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singrdk/base/Kernel/System/Threading/Thread.cs

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////////////////////////////////////////////////////////////////////////////////
//
// Microsoft Research Singularity
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// File: Thread.cs
//
// Note:
//
// The Thread class and the Scheduler interact through three mechanisms.
//
// First, the synchronization operations acquire the Scheduler's dispatch
// lock (via Scheduler.DispatchLock() and Scheduler.DispatchRelease()
// to ensure that no two processors ever attempt to dispatch on the block
// or release threads at exactly the same time.
//
// Second, the Thread class notifies the Scheduler of important events
// in the life of each thread. These notifications are done via overrides
// on the thread class. The mixin overrides are:
// Scheduler.OnThreadStateInitialize(): Thread has been created.
// Scheduler.OnThreadStart(): Thread is ready to start.
// Scheduler.OnThreadBlocked(): Thread just blocked on a handle.
// Scheduler.OnThreadUnblocked(): Thread is now runnable.
// Scheduler.OnThreadYield(): Thread yields processor.
// Scheduler.OnThreadStop(): Thread is ready to stop.
// Scheduler.OnThreadFreezeIncrement(): Freeze thread, incr count.
// Scheduler.OnThreadFreezeDecrement(): Decrement count, if 0 then unfreeze
//
// Third, the Scheduler calls Thread.Stopped() when it has finish with a
// thread that is no longer runnable.
//
// #define DEBUG_SWITCH
namespace System.Threading
{
using System.Threading;
using System.Runtime.InteropServices;
using System;
using System.Diagnostics;
using System.Globalization;
using System.GCs;
using System.Collections;
using System.Runtime.CompilerServices;
using Microsoft.Singularity;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Hal;
using Microsoft.Singularity.Scheduling;
using Microsoft.Singularity.Security;
using Microsoft.Singularity.V1.Threads;
using Microsoft.Singularity.X86;
using Microsoft.Singularity.Memory;
using Microsoft.Bartok.Runtime;
[CLSCompliant(false)]
public enum ThreadEvent : ushort
{
CreateIdle = 12,
Create = 13,
WaitAny = 30,
WaitFail = 31,
SwitchTo = 3,
ThreadPackageInit = 10
}
//| <include path='docs/doc[@for="Thread"]/*' />
[CCtorIsRunDuringStartup]
[CLSCompliant(false)]
[RequiredByBartok]
public class Thread
{
// GC fields.
[RequiredByBartok] // Thread-specific alloc heap
internal SegregatedFreeList segregatedFreeList;
[RequiredByBartok] // Thread-specific bump allocator
internal BumpAllocator bumpAllocator;
// MultiUseWord (object header) fields.
internal UIntPtr externalMultiUseObjAllocListHead;
internal UIntPtr externalMultiUseObjAllocListTail;
// Scheduling fields.
internal int processThreadIndex;
internal int threadIndex;
private ThreadStart threadStart;
private ThreadState threadState; // acquire Process.processLock when changing unstarted->running
private AutoResetEvent autoEvent;
private bool gcEventBlocked; // Are we blocked on the gcEvent?
private bool gcEventSignaled; // Has the gcEvent been signaled
private ManualResetEvent joinEvent;
internal Thread blockingCctorThread;
internal ThreadLocalServiceRequest localServiceRequest;
// Scheduler dispatching fields.
[AccessedByRuntime("referenced from c++")]
internal bool blocked; // Thread blocked on something.
[AccessedByRuntime("referenced from c++")]
private ThreadEntry[] blockedOn; // WaitHandles blocked on (if any).
[AccessedByRuntime("referenced from c++")]
private int blockedOnCount; // Number of valid WaitHandles.
[AccessedByRuntime("referenced from c++")]
private SchedulerTime blockedUntil; // Timeout of Wait.
public SchedulerTime BlockedUntil
{
[NoHeapAllocation]
get { return blockedUntil; }
}
private volatile int unblockedBy; // WaitHandle signaled in unblock.
internal int freezeCount; // >0 prevents thread from being scheduled.
[AccessedByRuntime("referenced from c++")]
public ThreadEntry schedulerEntry; // Entry for some scheduler queue.
public Processor ActiveProcessor; // Processor running this thread (null if not running).
public Processor AffinityProcessor; // Soft affinity.
public Processor LockedProcessor; // non-null if thread dedicated.
// Singularity specific fields
[AccessedByRuntime("referenced from c++")]
internal ThreadContext context;
[AccessedByRuntime("referenced from c++")]
internal Process process;
internal ThreadHandle threadHandle;
internal UIntPtr threadLocalValue;
// Most recently thrown exception object that the thread
// did not catch at all (i.e. that propagated to the bottom
// of the stack without encountering an appropriate catch clause).
internal Exception lastUncaughtException;
// Monitor fields.
// Remove these (& Monitor) as soon as stack is out of kernel.
internal Thread nextThread; // Link for linked lists of threads
private Object exceptionStateInfo; // Exception info latched to the thread on a thread abort
// Bartok specific fields
[RequiredByBartok]
internal TryAllManager tryAllManager;
private static long totalArrayAllocations;
private static long totalArrayBytesAllocated;
private static long totalBytes;
private static long totalStructBytesAllocated;
internal static Thread[] threadTable;
private static SpinLock threadTableLock;
private static LocalDataStore localDataStore;
internal static Thread initialThread;
private static SpinLock threadStopLock;
private static ProcessStopException processStopException;
#if PAGING
// For use when we temporarily switch to a different domain
private ProtectionDomain tempDomain;
#endif
// This is used by the Bartok backend. When Bartok try to generate
// callback stub for delegate, it checks to see if it is
// ThreadProc, if it is not, Bartok adds leaveGCSafeState and
// enterGCSafeState around the delegate call.
[RequiredByBartok]
private unsafe delegate uint ThreadProc(void *param);
//////////////////////////////////////////////////////////////////////
// This manager is responsible for storing the global data that is
// shared amongst all the thread local stores.
//
static private LocalDataStoreMgr m_LocalDataStoreMgr;
//////////////////////////////////////////////////////////////////////
// Creates a new Thread object which will begin execution at
// start.ThreadStart on a new thread when the Start method is called.
//
// Exceptions: ArgumentNullException if start == null.
//
//| <include path='docs/doc[@for="Thread.Thread"]/*' />
internal const int maxThreads = 1024; // Must be power of 2 >= 64
private static int threadIndexGenerator;
private Thread(Process process)
{
this.processThreadIndex = -1;
this.threadIndex = -1;
this.threadState = ThreadState.Unstarted;
this.SetKernelMode();
this.process = process;
context.threadIndex = unchecked((ushort)-1);
context.processThreadIndex = unchecked((ushort)-1);
context.processId = unchecked((ushort)-1);
Transitions.InitializeStatusWord(ref context);
// Allocate the kernel objects needed by the thread.
autoEvent = new AutoResetEvent(false);
joinEvent = new ManualResetEvent(false);
localServiceRequest = new ThreadLocalServiceRequest();
schedulerEntry = new ThreadEntry(this);
this.GetWaitEntries(1); // Cache allows wait without allocation
// Try to put the thread in the thread table.
bool iflag = Processor.DisableInterrupts();
try {
threadTableLock.Acquire(CurrentThread);
try {
for (int i = 0; i < threadTable.Length; i++) {
int index = (threadIndexGenerator + i) % threadTable.Length;
if (threadTable[index] == null) {
threadTable[index] = this;
this.threadIndex = index;
threadIndexGenerator = index + 1;
// NB: We call this once, subsequently the GC visitor calls it.
context.UpdateAfterGC(this);
break;
}
}
}
finally {
threadTableLock.Release(CurrentThread);
}
// Save the TID and PID into the thread context.
context.threadIndex = unchecked((ushort)(threadIndex));
Transitions.InitializeStatusWord(ref context);
if (process != null)
{
context.processId = unchecked((ushort)(process.ProcessId));
}
}
finally {
Processor.RestoreInterrupts(iflag);
}
// Allocate the thread's stack.
context.stackBegin = 0;
context.stackLimit = 0;
}
// Constructor for processor idle threads.
