public void OverlappingRegions()
{
RegionHandle allHandle = _tracking.BeginTracking(0, PageSize * 16);
allHandle.Reprotect();
(ulong address, ulong size)? readTrackingTriggeredAll = null;
Action registerReadAction = () =>
{
readTrackingTriggeredAll = null;
allHandle.RegisterAction((address, size) =>
{
readTrackingTriggeredAll = (address, size);
});
};
registerReadAction();
// Create 16 page sized handles contained within the allHandle.
RegionHandle[] containedHandles = new RegionHandle[16];
for (int i = 0; i < 16; i++)
{
containedHandles[i] = _tracking.BeginTracking((ulong)i * PageSize, PageSize);
containedHandles[i].Reprotect();
}
for (int i = 0; i < 16; i++)
{
// No handles are dirty.
Assert.False(allHandle.Dirty);
Assert.IsNull(readTrackingTriggeredAll);
for (int j = 0; j < 16; j++)
{
Assert.False(containedHandles[j].Dirty);
}
_tracking.VirtualMemoryEvent((ulong)i * PageSize, 1, true);
// Only the handle covering the entire range and the relevant contained handle are dirty.
Assert.True(allHandle.Dirty);
Assert.AreEqual(readTrackingTriggeredAll, ((ulong)i * PageSize, 1UL)); // Triggered read tracking
for (int j = 0; j < 16; j++)
{
if (j == i)
{
Assert.True(containedHandles[j].Dirty);
}
else
{
Assert.False(containedHandles[j].Dirty);
}
}
// Clear flags and reset read action.
registerReadAction();
allHandle.Reprotect();
containedHandles[i].Reprotect();
}
}
public void SingleRegion()
{
RegionHandle handle = _tracking.BeginTracking(0, PageSize);
(ulong address, ulong size)? readTrackingTriggered = null;
handle.RegisterAction((address, size) =>
{
readTrackingTriggered = (address, size);
});
bool dirtyInitial = handle.Dirty;
Assert.True(dirtyInitial); // Handle starts dirty.
handle.Reprotect();
bool dirtyAfterReprotect = handle.Dirty;
Assert.False(dirtyAfterReprotect); // Handle is no longer dirty.
_tracking.VirtualMemoryEvent(PageSize * 2, 4, true);
_tracking.VirtualMemoryEvent(PageSize * 2, 4, false);
bool dirtyAfterUnrelatedReadWrite = handle.Dirty;
Assert.False(dirtyAfterUnrelatedReadWrite); // Not dirtied, as the write was to an unrelated address.
Assert.IsNull(readTrackingTriggered); // Hasn't been triggered yet
_tracking.VirtualMemoryEvent(0, 4, false);
bool dirtyAfterRelatedRead = handle.Dirty;
Assert.False(dirtyAfterRelatedRead); // Only triggers on write.
Assert.AreEqual(readTrackingTriggered, (0UL, 4UL)); // Read action was triggered.
readTrackingTriggered = null;
_tracking.VirtualMemoryEvent(0, 4, true);
bool dirtyAfterRelatedWrite = handle.Dirty;
Assert.True(dirtyAfterRelatedWrite); // Dirty flag should now be set.
_tracking.VirtualMemoryEvent(4, 4, true);
bool dirtyAfterRelatedWrite2 = handle.Dirty;
Assert.True(dirtyAfterRelatedWrite2); // Dirty flag should still be set.
handle.Reprotect();
bool dirtyAfterReprotect2 = handle.Dirty;
Assert.False(dirtyAfterReprotect2); // Handle is no longer dirty.
handle.Dispose();
bool dirtyAfterDispose = TestSingleWrite(handle, 0, 4);
Assert.False(dirtyAfterDispose); // Handle cannot be triggered when disposed
}
public void PreciseAction()
{
RegionHandle handle = _tracking.BeginTracking(0, PageSize);
(ulong address, ulong size, bool write)? preciseTriggered = null;
handle.RegisterPreciseAction((address, size, write) =>
{
preciseTriggered = (address, size, write);
return(true);
});
(ulong address, ulong size)? readTrackingTriggered = null;
handle.RegisterAction((address, size) =>
{
readTrackingTriggered = (address, size);
});
handle.Reprotect();
_tracking.VirtualMemoryEvent(0, 4, false, precise: true);
Assert.IsNull(readTrackingTriggered); // Hasn't been triggered - precise action returned true.
