public static void main(String args[]) throws Exception {
Unsafe unsafe = Unsafe.getUnsafe();
// Allocate a byte, write to the location and read back the value
long address = unsafe.allocateMemory(1);
assertNotEquals(address, 0L);
unsafe.putByte(address, Byte.MAX_VALUE);
assertEquals(Byte.MAX_VALUE, unsafe.getByte(address));
unsafe.freeMemory(address);
// Call to allocateMemory() with a negative value should result in an IllegalArgumentException
try {
address = unsafe.allocateMemory(-1);
throw new RuntimeException("Did not get expected IllegalArgumentException");
} catch (IllegalArgumentException e) {
// Expected
assertNotEquals(address, 0L);
}
// allocateMemory() should throw an OutOfMemoryError when the underlying malloc fails,
// we test this by limiting the malloc using -XX:MallocMaxTestWords
try {
address = unsafe.allocateMemory(100 * 1024 * 1024 * 8);
} catch (OutOfMemoryError e) {
// Expected
return;
}
throw new RuntimeException("Did not get expected OutOfMemoryError");
}
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;
}
}