protected Thread(bool idle)
: this(Process.idleProcess)
{
UIntPtr stackSegment = Stacks.GetInitialStackSegment(ref context);
DebugStub.Assert(stackSegment != UIntPtr.Zero);
#if PAGING
context.InitializeIdle(threadIndex, stackSegment,
unchecked((uint)Process.kernelProcess.Domain.AddressSpace.PdptPage.Value));
#else
context.InitializeIdle(threadIndex, stackSegment, 0);
#endif
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.CreateIdle, 0,
(uint)threadIndex, 0, 0, 0, 0);
}
// Constructor for all other threads.
protected Thread(Process process, ThreadStart start)
: this(process)
{
if (start == null) {
throw new ArgumentNullException("start");
}
this.threadStart = start;
#if PAGING
context.abiStackHead = Stacks.GetStackSegment(0, ref context);
context.abiStackBegin = context.stackBegin;
context.abiStackLimit = context.stackLimit;
context.stackBegin = 0;
context.stackLimit = 0;
#endif
UIntPtr stackSegment = Stacks.GetInitialStackSegment(ref context);
DebugStub.Assert(stackSegment != UIntPtr.Zero);
#if PAGING
context.Initialize(threadIndex, stackSegment,
unchecked((uint)(Process.Domain.AddressSpace.PdptPage.Value)));
#else
context.Initialize(threadIndex, stackSegment, 0);
#endif
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.Create, 0,
(uint)threadIndex, 0, 0, 0, 0);
}
// To create a new idle thread.
public static Thread CreateIdleThread(Processor processor)
{
// Allocate the thread.
Thread idle = new Thread(true);
if (idle.threadIndex < 0) {
Tracing.Log(Tracing.Warning, "Thread table is full.");
DebugStub.Break();
return null;
}
//MemoryBarrier();?
DebugStub.WriteLine("CreateIdleThread tid={0:x3}, proc={1:x3}",
__arglist(idle.threadIndex,
processor.processorIndex));
idle.LockedProcessor = processor;
return idle;
}
// Entry point for kernel to create new process threads.
public static Thread CreateThread(Process process,
ThreadStart start)
{
if (process == null) {
process = CurrentProcess;
}
// Allocate the thread.
Thread thread = new Thread(process, start);
if (thread.threadIndex < 0) {
Tracing.Log(Tracing.Warning, "Thread table is full.");
DebugStub.Break();
return null;
}
ThreadHandle handle;
process.AddThread(thread, out handle);
//MemoryBarrier();?
// Tell the scheduler to initialize the thread.
Scheduler.OnThreadStateInitialize(thread, true);
PerfCounters.IncrementThreadsCreated();
return thread;
}
//////////////////////////////////////////////////////////////////////
// Spawns off a new thread which will begin executing at the
// ThreadStart delegate passed in the constructor. Once the thread is
// dead, it cannot be restarted with another call to Start.
//
// Exceptions: ThreadStateException if the thread has already been started.
//
//| <include path='docs/doc[@for="Thread.Start"]/*' />
public void Start()
{
process.StartThread(ref threadState);
StartRunningThread();
}
// precondition: process.processLock held
internal void SetMainThreadRunning()
{
VTable.Assert(threadState == ThreadState.Unstarted);
process.StartMainThread(ref threadState);
}
internal void StartRunningThread()
{
VTable.Assert(threadState == ThreadState.Running);
// Tell the GC that we have created the thread
GC.NewThreadNotification(this, false);
// Tell the scheduler to start the thread.
bool iflag = Processor.DisableInterrupts();
try {
Scheduler.DispatchLock();
try {
//Kernel.Waypoint(1);
Scheduler.OnThreadStart(this);
}
finally {
Scheduler.DispatchRelease();
}
}
finally {
//Kernel.Waypoint(114);
Processor.RestoreInterrupts(iflag);
}
}
// ThreadContext.InitializeIdle sets ThreadIdleStub as the first instruction to be
// executed in a new thread context.
[AccessedByRuntime("referenced from c++")]
private static unsafe void ThreadIdleStub(int index)
{
for (;;) {
// Check for a debug break.
// Tell the scheduler to start the thread.
bool iflag = Processor.DisableInterrupts();
try {
Processor.NextSampleIsIdle();
if (DebugStub.PollForBreak()) {
DebugStub.Print("Debugger breakin.\n");
DebugStub.Break();
}
}
finally {
//Kernel.Waypoint(114);
Processor.RestoreInterrupts(iflag);
}
Processor.HaltUntilInterrupt();
}
}
// ThreadContext.Initialize sets ThreadStub as the first instruction to be
// executed in a new thread context.
[AccessedByRuntime("referenced from c++")]
private static unsafe void ThreadStub(int threadIndex)
{
Thread currentThread = threadTable[threadIndex];
#if PAGING
// Give our Protection Domain a chance to set up
// if we're first in here. Run this before anything
// else!
currentThread.process.Domain.InitHook();
#endif
Transitions.ThreadStart();
GC.ThreadStartNotification(threadIndex);
Tracing.Log(Tracing.Trace, "ThreadStub() entered");
ThreadStart startFun = currentThread.threadStart;
Processor.InitFpu();
try {
startFun();
}
catch (ProcessStopException) {
// Ok, exit thread without failure.
}
catch (Exception e) {
// Not ok, fail.
Tracing.Log(Tracing.Notice,
"Thread failed with exception {0}.{1}",
e.GetType().Namespace, e.GetType().Name);
Tracing.Log(Tracing.Trace, "Exception message was {0}",
e.Message);
DebugStub.Assert(e == null,
"Thread {0} failed w/ exception {1}.{2}: {3}",
__arglist(threadIndex,
e.GetType().Namespace,
e.GetType().Name,
e.Message));
}
Tracing.Log(Tracing.Trace, "{0:x} ThreadStub() stopping",
Kernel.AddressOf(currentThread));
currentThread.threadState = ThreadState.Stopping;
currentThread.joinEvent.Set();
// The scheduler takes care of exiting MutatorState, so we
// don't need the following call.
// Transitions.ThreadEnd(threadIndex);
bool iflag = Processor.DisableInterrupts();
try {
Thread target = null;
// Block the ServiceStopped method until we acquire DispatchLock
// (but don't acquire DispatchLock yet, because
// CurrentThreadStopped would try to double-acquire it).
threadStopLock.Acquire();
// Tell service thread to call currentThread.ServiceStopped()
ThreadLocalServiceRequest.CurrentThreadStopped();
Scheduler.DispatchLock();
try {
threadStopLock.Release();
Kernel.Waypoint(1);
// We change to the Stopped state here so that
// Process.ServiceSuspend can stop waiting for us.
// (We can't wait for the service thread to
// set the Stopped state, because if the
// service thread is running Process.ServiceSuspend
// it could deadlock.)
currentThread.threadState = ThreadState.Stopped;
target = Scheduler.OnThreadStop(currentThread);
Scheduler.SelectingThread(target);
}
catch(Exception e) {
Scheduler.DispatchRelease();
throw e;
}
if (target == null) {
target = Processor.CurrentProcessor.IdleThread;
}
target.SwitchTo();
}
finally {
//Kernel.Waypoint(114);
Processor.RestoreInterrupts(iflag);
}
DebugStub.Break();
}
// ServiceStopped is called by the service thread when the thread is stopped.
internal void ServiceStopped()
{
// Make sure ThreadStub has gotten a chance to exit before
// we deallocate its stack:
bool iflag = Processor.DisableInterrupts();
try {
threadStopLock.Acquire();
Scheduler.DispatchLock();
Scheduler.DispatchRelease();
threadStopLock.Release();
} finally {
Processor.RestoreInterrupts(iflag);
}
VTable.Assert(threadState == ThreadState.Stopped);
VTable.Assert(threadIndex > 0);
VTable.Deny(Transitions.InMutatorState(threadIndex));
GC.DeadThreadNotification(this);
#if !PAGING
while (context.stackBegin != 0) {
Stacks.ReturnStackSegment(ref context);
}
#else
int count = 0;
while (context.stackBegin != 0) {
// HACK: if the thread stops abruptly, the stack
// may contain the abi segment
if (context.stackBegin == context.abiStackBegin) {
context.abiStackBegin = 0;
context.abiStackLimit = 0;
}
Stacks.ReturnStackSegment(ref context);
count++;
}
// VTable.Assert(count == 1); // due to unimplemented exception handling code, count may be >1
#endif
VTable.Assert(context.stackLimit == 0);
VTable.Assert(context.stackBegin == 0);
#if PAGING
// See HACK above for why abiStackBegin may be 0
if (context.abiStackBegin != 0) {
context.stackLimit = context.abiStackLimit;
context.stackBegin = context.abiStackBegin;
Stacks.ReturnStackSegment(ref context);
}
#endif
Thread currentThread = Thread.CurrentThread;
iflag = Processor.DisableInterrupts();
try {
threadTableLock.Acquire(currentThread);
try {
threadTable[threadIndex] = null;
Transitions.DeadThreadNotification(threadIndex);
} finally {
threadTableLock.Release(currentThread);
}
} finally {
Processor.RestoreInterrupts(iflag);
}
if (process != null) {
process.ServiceOnThreadStop(this);
}
}
//////////////////////////////////////////////////////////////////////
// Returns true if the thread has been started and is not dead.
