am fd2ca69a: am 42a6d80d: Merge "Expanded arraycopy function to deal with more types and updated benchmarking."
* commit 'fd2ca69a09c4efe76244f2fcf2612a0ff8b82d08':
Expanded arraycopy function to deal with more types and updated benchmarking.
diff --git a/benchmarks/src/benchmarks/SystemArrayCopyBenchmark.java b/benchmarks/src/benchmarks/SystemArrayCopyBenchmark.java
index c22e819..5095ee1 100644
--- a/benchmarks/src/benchmarks/SystemArrayCopyBenchmark.java
+++ b/benchmarks/src/benchmarks/SystemArrayCopyBenchmark.java
@@ -24,17 +24,77 @@
"2048", "4096", "8192", "16384", "32768", "65536", "131072", "262144"})
int arrayLength;
- // This copies a char array indirectly via String.getChars() as the
- // System.arraycopy() call site optimization currently works within
- // the core libraries only. Add direct System.arraycopy() benchmarks
- // (including ones for other primitive types) later once this
- // limitation goes away.
- public void timeStringCharArrayCopy(int reps) {
+ // Provides benchmarking for different types of arrays using the arraycopy function.
+
+ public void timeSystemCharArrayCopy(int reps) {
final int len = arrayLength;
+ char[] src = new char[len];
char[] dst = new char[len];
- String str = new String(new char[len]);
for (int rep = 0; rep < reps; ++rep) {
- str.getChars(0, len, dst, 0);
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemByteArrayCopy(int reps) {
+ final int len = arrayLength;
+ byte[] src = new byte[len];
+ byte[] dst = new byte[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemShortArrayCopy(int reps) {
+ final int len = arrayLength;
+ short[] src = new short[len];
+ short[] dst = new short[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemIntArrayCopy(int reps) {
+ final int len = arrayLength;
+ int[] src = new int[len];
+ int[] dst = new int[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemLongArrayCopy(int reps) {
+ final int len = arrayLength;
+ long[] src = new long[len];
+ long[] dst = new long[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemFloatArrayCopy(int reps) {
+ final int len = arrayLength;
+ float[] src = new float[len];
+ float[] dst = new float[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemDoubleArrayCopy(int reps) {
+ final int len = arrayLength;
+ double[] src = new double[len];
+ double[] dst = new double[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
+ }
+ }
+
+ public void timeSystemBooleanArrayCopy(int reps) {
+ final int len = arrayLength;
+ boolean[] src = new boolean[len];
+ boolean[] dst = new boolean[len];
+ for (int rep = 0; rep < reps; ++rep) {
+ System.arraycopy(src, 0, dst, 0, len);
}
}
}
diff --git a/luni/src/main/java/java/lang/System.java b/luni/src/main/java/java/lang/System.java
index 185701e..3bd443f 100644
--- a/luni/src/main/java/java/lang/System.java
+++ b/luni/src/main/java/java/lang/System.java
@@ -171,14 +171,68 @@
* @param length
* the number of elements to be copied.
*/
- public static native void arraycopy(Object src, int srcPos, Object dst, int dstPos, int length);
+
+ public static native void arraycopy(Object src, int srcPos,
+ Object dst, int dstPos, int length);
+
+ /**
+ * The type object array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version.
+ */
+
+ private static final int ARRAYCOPY_SHORT_T_ARRAY_THRESHOLD = 32;
+
+ /**
+ * An arraycopy variant that applies when both input arguments are compatible object arrays.
+ *
+ * @hide internal use only
+ */
+ public static <T> void arraycopy(T[] src, int srcPos, T[] dst, int dstPos, int length) {
+ if (src.getClass() != dst.getClass() || dst.getClass() != Object[].class ||
+ dst.getClass().isAssignableFrom(src.getClass())) {
+ // Call the native version if we can't easily deal with it here.
+ arraycopy(src, srcPos, dst, dstPos, length);
+ }
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_T_ARRAY_THRESHOLD) {
+ // Copy object by object for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for longer arrays.
+ arraycopy(src, srcPos, dst, dstPos, length);
+ }
+ }
/**
* The char array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
- private static final int ARRAYCOPY_SHORT_CHAR_ARRAY_THRESHOLD = 64;
+ private static final int ARRAYCOPY_SHORT_CHAR_ARRAY_THRESHOLD = 16;
/**
* The char[] specialized version of arraycopy().
