long id, int xoff, int yoff, int mip, int face,
                                    int w, int h, Object d, int sizeBytes, int dt,
                                    int mSize, boolean usePadding);
    synchronized void nAllocationData2D(long id, int xoff, int yoff, int mip, int face,
                                        int w, int h, Object d, int sizeBytes, Element.DataType dt,
                                        int mSize, boolean usePadding) {
        validate();
        rsnAllocationData2D(mContext, id, xoff, yoff, mip, face, w, h, d, sizeBytes, dt.mID, mSize, usePadding);
    }

    native void rsnAllocationData2D(long con, long id, int xoff, int yoff, int mip, int face, Bitmap b);
    synchronized void nAllocationData2D(long id, int xoff, int yoff, int mip, int face, Bitmap b) {
        validate();
        rsnAllocationData2D(mContext, id, xoff, yoff, mip, face, b);
    }

    native void rsnAllocationData3D(long con,
                                    long dstAlloc, int dstXoff, int dstYoff, int dstZoff,
                                    int dstMip,
                                    int width, int height, int depth,
                                    long srcAlloc, int srcXoff, int srcYoff, int srcZoff,
                                    int srcMip);
    synchronized void nAllocationData3D(long dstAlloc, int dstXoff, int dstYoff, int dstZoff,
                                        int dstMip,
                                        int width, int height, int depth,
                                        long srcAlloc, int srcXoff, int srcYoff, int srcZoff,
                                        int srcMip) {
        validate();
        rsnAllocationData3D(mContext,
                            dstAlloc, dstXoff, dstYoff, dstZoff,
                            dstMip, width, height, depth,
                            srcAlloc, srcXoff, srcYoff, srcZoff, srcMip);
    }


    native void rsnAllocationData3D(long con, long id, int xoff, int yoff, int zoff, int mip,
                                    int w, int h, int depth, Object d, int sizeBytes, int dt,
                                    int mSize, boolean usePadding);
    synchronized void nAllocationData3D(long id, int xoff, int yoff, int zoff, int mip,
                                        int w, int h, int depth, Object d, int sizeBytes, Element.DataType dt,
                                        int mSize, boolean usePadding) {
        validate();
        rsnAllocationData3D(mContext, id, xoff, yoff, zoff, mip, w, h, depth, d, sizeBytes,
                            dt.mID, mSize, usePadding);
    }

    native void rsnAllocationRead(long con, long id, Object d, int dt, int mSize, boolean usePadding);
    synchronized void nAllocationRead(long id, Object d, Element.DataType dt, int mSize, boolean usePadding) {
        validate();
        rsnAllocationRead(mContext, id, d, dt.mID, mSize, usePadding);
    }

    native void rsnAllocationRead1D(long con, long id, int off, int mip, int count, Object d,
                                    int sizeBytes, int dt, int mSize, boolean usePadding);
    synchronized void nAllocationRead1D(long id, int off, int mip, int count, Object d,
                                        int sizeBytes, Element.DataType dt, int mSize, boolean usePadding) {
        validate();
        rsnAllocationRead1D(mContext, id, off, mip, count, d, sizeBytes, dt.mID, mSize, usePadding);
    }

    /*
    native void rsnAllocationElementRead(long con,long id, int xoff, int yoff, int zoff,
                                         int mip, int compIdx, byte[] d, int sizeBytes);
    synchronized void nAllocationElementRead(long id, int xoff, int yoff, int zoff,
                                             int mip, int compIdx, byte[] d, int sizeBytes) {
        validate();
        rsnAllocationElementRead(mContext, id, xoff, yoff, zoff, mip, compIdx, d, sizeBytes);
    }
    */

    native void rsnAllocationRead2D(long con, long id, int xoff, int yoff, int mip, int face,
                                    int w, int h, Object d, int sizeBytes, int dt,
                                    int mSize, boolean usePadding);
    synchronized void nAllocationRead2D(long id, int xoff, int yoff, int mip, int face,
                                        int w, int h, Object d, int sizeBytes, Element.DataType dt,
                                        int mSize, boolean usePadding) {
        validate();
        rsnAllocationRead2D(mContext, id, xoff, yoff, mip, face, w, h, d, sizeBytes, dt.mID, mSize, usePadding);
    }

