private DesktopBlockingObject FindMonitor(ulong start, ulong stop)
{
ulong obj = 0;
foreach (ulong ptr in EnumeratePointersInRange(start, stop))
{
ulong tmp = 0;
if (_runtime.ReadPointer(ptr, out tmp))
{
if (_syncblks.TryGetValue(tmp, out tmp))
{
obj = tmp;
break;
}
}
}
DesktopBlockingObject result = null;
if (obj != 0 && _monitors.TryGetValue(obj, out result))
{
return(result);
}
return(null);
}
private DesktopBlockingObject FindLocks(ulong start, ulong stop, Func <ulong, ClrType, bool> isCorrectType)
{
foreach (ulong ptr in EnumeratePointersInRange(start, stop))
{
ulong val = 0;
if (_runtime.ReadPointer(ptr, out val))
{
DesktopBlockingObject result = null;
if (_locks.TryGetValue(val, out result) && isCorrectType(val, _heap.GetObjectType(val)))
{
return(result);
}
}
}
return(null);
}
internal DesktopBlockingObject[] InitLockInspection()
{
if (_result != null)
{
return(_result);
}
// First, enumerate all thinlocks on the heap.
foreach (var seg in _heap.Segments)
{
for (ulong obj = seg.FirstObject; obj != 0; obj = seg.NextObject(obj))
{
ClrType type = _heap.GetObjectType(obj);
if (IsReaderWriterLock(obj, type))
{
_locks[obj] = CreateRWLObject(obj, type);
}
else if (IsReaderWriterSlim(obj, type))
{
_locks[obj] = CreateRWSObject(obj, type);
}
// Does this object have a syncblk with monitor associated with it?
if (!_heap.GetObjectHeader(obj, out uint header))
{
continue;
}
if ((header & (BIT_SBLK_IS_HASH_OR_SYNCBLKINDEX | BIT_SBLK_SPIN_LOCK)) != 0)
{
continue;
}
uint threadId = header & SBLK_MASK_LOCK_THREADID;
if (threadId == 0)
{
continue;
}
ClrThread thread = _runtime.GetThreadFromThinlockID(threadId);
if (thread != null)
{
int recursion = ((int)header & SBLK_MASK_LOCK_RECLEVEL) >> SBLK_RECLEVEL_SHIFT;
_monitors[obj] = new DesktopBlockingObject(obj, true, recursion + 1, thread, BlockingReason.Monitor);
}
}
}
// Enumerate syncblocks to find locks
int syncblkCnt = _runtime.GetSyncblkCount();
for (int i = 0; i < syncblkCnt; ++i)
{
ISyncBlkData data = _runtime.GetSyncblkData(i);
if (data == null || data.Free)
{
continue;
}
_syncblks[data.Address] = data.Object;
_syncblks[data.Object] = data.Object;
ClrThread thread = null;
if (data.MonitorHeld)
{
ulong threadAddr = data.OwningThread;
foreach (var clrThread in _runtime.Threads)
{
if (clrThread.Address == threadAddr)
{
thread = clrThread;
break;
}
}
}
_monitors[data.Object] = new DesktopBlockingObject(data.Object, data.MonitorHeld, (int)data.Recursion, thread, BlockingReason.Monitor);
}
SetThreadWaiters();
int total = _monitors.Count + _locks.Count + _joinLocks.Count + _waitLocks.Count;
_result = new DesktopBlockingObject[total];
int j = 0;
foreach (DesktopBlockingObject blocker in _monitors.Values)
{
_result[j++] = blocker;
}
foreach (DesktopBlockingObject blocker in _locks.Values)
{
_result[j++] = blocker;
}
foreach (DesktopBlockingObject blocker in _joinLocks.Values)
{
_result[j++] = blocker;
}
foreach (DesktopBlockingObject blocker in _waitLocks.Values)
{
_result[j++] = blocker;
}
Debug.Assert(j == _result.Length);
// Free up some memory.
_monitors = null;
_locks = null;
_joinLocks = null;
_waitLocks = null;
_syncblks = null;
return(_result);
}
private void SetThreadWaiters()
{
HashSet <string> eventTypes = null;
List <BlockingObject> blobjs = new List <BlockingObject>();
foreach (DesktopThread thread in _runtime.Threads)
{
int max = thread.StackTrace.Count;
if (max > 10)
{
max = 10;
}
blobjs.Clear();
for (int i = 0; i < max; ++i)
{
DesktopBlockingObject blockingObj = null;
ClrMethod method = thread.StackTrace[i].Method;
if (method == null)
{
continue;
}
ClrType type = method.Type;
if (type == null)
{
continue;
}
switch (method.Name)
{
case "AcquireWriterLockInternal":
case "FCallUpgradeToWriterLock":
case "UpgradeToWriterLock":
case "AcquireReaderLockInternal":
case "AcquireReaderLock":
if (type.Name == "System.Threading.ReaderWriterLock")
{
blockingObj = FindLocks(thread.StackLimit, thread.StackTrace[i].StackPointer, IsReaderWriterLock);
if (blockingObj == null)
{
blockingObj = FindLocks(thread.StackTrace[i].StackPointer, thread.StackBase, IsReaderWriterLock);
}
if (blockingObj != null && (blockingObj.Reason == BlockingReason.Unknown || blockingObj.Reason == BlockingReason.None))
{
// This should have already been set correctly when the BlockingObject was created. This is just a best-guess.