//
//| <include path='docs/doc[@for="Thread.IsAlive"]/*' />
public bool IsAlive {
get { return (threadState == ThreadState.Running); }
}
#if false
// Returns a TimeSpan target for timeout.
static internal SchedulerTime GetTimeoutTarget(TimeSpan delay)
{
if (delay == TimeSpan.Infinite) {
#if DEBUG_SLEEP
DebugStub.Print(" GetTimeTarget(Infinite) = {0}\n",
__arglist(SchedulerTime.MaxValue.Ticks));
#endif
return SchedulerTime.MaxValue;
}
else if (delay < TimeSpan.Zero) {
throw new ArgumentOutOfRangeException("delay", "ArgumentOutOfRange_AddTimeout");
}
SchedulerTime now = SchedulerTime.Now;
#if DEBUG_SLEEP
DebugStub.Print(" GetTimeTarget({0}) = {1:d12} + {2:d12} => {3:d12}\n",
__arglist(
delay.ToString(),
now.Ticks,
delay.Ticks,
(now + delay).Ticks));
#endif
return now + delay;
}
#endif
[Inline]
static internal bool TimeoutTargetPassed(SchedulerTime target)
{
return SchedulerTime.Now >= target;
}
//////////////////////////////////////////////////////////////////////
// Waits for the thread to die.
//
// Exceptions: ThreadStateException if the thread has not been started yet.
//
//| <include path='docs/doc[@for="Thread.Join"]/*' />
public void Join()
{
Join(SchedulerTime.MaxValue);
}
//////////////////////////////////////////////////////////////////////
// Waits for the thread to die or for timeout milliseconds to elapse.
// Returns true if the thread died, or false if the wait timed out.
//
// Exceptions: ArgumentException if timeout < 0.
// ThreadStateException if the thread has not been started.
//
//| <include path='docs/doc[@for="Thread.Join2"]/*' />
public bool Join(TimeSpan timeout)
{
if (threadState == ThreadState.Unstarted) {
throw new ThreadStateException();
}
else if (threadState == ThreadState.Stopped) {
return true;
}
return joinEvent.WaitOne(timeout);
}
public bool Join(SchedulerTime timeout)
{
if (threadState == ThreadState.Unstarted) {
throw new ThreadStateException();
}
else if (threadState == ThreadState.Stopped) {
return true;
}
return joinEvent.WaitOne(timeout);
}
//////////////////////////////////////////////////////////////////////
// Suspends the current thread for timeout milliseconds. If timeout
// == 0, forces the thread to give up the remainder of its timeslice.
//
// Exceptions: ArgumentException if timeout < 0.
//
public static void Sleep(int milliseconds)
{
Sleep(TimeSpan.FromMilliseconds(milliseconds));
}
//| <include path='docs/doc[@for="Thread.Sleep"]/*' />
public static void Sleep(SchedulerTime stop)
{
Tracing.Log(Tracing.Audit, "Sleep until stop");
Thread.CurrentThread.WaitAny(null, 0, stop);
Tracing.Log(Tracing.Audit, "Sleep until stop finished");
}
//| <include path='docs/doc[@for="Thread.Sleep"]/*' />
public static void Sleep(TimeSpan timeout)
{
Tracing.Log(Tracing.Audit, "Sleep until time");
SchedulerTime stop = SchedulerTime.Now + timeout;
Thread.CurrentThread.WaitAny(null, 0, stop);
Tracing.Log(Tracing.Audit, "Sleep until time finished");
}
//////////////////////////////////////////////////////////////////////
// Wait for a length of time proportional to 'iterations'. Each
// iteration is should only take a few machine instructions. Calling
// this method is preferable to coding an explicit busy loop because the
// hardware can be informed that it is busy waiting.
//
//| <include path='docs/doc[@for="Thread.SpinWait"]/*' />
[NoHeapAllocation]
public static void SpinWait(int iterations)
{
for (int i = iterations; i > 0; i--) {
// Ensure that the optimizer doesn't remove this
NativeNoOp();
}
}
[Intrinsic]
[NoHeapAllocation]
public static extern void NativeNoOp();
internal static int GetCurrentProcessIndex() {
return Thread.CurrentProcess.ProcessId;
}
internal bool WaitForMonitor(SchedulerTime stop)
{
return autoEvent.WaitOne(stop);
}
internal bool WaitForEvent(SchedulerTime stop)
{
return autoEvent.WaitOne(stop);
}
internal bool WaitForEvent(TimeSpan timeout)
{
return autoEvent.WaitOne(timeout);
}
internal static void WaitForGCEvent(int currentThreadIndex)
{
Tracing.Log(Tracing.Audit, "WaitForGCEvent({0})",
(UIntPtr) currentThreadIndex);
VTable.Deny(Scheduler.IsIdleThread(currentThreadIndex));
bool iflag = Processor.DisableInterrupts();
try {
bool didLock =
Scheduler.EnsureDispatchLock(currentThreadIndex);
Thread target = null;
Thread currentThread = threadTable[currentThreadIndex];
try {
if (currentThread.gcEventSignaled) {
// Reset the flag, fall out and keep running.
currentThread.gcEventSignaled = false;
if (didLock) {
Scheduler.DispatchRelease();
}
return;
}
currentThread.gcEventBlocked = true;
target = Scheduler.OnThreadBlocked(currentThread,
SchedulerTime.MaxValue);
if (target == null) {
target = Processor.CurrentProcessor.IdleThread;
} else {
// This should not be called passing the idle thread
Scheduler.SelectingThread(target);
}
} catch {
if (didLock) {
Scheduler.DispatchRelease();
}
throw;
}
Processor.CurrentProcessor.NumContextSwitches++;
// This has the side effect of releasing the dispatcher lock.
Processor.SwitchToThreadContextNoGC(ref target.context);
} finally {
Processor.RestoreInterrupts(iflag);
}
}
internal void SignalEvent()
{
autoEvent.Set();
}
internal void SignalMonitor()
{
autoEvent.Set();
}
[Inline]
internal static void SignalGCEvent(int threadIndex) {
SignalGCEvent(Thread.GetCurrentThreadIndex(), threadIndex);
}
internal static void SignalGCEvent(int currentThreadIndex,
int threadIndex)
{
Tracing.Log(Tracing.Audit, "SignalGCEvent({0})",
(UIntPtr) threadIndex);
VTable.Deny(Scheduler.IsIdleThread(threadIndex));
bool iflag = Processor.DisableInterrupts();
try {
bool didLock =
Scheduler.EnsureDispatchLock(currentThreadIndex);
try {
Thread targetThread = threadTable[threadIndex];
if (targetThread == null) {
// There is nothing to signal, so just keep going.
