A SampleClient that buffers its received samples, using a pair of STL vectors, and then sends the buffered samples onto its SampleClients. More...

#include <SampleBuffer.h>

Inheritance diagram for nidas::core::SampleBuffer:

[legend]

Public Types
enum	runStatus { RUN_CANCELED = -1, RUN_OK = 0, NOT_RUNNING = 1, RUN_EXCEPTION = 2 }
	Values that can be returned by run method. More...

enum	SchedPolicy { NU_THREAD_OTHER =SCHED_OTHER, NU_THREAD_FIFO =SCHED_FIFO, NU_THREAD_RR =SCHED_RR }

Public Member Functions
	SampleBuffer (const std::string &name, bool raw)
	Constructor. More...

virtual	~SampleBuffer ()

void	setKeepStats (bool val)

bool	getKeepStats () const

SampleSource *	getRawSampleSource ()
	Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples. More...

SampleSource *	getProcessedSampleSource ()
	Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples. More...

void	addSampleTag (const SampleTag *tag) throw ()
	How to tell this SampleBuffer what sample tags it will be sorting. More...

void	removeSampleTag (const SampleTag *tag) throw ()

std::list< const SampleTag * >	getSampleTags () const
	Implementation of SampleSource::getSampleTags(). More...

SampleTagIterator	getSampleTagIterator () const
	Implementation of SampleSource::getSampleTagIterator(). More...

void	addSampleClient (SampleClient *client) throw ()
	Implementation of SampleSource::addSampleClient(). More...

void	removeSampleClient (SampleClient *client) throw ()
	Remove a SampleClient from this SampleSource. More...

void	addSampleClientForTag (SampleClient client, const SampleTag tag) throw ()
	Add a Client for a given SampleTag. More...

void	removeSampleClientForTag (SampleClient client, const SampleTag tag) throw ()
	Remove a SampleClient for a given SampleTag from this SampleSource. More...

int	getClientCount () const throw ()
	How many SampleClients are currently in my list. More...

const SampleStats &	getSampleStats () const

void	flush () throw ()
	flush all samples from buffer, distributing them to SampleClients. More...

void	interrupt ()
	Interrupt this thread. More...

bool	receive (const Sample *s) throw ()
	Insert a sample in the buffer, where it is then passed on to SampleClients. More...

size_t	size () const
	Current number of samples in the buffer. More...

void	setLengthSecs (float)

float	getLengthSecs () const

void	setHeapMax (size_t val)
	Set the maximum amount of heap memory to use for sorting samples. More...

size_t	getHeapMax () const

size_t	getHeapSize () const
	Get the current amount of heap being used for sorting. More...

void	setHeapBlock (bool val)

bool	getHeapBlock () const

size_t	getNumDiscardedSamples () const
	Number of samples discarded because of _heapSize > _heapMax and heapBlock == true. More...

size_t	getNumFutureSamples () const
	Number of samples discarded because their timetags were in the future. More...

void	setRealTime (bool val)
	Is this sorter running in real-time? If so then we can screen for bad time-tags by checking against the system clock, which is trusted. More...

bool	getRealTime () const

void	setLateSampleCacheSize (unsigned int)

unsigned int	getLateSampleCacheSize () const

virtual void	start () throw (Exception)
	Start the thread running, meaning execute the run method in a separate thread. More...

virtual int	join () throw (Exception)
	The calling thread joins this thread, waiting until the thread finishes, which means either that the run() method returned, the thread called pthread_exit() or the thread was cancelled. More...

virtual void	kill (int sig) throw (Exception)
	Send a signal to this thread. More...

virtual void	cancel () throw (Exception)
	Cancel this thread. More...

virtual bool	isInterrupted () const
	Return true when this thread has been interrupted. More...

virtual bool	isRunning () const
	Is this thread running? More...

virtual bool	isJoined () const
	Has this thread been joined? More...

virtual bool	isDetached () const
	Is this a detached thread. More...

bool	isCancelEnabled () const
	Return true if the cancel state of this thread is PTHREAD_CANCEL_ENABLE. More...

bool	isCancelDeferred () const
	Return true if the cancel type of this thread is PTHREAD_CANCEL_DEFERRED. More...

const std::string &	getName () const throw ()
	Return the name of this thread. More...

const std::string &	getFullName () throw ()
	Return a name with a bunch of descriptive fields, specifying whether it is detached, the real-time priority, etc. More...

bool	setRealTimeRoundRobinPriority (int val) throw (Exception)

bool	setRealTimeFIFOPriority (int val) throw (Exception)

bool	setNonRealTimePriority () throw (Exception)

void	setThreadScheduler (enum SchedPolicy policy, int priority) throw (Exception)

void	blockSignal (int)
	Block a signal in this thread. More...

void	unblockSignal (int)
	Install a signal handler and unblock the signal. More...