    /*
    native void rsnAllocationRead3D(long con, long id, int xoff, int yoff, int zoff, int mip,
                                    int w, int h, int depth, Object d, int sizeBytes, int dt,
                                    int mSize, boolean usePadding);
    synchronized void nAllocationRead3D(long id, int xoff, int yoff, int zoff, int mip,
                                        int w, int h, int depth, Object d, int sizeBytes, Element.DataType dt,
                                        int mSize, boolean usePadding) {
        validate();
        rsnAllocationRead3D(mContext, id, xoff, yoff, zoff, mip, w, h, depth, d, sizeBytes, dt.mID, mSize, usePadding);
    }
    */

    native long  rsnAllocationGetType(long con, long id);
    synchronized long nAllocationGetType(long id) {
        validate();
        return rsnAllocationGetType(mContext, id);
    }

    native void rsnAllocationResize1D(long con, long id, int dimX);
    synchronized void nAllocationResize1D(long id, int dimX) {
        validate();
        rsnAllocationResize1D(mContext, id, dimX);
    }
    native void rsnAllocationResize2D(long con, long id, int dimX, int dimY);
    synchronized void nAllocationResize2D(long id, int dimX, int dimY) {
        validate();
        rsnAllocationResize2D(mContext, id, dimX, dimY);
    }

    native void rsnScriptBindAllocation(long con, long script, long alloc, int slot, boolean mUseInc);
    synchronized void nScriptBindAllocation(long script, long alloc, int slot, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptBindAllocation(curCon, script, alloc, slot, mUseInc);
    }
    native void rsnScriptSetTimeZone(long con, long script, byte[] timeZone, boolean mUseInc);
    synchronized void nScriptSetTimeZone(long script, byte[] timeZone, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetTimeZone(curCon, script, timeZone, mUseInc);
    }
    native void rsnScriptInvoke(long con, long id, int slot, boolean mUseInc);
    synchronized void nScriptInvoke(long id, int slot, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptInvoke(curCon, id, slot, mUseInc);
    }
    native void rsnScriptForEach(long con, long incCon, long id, int slot, long ain, long aout, byte[] params, boolean mUseInc);
    native void rsnScriptForEach(long con, long incCon, long id, int slot, long ain, long aout, boolean mUseInc);
    native void rsnScriptForEachClipped(long con, long incCon, long id, int slot, long ain, long aout, byte[] params,
                                        int xstart, int xend, int ystart, int yend, int zstart, int zend, boolean mUseInc);
    native void rsnScriptForEachClipped(long con, long incCon, long id, int slot, long ain, long aout,
                                        int xstart, int xend, int ystart, int yend, int zstart, int zend, boolean mUseInc);
    synchronized void nScriptForEach(long id, int slot, long ain, long aout, byte[] params, boolean mUseInc) {
        validate();
        if (params == null) {
            rsnScriptForEach(mContext, mIncCon, id, slot, ain, aout, mUseInc);
        } else {
            rsnScriptForEach(mContext, mIncCon, id, slot, ain, aout, params, mUseInc);
        }
    }

    synchronized void nScriptForEachClipped(long id, int slot, long ain, long aout, byte[] params,
                                            int xstart, int xend, int ystart, int yend, int zstart, int zend, boolean mUseInc) {
        validate();
        if (params == null) {
            rsnScriptForEachClipped(mContext, mIncCon, id, slot, ain, aout, xstart, xend, ystart, yend, zstart, zend, mUseInc);
        } else {
            rsnScriptForEachClipped(mContext, mIncCon, id, slot, ain, aout, params, xstart, xend, ystart, yend, zstart, zend, mUseInc);
        }
    }

    native void rsnScriptInvokeV(long con, long id, int slot, byte[] params, boolean mUseInc);
    synchronized void nScriptInvokeV(long id, int slot, byte[] params, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptInvokeV(curCon, id, slot, params, mUseInc);
    }
    native void rsnScriptSetVarI(long con, long id, int slot, int val, boolean mUseInc);
    synchronized void nScriptSetVarI(long id, int slot, int val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarI(curCon, id, slot, val, mUseInc);
    }
    native void rsnScriptSetVarJ(long con, long id, int slot, long val, boolean mUseInc);
    synchronized void nScriptSetVarJ(long id, int slot, long val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarJ(curCon, id, slot, val, mUseInc);
    }
    native void rsnScriptSetVarF(long con, long id, int slot, float val, boolean mUseInc);
    synchronized void nScriptSetVarF(long id, int slot, float val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarF(curCon, id, slot, val, mUseInc);
    }
    native void rsnScriptSetVarD(long con, long id, int slot, double val, boolean mUseInc);
    synchronized void nScriptSetVarD(long id, int slot, double val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarD(curCon, id, slot, val, mUseInc);
    }
    native void rsnScriptSetVarV(long con, long id, int slot, byte[] val, boolean mUseInc);
    synchronized void nScriptSetVarV(long id, int slot, byte[] val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarV(curCon, id, slot, val, mUseInc);
    }
    native void rsnScriptSetVarVE(long con, long id, int slot, byte[] val,
                                  long e, int[] dims, boolean mUseInc);
    synchronized void nScriptSetVarVE(long id, int slot, byte[] val,
                                      long e, int[] dims, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarVE(curCon, id, slot, val, e, dims, mUseInc);
    }
    native void rsnScriptSetVarObj(long con, long id, int slot, long val, boolean mUseInc);
    synchronized void nScriptSetVarObj(long id, int slot, long val, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        rsnScriptSetVarObj(curCon, id, slot, val, mUseInc);
    }

