Java Code Examples for jdk.internal.misc.Unsafe#freeMemory()

The following examples show how to use jdk.internal.misc.Unsafe#freeMemory() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.

Example 1

Source File: GetPutLong.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("l");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals(-1L, unsafe.getLong(t, offset));
    unsafe.putLong(t, offset, 0L);
    assertEquals(0L, unsafe.getLong(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putLong(address, 1L);
    assertEquals(1L, unsafe.getLong(address));
    unsafe.freeMemory(address);

    long arrayLong[] = { -1, 0, 1, 2 };
    int scale = unsafe.arrayIndexScale(arrayLong.getClass());
    offset = unsafe.arrayBaseOffset(arrayLong.getClass());
    for (int i = 0; i < arrayLong.length; i++) {
        assertEquals(unsafe.getLong(arrayLong, offset), arrayLong[i]);
        offset += scale;
    }
}

Example 2

Source File: GetPutChar.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("c");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals('\u0000', unsafe.getChar(t, offset));
    unsafe.putChar(t, offset, '\u0001');
    assertEquals('\u0001', unsafe.getChar(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putChar(address, '\u0002');
    assertEquals('\u0002', unsafe.getChar(address));
    unsafe.freeMemory(address);

    char arrayChar[] = { '\uabcd', '\u00ff', '\uff00', };
    int scale = unsafe.arrayIndexScale(arrayChar.getClass());
    offset = unsafe.arrayBaseOffset(arrayChar.getClass());
    for (int i = 0; i < arrayChar.length; i++) {
        assertEquals(unsafe.getChar(arrayChar, offset), arrayChar[i]);
        offset += scale;
    }
}

Example 3

Source File: GetPutInt.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("i");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals(-1, unsafe.getInt(t, offset));
    unsafe.putInt(t, offset, 0);
    assertEquals(0, unsafe.getInt(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putInt(address, 1);
    assertEquals(1, unsafe.getInt(address));
    unsafe.freeMemory(address);

    int arrayInt[] = { -1, 0, 1, 2 };
    int scale = unsafe.arrayIndexScale(arrayInt.getClass());
    offset = unsafe.arrayBaseOffset(arrayInt.getClass());
    for (int i = 0; i < arrayInt.length; i++) {
        assertEquals(unsafe.getInt(arrayInt, offset), arrayInt[i]);
        offset += scale;
    }
}

Example 4

Source File: CopyMemory.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    long src = unsafe.allocateMemory(LENGTH);
    long dst = unsafe.allocateMemory(LENGTH);
    assertNotEquals(src, 0L);
    assertNotEquals(dst, 0L);

    // call copyMemory() with different lengths and verify the contents of
    // the destination array
    for (int i = 0; i < LENGTH; i++) {
        unsafe.putByte(src + i, (byte)i);
        unsafe.copyMemory(src, dst, i);
        for (int j = 0; j < i; j++) {
            assertEquals(unsafe.getByte(src + j), unsafe.getByte(src + j));
        }
    }
    unsafe.freeMemory(src);
    unsafe.freeMemory(dst);
}

Example 5

Source File: GetPutDouble.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("d");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals(-1.0, unsafe.getDouble(t, offset));
    unsafe.putDouble(t, offset, 0.0);
    assertEquals(0.0, unsafe.getDouble(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putDouble(address, 1.0);
    assertEquals(1.0, unsafe.getDouble(address));
    unsafe.freeMemory(address);

    double arrayDouble[] = { -1.0, 0.0, 1.0, 2.0 };
    int scale = unsafe.arrayIndexScale(arrayDouble.getClass());
    offset = unsafe.arrayBaseOffset(arrayDouble.getClass());
    for (int i = 0; i < arrayDouble.length; i++) {
        assertEquals(unsafe.getDouble(arrayDouble, offset), arrayDouble[i]);
        offset += scale;
    }
}

Example 6

Source File: GetPutAddress.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    int addressSize = unsafe.addressSize();
    // Ensure the size returned from Unsafe.addressSize is correct
    assertEquals(unsafe.addressSize(), Platform.is32bit() ? 4 : 8);

    // Write the address, read it back and make sure it's the same value
    long address = unsafe.allocateMemory(addressSize);
    unsafe.putAddress(address, address);
    long readAddress = unsafe.getAddress(address);
    if (addressSize == 4) {
      readAddress &= 0x00000000FFFFFFFFL;
    }
    assertEquals(address, readAddress);
    unsafe.freeMemory(address);
}

Example 7

Source File: GetPutFloat.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("f");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals(-1.0f, unsafe.getFloat(t, offset));
    unsafe.putFloat(t, offset, 0.0f);
    assertEquals(0.0f, unsafe.getFloat(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putFloat(address, 1.0f);
    assertEquals(1.0f, unsafe.getFloat(address));
    unsafe.freeMemory(address);

    float arrayFloat[] = { -1.0f, 0.0f, 1.0f, 2.0f };
    int scale = unsafe.arrayIndexScale(arrayFloat.getClass());
    offset = unsafe.arrayBaseOffset(arrayFloat.getClass());
    for (int i = 0; i < arrayFloat.length; i++) {
        assertEquals(unsafe.getFloat(arrayFloat, offset), arrayFloat[i]);
        offset += scale;
    }
}

Example 8

Source File: GetPutShort.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("s");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals((short)-1, unsafe.getShort(t, offset));
    unsafe.putShort(t, offset, (short)0);
    assertEquals((short)0, unsafe.getShort(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putShort(address, (short)1);
    assertEquals((short)1, unsafe.getShort(address));
    unsafe.freeMemory(address);

    short arrayShort[] = { -1, 0, 1, 2 };
    int scale = unsafe.arrayIndexScale(arrayShort.getClass());
    offset = unsafe.arrayBaseOffset(arrayShort.getClass());
    for (int i = 0; i < arrayShort.length; i++) {
        assertEquals(unsafe.getShort(arrayShort, offset), arrayShort[i]);
        offset += scale;
    }
}

Example 9

Source File: GetPutByte.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    Test t = new Test();
    Field field = Test.class.getField("b");

    long offset = unsafe.objectFieldOffset(field);
    assertEquals((byte)0, unsafe.getByte(t, offset));
    unsafe.putByte(t, offset, (byte)1);
    assertEquals((byte)1, unsafe.getByte(t, offset));

    long address = unsafe.allocateMemory(8);
    unsafe.putByte(address, (byte)2);
    assertEquals((byte)2, unsafe.getByte(address));
    unsafe.freeMemory(address);

    byte arrayByte[] = { -1, 0, 1, 2 };
    int scale = unsafe.arrayIndexScale(arrayByte.getClass());
    offset = unsafe.arrayBaseOffset(arrayByte.getClass());
    for (int i = 0; i < arrayByte.length; i++) {
        assertEquals(unsafe.getByte(arrayByte, offset), arrayByte[i]);
        offset += scale;
    }
}

Example 10

Source File: SetMemory.java From openjdk-jdk9 with GNU General Public License v2.0

5 votes

public static void main(String args[]) throws Exception {
    Unsafe unsafe = Unsafe.getUnsafe();
    long address = unsafe.allocateMemory(1);
    assertNotEquals(address, 0L);
    unsafe.setMemory(address, 1, (byte)17);
    assertEquals((byte)17, unsafe.getByte(address));
    unsafe.freeMemory(address);
}