@@ -227,6 +281,377 @@
char[] dst, int dstPos, int length);
/**
+ * The byte array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_BYTE_ARRAY_THRESHOLD = 16;
+
+ /**
+ * The byte[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(byte[] src, int srcPos, byte[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_BYTE_ARRAY_THRESHOLD) {
+ // Copy byte by byte for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for longer arrays.
+ arraycopyByteUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The byte[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyByteUnchecked(byte[] src, int srcPos,
+ byte[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_SHORT_ARRAY_THRESHOLD = 16;
+
+ /**
+ * The short[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(short[] src, int srcPos, short[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_SHORT_ARRAY_THRESHOLD) {
+ // Copy short by short for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for longer arrays.
+ arraycopyShortUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The short[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyShortUnchecked(short[] src, int srcPos,
+ short[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_INT_ARRAY_THRESHOLD = 32;
+
+ /**
+ * The int[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(int[] src, int srcPos, int[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_INT_ARRAY_THRESHOLD) {
+ // Copy int by int for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for longer arrays.
+ arraycopyIntUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The int[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyIntUnchecked(int[] src, int srcPos,
+ int[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_LONG_ARRAY_THRESHOLD = 32;
+
+ /**
+ * The long[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(long[] src, int srcPos, long[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_LONG_ARRAY_THRESHOLD) {
+ // Copy long by long for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for longer arrays.
+ arraycopyLongUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The long[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyLongUnchecked(long[] src, int srcPos,
+ long[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_FLOAT_ARRAY_THRESHOLD = 2;
+
+ /**
+ * The float[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(float[] src, int srcPos, float[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_FLOAT_ARRAY_THRESHOLD) {
+ // Copy float by float for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for floater arrays.
+ arraycopyFloatUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The float[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyFloatUnchecked(float[] src, int srcPos,
+ float[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_DOUBLE_ARRAY_THRESHOLD = 64;
+
+ /**
+ * The double[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(double[] src, int srcPos, double[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_DOUBLE_ARRAY_THRESHOLD) {
+ // Copy double by double for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for floater arrays.
+ arraycopyDoubleUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The double[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyDoubleUnchecked(double[] src, int srcPos,
+ double[] dst, int dstPos, int length);
+
+ /**
+ * The short array length threshold below which to use a Java
+ * (non-native) version of arraycopy() instead of the native
+ * version. See b/7103825.
+ */
+ private static final int ARRAYCOPY_SHORT_BOOLEAN_ARRAY_THRESHOLD = 128;
+
+ /**
+ * The boolean[] specialized version of arraycopy().
+ *
+ * @hide internal use only
+ */
+ public static void arraycopy(boolean[] src, int srcPos, boolean[] dst, int dstPos, int length) {
+ if (src == null) {
+ throw new NullPointerException("src == null");
+ }
+ if (dst == null) {
+ throw new NullPointerException("dst == null");
+ }
+ if (srcPos < 0 || dstPos < 0 || length < 0 ||
+ srcPos > src.length - length || dstPos > dst.length - length) {
+ throw new ArrayIndexOutOfBoundsException(
+ "src.length=" + src.length + " srcPos=" + srcPos +
+ " dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
+ }
+ if (length <= ARRAYCOPY_SHORT_BOOLEAN_ARRAY_THRESHOLD) {
+ // Copy boolean by boolean for shorter arrays.
+ if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
+ // Copy backward (to avoid overwriting elements before
+ // they are copied in case of an overlap on the same
+ // array.)
+ for (int i = length - 1; i >= 0; --i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ } else {
+ // Copy forward.
+ for (int i = 0; i < length; ++i) {
+ dst[dstPos + i] = src[srcPos + i];
+ }
+ }
+ } else {
+ // Call the native version for floater arrays.
+ arraycopyBooleanUnchecked(src, srcPos, dst, dstPos, length);
+ }
+ }
+
+ /**
+ * The boolean[] specialized, unchecked, native version of
+ * arraycopy(). This assumes error checking has been done.
+ */
+ private static native void arraycopyBooleanUnchecked(boolean[] src, int srcPos,
+ boolean[] dst, int dstPos, int length);
+
+ /**
* Returns the current time in milliseconds since January 1, 1970 00:00:00.0 UTC.
*
* <p>This method always returns UTC times, regardless of the system's time zone.