} else if (targetThread.gcEventBlocked) {
targetThread.gcEventBlocked = false;
Scheduler.OnThreadUnblocked(targetThread);
} else {
// Nobody was waiting for the event.
targetThread.gcEventSignaled = true;
}
} finally {
if (didLock) {
Scheduler.DispatchRelease();
}
}
} finally {
Processor.RestoreInterrupts(iflag);
}
}
//| <include path='docs/doc[@for="Thread.CurrentThread"]/*' />
public static extern Thread CurrentThread
{
[NoStackLinkCheck]
[NoHeapAllocation]
[Intrinsic]
get;
}
public static Process CurrentProcess
{
[NoStackLinkCheck]
[NoHeapAllocation]
get {
return Processor.GetCurrentThread().process;
}
}
public Process Process
{
[NoHeapAllocation]
get { return process; }
}
public ThreadHandle Handle
{
[NoHeapAllocation]
get { return threadHandle; }
}
[NoStackLinkCheck]
[RequiredByBartok]
[NoHeapAllocation]
private static Thread GetCurrentThreadNative()
{
return Processor.GetCurrentThread();
}
[NoStackLinkCheck]
[RequiredByBartok]
[NoHeapAllocation]
public static int GetCurrentThreadIndex()
{
return Processor.GetCurrentThread().threadIndex;
}
[NoHeapAllocation]
public static UIntPtr GetThreadLocalValue()
{
return Processor.GetCurrentThread().threadLocalValue;
}
[NoHeapAllocation]
public static void SetThreadLocalValue(UIntPtr value)
{
Processor.GetCurrentThread().threadLocalValue = value;
}
//////////////////////////////////////////////////////////////////////
// Return the thread state as a consistent set of bits. This is more
// general then IsAlive or IsBackground.
//
//| <include path='docs/doc[@for="Thread.ThreadState"]/*' />
public ThreadState ThreadState
{
[NoHeapAllocation]
get { return threadState; }
}
[NoHeapAllocation]
public int GetThreadId()
{
return threadIndex;
}
// Return true if the thread is in kernel mode, false if the
// thread is in process mode.
// Note that by the time this method returns, the thread might
// have already switched to a different mode; in other words,
// don't rely on this result of this method being up-to-date unless
// the thread is suspended or blocked.
[NoHeapAllocation]
public unsafe bool IsInKernelMode()
{
return context.IsInKernelMode();
}
[NoHeapAllocation]
internal unsafe void SetKernelMode()
{
context.SetKernelMode();
}
[NoHeapAllocation]
internal unsafe void SetProcessMode()
{
context.SetProcessMode();
}
// Briefly suspend a thread in order to modify its state.
// When Freeze() returns, the thread is guaranteed to:
// - be unscheduled (not running on any processor)
// - not to be inside a DisableInterrupts block
// (unless that block voluntarily context switches)
// - not to hold the dispatch lock (because
// CurrentThread holds the dispatch lock)
// These guarantees hold only until the dispatch lock
// is released.
//
// No other guarantees are made about the thread state; in particular,
// the thread could be in the middle of a kernel operation. (This
// distinguishes Freeze from Suspend.)
//
// A thread should not try to freeze itself
// (this would deadlock, as can many other uses of Freeze).
//
// precondition: interrupts enabled
// precondition: dispatch lock not acquired
// (so that other processor schedulers can run)
// postcondition: interrupts disabled
// postcondition: dispatch lock acquired
// postcondition: ActiveProcessor == null
// postcondition: freezeCount > 0
//
// Example:
// t.Freeze();
// ...(do some stuff, without releasing dispatch lock)...
// Scheduler.DispatchRelease();
// Processor.RestoreInterrupts(true);
internal void Freeze()
{
Debug.Assert(this != CurrentThread);
bool iflag = Processor.DisableInterrupts();
Debug.Assert(iflag);
try {
Scheduler.DispatchLock();
try {
switch (threadState) {
case ThreadState.Unstarted:
case ThreadState.Stopped:
case ThreadState.Suspended:
break;
case ThreadState.Running:
case ThreadState.Stopping:
if (ActiveProcessor == null) {
break;
}
Scheduler.OnThreadFreezeIncrement(this);
WaitUntilInactive();
// (Try to be courteous to the scheduler -- don't
// ask it to resume a stopped thread.)
if (threadState != ThreadState.Stopped) {
Scheduler.OnThreadFreezeDecrement(this);
}
break;
default:
Debug.Assert(false, "unreachable default case");
return;
}
}
catch(Exception e) {
Scheduler.DispatchRelease();
throw e;
}
}
catch(Exception e) {
Processor.RestoreInterrupts(iflag);
throw e;
}
Debug.Assert(ActiveProcessor == null);
Scheduler.AssertDispatchLockHeld();
}
internal void Unfreeze()
{
Scheduler.DispatchRelease();
Processor.RestoreInterrupts(true);
}
// precondition: interrupts disabled with iflag==true
// precondition: dispatch lock acquired
// invariant: freezeCount > 0
// postcondition: interrupts disabled with iflag==true
// postcondition: dispatch lock acquired
// postcondition: ActiveProcessor == null
private void WaitUntilInactive()
{
Scheduler.AssertDispatchLockHeld();
Debug.Assert(this != CurrentThread);
Debug.Assert(freezeCount > 0);
if (ActiveProcessor != null) {
// TODO: send interrupt to ActiveProcessor
// spin for exponentially backed off delay
int count = 31;
while (ActiveProcessor != null) {
Scheduler.DispatchRelease();
Processor.RestoreInterrupts(true);
Thread.SpinWait(count);
count = (count == 0x7ffffffu) ? count : count + count + 1;
bool iflag = Processor.DisableInterrupts();
Debug.Assert(iflag);
Scheduler.DispatchLock();
}
}
}
// Do not call Thread.Suspend unless you are suspending all the
// threads in a process. This should only be called from the
// kernel service thread.
//
// Return value:
// true means the thread is now suspended, unstarted, or stopped.
// false means the thread must be allowed to run a little longer,
// so try calling Suspend later.
//
// precondition: interrupts enabled
// precondition: dispatch lock not acquired
// postcondition: interrupts enabled
// postcondition: dispatch lock not acquired
internal bool Suspend(bool aboutToStop)
{
/*
case (kernel, unblocked, running): return false;
case (kernel, unblocked, stopping): return false;
case (process, unblocked, running): DoSuspend(); return true;
case (kernel, blocked, running): DoSuspend(); return true;
case (kernel, unblocked, unstarted): return true;
case (_, _, suspended): return true;
case (kernel, unblocked, stopped): return true;
case _: error
// Also: in the (kernel, blocked, running) case, if
// aboutToStop==true, call WaitDone().
*/
Freeze();
try {
if (threadState == ThreadState.Suspended) {
return true;
}
else if (IsInKernelMode()) { // in kernel mode, not suspended
if (blocked) {
if (threadState == ThreadState.Running) {
DoSuspend();
if (aboutToStop) {
WaitDone(null);
}
return true;
}
else {
Debug.Assert(false, "unexpected thread state");
return false;
}
}
else { // in kernel mode, unblocked, not suspended
switch (threadState) {
case ThreadState.Running:
case ThreadState.Stopping:
// Let the thread run a while longer, but
// let it know that eventually, it should
// suspend:
// MULTIPROCESSOR NOTE: halforgc.asm reads
// suspendAlert with no explicit
// synchronization. We don't need the
// read to be consistent with the
// following write immediately, but it
// must become consistent eventually.
context.suspendAlert = true;
return false;
case ThreadState.Unstarted:
case ThreadState.Stopped:
// Note: now that process.state==Suspending[Recursive], a barrier
// prevents starting threads, an Unstarted thread stays
// Unstarted.
return true;
case ThreadState.Suspended:
Debug.Assert(false, "unexpected thread state");
return false;
default:
Debug.Assert(false, "unreachable default case");
return false;
}
}
}
else { // in process mode, not suspended
if (!blocked && threadState == ThreadState.Running) {
DoSuspend();
return true;
}
else {
Debug.Assert(false, "unexpected thread state");
return false;
}
}
}
finally {
Scheduler.DispatchRelease();
Processor.RestoreInterrupts(true);
}
}
private void DoSuspend()
{
threadState = ThreadState.Suspended;
Scheduler.OnThreadFreezeIncrement(this);
}
// Do not call Thread.Resume unless you are resuming all the
// threads in a process. This should only be called from the
// kernel service thread.
internal void Resume()
{
bool iflag = Processor.DisableInterrupts();
try {
Scheduler.DispatchLock();
try {
if (threadState == ThreadState.Suspended) {
threadState = ThreadState.Running;
Scheduler.OnThreadFreezeDecrement(this);
}
}
finally {
Scheduler.DispatchRelease();
}
}
finally {
Processor.RestoreInterrupts(iflag);
}
}
// Do not call Thread.Stop unless you are stopping all the
// threads in a process. This should only be called from the
// kernel service thread.
