public void clear_all_buffers_from_current_generation_on_low_memory(LowMemorySeverity lowMemorySeverity)
{
var encryptionBuffersPool = new EncryptionBuffersPool();
var generation = encryptionBuffersPool.Generation;
var i = 1;
var toFree = new List <(IntPtr, long)>();
while (i <= new Size(8, SizeUnit.Megabytes).GetValue(SizeUnit.Bytes))
{
var ptr = encryptionBuffersPool.Get(i, out _);
toFree.Add(((IntPtr)ptr, i));
i *= 2;
}
var stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalSize);
encryptionBuffersPool.LowMemory(lowMemorySeverity);
stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalSize);
foreach (var o in toFree)
{
encryptionBuffersPool.Return((byte *)o.Item1, o.Item2, NativeMemory.ThreadAllocations.Value, generation);
}
stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalSize);
var size = 8 * 1024;
var pointer = encryptionBuffersPool.Get(size, out _);
encryptionBuffersPool.Return(pointer, size, NativeMemory.ThreadAllocations.Value, encryptionBuffersPool.Generation);
// will cache the buffer
stats = encryptionBuffersPool.GetStats();
Assert.Equal(size, stats.TotalSize);
// will continue to cache the buffer
encryptionBuffersPool.LowMemory(lowMemorySeverity);
stats = encryptionBuffersPool.GetStats();
Assert.Equal(size, stats.TotalSize);
encryptionBuffersPool.LowMemoryOver();
ClearMemory(encryptionBuffersPool);
}
public void clear_all_buffers_on_extremely_low_memory()
{
var encryptionBuffersPool = new EncryptionBuffersPool();
var generation = encryptionBuffersPool.Generation;
var i = 1;
var toFree = new List <(IntPtr, long)>();
while (i <= new Size(8, SizeUnit.Megabytes).GetValue(SizeUnit.Bytes))
{
var ptr = encryptionBuffersPool.Get(i, out _);
toFree.Add(((IntPtr)ptr, i));
i *= 2;
}
var stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalSize);
foreach (var o in toFree)
{
encryptionBuffersPool.Return((byte *)o.Item1, o.Item2, NativeMemory.ThreadAllocations.Value, generation);
}
stats = encryptionBuffersPool.GetStats();
var allocated = toFree.Sum(x => x.Item2);
Assert.Equal(allocated, stats.TotalSize);
ClearMemory(encryptionBuffersPool);
}
public void properly_calculate_thread_total_allocations_when_we_cant_put_buffer_in_pool()
{
var encryptionBuffersPool = new EncryptionBuffersPool(registerLowMemory: false, registerCleanup: false);
var ptr = encryptionBuffersPool.Get(1, out var initialSize, out var threadStats);
var size = initialSize;
var free4KbAlignedMemoryCount = 0;
var updateMemoryStatsForThreadCount = 0;
var testingStuff = encryptionBuffersPool.ForTestingPurposesOnly();
testingStuff.CanAddToPerCorePool = false;
testingStuff.CanAddToGlobalPool = false;
testingStuff.OnFree4KbAlignedMemory = s =>
{
free4KbAlignedMemoryCount++;
size -= s;
};
testingStuff.OnUpdateMemoryStatsForThread = s =>
{
updateMemoryStatsForThreadCount++;
};
encryptionBuffersPool.Return(ptr, initialSize, threadStats, encryptionBuffersPool.Generation);
Assert.Equal(1, free4KbAlignedMemoryCount);
Assert.Equal(0, size);
Assert.Equal(0, updateMemoryStatsForThreadCount);
}
public override void BreakLargeAllocationToSeparatePages(IPagerLevelTransactionState tx, long pageNumber)
{
if (tx == null)
{
throw new NotSupportedException("Cannot use crypto pager without a transaction");
}
var state = GetTransactionState(tx);
if (state.LoadedBuffers.TryGetValue(pageNumber, out var encBuffer) == false)
{
throw new InvalidOperationException("Tried to break buffer that wasn't allocated in this tx");
}
for (int i = 1; i < encBuffer.Size / Constants.Storage.PageSize; i++)