    native long  rsnScriptCCreate(long con, String resName, String cacheDir,
                                 byte[] script, int length);
    synchronized long nScriptCCreate(String resName, String cacheDir, byte[] script, int length) {
        validate();
        return rsnScriptCCreate(mContext, resName, cacheDir, script, length);
    }

    native long  rsnScriptIntrinsicCreate(long con, int id, long eid, boolean mUseInc);
    synchronized long nScriptIntrinsicCreate(int id, long eid, boolean mUseInc) {
        validate();
        if (mUseInc) {
            if (!mIncLoaded) {
                try {
                    System.loadLibrary("RSSupport");
                } catch (UnsatisfiedLinkError e) {
                    Log.e(LOG_TAG, "Error loading RS Compat library for Incremental Intrinsic Support: " + e);
                    throw new RSRuntimeException("Error loading RS Compat library for Incremental Intrinsic Support: " + e);
                }
                if (!nIncLoadSO(sSdkVersion)) {
                    throw new RSRuntimeException("Error loading libRSSupport library for Incremental Intrinsic Support");
                }
                mIncLoaded = true;
            }
            if (mIncDev == 0) {
                mIncDev = nIncDeviceCreate();
            }
            if (mIncCon == 0) {
                //Create a dummy compat context (synchronous).
                mIncCon = nIncContextCreate(mIncDev, 0, 0, 0);
            }
            return rsnScriptIntrinsicCreate(mIncCon, id, eid, mUseInc);
        } else {
            return rsnScriptIntrinsicCreate(mContext, id, eid, mUseInc);
        }
    }

    native long  rsnScriptKernelIDCreate(long con, long sid, int slot, int sig, boolean mUseInc);
    synchronized long nScriptKernelIDCreate(long sid, int slot, int sig, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        return rsnScriptKernelIDCreate(curCon, sid, slot, sig, mUseInc);
    }

    native long  rsnScriptInvokeIDCreate(long con, long sid, int slot);
    synchronized long nScriptInvokeIDCreate(long sid, int slot) {
        validate();
        return rsnScriptInvokeIDCreate(mContext, sid, slot);
    }

    native long  rsnScriptFieldIDCreate(long con, long sid, int slot, boolean mUseInc);
    synchronized long nScriptFieldIDCreate(long sid, int slot, boolean mUseInc) {
        validate();
        long curCon = mContext;
        if (mUseInc) {
            curCon = mIncCon;
        }
        return rsnScriptFieldIDCreate(curCon, sid, slot, mUseInc);
    }

    native long  rsnScriptGroupCreate(long con, long[] kernels, long[] src, long[] dstk, long[] dstf, long[] types);
    synchronized long nScriptGroupCreate(long[] kernels, long[] src, long[] dstk, long[] dstf, long[] types) {
        validate();
        return rsnScriptGroupCreate(mContext, kernels, src, dstk, dstf, types);
    }

    native void rsnScriptGroupSetInput(long con, long group, long kernel, long alloc);
    synchronized void nScriptGroupSetInput(long group, long kernel, long alloc) {
        validate();
        rsnScriptGroupSetInput(mContext, group, kernel, alloc);
    }

    native void rsnScriptGroupSetOutput(long con, long group, long kernel, long alloc);
    synchronized void nScriptGroupSetOutput(long group, long kernel, long alloc) {
        validate();
        rsnScriptGroupSetOutput(mContext, group, kernel, alloc);
    }

    native void rsnScriptGroupExecute(long con, long group);
    synchronized void nScriptGroupExecute(long group) {
        validate();
        rsnScriptGroupExecute(mContext, group);
    }

    native long  rsnSamplerCreate(long con, int magFilter, int minFilter,
                                 int wrapS, int wrapT, int wrapR, float aniso);
    synchronized long nSamplerCreate(int magFilter, int minFilter,
                                 int wrapS, int wrapT, int wrapR, float aniso) {
        validate();
        return rsnSamplerCreate(mContext, magFilter, minFilter, wrapS, wrapT, wrapR, aniso);
    }