//
// precondition: interrupts enabled
// precondition: dispatch lock not acquired
// postcondition: interrupts enabled
// postcondition: dispatch lock not acquired
internal void Stop()
{
/*
case (kernel, unblocked, unstarted): return;
case (kernel, unblocked, stopped): return;
case (kernel, _, suspended):
if (blocked) WaitDone(null);
t.throw ProcessStopException
threadState = ThreadState.Running;
Scheduler.OnThreadFreezeDecrement(this);
return;
case (process, unblocked, suspended):
t.(pop frames and throw ProcessStopException)
threadState = ThreadState.Running;
Scheduler.OnThreadFreezeDecrement(this);
return;
case _: error
*/
Freeze();
try {
bool kernelMode = IsInKernelMode();
if (threadState == ThreadState.Suspended) {
if (kernelMode) {
if (blocked) {
WaitDone(null);
}
// context.eip = __throwBeyondMarker;
// context.eax = context.stackMarkers; // kernel->kernel marker;
// context.ecx = processStopException;
setStopContext(this, processStopException);
}
else if (!kernelMode && !blocked) {
// context.eip = __throwBeyondMarker;
// context.eax = context.stackMarkers; // kernel->process marker;
// context.ecx = processStopException;
setStopContext(this, processStopException);
}
else {
Debug.Assert(false, "unexpected thread state");
}
Debug.Assert(!blocked);
threadState = ThreadState.Running;
Scheduler.OnThreadFreezeDecrement(this);
}
else if (
kernelMode && !blocked &&
( threadState == ThreadState.Stopped
|| threadState == ThreadState.Unstarted)) {
// nothing needs to happen here.
}
else {
Debug.Assert(false, "unexpected thread state");
}
}
finally {
Scheduler.DispatchRelease();
Processor.RestoreInterrupts(true);
}
}
[MethodImpl(MethodImplOptions.InternalCall)]
[NoHeapAllocation]
[StackBound(4)]
private static extern void setStopContext(Thread t, Exception exn);
//////////////////////////////////////////////////////////////////////
// Allocates an un-named data slot. The slot is allocated on ALL the
// threads.
//| <include path='docs/doc[@for="Thread.AllocateDataSlot"]/*' />
public static LocalDataStoreSlot AllocateDataSlot()
{
return m_LocalDataStoreMgr.AllocateDataSlot();
}
//////////////////////////////////////////////////////////////////////
// Allocates a named data slot. The slot is allocated on ALL the
// threads. Named data slots are "public" and can be manipulated by
// anyone.
//| <include path='docs/doc[@for="Thread.AllocateNamedDataSlot"]/*' />
public static LocalDataStoreSlot AllocateNamedDataSlot(String name)
{
return m_LocalDataStoreMgr.AllocateNamedDataSlot(name);
}
//////////////////////////////////////////////////////////////////////
// Looks up a named data slot. If the name has not been used, a new
// slot is allocated. Named data slots are "public" and can be
// manipulated by anyone.
//| <include path='docs/doc[@for="Thread.GetNamedDataSlot"]/*' />
public static LocalDataStoreSlot GetNamedDataSlot(String name)
{
return m_LocalDataStoreMgr.GetNamedDataSlot(name);
}
//////////////////////////////////////////////////////////////////////
// Frees a named data slot. The slot is allocated on ALL the
// threads. Named data slots are "public" and can be manipulated by
// anyone.
//| <include path='docs/doc[@for="Thread.FreeNamedDataSlot"]/*' />
public static void FreeNamedDataSlot(String name)
{
m_LocalDataStoreMgr.FreeNamedDataSlot(name);
}
//////////////////////////////////////////////////////////////////////
// Retrieves the value from the specified slot on the current thread.
//| <include path='docs/doc[@for="Thread.GetData"]/*' />
public static Object GetData(LocalDataStoreSlot slot)
{
m_LocalDataStoreMgr.ValidateSlot(slot);
if (localDataStore != null) {
return localDataStore.GetData(slot);
}
return null;
}
//////////////////////////////////////////////////////////////////////
// Sets the data in the specified slot on the currently running thread.
//| <include path='docs/doc[@for="Thread.SetData"]/*' />
public static void SetData(LocalDataStoreSlot slot, Object data)
{
// Create new DLS if one hasn't been created for this thread.
if (localDataStore == null) {
localDataStore = m_LocalDataStoreMgr.CreateLocalDataStore();
}
localDataStore.SetData(slot, data);
}
/*=============================================================*/
internal Object ExceptionState
{
[NoHeapAllocation]
get { return exceptionStateInfo;}
[NoHeapAllocation]
set { exceptionStateInfo = value;}
}
//
// This is just designed to prevent compiler warnings.
// This field is used from native, but we need to prevent the compiler warnings.
//
#if _DEBUG
private void DontTouchThis()
{
threadStart = null;
m_Priority = 0;
}
#endif
//////////////////////////////////////////////////////////////////////
// Volatile Read & Write and MemoryBarrier methods.
// Provides the ability to read and write values ensuring that the values
// are read/written each time they are accessed.
//
//| <include path='docs/doc[@for="Thread.VolatileRead"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern byte VolatileRead(ref byte address);
//| <include path='docs/doc[@for="Thread.VolatileRead1"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern short VolatileRead(ref short address);
//| <include path='docs/doc[@for="Thread.VolatileRead2"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern int VolatileRead(ref int address);
//| <include path='docs/doc[@for="Thread.VolatileRead3"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern long VolatileRead(ref long address);
//| <include path='docs/doc[@for="Thread.VolatileRead4"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern sbyte VolatileRead(ref sbyte address);
//| <include path='docs/doc[@for="Thread.VolatileRead5"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern ushort VolatileRead(ref ushort address);
//| <include path='docs/doc[@for="Thread.VolatileRead6"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern uint VolatileRead(ref uint address);
//| <include path='docs/doc[@for="Thread.VolatileRead7"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern IntPtr VolatileRead(ref IntPtr address);
//| <include path='docs/doc[@for="Thread.VolatileRead8"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern UIntPtr VolatileRead(ref UIntPtr address);
//| <include path='docs/doc[@for="Thread.VolatileRead9"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern ulong VolatileRead(ref ulong address);
//| <include path='docs/doc[@for="Thread.VolatileRead10"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern float VolatileRead(ref float address);
//| <include path='docs/doc[@for="Thread.VolatileRead11"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern double VolatileRead(ref double address);
//| <include path='docs/doc[@for="Thread.VolatileRead12"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern Object VolatileRead(ref Object address);
//| <include path='docs/doc[@for="Thread.VolatileWrite"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref byte address, byte value);
//| <include path='docs/doc[@for="Thread.VolatileWrite1"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref short address, short value);
//| <include path='docs/doc[@for="Thread.VolatileWrite2"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref int address, int value);
//| <include path='docs/doc[@for="Thread.VolatileWrite3"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref long address, long value);
//| <include path='docs/doc[@for="Thread.VolatileWrite4"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref sbyte address, sbyte value);
//| <include path='docs/doc[@for="Thread.VolatileWrite5"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref ushort address, ushort value);
//| <include path='docs/doc[@for="Thread.VolatileWrite6"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref uint address, uint value);
//| <include path='docs/doc[@for="Thread.VolatileWrite7"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref IntPtr address, IntPtr value);
//| <include path='docs/doc[@for="Thread.VolatileWrite8"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref UIntPtr address, UIntPtr value);
//| <include path='docs/doc[@for="Thread.VolatileWrite9"]/*' />
[CLSCompliant(false)]
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref ulong address, ulong value);
//| <include path='docs/doc[@for="Thread.VolatileWrite10"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref float address, float value);
//| <include path='docs/doc[@for="Thread.VolatileWrite11"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref double address, double value);
//| <include path='docs/doc[@for="Thread.VolatileWrite12"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void VolatileWrite(ref Object address, Object value);
//| <include path='docs/doc[@for="Thread.MemoryBarrier"]/*' />
[Intrinsic]
[NoHeapAllocation]
public static extern void MemoryBarrier();
[NoHeapAllocation]
internal static unsafe void DisplayAbbrev(ref ThreadContext context, String s)
{
fixed (ThreadContext * pContext = &context) {
DebugStub.Print("{0}: ctx={1:x8} esp={2:x8} ebp={3:x8} eip={4:x8} " +
"thr={5:x8} efl={6:x8} p={7:x8} n={8:x8}\n",
__arglist(
s,
(UIntPtr)pContext,
context.esp,
context.ebp,
context.eip,
Kernel.AddressOf(context.thread),
context.efl,
(UIntPtr)context.prev,
(UIntPtr)context.next));
}
}
[NoHeapAllocation]
internal static unsafe void Display(ref ThreadContext context, String s)
{
fixed (ThreadContext * pContext = &context) {
DebugStub.Print("{0}: ctx={1:x8} num={2:x2}\n",
__arglist(
s,
(UIntPtr)pContext,
context.num));
}
DebugStub.Print(" thr={0:x8} prv={1:x8} nxt={2:x8}\n",
__arglist(
(UIntPtr)Kernel.AddressOf(context.thread),
(UIntPtr)context.prev,
(UIntPtr)context.next));
DebugStub.Print(" eax={0:x8} ebx={1:x8} ecx={2:x8} edx={3:x8}\n",
__arglist(
context.eax,
context.ebx,
context.ecx,
context.edx));
DebugStub.Print(" esp={0:x8} ebp={1:x8} esi={2:x8} edi={3:x8}\n",
__arglist(
context.esp,
context.ebp,
context.esi,
context.edi));
DebugStub.Print(" eip={0:x8} efl={1:x8} err={2:x8} cr2={3:x8}\n",
__arglist(
context.eip,
context.efl,
context.err,
context.cr2));
}
///////////////////////////////////////////////// Blocking operations.
