public void WhenDone_is_called_when_lock_is_acquired()
{
var l = new Lock<int>(1);
var first = l.Capture(new Result());
var second = l.Capture(new Result());
Assert.IsTrue(first.HasValue);
Assert.IsFalse(second.HasValue);
var reset = new ManualResetEvent(false);
second.WhenDone( _ => reset.Set());
l.Release();
Assert.IsTrue(reset.WaitOne(TimeSpan.FromSeconds(10),true));
Assert.IsTrue(second.HasValue);
l.Release();
}
public void Only_one_thread_can_acquire_the_lock_at_a_time()
{
var l = new Lock<int>(1);
var trigger = new ManualResetEvent(false);
var first = Async.Fork(() =>
{
trigger.WaitOne();
Thread.Sleep(200);
l.Capture(new Result()).Wait();
}, new Result());
Result secondInternal = null;
var second = Async.Fork(() =>
{
trigger.WaitOne();
secondInternal = l.Capture(new Result());
}, new Result());
trigger.Set();
Assert.IsFalse(first.HasValue);
second.Wait();
l.Release();
Assert.IsTrue(secondInternal.HasValue);
Assert.IsFalse(first.HasValue);
secondInternal.Wait();
first.Wait();
Assert.IsTrue(first.HasValue);
}
public override void PerformTest()
{
Log("Creating " + _numberOfThreads + " threads");
Thread[] threads = new Thread[_numberOfThreads];
for (int i = 0; i < _numberOfThreads; i++)
{
threads[i] = new Thread(Work, ThreadPriority.Normal);
}
_startedThreads = 0;
_startedThreadsLock = new Lock();
_allThreadsStartedLock = new Lock();
_allThreadsStartedCondition = new Condition(_allThreadsStartedLock);
_allThreadsStartedLock.Acquire();
Log("Starting " + _numberOfThreads + " threads"); // TODO: ParametizedThreadStart doesn't work properly
for (int i = 0; i < _numberOfThreads; i++)
{
threads[i].Start();
}
// wait for all threads to be running
_allThreadsStartedCondition.Await();
_allThreadsStartedLock.Release();
Log("Waiting for all threads to finish");
_semaphore.Acquire(_numberOfThreads); // wait for all threads to finish
Assert(_failedThreads + " threads failed the calculation", _failedThreads == 0);
Log("All " + _numberOfThreads + " threads finished");
}
private void PerformCallback(bool timedOut)
{
bool lockAcquired;
var spinner = new SpinWait();
// Prevent the race condition with Unregister and the previous PerformCallback call, which may still be
// holding the _lock.
while (!(lockAcquired = _lock.TryAcquire(0)) && !Volatile.Read(ref _unregistering))
{
spinner.SpinOnce();
}
// If another thread is running Unregister, no need to restart the timer or clean up
if (lockAcquired)
{
try
{
if (!_unregistering)
{
if (_repeating)
{
// Allow this wait to fire again. Restart the timer before executing the callback.
RestartWait();
}
else
{
// This wait will not be fired again. Free the GC handle to allow the GC to collect this object.
Debug.Assert(_gcHandle.IsAllocated);
_gcHandle.Free();
}
}
}
finally
{
_lock.Release();
}
}
_ThreadPoolWaitOrTimerCallback.PerformWaitOrTimerCallback(_callbackHelper, timedOut);
}
public void Dispose()
{
_lock.Release();
}
/// <summary>
/// Blocks the current thread until it can enter the <see cref="SemaphoreSlim"/>,
/// using a 32-bit signed integer to measure the time interval,
/// while observing a <see cref="T:System.Threading.CancellationToken"/>.