if (method.Name == "AcquireReaderLockInternal" || method.Name == "AcquireReaderLock")
{
blockingObj.Reason = BlockingReason.WriterAcquired;
}
else
{
blockingObj.Reason = BlockingReason.ReaderAcquired;
}
}
}
break;
case "TryEnterReadLockCore":
case "TryEnterReadLock":
case "TryEnterUpgradeableReadLock":
case "TryEnterUpgradeableReadLockCore":
case "TryEnterWriteLock":
case "TryEnterWriteLockCore":
if (type.Name == "System.Threading.ReaderWriterLockSlim")
{
blockingObj = FindLocks(thread.StackLimit, thread.StackTrace[i].StackPointer, IsReaderWriterSlim);
if (blockingObj == null)
{
blockingObj = FindLocks(thread.StackTrace[i].StackPointer, thread.StackBase, IsReaderWriterSlim);
}
if (blockingObj != null && (blockingObj.Reason == BlockingReason.Unknown || blockingObj.Reason == BlockingReason.None))
{
// This should have already been set correctly when the BlockingObject was created. This is just a best-guess.
if (method.Name == "TryEnterWriteLock" || method.Name == "TryEnterWriteLockCore")
{
blockingObj.Reason = BlockingReason.ReaderAcquired;
}
else
{
blockingObj.Reason = BlockingReason.WriterAcquired;
}
}
}
break;
case "JoinInternal":
case "Join":
if (type.Name == "System.Threading.Thread")
{
if (FindThread(thread.StackLimit, thread.StackTrace[i].StackPointer, out ulong threadAddr, out ClrThread target) ||
FindThread(thread.StackTrace[i].StackPointer, thread.StackBase, out threadAddr, out target))
{
if (!_joinLocks.TryGetValue(target, out blockingObj))
{
_joinLocks[target] = blockingObj = new DesktopBlockingObject(threadAddr, true, 0, target, BlockingReason.ThreadJoin);
}
}
}
break;
case "Wait":
case "ObjWait":
if (type.Name == "System.Threading.Monitor")
{
blockingObj = FindMonitor(thread.StackLimit, thread.StackTrace[i].StackPointer);
if (blockingObj == null)
{
blockingObj = FindMonitor(thread.StackTrace[i].StackPointer, thread.StackBase);
}
blockingObj.Reason = BlockingReason.MonitorWait;
}
break;
case "WaitAny":
case "WaitAll":
if (type.Name == "System.Threading.WaitHandle")
{
ulong obj = FindWaitObjects(thread.StackLimit, thread.StackTrace[i].StackPointer, "System.Threading.WaitHandle[]");
if (obj == 0)
{
obj = FindWaitObjects(thread.StackTrace[i].StackPointer, thread.StackBase, "System.Threading.WaitHandle[]");
}
if (obj != 0)
{
BlockingReason reason = method.Name == "WaitAny" ? BlockingReason.WaitAny : BlockingReason.WaitAll;
if (!_waitLocks.TryGetValue(obj, out blockingObj))
{
_waitLocks[obj] = blockingObj = new DesktopBlockingObject(obj, true, 0, null, reason);
}
}
}
break;
case "WaitOne":
case "InternalWaitOne":
case "WaitOneNative":
if (type.Name == "System.Threading.WaitHandle")
{
if (eventTypes == null)
{
eventTypes = new HashSet <string>
{
"System.Threading.Mutex",
"System.Threading.Semaphore",
"System.Threading.ManualResetEvent",
"System.Threading.AutoResetEvent",
"System.Threading.WaitHandle",
"Microsoft.Win32.SafeHandles.SafeWaitHandle"
};
}
ulong obj = FindWaitHandle(thread.StackLimit, thread.StackTrace[i].StackPointer, eventTypes);
if (obj == 0)
{
obj = FindWaitHandle(thread.StackTrace[i].StackPointer, thread.StackBase, eventTypes);
}
if (obj != 0)
{
if (_waitLocks == null)
{
_waitLocks = new Dictionary <ulong, DesktopBlockingObject>();
}
if (!_waitLocks.TryGetValue(obj, out blockingObj))
{
_waitLocks[obj] = blockingObj = new DesktopBlockingObject(obj, true, 0, null, BlockingReason.WaitOne);
}
}
}
break;
case "TryEnter":
case "ReliableEnterTimeout":
case "TryEnterTimeout":
case "ReliableEnter":
case "Enter":
if (type.Name == "System.Threading.Monitor")
{
blockingObj = FindMonitor(thread.StackLimit, thread.StackTrace[i].StackPointer);
if (blockingObj != null)
{
blockingObj.Reason = BlockingReason.Monitor;
}
}
break;
}
if (blockingObj != null)
{
bool alreadyEncountered = false;
foreach (var blobj in blobjs)
{
if (blobj.Object == blockingObj.Object)
{
alreadyEncountered = true;
break;
}
}
if (!alreadyEncountered)
{
blobjs.Add(blockingObj);
}
}
}
foreach (DesktopBlockingObject blobj in blobjs)
{
blobj.AddWaiter(thread);
}
thread.SetBlockingObjects(blobjs.ToArray());
}
}