//
internal int WaitAny(WaitHandle[] waitHandles,
int waitHandlesCount,
TimeSpan timeout)
{
SchedulerTime stop = SchedulerTime.Now + timeout;
return WaitAny(waitHandles, waitHandlesCount, stop);
}
internal int WaitAny(WaitHandle[] waitHandles,
int waitHandlesCount,
SchedulerTime stop)
{
VTable.Assert(threadState == ThreadState.Running);
VTable.Assert(!blocked);
Kernel.Waypoint(100);
ThreadEntry[] entries = GetWaitEntries(waitHandlesCount);
bool iflag = Processor.DisableInterrupts();
try {
Thread target = null;
Scheduler.DispatchLock();
try {
Kernel.Waypoint(101);
// Enqueue on all of the non-signaled handles.
for (int marked = 0; marked < waitHandlesCount; marked++) {
if (waitHandles[marked].AcquireOrEnqueue(entries[marked])) {
// If one of the handles was signaled, then abort waits...
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} WaitAny 004 [Presignal] "+
"on {1:x8}\n",
__arglist(
Kernel.AddressOf(this),
Kernel.AddressOf(waitHandles[marked])));
#endif // DEBUG_DISPATCH
for (int released = 0; released < marked; released++) {
entries[released].RemoveFromQueue();
}
Scheduler.DispatchRelease();
return marked;
}
}
blocked = true;
blockedOn = entries;
blockedOnCount = waitHandlesCount;
blockedUntil = stop;
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.WaitAny, 0,
(uint)stop.Ticks, (uint)(stop.Ticks >> 32),
(uint)this.threadIndex, 0, 0);
unblockedBy = WaitHandle.WaitTimeout;
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} WaitAny 007 [Blocking] on\n",
__arglist(Kernel.AddressOf(this)));
for (int i = 0; i < waitHandlesCount; i++) {
DebugStub.Print(" {0:d3}: {1:x8}\n",
__arglist(i, Kernel.AddressOf(waitHandles[i])));
}
#endif // DEBUG_DISPATCH
target = Scheduler.OnThreadBlocked(this, stop);
Scheduler.SelectingThread(target);
}
catch(Exception e) {
Scheduler.DispatchRelease();
throw e;
}
if (target == null) {
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} WaitAny 013 [Idle Thread]\n",
__arglist(Kernel.AddressOf(this)));
#endif // DEBUG_DISPATCH
target = Processor.CurrentProcessor.IdleThread;
VTable.Deny(Transitions.UnderGCControl(target.threadIndex));
}
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} WaitAny 014 [SwitchTo] thread {1:x8}\n",
__arglist(
Kernel.AddressOf(this),
Kernel.AddressOf(target)));
#endif // DEBUG_DISPATCH
target.SwitchTo();
// Execution will return here only after either the timeout
// period has been passed or one of the handles has been
// signalled. If we were unblocked, then WaitDone will have
// been called and unblockedBy will not be WaitHandle.WaitTimeout.
// If we timed out, then WaitFail will have been called.
}
finally {
//Kernel.Waypoint(114);
Processor.RestoreInterrupts(iflag);
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} WaitAny 019\n",
__arglist(Kernel.AddressOf(this)));
#endif // DEBUG_DISPATCH
}
return unblockedBy;
}
// This method should only be called by low-level synchronization
// primitives derived from WaitHandle. If you need to cause a
// thread to sleep or wake up, you should use those primitives
// instead.
[NoHeapAllocation]
internal void WaitDone(ThreadEntry entry)
{
Scheduler.AssertDispatchLockHeld();
// DebugStub.Break(); //
for (int i = 0; i < blockedOnCount; i++) {
if (blockedOn[i] == entry) {
unblockedBy = i;
}
else {
blockedOn[i].RemoveFromQueue();
}
}
// Tell the scheduler this thread is no longer blocked.
Scheduler.OnThreadUnblocked(this);
// Clear out the blocked information, after we know we won't want it.
blocked = false;
blockedOn = null; //No more beneficiaries of inherited time.
blockedOnCount = 0;
}
// This method is called when the scheduler has timed-out the wait.
[NoHeapAllocation]
internal void WaitFail()
{
Scheduler.AssertDispatchLockHeld();
// DebugStub.Break(); //
#if DEBUG_DISPATCH
DebugStub.Print("Thread {0:x8} [WaitFail]\n",
__arglist(Kernel.AddressOf(this)));
#endif // DEBUG_DISPATCH
VTable.Assert(unblockedBy == WaitHandle.WaitTimeout);
for (int i = 0; i < blockedOnCount; i++) {
blockedOn[i].RemoveFromQueue();
}
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.WaitFail, 0,
(uint)blockedUntil.Ticks,
(uint)(blockedUntil.Ticks >> 32),
(uint)this.threadIndex, 0, 0);
// Clear out the blocked information, after we know we won't want it.
blocked = false;
blockedOn = null; //No more beneficiaries of inherited time.
blockedOnCount = 0;
}
///////////////////////////////////////////////// Context Switch Code.
//
// This method should only be called by the scheduler and by Yield().
// precondition: Scheduler.dispatchLock held
// postcondition: Scheduler.dispatchLock released
[NoHeapAllocation]
private void SwitchTo()
{
Thread currentThread = CurrentThread;
#if DONT
Tracing.Log(Tracing.Audit, "Schedule(old={0:x}, new={1:x})",
Kernel.AddressOf(currentThread),
Kernel.AddressOf(this));
#endif
#if DEBUG_SWITCH
Display(ref this.context, "New Context");
#endif
Scheduler.AssertDispatchLockHeld();
Processor.CurrentProcessor.NumContextSwitches++;
//Tracing.LogContextSwitch(CurrentThread.GetThreadId(), this.GetThreadId());
#if DEBUG_SWITCH
Thread.DisplayAbbrev(ref currentThread.context, "swi bef");
#endif
Kernel.Waypoint(2);
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.SwitchTo, 0,
(uint)this.context.threadIndex, 0, 0, 0, 0);
Processor.SwitchToThreadContext(ref currentThread.context,
ref this.context);
// Kernel.Waypoint(7);
#if DEBUG_SWITCH
Thread.DisplayAbbrev(ref Thread.CurrentThread.context, "swi aft");
#endif
#if DONT
Display(ref currentThread.context, "Old Context");
Display(ref threadTable[0].context, "[0] Context");
Display(ref threadTable[1].context, "[1] Context");
#endif
}
//
//////////////////////////////////////////////////////////////////////
[NoHeapAllocation]
public static void Yield()
{
bool iflag = Processor.DisableInterrupts();
try {
Thread target = CurrentThread;
Scheduler.DispatchLock();
try {
Kernel.Waypoint(1);
target = Scheduler.OnThreadYield(CurrentThread);
#if DEBUG_DISPATCH
DebugStub.Print("Yield.Selecting\n");
#endif // DEBUG_DISPATCH
Scheduler.SelectingThread(target);
}
catch(Exception e) {
Scheduler.DispatchRelease();
throw e;
}
if (target == null) {
target = CurrentThread;
}
target.SwitchTo();
}
finally {
//Kernel.Waypoint(114);
Processor.RestoreInterrupts(iflag);
}
}
[NoHeapAllocation]
public bool IsWaiting()
{
return blocked;
}
[NoHeapAllocation]
public bool IsStopped()
{
return (threadState == ThreadState.Stopped);
}
[NoHeapAllocation]
public bool IsStopping()
{
return (threadState == ThreadState.Stopping ||
threadState == ThreadState.Stopped);
}
[PreInitRefCounts]
static unsafe Thread()
{
threadIndexGenerator = 1;
DebugStub.Print("Thread()");
// Enable Thread.CurrentThread as soon as we can!
