public void LargestFreeBlockSizeTest()
{
IMemorySlab target = CreateIMemorySlab();
long actual;
//LargestFreeBlockSize should be initially the total size of the slab
actual = target.LargestFreeBlockSize;
Assert.AreEqual <long>(totalSize, actual);
//Allocate a small block, LargestFreeBlockSize should be the difference from the total slab size
IMemoryBlock allocatedBlock;
target.TryAllocate(4321, out allocatedBlock);
actual = target.LargestFreeBlockSize;
Assert.AreEqual <long>(totalSize - 4321, actual);
//Allocate a bigger block, LargestFreeBlockSize should decrease by that block size
IMemoryBlock allocatedBlock2;
target.TryAllocate(19500, out allocatedBlock2);
actual = target.LargestFreeBlockSize;
Assert.AreEqual <long>(totalSize - 4321 - 19500, actual);
//Free the original small allocation
target.Free(allocatedBlock);
//LargestFreeBlockSize should be the greater of it's previous and the freed block
Assert.AreEqual <long>(Math.Max(4321, (totalSize - 4321 - 19500)), actual);
target.Free(allocatedBlock2);
}
public void TryAllocateTest()
{
IMemorySlab target = CreateIMemorySlab();
//allocate 1 byte
long smallLength = 1;
IMemoryBlock allocatedBlock = null;
bool result1 = target.TryAllocate(smallLength, out allocatedBlock);
Assert.AreEqual <long>(smallLength, allocatedBlock.Length);
Assert.AreEqual <long>(0, allocatedBlock.StartLocation);
Assert.AreEqual <bool>(true, result1);
//allocate rest of slab
long restLength = totalSize - 1;
IMemoryBlock allocatedBlock2 = null;
bool result2 = target.TryAllocate(restLength, out allocatedBlock2);
Assert.AreEqual <long>(restLength, allocatedBlock2.Length);
Assert.AreEqual <long>(1, allocatedBlock2.StartLocation);
Assert.AreEqual <bool>(true, result2);
//Now try to allocate another byte and expect it to fail
IMemoryBlock allocatedBlock3 = null;
bool result3 = target.TryAllocate(smallLength, out allocatedBlock3);
Assert.AreEqual <bool>(false, result3);
//Clean up
target.Free(allocatedBlock);
target.Free(allocatedBlock2);
}
public void FreeTest()
{
IMemorySlab target = CreateIMemorySlab();
IMemoryBlock block1, block2, block3, block4, block5, block6;
target.TryAllocate(10, out block1);
target.TryAllocate(10, out block2);
target.TryAllocate(10, out block3);
target.TryAllocate(10, out block4);
target.TryAllocate(10, out block5);
target.TryAllocate(target.LargestFreeBlockSize, out block6);
//entire slab is now used up
//Free block1
target.Free(block1);
//reassign block1 to be 4 bytes;
target.TryAllocate(4, out block1);
//Free space should be 6 bytes now;
Assert.AreEqual <long>(6, target.LargestFreeBlockSize);
//Free Block2
target.Free(block2);
//Free space should now be 16 bytes;
Assert.AreEqual <long>(16, target.LargestFreeBlockSize);
//Free Block5
target.Free(block5);
//Free Block4
target.Free(block4);
//Largest free space should now be 20 bytes;
Assert.AreEqual <long>(20, target.LargestFreeBlockSize);
//Free Block3
target.Free(block3);
//Largest free space should now be 20 + 10 + 16 = 46 bytes
Assert.AreEqual <long>(46, target.LargestFreeBlockSize);
//Free Block6
target.Free(block6);
//Largest free block should be slab size - block1 size
Assert.AreEqual <long>(target.Size - block1.Length, target.LargestFreeBlockSize);
//Free Block1
target.Free(block1);
//Largest free block should now be slab size
Assert.AreEqual <long>(target.Size, target.LargestFreeBlockSize);
}