Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all \u003cpre\u003e\u003ccode\u003e blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks"); } } catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); } })(); (function(){ try { var __m = "github.com"; var __re = new RegExp('^' + "github\\.com" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix"); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length \u003e 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms"); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links"); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default"); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers"); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + '
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode"); } } catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); } })(); })();
Skip to content

Fix thread pool hang#56346

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kouvel merged 4 commits into from
Jul 27, 2021
Merged

Fix thread pool hang #56346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
2d0aa63
Fix thread pool hang
Jul 26, 2021
b5464ab
Revert "mitigation for quic tests hangs (#55985)"
Jul 24, 2021
a77ce96
Add test
Jul 27, 2021
0bcdc77
Fix test
Jul 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 2 additions & 6 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Implementations/MsQuic/MsQuicStream.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -595,9 +595,7 @@ internal override int Read(Span<byte> buffer)
byte[] rentedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
try
{
Task<int> t = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
int readLength = t.GetAwaiter().GetResult();
int readLength = ReadAsync(new Memory<byte>(rentedBuffer, 0, buffer.Length)).AsTask().GetAwaiter().GetResult();
rentedBuffer.AsSpan(0, readLength).CopyTo(buffer);
return readLength;
}
Expand All@@ -612,9 +610,7 @@ internal override void Write(ReadOnlySpan<byte> buffer)
ThrowIfDisposed();

// TODO: optimize this.
Task t = WriteAsync(buffer.ToArray()).AsTask();
((IAsyncResult)t).AsyncWaitHandle.WaitOne();
t.GetAwaiter().GetResult();
WriteAsync(buffer.ToArray()).AsTask().GetAwaiter().GetResult();
}

// MsQuic doesn't support explicit flushing
Expand Down
15 changes: 8 additions & 7 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.Blocking.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -12,7 +12,7 @@ public short MinThreadsGoal
get
{
_threadAdjustmentLock.VerifyIsLocked();
return Math.Min(_separated.numThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
return Math.Min(_separated.counts.NumThreadsGoal, TargetThreadsGoalForBlockingAdjustment);
}
}

Expand DownExpand Up@@ -44,7 +44,7 @@ public bool NotifyThreadBlocked()
Debug.Assert(_numBlockedThreads > 0);

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.WithDelayIfNecessary &&
_separated.numThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal < TargetThreadsGoalForBlockingAdjustment)
{
if (_pendingBlockingAdjustment == PendingBlockingAdjustment.None)
{
Expand DownExpand Up@@ -79,7 +79,7 @@ public void NotifyThreadUnblocked()

if (_pendingBlockingAdjustment != PendingBlockingAdjustment.Immediately &&
_numThreadsAddedDueToBlocking > 0 &&
_separated.numThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
_separated.counts.NumThreadsGoal > TargetThreadsGoalForBlockingAdjustment)
{
wakeGateThread = true;
_pendingBlockingAdjustment = PendingBlockingAdjustment.Immediately;
Expand DownExpand Up@@ -126,7 +126,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
addWorker = false;

short targetThreadsGoal = TargetThreadsGoalForBlockingAdjustment;
short numThreadsGoal = _separated.numThreadsGoal;
ThreadCounts counts = _separated.counts;
short numThreadsGoal = counts.NumThreadsGoal;
if (numThreadsGoal == targetThreadsGoal)
{
return 0;
Expand All@@ -144,7 +145,8 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo

short toSubtract = Math.Min((short)(numThreadsGoal - targetThreadsGoal), _numThreadsAddedDueToBlocking);
_numThreadsAddedDueToBlocking -= toSubtract;
_separated.numThreadsGoal = numThreadsGoal -= toSubtract;
numThreadsGoal -= toSubtract;
_separated.counts.InterlockedSetNumThreadsGoal(numThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
numThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand All@@ -158,7 +160,6 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
{
// Calculate how many threads can be added without a delay. Threads that were already created but may be just
// waiting for work can be released for work without a delay, but creating a new thread may need a delay.
ThreadCounts counts = _separated.counts;
short maxThreadsGoalWithoutDelay =
Math.Max(configuredMaxThreadsWithoutDelay, Math.Min(counts.NumExistingThreads, _maxThreads));
short targetThreadsGoalWithoutDelay = Math.Min(targetThreadsGoal, maxThreadsGoalWithoutDelay);
Expand DownExpand Up@@ -225,7 +226,7 @@ private uint PerformBlockingAdjustment(bool previousDelayElapsed, out bool addWo
} while (false);

_numThreadsAddedDueToBlocking += (short)(newNumThreadsGoal - numThreadsGoal);
_separated.numThreadsGoal = newNumThreadsGoal;
counts = _separated.counts.InterlockedSetNumThreadsGoal(newNumThreadsGoal);
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.CooperativeBlocking);
Expand Down
27 changes: 19 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.GateThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -126,20 +126,31 @@ private static void GateThreadStart()
// of the number of existing threads, is compared with the goal. There may be alternative
// solutions, for now this is only to maintain consistency in behavior.
ThreadCounts counts = threadPoolInstance._separated.counts;
if (counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
while (
counts.NumProcessingWork < threadPoolInstance._maxThreads &&
counts.NumProcessingWork >= counts.NumThreadsGoal)
{
if (debuggerBreakOnWorkStarvation)
{
Debugger.Break();
}

ThreadCounts newCounts = counts;
short newNumThreadsGoal = (short)(counts.NumProcessingWork + 1);
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts countsBeforeUpdate =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.Starvation);
addWorker = true;
break;
}

counts = countsBeforeUpdate;
}
}
finally
Expand DownExpand Up@@ -183,7 +194,7 @@ private static bool SufficientDelaySinceLastDequeue(PortableThreadPool threadPoo
}
else
{
minimumDelay = (uint)threadPoolInstance._separated.numThreadsGoal * DequeueDelayThresholdMs;
minimumDelay = (uint)threadPoolInstance._separated.counts.NumThreadsGoal * DequeueDelayThresholdMs;
}

return delay > minimumDelay;
Expand Down
59 changes: 51 additions & 8 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.ThreadCounts.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -16,14 +16,15 @@ private struct ThreadCounts
// SOS's ThreadPool command depends on this layout
private const byte NumProcessingWorkShift = 0;
private const byte NumExistingThreadsShift = 16;
private const byte NumThreadsGoalShift = 32;

private uint _data; // SOS's ThreadPool command depends on this name
private ulong _data; // SOS's ThreadPool command depends on this name

private ThreadCounts(uint data) => _data = data;
private ThreadCounts(ulong data) => _data = data;

private short GetInt16Value(byte shift) => (short)(_data >> shift);
private void SetInt16Value(short value, byte shift) =>
_data = (_data & ~((uint)ushort.MaxValue << shift)) | ((uint)(ushort)value << shift);
_data = (_data & ~((ulong)ushort.MaxValue << shift)) | ((ulong)(ushort)value << shift);

/// <summary>
/// Number of threads processing work items.
Expand All@@ -43,7 +44,7 @@ public void SubtractNumProcessingWork(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumProcessingWork);

_data -= (uint)(ushort)value << NumProcessingWorkShift;
_data -= (ulong)(ushort)value << NumProcessingWorkShift;
}

public void InterlockedDecrementNumProcessingWork()
Expand DownExpand Up@@ -72,19 +73,61 @@ public void SubtractNumExistingThreads(short value)
Debug.Assert(value >= 0);
Debug.Assert(value <= NumExistingThreads);

_data -= (uint)(ushort)value << NumExistingThreadsShift;
_data -= (ulong)(ushort)value << NumExistingThreadsShift;
}