initialThread = Magic.toThread(GCs.BootstrapMemory.Allocate(typeof(Thread)));
initialThread.threadState = ThreadState.Running;
initialThread.SetKernelMode();
initialThread.threadIndex = 0;
// Allocate tables for thread management
threadTable = (Thread[])
GCs.BootstrapMemory.Allocate(typeof(Thread[]), maxThreads);
// Initialize the thread and event tables
threadTable[initialThread.threadIndex] = initialThread;
initialThread.context.threadIndex =
unchecked((ushort)(initialThread.threadIndex));
Transitions.InitializeStatusWord(ref initialThread.context);
initialThread.context.processId = unchecked((ushort)(1));
// Prevent stack linking.
initialThread.context.stackBegin = 0;
initialThread.context.stackLimit = 0;
initialThread.context.UpdateAfterGC(initialThread);
Processor.SetCurrentThreadContext(ref initialThread.context);
#if DEBUG_THREAD_CONTEXT_ALIGNMENT
Tracing.Log(Tracing.Debug, "Thread.alignment = {0}",
(((RuntimeType)typeof(Thread)).classVtable).baseAlignment);
Tracing.Log(Tracing.Debug, "ThreadContext.alignment = {0}",
(((RuntimeType)typeof(ThreadContext)).classVtable).baseAlignment);
Tracing.Log(Tracing.Debug, "MmxContext.alignment = {0}",
(((RuntimeType)typeof(MmxContext)).classVtable).baseAlignment);
Tracing.Log(Tracing.Debug, "&initialThread = {0:x8}",
Kernel.AddressOf(initialThread));
fixed (void *v = &initialThread.context) {
Tracing.Log(Tracing.Debug, "&initialThread.context = {0:x8}",
(UIntPtr)v);
}
fixed (void *v = &initialThread.context.mmx) {
Tracing.Log(Tracing.Debug, "&initialThread.context.mmx = {0:x8}",
(UIntPtr)v);
}
fixed (void *v = &initialThread.context.mmx.st0) {
Tracing.Log(Tracing.Debug, "&initialThread.context.mmx.st0 = {0:x8}",
(UIntPtr)v);
}
#endif
VTable.Assert((int)(((RuntimeType)typeof(Thread)).classVtable).baseAlignment == 16);
VTable.Assert((int)(((RuntimeType)typeof(ThreadContext)).classVtable).baseAlignment == 16);
VTable.Assert((int)(((RuntimeType)typeof(MmxContext)).classVtable).baseAlignment == 16);
Tracing.Log(Tracing.Debug, "InitialThread={0:x8}",
Kernel.AddressOf(initialThread));
Monitoring.Log(Monitoring.Provider.Thread,
(ushort)ThreadEvent.ThreadPackageInit);
initialThread.bumpAllocator.Dump();
Tracing.Log(Tracing.Debug, "Class constructor Thread() exiting\n");
}
internal static unsafe void FinishInitializeThread()
{
// Set the fields of initialThread
int stackVariable;
initialThread.context.stackBegin =
(new UIntPtr(&stackVariable) + 0xfff) & new UIntPtr(~0xfffU);
initialThread.context.stackLimit = 0;
initialThread.autoEvent = new AutoResetEvent(false);
initialThread.joinEvent = new ManualResetEvent(false);
initialThread.schedulerEntry = new ThreadEntry(initialThread);
initialThread.GetWaitEntries(1); // Cache allows wait without alloc
Transitions.RuntimeInitialized();
Transitions.ThreadStart();
// Instantiate the static variable that needs to be initialized
m_LocalDataStoreMgr = new LocalDataStoreMgr();
processStopException = new ProcessStopException();
// Tell the scheduler to initialize the thread.
Scheduler.OnThreadStateInitialize(initialThread, false);
}
/// <summary> Prepares a new Thread to take on role as kernel thread
/// for upcoming processor. Called by Bootstrap processor. </summary>
public static Thread PrepareKernelThread()
{
Thread kernelThread = new Thread(null);
GC.NewThreadNotification(kernelThread, false);
return kernelThread;
}
public static void BindKernelThread(Thread kernelThread,
UIntPtr stackBegin,
UIntPtr stackLimit)
{
kernelThread.context.processId = initialThread.context.processId;
kernelThread.context.stackBegin = stackBegin;
kernelThread.context.stackLimit = 0/* stackLimit */;
kernelThread.context.UpdateAfterGC(kernelThread);
Processor.SetCurrentThreadContext(ref kernelThread.context);
kernelThread.threadState = ThreadState.Running;
Transitions.ThreadStart();
}
[NoHeapAllocation]
public void DumpStackInfo()
{
Tracing.Log(Tracing.Debug, "<< thr={0:x8} beg={1:x8} lim={2:x8} ptr={3:x8} >>",
Kernel.AddressOf(this),
context.stackBegin,
context.stackLimit,
Processor.GetStackPointer());
}
public Thread GetRunnableBeneficiary()
{
// this does a depth first search, not sure if that is a good idea.
if (threadState == ThreadState.Running) {
return this;
}
Thread tempThread;
for (int i = 0; blockedOn != null && i < blockedOnCount; i++) {
if (blockedOn[i] != null) {
tempThread = blockedOn[i].GetBeneficiary();
if (tempThread != null) {
tempThread = tempThread.GetRunnableBeneficiary();
}
if (tempThread != null) {
return tempThread;
}
}
}
return null;
}
#if THREAD_TIME_ACCOUNTING
// timestamp of last update for ExecutionTime
internal ulong LastUpdateTime
{
[NoHeapAllocation]
get { return context.lastExecutionTimeUpdate; }
[NoHeapAllocation]
set { context.lastExecutionTimeUpdate = value; }
}
// fixme: where to init. this one ???
// FinishInitializeThread() seems to be called before
// Processor.CyclesPerSecond is set up
//static private ulong multiplier = Processor.CyclesPerSecond /
// TimeSpan.TicksPerSecond
#else
protected TimeSpan executionTime;
#endif
public TimeSpan ExecutionTime
{
#if THREAD_TIME_ACCOUNTING
//[NoHeapAllocation]
get
{
ulong m = Processor.CyclesPerSecond / TimeSpan.TicksPerSecond;
bool saved = Processor.DisableInterrupts();
try
{
if (Processor.GetCurrentThread() == this)
{
ulong now = Processor.CycleCount;
context.executionTime += now -
context.lastExecutionTimeUpdate;
LastUpdateTime = now;
}
}
finally
{
Processor.RestoreInterrupts(saved);
}
// fixme: this division is bad (slow), hot to get rid of it?
return new TimeSpan((long)(context.executionTime / m));
}
#else
[NoHeapAllocation]
get { return executionTime; }
#endif
}
#if THREAD_TIME_ACCOUNTING
// This provides access to the raw cycle counter, so access to it
// should be fast, compared to ExecutionTime. This might be useful
// for monitoring code which calls this often and can postprocess
// these times otherwise
public ulong RawExecutionTime
{
//[NoHeapAllocation]
get
{
bool saved = Processor.DisableInterrupts();
try
{
if (Processor.GetCurrentThread() == this)
{
ulong now = Processor.CycleCount;
context.executionTime += now -
context.lastExecutionTimeUpdate;
LastUpdateTime = now;
}
}
finally
{
Processor.RestoreInterrupts(saved);
}
return context.executionTime;
}
}
#endif
internal static
void VisitBootstrapData(NonNullReferenceVisitor visitor)
{
visitor.VisitReferenceFields(initialThread);
visitor.VisitReferenceFields(threadTable);
}
internal static void UpdateAfterGC()
{
// Update all the thread pointers in the thread contexts
for (int i = 0; i < threadTable.Length; i++) {
Thread thread = threadTable[i];
if (thread != null) {
thread.context.UpdateAfterGC(thread);
}
}
}
// Cache for ABI synchronization
private WaitHandle[] syncHandles;
internal WaitHandle[] GetSyncHandles(int num)
{
if (syncHandles == null || syncHandles.Length < num) {
syncHandles = new WaitHandle[num + 8];
}
return syncHandles;
}
// Cache for handle synchronization
private ThreadEntry[] entries;
internal ThreadEntry[] GetWaitEntries(int num)
{
if (entries == null || entries.Length < num) {
num += 8; // So we don't have to do this too frequently.
entries = new ThreadEntry[num];
for (int i = 0; i < num; i++) {
entries[i] = new ThreadEntry(this);
}
}
return entries;
}
// Caches for Select synchronization
// We use stacks, because selectable abstractions might
// internally implement HeadMatches using select receive
// which is called from within an outer select.