/// </summary>
/// <param name="millisecondsTimeout">The number of milliseconds to wait, or <see cref="Timeout.Infinite"/>(-1) to
/// wait indefinitely.</param>
/// <param name="cancellationToken">The <see cref="T:System.Threading.CancellationToken"/> to observe.</param>
/// <returns>true if the current thread successfully entered the <see cref="SemaphoreSlim"/>; otherwise, false.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="millisecondsTimeout"/> is a negative number other than -1,
/// which represents an infinite time-out.</exception>
/// <exception cref="System.OperationCanceledException"><paramref name="cancellationToken"/> was canceled.</exception>
public bool Wait(int millisecondsTimeout, CancellationToken cancellationToken)
{
CheckDispose();
// Validate input
if (millisecondsTimeout < -1)
{
throw new ArgumentOutOfRangeException(
"totalMilliSeconds", millisecondsTimeout, SR.SemaphoreSlim_Wait_TimeoutWrong);
}
cancellationToken.ThrowIfCancellationRequested();
uint startTime = 0;
if (millisecondsTimeout != Timeout.Infinite && millisecondsTimeout > 0)
{
startTime = TimeoutHelper.GetTime();
}
bool waitSuccessful = false;
Task <bool> asyncWaitTask = null;
bool lockTaken = false;
//Register for cancellation outside of the main lock.
//NOTE: Register/deregister inside the lock can deadlock as different lock acquisition orders could
// occur for (1)this.m_lockObj and (2)cts.internalLock
CancellationTokenRegistration cancellationTokenRegistration = cancellationToken.InternalRegisterWithoutEC(s_cancellationTokenCanceledEventHandler, this);
try
{
// Perf: first spin wait for the count to be positive, but only up to the first planned yield.
// This additional amount of spinwaiting in addition
// to Monitor.Enter()’s spinwaiting has shown measurable perf gains in test scenarios.
//
SpinWait spin = new SpinWait();
while (m_currentCount == 0 && !spin.NextSpinWillYield)
{
spin.SpinOnce();
}
// entering the lock and incrementing waiters must not suffer a thread-abort, else we cannot
// clean up m_waitCount correctly, which may lead to deadlock due to non-woken waiters.
try { }
finally
{
m_lock.Acquire();
lockTaken = true;
if (lockTaken)
{
m_waitCount++;
}
}
// If there are any async waiters, for fairness we'll get in line behind
// then by translating our synchronous wait into an asynchronous one that we
// then block on (once we've released the lock).
if (m_asyncHead != null)
{
Debug.Assert(m_asyncTail != null, "tail should not be null if head isn't");
asyncWaitTask = WaitAsync(millisecondsTimeout, cancellationToken);
}
// There are no async waiters, so we can proceed with normal synchronous waiting.
else
{
// If the count > 0 we are good to move on.
// If not, then wait if we were given allowed some wait duration
OperationCanceledException oce = null;
if (m_currentCount == 0)
{
if (millisecondsTimeout == 0)
{
return(false);
}
// Prepare for the main wait...
// wait until the count become greater than zero or the timeout is expired
try
{
waitSuccessful = WaitUntilCountOrTimeout(millisecondsTimeout, startTime, cancellationToken);
}
catch (OperationCanceledException e) { oce = e; }
}
// Now try to acquire. We prioritize acquisition over cancellation/timeout so that we don't
// lose any counts when there are asynchronous waiters in the mix. Asynchronous waiters
// defer to synchronous waiters in priority, which means that if it's possible an asynchronous
// waiter didn't get released because a synchronous waiter was present, we need to ensure
// that synchronous waiter succeeds so that they have a chance to release.
Debug.Assert(!waitSuccessful || m_currentCount > 0,
"If the wait was successful, there should be count available.");
if (m_currentCount > 0)
{
waitSuccessful = true;
m_currentCount--;
}
else if (oce != null)
{
throw oce;
}
// Exposing wait handle which is lazily initialized if needed
if (m_waitHandle != null && m_currentCount == 0)
{
m_waitHandle.Reset();
}
}
}
finally
{
// Release the lock
if (lockTaken)
{
m_waitCount--;
m_lock.Release();
}
// Unregister the cancellation callback.
cancellationTokenRegistration.Dispose();
}
// If we had to fall back to asynchronous waiting, block on it
// here now that we've released the lock, and return its
// result when available. Otherwise, this was a synchronous
// wait, and whether we successfully acquired the semaphore is
// stored in waitSuccessful.
return((asyncWaitTask != null) ? asyncWaitTask.GetAwaiter().GetResult() : waitSuccessful);
}
internal readonly Codec Codec; // for writing new segments
/// <summary>
/// Constructs a new IndexWriter per the settings given in <code>conf</code>.