Assert.AreEqual(preciseTriggered, (0UL, 4UL, false)); // Precise action was triggered.
_tracking.VirtualMemoryEvent(0, 4, true, precise: true);
Assert.IsNull(readTrackingTriggered); // Still hasn't been triggered.
bool dirtyAfterPreciseActionTrue = handle.Dirty;
Assert.False(dirtyAfterPreciseActionTrue); // Not dirtied - precise action returned true.
Assert.AreEqual(preciseTriggered, (0UL, 4UL, true)); // Precise action was triggered.
// Handle is now dirty.
handle.Reprotect(true);
preciseTriggered = null;
_tracking.VirtualMemoryEvent(4, 4, true, precise: true);
Assert.AreEqual(preciseTriggered, (4UL, 4UL, true)); // Precise action was triggered even though handle was dirty.
handle.Reprotect();
handle.RegisterPreciseAction((address, size, write) =>
{
preciseTriggered = (address, size, write);
return(false); // Now, we return false, which indicates that the regular read/write behaviours should trigger.
});
_tracking.VirtualMemoryEvent(8, 4, true, precise: true);
Assert.AreEqual(readTrackingTriggered, (8UL, 4UL)); // Read action triggered, as precise action returned false.
bool dirtyAfterPreciseActionFalse = handle.Dirty;
Assert.True(dirtyAfterPreciseActionFalse); // Dirtied, as precise action returned false.
Assert.AreEqual(preciseTriggered, (8UL, 4UL, true)); // Precise action was triggered.
}
public void DisposeHandles()
{
// Ensure that disposed handles correctly remove their virtual and physical regions.
RegionHandle handle = _tracking.BeginTracking(0, PageSize);
handle.Reprotect();
Assert.AreEqual((1, 1), _tracking.GetRegionCounts());
handle.Dispose();
Assert.AreEqual((0, 0), _tracking.GetRegionCounts());
// Two handles, small entirely contains big.
// We expect there to be three regions after creating both, one for the small region and two covering the big one around it.
// Regions are always split to avoid overlapping, which is why there are three instead of two.
RegionHandle handleSmall = _tracking.BeginTracking(PageSize, PageSize);
RegionHandle handleBig = _tracking.BeginTracking(0, PageSize * 4);
Assert.AreEqual((3, 3), _tracking.GetRegionCounts());
// After disposing the big region, only the small one will remain.
handleBig.Dispose();
Assert.AreEqual((1, 1), _tracking.GetRegionCounts());
handleSmall.Dispose();
Assert.AreEqual((0, 0), _tracking.GetRegionCounts());
}
private bool TestSingleWrite(RegionHandle handle, ulong address, ulong size)
{
handle.Reprotect();
_tracking.VirtualMemoryEvent(address, size, true);
return(handle.Dirty);
}
private bool TestSingleWrite(RegionHandle handle, ulong address, ulong size, bool physical = false)
{
handle.Reprotect();
if (physical)
{
_tracking.PhysicalMemoryEvent(address, true);
}
else
{
_tracking.VirtualMemoryEvent(address, size, true);
}
return(handle.Dirty);
}
public void Reprotect(bool asDirty = false) => _impl.Reprotect(asDirty);
public void Multithreading()
{
// Multithreading sanity test
// Multiple threads can easily read/write memory regions from any existing handle.
// Handles can also be owned by different threads, though they should have one owner thread.
// Handles can be created and disposed at any time, by any thread.