Static Public Member Functions
static Thread *	currentThread ()
	Return the thread object for the current thread. More...

static pthread_t	currentThreadId ()

static Thread *	lookupThread (pthread_t id)

static const std::string &	currentName ()
	Convenience routine to return the name for the current thread, or a string indicating that the name of the thread is unknown. More...

static std::string	getPolicyString (int policy)
	Convenience function to return a string for the given scheduler policy: "Non-RT", "RT:FIFO", "RT:RR" or "RT:Unknown". More...

static int	test (int argc, char **argv)
	a test method. More...

Protected Member Functions
void	setCancelEnabled (bool val)
	Set the cancel state for this thread - false means cancel requests are ignored. More...

void	setCancelDeferred (bool val)
	Set the cancel type for this thread. More...

pthread_t	getId () const

void	testCancel () const
	Check if we have been cancelled. More...

virtual bool	amInterrupted () const
	Call testCancel, and return true when this thread has been interrupted. More...

Private Member Functions
int	run () throw (nidas::util::Exception)
	Thread run function. More...

void	heapDecrement (size_t bytes)
	Utility function to decrement the heap size after writing one or more samples. More...

size_t	sizeNoLock () const

bool	emptyNoLock () const

	SampleBuffer (const SampleBuffer &)
	No copy. More...

SampleBuffer &	operator= (const SampleBuffer &)
	No assignment. More...

Private Attributes
std::vector< const Sample * >	_sampleBufs [2]

std::vector< const Sample * > *	_inserterBuf

std::vector< const Sample * > *	_consumerBuf

SampleSourceSupport	_source

nidas::util::Cond	_sampleBufCond

nidas::util::Cond	_flushCond

size_t	_heapMax
	Limit on the maximum size of memory to use while buffering samples. More...

size_t	_heapSize
	Current heap size, in bytes. More...

bool	_heapBlock
	_heapBlock controls what happens when the number of bytes in _samples exceeds _heapMax. More...

nidas::util::Cond	_heapCond

size_t	_discardedSamples
	Number of samples discarded because of _heapSize > _heapMax and heapBlock == true. More...

size_t	_realTimeFutureSamples
	Number of samples discarded because getRealTime() is true and the samples have timetags later than the system clock. More...

int	_discardWarningCount
	How often to log warnings about discardedSamples. More...

bool	_doFlush

bool	_flushed

bool	_realTime
	Is this sorter running in real-time? If so then we can screen for bad time-tags by checking against the system clock, which is trusted. More...

Detailed Description

A SampleClient that buffers its received samples, using a pair of STL vectors, and then sends the buffered samples onto its SampleClients.

Member Enumeration Documentation

enum nidas::util::Thread::runStatus

inherited

Values that can be returned by run method.

User can define other values greater than RUN_EXCEPTION. These values are then returned by int join(). Note that PTHREAD_CANCELLED is -1

Enumerator
RUN_CANCELED
RUN_OK
NOT_RUNNING
RUN_EXCEPTION

enum nidas::util::Thread::SchedPolicy

inherited

Enumerator
NU_THREAD_OTHER
NU_THREAD_FIFO
NU_THREAD_RR

Constructor & Destructor Documentation

SampleBuffer::SampleBuffer	(	const std::string &	name,
		bool	raw
	)

Constructor.

References _consumerBuf, _inserterBuf, and _sampleBufs.

SampleBuffer::~SampleBuffer ( )

virtual

References nidas::util::Logger::getInstance(), interrupt(), nidas::util::Thread::isJoined(), nidas::util::Thread::isRunning(), nidas::util::Thread::join(), nidas::util::Logger::log(), LOG_WARNING, and nidas::util::Exception::what().

nidas::core::SampleBuffer::SampleBuffer ( const SampleBuffer & )

private

No copy.

Member Function Documentation

void nidas::core::SampleBuffer::addSampleClient	(	SampleClient *	client	)
throw	(
	)

inlinevirtual

Implementation of SampleSource::addSampleClient().

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::addSampleClient().

void nidas::core::SampleBuffer::addSampleClientForTag	(	SampleClient *	client,
		const SampleTag *	tag
	)
throw	(
	)

inlinevirtual

Add a Client for a given SampleTag.

Implementation of SampleSource::addSampleClient().

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::addSampleClientForTag().

void nidas::core::SampleBuffer::addSampleTag	(	const SampleTag *	tag	)
throw	(
	)

inlinevirtual

How to tell this SampleBuffer what sample tags it will be sorting.

SampleClients can then query it.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::addSampleTag().

bool Runnable::amInterrupted ( ) const

protectedvirtualinherited

Call testCancel, and return true when this thread has been interrupted.

This is protected because it should only called within the run method of the thread.