// entry points for ScriptGroup2
    native long rsnClosureCreate(long con, long kernelID, long returnValue,
        long[] fieldIDs, long[] values, int[] sizes, long[] depClosures,
        long[] depFieldIDs);
    synchronized long nClosureCreate(long kernelID, long returnValue,
        long[] fieldIDs, long[] values, int[] sizes, long[] depClosures,
        long[] depFieldIDs) {
      validate();
      long c = rsnClosureCreate(mContext, kernelID, returnValue, fieldIDs, values,
          sizes, depClosures, depFieldIDs);
      if (c == 0) {
          throw new RSRuntimeException("Failed creating closure.");
      }
      return c;
    }

    native long rsnInvokeClosureCreate(long con, long invokeID, byte[] params,
        long[] fieldIDs, long[] values, int[] sizes);
    synchronized long nInvokeClosureCreate(long invokeID, byte[] params,
        long[] fieldIDs, long[] values, int[] sizes) {
      validate();
      long c = rsnInvokeClosureCreate(mContext, invokeID, params, fieldIDs,
          values, sizes);
      if (c == 0) {
          throw new RSRuntimeException("Failed creating closure.");
      }
      return c;
    }

    native void rsnClosureSetArg(long con, long closureID, int index,
      long value, int size);
    synchronized void nClosureSetArg(long closureID, int index, long value,
        int size) {
      validate();
      rsnClosureSetArg(mContext, closureID, index, value, size);
    }

    native void rsnClosureSetGlobal(long con, long closureID, long fieldID,
        long value, int size);
    // Does this have to be synchronized?
    synchronized void nClosureSetGlobal(long closureID, long fieldID,
        long value, int size) {
      validate(); // TODO: is this necessary?
      rsnClosureSetGlobal(mContext, closureID, fieldID, value, size);
    }

    native long rsnScriptGroup2Create(long con, String name, String cachePath,
                                      long[] closures);
    synchronized long nScriptGroup2Create(String name, String cachePath,
                                          long[] closures) {
      validate();
      return rsnScriptGroup2Create(mContext, name, cachePath, closures);
    }

    native void rsnScriptGroup2Execute(long con, long groupID);
    synchronized void nScriptGroup2Execute(long groupID) {
      validate();
      rsnScriptGroup2Execute(mContext, groupID);
    }


// Additional Entry points For inc libRSSupport

    native boolean nIncLoadSO(int deviceApi);
    native long nIncDeviceCreate();
    native void nIncDeviceDestroy(long dev);
    // Methods below are wrapped to protect the non-threadsafe
    // lockless fifo.
    native long  rsnIncContextCreate(long dev, int ver, int sdkVer, int contextType);
    synchronized long nIncContextCreate(long dev, int ver, int sdkVer, int contextType) {
        return rsnIncContextCreate(dev, ver, sdkVer, contextType);
    }
    native void rsnIncContextDestroy(long con);
    synchronized void nIncContextDestroy() {
        validate();

        // take teardown lock
        // teardown lock can only be taken when no objects are being destroyed
        ReentrantReadWriteLock.WriteLock wlock = mRWLock.writeLock();
        wlock.lock();

        long curCon = mIncCon;
        // context is considered dead as of this point
        mIncCon = 0;

        wlock.unlock();
        rsnIncContextDestroy(curCon);
    }

    native void rsnIncContextFinish(long con);
    synchronized void nIncContextFinish() {
        validate();
        rsnIncContextFinish(mIncCon);
    }

    native void rsnIncObjDestroy(long con, long id);
    void nIncObjDestroy(long id) {
        // There is a race condition here.  The calling code may be run
        // by the gc while teardown is occuring.  This protects againts
        // deleting dead objects.
        if (mIncCon != 0) {
            rsnIncObjDestroy(mIncCon, id);
        }
    }
    native long  rsnIncElementCreate(long con, long type, int kind, boolean norm, int vecSize);
    synchronized long nIncElementCreate(long type, int kind, boolean norm, int vecSize) {
        validate();
        return rsnIncElementCreate(mIncCon, type, kind, norm, vecSize);
    }
    native long rsnIncTypeCreate(long con, long eid, int x, int y, int z, boolean mips, boolean faces, int yuv);
    synchronized long nIncTypeCreate(long eid, int x, int y, int z, boolean mips, boolean faces, int yuv) {
        validate();
        return rsnIncTypeCreate(mIncCon, eid, x, y, z, mips, faces, yuv);
    }
    native long  rsnIncAllocationCreateTyped(long con, long incCon, long alloc, long type);
    synchronized long nIncAllocationCreateTyped(long alloc, long type) {
        validate();
        return rsnIncAllocationCreateTyped(mContext, mIncCon, alloc, type);
    }

    long     mDev;
    long     mContext;
    //Dummy device & context for Inc Support Lib
    long     mIncDev;
    long     mIncCon;
    //indicator of whether inc support lib has been loaded or not.
    boolean  mIncLoaded;
    ReentrantReadWriteLock mRWLock;
    @SuppressWarnings({"FieldCanBeLocal"})
    MessageThread mMessageThread;