// NOTE however that internal selects should never block
// (use timeout)
private Stack selectBoolsStack;
private Stack selectObjectsStack;
private Stack selectSyncHandlesStack;
public bool[] PopSelectBools(int size)
{
if (selectBoolsStack == null) {
selectBoolsStack = new Stack();
}
if (selectBoolsStack.Count == 0) {
return new bool [size];
}
bool[] selectBools = (bool[])selectBoolsStack.Pop();
if (selectBools.Length < size) {
return new bool [size];
}
return selectBools;
}
public void PushSelectBools(bool[] cache) {
selectBoolsStack.Push(cache);
}
public ISelectable[] PopSelectObjects(int size)
{
if (selectObjectsStack == null) {
selectObjectsStack = new Stack();
}
if (selectObjectsStack.Count == 0) {
return new ISelectable [size];
}
ISelectable[] selectObjects = (ISelectable[])selectObjectsStack.Pop();
if (selectObjects.Length < size) {
return new ISelectable [size];
}
return selectObjects;
}
public void PushSelectObjects(ISelectable[] cache) {
for (int i=0; i<cache.Length; i++) {
cache[i] = null;
}
selectObjectsStack.Push(cache);
}
public SyncHandle[] PopSelectSyncHandles(int size)
{
if (selectSyncHandlesStack == null) {
selectSyncHandlesStack = new Stack();
}
if (selectSyncHandlesStack.Count == 0) {
return new SyncHandle [size];
}
SyncHandle[] selectSyncHandles = (SyncHandle[])selectSyncHandlesStack.Pop();
if (selectSyncHandles.Length < size) {
return new SyncHandle [size];
}
return selectSyncHandles;
}
public void PushSelectSyncHandles(SyncHandle[] cache) {
for (int i=0; i<cache.Length; i++) {
cache[i] = new SyncHandle();
}
selectSyncHandlesStack.Push(cache);
}
// Given a frame's range in memory (its esp/ebp), check whether
// the frame contains the top transition record. If so,
// prepare to skip over a process's frames.
[AccessedByRuntime("referenced from halasm.asm")]
[NoStackLinkCheck] // We don't want to throw an exception here;
// Therefore, we cannot risk allocating stack segments,
// and we should only call other NoStackLinkCheck functions (XXX).
internal static unsafe UIntPtr CheckKernelProcessBoundary(UIntPtr esp, UIntPtr ebp, Exception exn)
{
ThreadContext *context = Processor.GetCurrentThreadContext();
System.GCs.CallStack.TransitionRecord *topMarker = context->processMarkers;
System.GCs.CallStack.TransitionRecord *secondMarker = context->stackMarkers;
UIntPtr topMarkerPtr = (UIntPtr) topMarker;
// If the top marker is in our frame, we've reached a boundary:
if (esp < topMarkerPtr && topMarkerPtr <= ebp) {
Thread.CurrentThread.lastUncaughtException = exn;
// Is this a ProcessStopException? If not, it's a bug; log the bug.
if (!(exn is ProcessStopException)) {
// Log the bug, but don't do anything that could
// throw another exception (e.g. memory allocation).
// XXX: what if stack allocation throws an exception here?
DebugStub.Print("Bug: kernel exception thrown to process (saved to Thread.LastUncaughtException)\n");
Tracing.Log(Tracing.Warning, "Bug: kernel exception thrown to process (saved to Thread.LastUncaughtException)\n");
}
// atomic
// { // do these together so we never enter process mode
// remove top process->kernel marker from marker list
// remove top kernel->process marker from marker list
// }
bool iflag = Processor.DisableInterrupts();
Scheduler.DispatchLock();
try {
context->processMarkers = context->processMarkers->oldTransitionRecord;
context->stackMarkers = context->stackMarkers->oldTransitionRecord;
context->SetKernelMode();
}
finally {
Scheduler.DispatchRelease();
Processor.RestoreInterrupts(iflag);
}
//Return the kernel->process marker, in preparation for these operations:
// edx := retAddr from *stackBottom from kernel->process marker
// restore esp,ebp from kernel->process marker
// while(top kernel->process marker not in stack segment)
// pop (and free) stack segment
// restore ebx,edi,esi from kernel->process marker
return new UIntPtr(secondMarker);
}
else {
return 0;
}
}
// Discard any garbage stack segments that follow the segment
// containing the marker. After this runs, the topmost stack
// segment will contain the marker.
[AccessedByRuntime("referenced from halasm.asm")]
[NoStackLinkCheck]
internal static unsafe void DiscardSkippedStackSegments(System.GCs.CallStack.TransitionRecord *marker)
{
ThreadContext *context = Processor.GetCurrentThreadContext();
UIntPtr markerPtr = new UIntPtr(marker);
// while(top kernel->process marker not in stack segment)
// pop (and free) stack segment
//
// HACKHACK think about what this is doing. The topmost
// stack segment is the one *currently in use*. On a paging
// system, freeing it unmaps the underlying physical page.
// Needless to say, our ability to use esp after that is
// severely compromised.
//
#if !PAGING
while ((context->stackBegin != 0) && !(context->stackLimit <= markerPtr && markerPtr < context->stackBegin)) {
Microsoft.Singularity.Memory.Stacks.ReturnStackSegment(ref *context);
}
#endif
// Unlink marker:
context->stackMarkers = marker->oldTransitionRecord;
}
// Most recently thrown exception object that the thread
// did not catch at all (i.e. that propagated to the bottom
// of the stack without encountering an appropriate catch clause).
public Exception LastUncaughtException
{
[NoHeapAllocation]
get {
return lastUncaughtException;
}
}
#if PAGING
// Switch to a different protection domain. This is an advanced stunt
// for use by kernel threads only
internal static void SwitchToDomain(ProtectionDomain newDomain)
{
Thread currentThread = CurrentThread;
currentThread.CheckAddressSpaceConsistency();
AddressSpace processorSpace = Processor.GetCurrentAddressSpace();
AddressSpace newSpace = newDomain.AddressSpace;
if (newSpace != processorSpace) {
Processor.ChangeAddressSpace(newSpace);
currentThread.tempDomain = newDomain;
}
currentThread.CheckAddressSpaceConsistency();
}
// Call this to snap back to our parent process' domain.
internal static void RevertToParentDomain()
{
Thread currentThread = CurrentThread;
currentThread.CheckAddressSpaceConsistency();
Processor.ChangeAddressSpace(currentThread.process.Domain.AddressSpace);
currentThread.tempDomain = null;
currentThread.CheckAddressSpaceConsistency();
}
// This property provides the correct answer even when an
// arbitrary protection domain is temporarily being used
internal ProtectionDomain CurrentDomain {
get {
CheckAddressSpaceConsistency();
return (tempDomain != null) ? tempDomain : process.Domain;
}
}
[Inline]
private void CheckAddressSpaceConsistency()
{
ProtectionDomain currentDomain = (tempDomain != null) ? tempDomain : process.Domain;
DebugStub.Assert(Processor.GetCurrentAddressSpace() ==
currentDomain.AddressSpace);
}
#endif
}
}
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