Referenced by nidas::core::SampleOutputRequestThread::run(), nidas::core::Looper::run(), nidas::dynld::isff::GOESOutput::run(), nidas::core::DSMServerStat::run(), and nidas::util::Thread::test().

void Thread::blockSignal ( int sig )

inherited

Block a signal in this thread.

This method is usually called before this Thread has started. If this Thread is currently running, then this method is only effective if called from this Thread, i.e. from its own run() method.

Because SIGINT, SIGTERM and SIGHUP are typically caught in the main thread, they are blocked by default in a Thread. Call unblockSignal(sig) if you want to catch them in a Thread.

References nidas::util::Thread::_blockedSignals, nidas::util::Thread::_unblockedSignals, nidas::util::Thread::currentThread(), nidas::util::Thread::isRunning(), and nidas::util::Thread::thr_add_sig().

Referenced by nidas::dynld::UDPSampleOutput::ConnectionMonitor::ConnectionMonitor(), nidas::core::ServerSocket::ConnectionThread::ConnectionThread(), nidas::core::DerivedDataReader::DerivedDataReader(), nidas::util::McSocketListener::McSocketListener(), nidas::util::McSocketMulticaster< SocketTT >::McSocketMulticaster(), nidas::core::SensorHandler::SensorHandler(), nidas::core::SensorOpener::SensorOpener(), nidas::util::Thread::test(), nidas::dynld::RawSampleService::Worker::Worker(), nidas::core::XmlRpcThread::XmlRpcThread(), and nidas::dynld::UDPSampleOutput::XMLSocketListener::XMLSocketListener().

void Thread::cancel	(		)
throw	(	Exception
	)

virtualinherited

Cancel this thread.

References nidas::util::Thread::_id, nidas::util::Thread::_mutex, nidas::util::Exception::errnoToString(), and nidas::util::Thread::getName().

Referenced by nidas::core::DSMService::cancel(), nidas::dynld::isff::GOESOutput::cancelThread(), nidas::core::DerivedDataReader::deleteInstance(), and nidas::core::DSMEngine::joinDataThreads().

static const std::string& nidas::util::Thread::currentName ( )

inlinestaticinherited

Convenience routine to return the name for the current thread, or a string indicating that the name of the thread is unknown.

References nidas::util::Thread::currentThread(), nidas::util::Thread::getName(), and nidas::util::Thread::unknownName.

Referenced by nidas::util::Logger::msg_locked().

Thread * Thread::currentThread ( )

staticinherited

Return the thread object for the current thread.

Returns null if not found.

Referenced by nidas::util::Thread::blockSignal(), nidas::util::Thread::currentName(), and nidas::util::Thread::unblockSignal().

pthread_t Thread::currentThreadId ( )

staticinherited

Referenced by nidas::core::Looper::removeClient().

bool SampleBuffer::emptyNoLock ( ) const

private

References _consumerBuf, and _inserterBuf.

Referenced by run().

void SampleBuffer::flush	(	)
throw	(
	)

virtual

flush all samples from buffer, distributing them to SampleClients.

Implements nidas::core::SampleThread.

int nidas::core::SampleBuffer::getClientCount	(	)	const
throw	(
	)

inlinevirtual

How many SampleClients are currently in my list.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getClientCount().

const std::string & Thread::getFullName	(	)
throw	(
	)

inherited

Return a name with a bunch of descriptive fields, specifying whether it is detached, the real-time priority, etc.

References nidas::util::Thread::_fullname.

Referenced by nidas::util::Thread::pRun(), nidas::util::Thread::test(), nidas::util::Thread::thr_cleanup(), and nidas::util::Thread::thr_cleanup_delete().

bool nidas::core::SampleBuffer::getHeapBlock ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

References _heapBlock.

size_t nidas::core::SampleBuffer::getHeapMax ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

References _heapMax.

size_t nidas::core::SampleBuffer::getHeapSize ( ) const

inlinevirtual

Get the current amount of heap being used for sorting.

Implements nidas::core::SampleThread.

References _heapSize.

pthread_t nidas::util::Thread::getId ( ) const

inlineprotectedinherited

References nidas::util::Thread::_id, and nidas::util::Thread::_mutex.

Referenced by nidas::util::Thread::isJoined(), nidas::util::Thread::join(), nidas::util::Thread::pRun(), and nidas::core::Looper::removeClient().

bool nidas::core::SampleBuffer::getKeepStats ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

References _source, and nidas::core::SampleSourceSupport::getKeepStats().

unsigned int nidas::core::SampleBuffer::getLateSampleCacheSize ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

float nidas::core::SampleBuffer::getLengthSecs ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

const std::string & Thread::getName	(	)	const
throw	(
	)

inherited

Return the name of this thread.

References nidas::util::Thread::_name.

size_t nidas::core::SampleBuffer::getNumDiscardedSamples ( ) const

inlinevirtual

Number of samples discarded because of _heapSize > _heapMax and heapBlock == true.