    Element mElement_U8;
    Element mElement_I8;
    Element mElement_U16;
    Element mElement_I16;
    Element mElement_U32;
    Element mElement_I32;
    Element mElement_U64;
    Element mElement_I64;
    Element mElement_F32;
    Element mElement_F64;
    Element mElement_BOOLEAN;

    Element mElement_ELEMENT;
    Element mElement_TYPE;
    Element mElement_ALLOCATION;
    Element mElement_SAMPLER;
    Element mElement_SCRIPT;

    Element mElement_A_8;
    Element mElement_RGB_565;
    Element mElement_RGB_888;
    Element mElement_RGBA_5551;
    Element mElement_RGBA_4444;
    Element mElement_RGBA_8888;

    Element mElement_FLOAT_2;
    Element mElement_FLOAT_3;
    Element mElement_FLOAT_4;

    Element mElement_DOUBLE_2;
    Element mElement_DOUBLE_3;
    Element mElement_DOUBLE_4;

    Element mElement_UCHAR_2;
    Element mElement_UCHAR_3;
    Element mElement_UCHAR_4;

    Element mElement_CHAR_2;
    Element mElement_CHAR_3;
    Element mElement_CHAR_4;

    Element mElement_USHORT_2;
    Element mElement_USHORT_3;
    Element mElement_USHORT_4;

    Element mElement_SHORT_2;
    Element mElement_SHORT_3;
    Element mElement_SHORT_4;

    Element mElement_UINT_2;
    Element mElement_UINT_3;
    Element mElement_UINT_4;

    Element mElement_INT_2;
    Element mElement_INT_3;
    Element mElement_INT_4;

    Element mElement_ULONG_2;
    Element mElement_ULONG_3;
    Element mElement_ULONG_4;

    Element mElement_LONG_2;
    Element mElement_LONG_3;
    Element mElement_LONG_4;

    Element mElement_MATRIX_4X4;
    Element mElement_MATRIX_3X3;
    Element mElement_MATRIX_2X2;

    Sampler mSampler_CLAMP_NEAREST;
    Sampler mSampler_CLAMP_LINEAR;
    Sampler mSampler_CLAMP_LINEAR_MIP_LINEAR;
    Sampler mSampler_WRAP_NEAREST;
    Sampler mSampler_WRAP_LINEAR;
    Sampler mSampler_WRAP_LINEAR_MIP_LINEAR;
    Sampler mSampler_MIRRORED_REPEAT_NEAREST;
    Sampler mSampler_MIRRORED_REPEAT_LINEAR;
    Sampler mSampler_MIRRORED_REPEAT_LINEAR_MIP_LINEAR;


    ///////////////////////////////////////////////////////////////////////////////////
    //

    /**
     * The base class from which an application should derive in order
     * to receive RS messages from scripts. When a script calls {@code
     * rsSendToClient}, the data fields will be filled, and the run
     * method will be called on a separate thread.  This will occur
     * some time after {@code rsSendToClient} completes in the script,
     * as {@code rsSendToClient} is asynchronous. Message handlers are
     * not guaranteed to have completed when {@link
     * android.support.v8.renderscript.RenderScript#finish} returns.
     *
     */
    public static class RSMessageHandler implements Runnable {
        protected int[] mData;
        protected int mID;
        protected int mLength;
        public void run() {
        }
    }
    /**
     * If an application is expecting messages, it should set this
     * field to an instance of {@link RSMessageHandler}.  This
     * instance will receive all the user messages sent from {@code
     * sendToClient} by scripts from this context.
     *
     */
    RSMessageHandler mMessageCallback = null;

    public void setMessageHandler(RSMessageHandler msg) {
        mMessageCallback = msg;
    }
    public RSMessageHandler getMessageHandler() {
        return mMessageCallback;
    }

    /**
     * Place a message into the message queue to be sent back to the message
     * handler once all previous commands have been executed.
     *
     * @param id
     * @param data
     */
    public void sendMessage(int id, int[] data) {
        nContextSendMessage(id, data);
    }

    /**
     * The runtime error handler base class.  An application should derive from this class
     * if it wishes to install an error handler.  When errors occur at runtime,
     * the fields in this class will be filled, and the run method will be called.
     *
     */
    public static class RSErrorHandler implements Runnable {
        protected String mErrorMessage;
        protected int mErrorNum;
        public void run() {
        }
    }