// This test should not throw or deadlock due to invalid state.
const int threadCount = 1;
const int handlesPerThread = 16;
long finishedTime = 0;
RegionHandle[] handles = new RegionHandle[threadCount * handlesPerThread];
Random globalRand = new Random();
for (int i = 0; i < handles.Length; i++)
{
handles[i] = _tracking.BeginTracking((ulong)i * PageSize, PageSize);
handles[i].Reprotect();
}
List <Thread> testThreads = new List <Thread>();
// Dirty flag consumer threads
int dirtyFlagReprotects = 0;
for (int i = 0; i < threadCount; i++)
{
int randSeed = i;
testThreads.Add(new Thread(() =>
{
int handleBase = randSeed * handlesPerThread;
while (Stopwatch.GetTimestamp() < finishedTime)
{
Random random = new Random(randSeed);
RegionHandle handle = handles[handleBase + random.Next(handlesPerThread)];
if (handle.Dirty)
{
handle.Reprotect();
Interlocked.Increment(ref dirtyFlagReprotects);
}
}
}));
}
// Write trigger threads
int writeTriggers = 0;
for (int i = 0; i < threadCount; i++)
{
int randSeed = i;
testThreads.Add(new Thread(() =>
{
Random random = new Random(randSeed);
ulong handleBase = (ulong)(randSeed * handlesPerThread * PageSize);
while (Stopwatch.GetTimestamp() < finishedTime)
{
_tracking.VirtualMemoryEvent(handleBase + (ulong)random.Next(PageSize * handlesPerThread), PageSize / 2, true);
Interlocked.Increment(ref writeTriggers);
}
}));
}
// Handle create/delete threads
int handleLifecycles = 0;
for (int i = 0; i < threadCount; i++)
{
int randSeed = i;
testThreads.Add(new Thread(() =>
{
int maxAddress = threadCount * handlesPerThread * PageSize;
Random random = new Random(randSeed + 512);
while (Stopwatch.GetTimestamp() < finishedTime)
{
RegionHandle handle = _tracking.BeginTracking((ulong)random.Next(maxAddress), (ulong)random.Next(65536));
handle.Dispose();
Interlocked.Increment(ref handleLifecycles);
}
}));
}
finishedTime = Stopwatch.GetTimestamp() + Stopwatch.Frequency / 2; // Run for 500ms;
foreach (Thread thread in testThreads)
{
thread.Start();
}
foreach (Thread thread in testThreads)
{
thread.Join();
}
Assert.Greater(dirtyFlagReprotects, 10);
Assert.Greater(writeTriggers, 10);
Assert.Greater(handleLifecycles, 10);
}
public void ReadAndWriteProtection()
{
MemoryPermission protection = MemoryPermission.ReadAndWrite;
_memoryManager.OnProtect += (va, size, newProtection) =>
{
Assert.AreEqual((0, PageSize), (va, size)); // Should protect the exact region all the operations use.
protection = newProtection;
};
RegionHandle handle = _tracking.BeginTracking(0, PageSize);
// After creating the handle, there is no protection yet.
Assert.AreEqual(MemoryPermission.ReadAndWrite, protection);
bool dirtyInitial = handle.Dirty;
Assert.True(dirtyInitial); // Handle starts dirty.
handle.Reprotect();
// After a reprotect, there is write protection, which will set a dirty flag when any write happens.
Assert.AreEqual(MemoryPermission.Read, protection);
(ulong address, ulong size)? readTrackingTriggered = null;
handle.RegisterAction((address, size) =>
{
readTrackingTriggered = (address, size);
});
// Registering an action adds read/write protection.
Assert.AreEqual(MemoryPermission.None, protection);
bool dirtyAfterReprotect = handle.Dirty;
Assert.False(dirtyAfterReprotect); // Handle is no longer dirty.
// First we should read, which will trigger the action. This _should not_ remove write protection on the memory.
_tracking.VirtualMemoryEvent(0, 4, false);
bool dirtyAfterRead = handle.Dirty;
Assert.False(dirtyAfterRead); // Not dirtied, as this was a read.
Assert.AreEqual(readTrackingTriggered, (0UL, 4UL)); // Read action was triggered.
Assert.AreEqual(MemoryPermission.Read, protection); // Write protection is still present.
readTrackingTriggered = null;
// Now, perform a write.
_tracking.VirtualMemoryEvent(0, 4, true);
bool dirtyAfterWriteAfterRead = handle.Dirty;
Assert.True(dirtyAfterWriteAfterRead); // Should be dirty.
Assert.AreEqual(MemoryPermission.ReadAndWrite, protection); // All protection is now be removed from the memory.
Assert.IsNull(readTrackingTriggered); // Read tracking was removed when the action fired, as it can only fire once.
handle.Dispose();
}
public void Reprotect() => _impl.Reprotect();