{
var buffer = new EncryptionBuffer
{
Pointer = encBuffer.Pointer + i * Constants.Storage.PageSize,
Size = Constants.Storage.PageSize,
OriginalSize = 0,
};
buffer.Hash = _encryptionBuffersPool.Get(EncryptionBuffer.HashSizeInt, out var thread);
buffer.AllocatingThread = thread;
// here we _intentionally_ copy the old hash from the large page, so when we commit
// the tx, the pager will realize that we need to write this page
Memory.Copy(buffer.Hash, encBuffer.Hash, EncryptionBuffer.HashSizeInt);
state.LoadedBuffers[pageNumber + i] = buffer;
}
encBuffer.OriginalSize = encBuffer.Size;
encBuffer.Size = Constants.Storage.PageSize;
// here we _intentionally_ don't modify the hash of the page, even though its size was
// changed, because we need the pager to recognize that it was modified on tx commit
// encBuffer.Hash = remains the same
}
private EncryptionBuffer GetBufferAndAddToTxState(long pageNumber, CryptoTransactionState state, int size)
{
var ptr = _encryptionBuffersPool.Get(size, out var thread);
var buffer = new EncryptionBuffer
{
Size = size,
Pointer = ptr,
AllocatingThread = thread
};
state.LoadedBuffers[pageNumber] = buffer;
return(buffer);
}
public void clear_buffers_only_when_in_extremely_low_memory()
{
var encryptionBuffersPool = new EncryptionBuffersPool();
var ptr = encryptionBuffersPool.Get(1, out _);
var stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalSize);
encryptionBuffersPool.Return(ptr, 1, NativeMemory.ThreadAllocations.Value, encryptionBuffersPool.Generation);
stats = encryptionBuffersPool.GetStats();
Assert.Equal(1, stats.TotalSize);
encryptionBuffersPool.LowMemory(LowMemorySeverity.Low);
stats = encryptionBuffersPool.GetStats();
Assert.Equal(1, stats.TotalSize);
ClearMemory(encryptionBuffersPool);
}
public void dont_pool_buffers_larger_than_8Mb()
{
var encryptionBuffersPool = new EncryptionBuffersPool();
var i = 1;
var toFree = new List <(IntPtr, long)>();
while (i < new Size(64, SizeUnit.Megabytes).GetDoubleValue(SizeUnit.Bytes))
{
var ptr = encryptionBuffersPool.Get(i, out _);
toFree.Add(((IntPtr)ptr, i));
i *= 2;
}
var maxSize = new Size(8, SizeUnit.Megabytes).GetValue(SizeUnit.Bytes);
var totalSize = 0L;
foreach (var o in toFree)
{
if (o.Item2 <= maxSize)
{
totalSize += o.Item2;
}
encryptionBuffersPool.Return((byte *)o.Item1, o.Item2, NativeMemory.ThreadAllocations.Value, encryptionBuffersPool.Generation);
}
var stats = encryptionBuffersPool.GetStats();
Assert.Equal(totalSize, stats.TotalSize);
i = 1;
foreach (var allocationInfo in stats.Details)
{
Assert.Equal(1, allocationInfo.NumberOfItems);
Assert.Equal(i, allocationInfo.AllocationSize);
i *= 2;
}
ClearMemory(encryptionBuffersPool);
}
public void can_save_buffers_after_low_memory()
{
var encryptionBuffersPool = new EncryptionBuffersPool();
encryptionBuffersPool.LowMemory(LowMemorySeverity.ExtremelyLow);
encryptionBuffersPool.LowMemoryOver();
var i = 1;
var toFree = new List <(IntPtr, long)>();
var generation = encryptionBuffersPool.Generation;
while (i <= 1024)
{
var ptr = encryptionBuffersPool.Get(i, out var size, out _);
toFree.Add(((IntPtr)ptr, i));
i *= 2;
}
var stats = encryptionBuffersPool.GetStats();
Assert.Equal(0, stats.TotalPoolSize);
foreach (var o in toFree)
{
encryptionBuffersPool.Return((byte *)o.Item1, o.Item2, NativeMemory.ThreadAllocations.Value, generation);
}
stats = encryptionBuffersPool.GetStats();
var allocated = toFree.Sum(x => x.Item2);
Assert.Equal(allocated, stats.TotalPoolSize);
ClearMemory(encryptionBuffersPool);
}