    /**
     * Application Error handler.  All runtime errors will be dispatched to the
     * instance of RSAsyncError set here.  If this field is null a
     * {@link RSRuntimeException} will instead be thrown with details about the error.
     * This will cause program termaination.
     *
     */
    RSErrorHandler mErrorCallback = null;

    public void setErrorHandler(RSErrorHandler msg) {
        mErrorCallback = msg;
    }
    public RSErrorHandler getErrorHandler() {
        return mErrorCallback;
    }

    /**
     * RenderScript worker thread priority enumeration.  The default value is
     * NORMAL.  Applications wishing to do background processing should set
     * their priority to LOW to avoid starving forground processes.
     */
    public enum Priority {
        LOW (Process.THREAD_PRIORITY_BACKGROUND + (5 * Process.THREAD_PRIORITY_LESS_FAVORABLE)),
        NORMAL (Process.THREAD_PRIORITY_DISPLAY);

        int mID;
        Priority(int id) {
            mID = id;
        }
    }

    void validate() {
        if (mContext == 0) {
            throw new RSInvalidStateException("Calling RS with no Context active.");
        }
    }

    /**
     * check if IO support lib is available.
     */
    boolean usingIO() {
        return useIOlib;
    }
    /**
     * Change the priority of the worker threads for this context.
     *
     * @param p New priority to be set.
     */
    public void setPriority(Priority p) {
        validate();
        nContextSetPriority(p.mID);
    }

    static class MessageThread extends Thread {
        RenderScript mRS;
        boolean mRun = true;
        int[] mAuxData = new int[2];

        static final int RS_MESSAGE_TO_CLIENT_NONE = 0;
        static final int RS_MESSAGE_TO_CLIENT_EXCEPTION = 1;
        static final int RS_MESSAGE_TO_CLIENT_RESIZE = 2;
        static final int RS_MESSAGE_TO_CLIENT_ERROR = 3;

        static final int RS_MESSAGE_TO_CLIENT_USER = 4;
        static final int RS_ERROR_FATAL_UNKNOWN = 0x1000;

        MessageThread(RenderScript rs) {
            super("RSMessageThread");
            mRS = rs;

        }

        public void run() {
            // This function is a temporary solution.  The final solution will
            // used typed allocations where the message id is the type indicator.
            int[] rbuf = new int[16];
            mRS.nContextInitToClient(mRS.mContext);
            while(mRun) {
                rbuf[0] = 0;
                int msg = mRS.nContextPeekMessage(mRS.mContext, mAuxData);
                int size = mAuxData[1];
                int subID = mAuxData[0];

                if (msg == RS_MESSAGE_TO_CLIENT_USER) {
                    if ((size>>2) >= rbuf.length) {
                        rbuf = new int[(size + 3) >> 2];
                    }
                    if (mRS.nContextGetUserMessage(mRS.mContext, rbuf) !=
                        RS_MESSAGE_TO_CLIENT_USER) {
                        throw new RSDriverException("Error processing message from RenderScript.");
                    }

                    if(mRS.mMessageCallback != null) {
                        mRS.mMessageCallback.mData = rbuf;
                        mRS.mMessageCallback.mID = subID;
                        mRS.mMessageCallback.mLength = size;
                        mRS.mMessageCallback.run();
                    } else {
                        throw new RSInvalidStateException("Received a message from the script with no message handler installed.");
                    }
                    continue;
                }

                if (msg == RS_MESSAGE_TO_CLIENT_ERROR) {
                    String e = mRS.nContextGetErrorMessage(mRS.mContext);

                    if (subID >= RS_ERROR_FATAL_UNKNOWN) {
                        throw new RSRuntimeException("Fatal error " + subID + ", details: " + e);
                    }

                    if(mRS.mErrorCallback != null) {
                        mRS.mErrorCallback.mErrorMessage = e;
                        mRS.mErrorCallback.mErrorNum = subID;
                        mRS.mErrorCallback.run();
                    } else {
                        android.util.Log.e(LOG_TAG, "non fatal RS error, " + e);
                        // Do not throw here. In these cases, we do not have
                        // a fatal error.
                    }
                    continue;
                }

                // 2: teardown.
                // But we want to avoid starving other threads during
                // teardown by yielding until the next line in the destructor
                // can execute to set mRun = false
                try {
                    sleep(1, 0);
                } catch(InterruptedException e) {
                }
            }
            //Log.d(LOG_TAG, "MessageThread exiting.");
        }
    }

    RenderScript(Context ctx) {
        mContextType = ContextType.NORMAL;
        if (ctx != null) {
            mApplicationContext = ctx.getApplicationContext();
            mNativeLibDir = mApplicationContext.getApplicationInfo().nativeLibraryDir;
        }
        mIncDev = 0;
        mIncCon = 0;
        mIncLoaded = false;
        mRWLock = new ReentrantReadWriteLock();
    }