/// <summary>
/// Max possible thread pool threads we want to have.
/// </summary>
public short NumThreadsGoal
{
get => GetInt16Value(NumThreadsGoalShift);
set
{
Debug.Assert(value > 0);
SetInt16Value(value, NumThreadsGoalShift);
}
}

public ThreadCounts InterlockedSetNumThreadsGoal(short value)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();

ThreadCounts counts = this;
while (true)
{
ThreadCounts newCounts = counts;
newCounts.NumThreadsGoal = value;

ThreadCounts countsBeforeUpdate = InterlockedCompareExchange(newCounts, counts);
if (countsBeforeUpdate == counts)
{
return newCounts;
}

counts = countsBeforeUpdate;
}
}

public ThreadCounts VolatileRead() => new ThreadCounts(Volatile.Read(ref _data));

public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts) =>
new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
public ThreadCounts InterlockedCompareExchange(ThreadCounts newCounts, ThreadCounts oldCounts)
{
#if DEBUG
if (newCounts.NumThreadsGoal != oldCounts.NumThreadsGoal)
{
ThreadPoolInstance._threadAdjustmentLock.VerifyIsLocked();
}
#endif

return new ThreadCounts(Interlocked.CompareExchange(ref _data, newCounts._data, oldCounts._data));
}

public static bool operator ==(ThreadCounts lhs, ThreadCounts rhs) => lhs._data == rhs._data;
public static bool operator !=(ThreadCounts lhs, ThreadCounts rhs) => lhs._data != rhs._data;

public override bool Equals([NotNullWhen(true)] object? obj) => obj is ThreadCounts other && _data == other._data;
public override int GetHashCode() => (int)_data;
public override int GetHashCode() => (int)_data + (int)(_data >> 32);
}
}
}
29 changes: 13 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Threading/PortableThreadPool.WorkerThread.cs
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -124,22 +124,19 @@ private static void WorkerThreadStart()
ThreadCounts newCounts = counts;
newCounts.SubtractNumExistingThreads(1);
short newNumExistingThreads = (short)(numExistingThreads - 1);

ThreadCounts oldCounts = threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, counts.NumThreadsGoal));
newCounts.NumThreadsGoal = newNumThreadsGoal;

ThreadCounts oldCounts =
threadPoolInstance._separated.counts.InterlockedCompareExchange(newCounts, counts);
if (oldCounts == counts)
{
short newNumThreadsGoal =
Math.Max(
threadPoolInstance.MinThreadsGoal,
Math.Min(newNumExistingThreads, threadPoolInstance._separated.numThreadsGoal));
if (threadPoolInstance._separated.numThreadsGoal != newNumThreadsGoal)
{
threadPoolInstance._separated.numThreadsGoal = newNumThreadsGoal;
HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
}

HillClimbing.ThreadPoolHillClimber.ForceChange(
newNumThreadsGoal,
HillClimbing.StateOrTransition.ThreadTimedOut);
if (NativeRuntimeEventSource.Log.IsEnabled())
{
NativeRuntimeEventSource.Log.ThreadPoolWorkerThreadStop((uint)newNumExistingThreads);
Expand DownExpand Up@@ -181,7 +178,7 @@ internal static void MaybeAddWorkingWorker(PortableThreadPool threadPoolInstance
while (true)
{
numProcessingWork = counts.NumProcessingWork;
if (numProcessingWork >= threadPoolInstance._separated.numThreadsGoal)
if (numProcessingWork >= counts.NumThreadsGoal)
{
return;
}
Expand DownExpand Up@@ -256,7 +253,7 @@ internal static bool ShouldStopProcessingWorkNow(PortableThreadPool threadPoolIn
// code from which this implementation was ported, which turns a processing thread into a retired thread
// and checks for pending requests like RemoveWorkingWorker. In this implementation there are
// no retired threads, so only the count of threads processing work is considered.
if (counts.NumProcessingWork <= threadPoolInstance._separated.numThreadsGoal)
if (counts.NumProcessingWork <= counts.NumThreadsGoal)
{
return false;
}
Expand Down
Loading