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");
}