/// If you want to make "live" changes to this writer instance, use
/// <seealso cref="#getConfig()"/>.
///
/// <p>
/// <b>NOTE:</b> after ths writer is created, the given configuration instance
/// cannot be passed to another writer. If you intend to do so, you should
/// <seealso cref="IndexWriterConfig#clone() clone"/> it beforehand.
/// </summary>
/// <param name="d">
/// the index directory. The index is either created or appended
/// according <code>conf.getOpenMode()</code>. </param>
/// <param name="conf">
/// the configuration settings according to which IndexWriter should
/// be initialized. </param>
/// <exception cref="IOException">
/// if the directory cannot be read/written to, or if it does not
/// exist and <code>conf.getOpenMode()</code> is
/// <code>OpenMode.APPEND</code> or if there is any other low-level
/// IO error </exception>
public IndexWriter(Directory d, IndexWriterConfig conf)
{
/*if (!InstanceFieldsInitialized)
{
InitializeInstanceFields();
InstanceFieldsInitialized = true;
}*/
readerPool = new ReaderPool(this);
conf.SetIndexWriter(this); // prevent reuse by other instances
Config_Renamed = new LiveIndexWriterConfig(conf);
directory = d;
analyzer = Config_Renamed.Analyzer;
infoStream = Config_Renamed.InfoStream;
mergePolicy = Config_Renamed.MergePolicy;
mergePolicy.IndexWriter = this;
mergeScheduler = Config_Renamed.MergeScheduler;
Codec = Config_Renamed.Codec;
BufferedUpdatesStream = new BufferedUpdatesStream(infoStream);
PoolReaders = Config_Renamed.ReaderPooling;
WriteLock = directory.MakeLock(WRITE_LOCK_NAME);
if (!WriteLock.Obtain(Config_Renamed.WriteLockTimeout)) // obtain write lock
{
throw new LockObtainFailedException("Index locked for write: " + WriteLock);
}
bool success = false;
try
{
OpenMode_e? mode = Config_Renamed.OpenMode;
bool create;
if (mode == OpenMode_e.CREATE)
{
create = true;
}
else if (mode == OpenMode_e.APPEND)
{
create = false;
}
else
{
// CREATE_OR_APPEND - create only if an index does not exist
create = !DirectoryReader.IndexExists(directory);
}
// If index is too old, reading the segments will throw
// IndexFormatTooOldException.
segmentInfos = new SegmentInfos();
bool initialIndexExists = true;
if (create)
{
// Try to read first. this is to allow create
// against an index that's currently open for
// searching. In this case we write the next
// segments_N file with no segments:
try
{
segmentInfos.Read(directory);
segmentInfos.Clear();
}
catch (IOException)
{
// Likely this means it's a fresh directory
initialIndexExists = false;
}
// Record that we have a change (zero out all
// segments) pending:
Changed();
}
else
{
segmentInfos.Read(directory);
IndexCommit commit = Config_Renamed.IndexCommit;
if (commit != null)
{
// Swap out all segments, but, keep metadata in
// SegmentInfos, like version & generation, to
// preserve write-once. this is important if
// readers are open against the future commit
// points.