    /**
     * Gets the application context associated with the RenderScript context.
     *
     * @return The application context.
     */
    public final Context getApplicationContext() {
        return mApplicationContext;
    }

    /**
     * Create a RenderScript context.
     *
     * @param ctx The context.
     * @return RenderScript
     */
    private static RenderScript internalCreate(Context ctx, int sdkVersion, ContextType ct, int flags) {
        RenderScript rs = new RenderScript(ctx);

        if (sSdkVersion == -1) {
            sSdkVersion = sdkVersion;
        } else if (sSdkVersion != sdkVersion) {
            throw new RSRuntimeException("Can't have two contexts with different SDK versions in support lib");
        }
        useNative = setupNative(sSdkVersion, ctx);
        synchronized(lock) {
            if (sInitialized == false) {
                try {
                    Class<?> vm_runtime = Class.forName("dalvik.system.VMRuntime");
                    Method get_runtime = vm_runtime.getDeclaredMethod("getRuntime");
                    sRuntime = get_runtime.invoke(null);
                    registerNativeAllocation = vm_runtime.getDeclaredMethod("registerNativeAllocation", Integer.TYPE);
                    registerNativeFree = vm_runtime.getDeclaredMethod("registerNativeFree", Integer.TYPE);
                    sUseGCHooks = true;
                } catch (Exception e) {
                    Log.e(LOG_TAG, "No GC methods");
                    sUseGCHooks = false;
                }
                try {
                    System.loadLibrary("rsjni");
                    sInitialized = true;
                    sPointerSize = rsnSystemGetPointerSize();
                } catch (UnsatisfiedLinkError e) {
                    Log.e(LOG_TAG, "Error loading RS jni library: " + e);
                    throw new RSRuntimeException("Error loading RS jni library: " + e);
                }
            }
        }

        if (useNative) {
            android.util.Log.v(LOG_TAG, "RS native mode");
        } else {
            android.util.Log.v(LOG_TAG, "RS compat mode");
        }

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
            useIOlib = true;
        }
        if (!rs.nLoadSO(useNative, sdkVersion)) {
            if (useNative) {
                android.util.Log.v(LOG_TAG, "Unable to load libRS.so, falling back to compat mode");
                useNative = false;
            }
            try {
                System.loadLibrary("RSSupport");
            } catch (UnsatisfiedLinkError e) {
                Log.e(LOG_TAG, "Error loading RS Compat library: " + e);
                throw new RSRuntimeException("Error loading RS Compat library: " + e);
            }
            if (!rs.nLoadSO(false, sdkVersion)) {
                throw new RSRuntimeException("Error loading libRSSupport library");
            }
        }

        if (useIOlib) {
            try {
                System.loadLibrary("RSSupportIO");
            } catch (UnsatisfiedLinkError e) {
                useIOlib = false;
            }
            if (!useIOlib || !rs.nLoadIOSO()) {
                android.util.Log.v(LOG_TAG, "Unable to load libRSSupportIO.so, USAGE_IO not supported");
                useIOlib = false;
            }
        }

        rs.mDev = rs.nDeviceCreate();
        rs.mContext = rs.nContextCreate(rs.mDev, 0, sdkVersion, ct.mID, rs.mNativeLibDir);
        rs.mContextType = ct;
        rs.mContextFlags = flags;
        rs.mContextSdkVersion = sdkVersion;
        if (rs.mContext == 0) {
            throw new RSDriverException("Failed to create RS context.");
        }
        rs.mMessageThread = new MessageThread(rs);
        rs.mMessageThread.start();
        return rs;
    }

    /**
     * Create a RenderScript context.
     *
     * See documentation for @create for details
     *
     * @param ctx The context.
     * @return RenderScript
     */
    public static RenderScript create(Context ctx) {
        return create(ctx, ContextType.NORMAL);
    }

    /**
     * calls create(ctx, ct, CREATE_FLAG_NONE)
     *
     * See documentation for @create for details
     *
     * @param ctx The context.
     * @param ct The type of context to be created.
     * @return RenderScript
     */
    public static RenderScript create(Context ctx, ContextType ct) {
        return create(ctx, ct, CREATE_FLAG_NONE);
    }

    /**
     * Gets or creates a RenderScript context of the specified type.
     *
     * The returned context will be cached for future reuse within
     * the process. When an application is finished using
     * RenderScript it should call releaseAllContexts()
     *
     * A process context is a context designed for easy creation and
     * lifecycle management.  Multiple calls to this function will
     * return the same object provided they are called with the same
     * options.  This allows it to be used any time a RenderScript
     * context is needed.
     *
     *
     * @param ctx The context.
     * @param ct The type of context to be created.
     * @param flags The OR of the CREATE_FLAG_* options desired
     * @return RenderScript
     */
    public static RenderScript create(Context ctx, ContextType ct, int flags) {
        int v = ctx.getApplicationInfo().targetSdkVersion;
        return create(ctx, v, ct, flags);
    }

