///<summary>Derived class overrides <c>OnEnter</c> to provide specific reader locking semantics.</summary>
protected override void OnEnter(Boolean exclusive)
{
if (exclusive)
{
Interlocked.Increment(ref m_WriteRequests);
Interlocked.Increment(ref m_WritersWaiting);
Int64 startTime = Environment.TickCount;
InnerLock.Enter(exclusive);
// Only 1 thread is writing, so no thread safety is required here
m_WriterMaxWaitTime = Math.Max(m_WriterMaxWaitTime, checked ((Int64)(Environment.TickCount - startTime)));
Interlocked.Decrement(ref m_WritersWaiting);
Interlocked.Increment(ref m_WritersWriting);
m_WriterStartHoldTime = Environment.TickCount;
}
else
{
Interlocked.Increment(ref m_ReadRequests);
Interlocked.Increment(ref m_ReadersWaiting);
Int64 startTime = Environment.TickCount;
InnerLock.Enter(exclusive);
InterlockedEx.Max(ref m_ReaderMaxWaitTime, checked ((Int64)(Environment.TickCount - startTime)));
Interlocked.Decrement(ref m_ReadersWaiting);
Interlocked.Increment(ref m_ReadersReading);
Monitor.Enter(m_ReaderStartHoldTime);
m_ReaderStartHoldTime.Add(Thread.CurrentThread.ManagedThreadId, Environment.TickCount);
Monitor.Exit(m_ReaderStartHoldTime);
}
}
/// <summary>Implements the ResourceLock's WaitToWrite behavior.</summary>
protected override void OnEnter(Boolean exclusive)
{
Int32 CallingThreadId = Thread.CurrentThread.ManagedThreadId;
if (exclusive)
{
// If the calling thread already owns the lock, add 1 to the recursion count and return
if (CallingThreadId == m_WriterThreadIdAndRecurseCount.m_Id)
{
m_WriterThreadIdAndRecurseCount.m_Count++;
return;
}
InnerLock.Enter(exclusive);
Interlocked.Exchange(ref m_WriterThreadIdAndRecurseCount.m_Id, CallingThreadId);
m_WriterThreadIdAndRecurseCount.m_Count = 0;
}
else
{
Int32 index;
if (TryFindThreadIdIndex(CallingThreadId, out index))
{
// This thread has the reader lock, increment the count and return
m_ReaderThreadIdsAndRecurseCounts[index].m_Count++;
return;
}
// This thread doesn't have the lock, wait for it
InnerLock.Enter(exclusive);
// Record that this thread has the reader lock once
AddThreadIdWithRecurseCountOf1(CallingThreadId);
}
}
/// <summary>Implements the ResourceLock's Enter behavior.</summary>
protected override void OnEnter(Boolean exclusive)
{
StackTrace st = new System.Diagnostics.StackTrace(0, true);
using (new Timer(OnTimeout, st, m_timeout, -1)) {
if (exclusive)
{
InnerLock.Enter(exclusive);
}
}
}
protected override void OnEnter(Boolean exclusive)
{
if (exclusive)
{
InnerLock.Enter(exclusive);
VerifyNoWriters("Writing while already writing!");
VerifyNoReaders("Writing while already reading!");
InterlockedEx.BitTestAndSet(ref m_LockState, 31); // Add the writer
}
else
{
InnerLock.Enter(exclusive);
VerifyNoWriters("Reading while already writing!"); // Sanity check for no writers
Interlocked.Increment(ref m_LockState); // Add a reader
}
}