if (commit.Directory != directory)
{
throw new System.ArgumentException("IndexCommit's directory doesn't match my directory");
}
SegmentInfos oldInfos = new SegmentInfos();
oldInfos.Read(directory, commit.SegmentsFileName);
segmentInfos.Replace(oldInfos);
Changed();
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "init: loaded commit \"" + commit.SegmentsFileName + "\"");
}
}
}
RollbackSegments = segmentInfos.CreateBackupSegmentInfos();
// start with previous field numbers, but new FieldInfos
GlobalFieldNumberMap = FieldNumberMap;
Config_Renamed.FlushPolicy.Init(Config_Renamed);
DocWriter = new DocumentsWriter(this, Config_Renamed, directory);
eventQueue = DocWriter.EventQueue();
// Default deleter (for backwards compatibility) is
// KeepOnlyLastCommitDeleter:
lock (this)
{
Deleter = new IndexFileDeleter(directory, Config_Renamed.DelPolicy, segmentInfos, infoStream, this, initialIndexExists);
}
if (Deleter.StartingCommitDeleted)
{
// Deletion policy deleted the "head" commit point.
// We have to mark ourself as changed so that if we
// are closed w/o any further changes we write a new
// segments_N file.
Changed();
}
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "init: create=" + create);
MessageState();
}
success = true;
}
finally
{
if (!success)
{
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "init: hit exception on init; releasing write lock");
}
WriteLock.Release();
IOUtils.CloseWhileHandlingException(WriteLock);
WriteLock = null;
}
}
}
private void RollbackInternal()
{
bool success = false;
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "rollback");
}
try
{
lock (this)
{
FinishMerges(false);
StopMerges = true;
}
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "rollback: done finish merges");
}
// Must pre-close these two, in case they increment
// changeCount so that we can then set it to false
// before calling closeInternal
mergePolicy.Dispose();
mergeScheduler.Dispose();
BufferedUpdatesStream.Clear();
DocWriter.Dispose(); // mark it as closed first to prevent subsequent indexing actions/flushes
DocWriter.Abort(this); // don't sync on IW here
lock (this)
{
if (PendingCommit != null)
{
PendingCommit.RollbackCommit(directory);
Deleter.DecRef(PendingCommit);
PendingCommit = null;
Monitor.PulseAll(this);
}
// Don't bother saving any changes in our segmentInfos
readerPool.DropAll(false);
// Keep the same segmentInfos instance but replace all
// of its SegmentInfo instances. this is so the next
// attempt to commit using this instance of IndexWriter
// will always write to a new generation ("write
// once").
segmentInfos.RollbackSegmentInfos(RollbackSegments);
if (infoStream.IsEnabled("IW"))
{
infoStream.Message("IW", "rollback: infos=" + SegString(segmentInfos.Segments));
}
Debug.Assert(TestPoint("rollback before checkpoint"));
// Ask deleter to locate unreferenced files & remove
// them:
Deleter.Checkpoint(segmentInfos, false);
Deleter.Refresh();
LastCommitChangeCount = ChangeCount;
Deleter.Refresh();
Deleter.Dispose();
WriteLock.Release();
IOUtils.Close(WriteLock); // release write lock
WriteLock = null;
Debug.Assert(DocWriter.PerThreadPool.NumDeactivatedThreadStates() == DocWriter.PerThreadPool.MaxThreadStates, "" + DocWriter.PerThreadPool.NumDeactivatedThreadStates() + " " + DocWriter.PerThreadPool.MaxThreadStates);
}
success = true;
}
catch (System.OutOfMemoryException oom)
{
HandleOOM(oom, "rollbackInternal");
}
finally
{
if (!success)
{
// Must not hold IW's lock while closing
// mergePolicy/Scheduler: this can lead to deadlock,
// e.g. TestIW.testThreadInterruptDeadlock
IOUtils.CloseWhileHandlingException(mergePolicy, mergeScheduler);
}
lock (this)
{
if (!success)
{
// we tried to be nice about it: do the minimum
// don't leak a segments_N file if there is a pending commit
if (PendingCommit != null)
{
try
{
PendingCommit.RollbackCommit(directory);
Deleter.DecRef(PendingCommit);
}
catch (Exception)
{
}
}
// close all the closeables we can (but important is readerPool and writeLock to prevent leaks)
if (WriteLock != null)
{
WriteLock.Release();
}
IOUtils.CloseWhileHandlingException(readerPool, Deleter, WriteLock);
WriteLock = null;
}
closed = true;
Closing = false;
}
}
}