    /**
     * calls create(ctx, sdkVersion, ContextType.NORMAL, CREATE_FLAG_NONE)
     *
     * Used by the RenderScriptThunker to maintain backward compatibility.
     *
     * @hide
     * @param ctx The context.
     * @param sdkVersion The target SDK Version.
     * @return RenderScript
     */
    public static RenderScript create(Context ctx, int sdkVersion) {
        return create(ctx, sdkVersion, ContextType.NORMAL, CREATE_FLAG_NONE);
    }


    /**
     * calls create(ctx, sdkVersion, ct, CREATE_FLAG_NONE)
     * Create a RenderScript context.
     *
     * @hide
     * @param ctx The context.
     * @return RenderScript
     */
    public static RenderScript create(Context ctx, int sdkVersion, ContextType ct) {
        return create(ctx, sdkVersion, ct, CREATE_FLAG_NONE);
    }

     /**
     * Gets or creates a RenderScript context of the specified type.
     *
     * @param ctx The context.
     * @param ct The type of context to be created.
     * @param sdkVersion The target SDK Version.
     * @param flags The OR of the CREATE_FLAG_* options desired
     * @return RenderScript
     */
    public static RenderScript create(Context ctx, int sdkVersion, ContextType ct, int flags) {
        synchronized (mProcessContextList) {
            for (RenderScript prs : mProcessContextList) {
                if ((prs.mContextType == ct) &&
                    (prs.mContextFlags == flags) &&
                    (prs.mContextSdkVersion == sdkVersion)) {

                    return prs;
                }
            }

            RenderScript prs = internalCreate(ctx, sdkVersion, ct, flags);
            prs.mIsProcessContext = true;
            mProcessContextList.add(prs);
            return prs;
        }
    }

    /**
     *
     * Releases all the process contexts.  This is the same as
     * calling .destroy() on each unique context retreived with
     * create(...). If no contexts have been created this
     * function does nothing.
     *
     * Typically you call this when your application is losing focus
     * and will not be using a context for some time.
     *
     * This has no effect on a context created with
     * createMultiContext()
     */
    public static void releaseAllContexts() {
        ArrayList<RenderScript> oldList;
        synchronized (mProcessContextList) {
            oldList = mProcessContextList;
            mProcessContextList = new ArrayList<RenderScript>();
        }

        for (RenderScript prs : oldList) {
            prs.mIsProcessContext = false;
            prs.destroy();
        }
        oldList.clear();
    }


    /**
     * Create a RenderScript context.
     *
     * This is an advanced function intended for applications which
     * need to create more than one RenderScript context to be used
     * at the same time.
     *
     * If you need a single context please use create()
     *
     * @param ctx The context.
     * @return RenderScript
     */
    public static RenderScript createMultiContext(Context ctx, ContextType ct, int flags, int API_number) {
        return internalCreate(ctx, API_number, ct, flags);
    }

    /**
     * Print the currently available debugging information about the state of
     * the RS context to the log.
     *
     */
    public void contextDump() {
        validate();
        nContextDump(0);
    }

    /**
     * Wait for any pending asynchronous opeations (such as copies to a RS
     * allocation or RS script executions) to complete.
     *
     */
    public void finish() {
        nContextFinish();
    }

    /**
     * Destroys this RenderScript context.  Once this function is called,
     * using this context or any objects belonging to this context is
     * illegal.
     *
     * This function is a NOP if the context was created
     * with create().  Please use releaseAllContexts() to clean up
     * contexts created with the create function.
     */
    public void destroy() {
        if (mIsProcessContext) {
            // users cannot destroy a process context
            return;
        }
        validate();
        nContextFinish();
        if (mIncCon != 0) {
            nIncContextFinish();
            nIncContextDestroy();
            mIncCon = 0;
        }
        nContextDeinitToClient(mContext);
        mMessageThread.mRun = false;
        try {
            mMessageThread.join();
        } catch(InterruptedException e) {
        }

        nContextDestroy();
        nDeviceDestroy(mDev);
        if (mIncDev != 0) {
            nIncDeviceDestroy(mIncDev);
            mIncDev = 0;
        }
        mDev = 0;
    }

    boolean isAlive() {
        return mContext != 0;
    }

    long safeID(BaseObj o) {
        if(o != null) {
            return o.getID(this);
        }
        return 0;
    }
}