Implements nidas::core::SampleThread.

References _discardedSamples.

size_t nidas::core::SampleBuffer::getNumFutureSamples ( ) const

inlinevirtual

Number of samples discarded because their timetags were in the future.

Implements nidas::core::SampleThread.

References _realTimeFutureSamples.

string Thread::getPolicyString ( int policy )

staticinherited

Convenience function to return a string for the given scheduler policy: "Non-RT", "RT:FIFO", "RT:RR" or "RT:Unknown".

References nidas::util::Thread::NU_THREAD_FIFO, nidas::util::Thread::NU_THREAD_OTHER, and nidas::util::Thread::NU_THREAD_RR.

Referenced by nidas::core::DSMSensor::getLooper(), and nidas::util::Thread::makeFullName().

SampleSource* nidas::core::SampleBuffer::getProcessedSampleSource ( )

inlinevirtual

Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples.

SampleClients use this method to get a pointer to whatever sample source they are interested in. Derived classes can return NULL if they are not a SampleSource of processed samples.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getProcessedSampleSource().

SampleSource* nidas::core::SampleBuffer::getRawSampleSource ( )

inlinevirtual

Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples.

SampleClients use this method to get a pointer to whatever sample source they are interested in. Derived classes can return NULL if they are not a SampleSource of raw samples.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getRawSampleSource().

bool nidas::core::SampleBuffer::getRealTime ( ) const

inlinevirtual

Implements nidas::core::SampleThread.

References _realTime.

const SampleStats& nidas::core::SampleBuffer::getSampleStats ( ) const

inlinevirtual

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getSampleStats().

SampleTagIterator nidas::core::SampleBuffer::getSampleTagIterator ( ) const

inlinevirtual

Implementation of SampleSource::getSampleTagIterator().

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getSampleTagIterator().

std::list<const SampleTag*> nidas::core::SampleBuffer::getSampleTags ( ) const

inlinevirtual

Implementation of SampleSource::getSampleTags().

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::getSampleTags().

void SampleBuffer::heapDecrement ( size_t bytes )

private

Utility function to decrement the heap size after writing one or more samples.

If the heapSize has has shrunk below heapMax then signal any threads waiting on heapCond.

References _heapBlock, _heapCond, _heapMax, _heapSize, nidas::util::Cond::lock(), nidas::util::Cond::signal(), and nidas::util::Cond::unlock().

Referenced by run().

void SampleBuffer::interrupt ( )

virtual

Interrupt this thread.

This sets a boolean which can be tested with isInterrupted(). It is up to the run() implementation to return when interrupted. This is a "soft" request to terminate the thread.

What follows is a discussion of when to use cancel(), kill(), or interrupt() to terminate a thread.

If you can consistently check the state of isInterrupted() in the run method, and return if it is true, at a time interval which is an acceptable amount of time to wait for the thread to terminate, then using interrupt() should work well.

If the run method does I/O, then things are usually a bit more complicated.

If all I/O is guaranteed to finish quickly, which is a rare situation, or is done with a timeout, such as using select/poll with a timeout before every read/write, then one could still use interrupt() as above, and the thread will terminate within the timeout period.

If the thread does blocking I/O operations, and the I/O might block for a period of time longer than you're willing to wait for the thread to terminate, then you need to use kill(sig) or cancel().

If a signal is sent to the thread with kill(sig) while the thread is blocking on an I/O operation, the I/O will immediately return with an errno of EINTR, and one could then return from the run method, after any necessary cleanup.

However there is a possibility that the signal could be missed. In order to make sure you receive a signal, you must block it, so that any received signals are held as pending, and then atomically unblock it with pselect/ppoll/epoll_pwait before performing the I/O operation.

If you do not use I/O timeouts, or kill(sig) with pselect/ppoll/epoll_pwait, or other tricks such as writing to a pipe that is watched with select/poll in the run method, then using cancel() is the only way to guarantee that your thread will terminate in an acceptable amount of time.

All NIDAS Threads support deferred cancelation. Immediate asynchronous cancellation is not fully supported (and is very hard to get right). Deferred cancelation means that cancellation is delayed until the thread next calls a system function that is a cancellation point. At that point the thread run method will simply terminate without any return value from the system function, and then execute any cleanup methods that may have been registered with pthread_cleanup_push.

A list of cancellation points is provided in the pthreads(7) man page. Cancellation points are typically I/O operations, waits or sleeps.

This immediate thread termination can be a problem if there is a possibility that your objects could be left in a bad state, such as with a mutex locked, though it isn't generally a good practice to hold mutexes during a time-consuming I/O operation, wait or sleep.

One should check the run method to see if the state of the objects is OK if execution stops at any of the cancellation points. Note that logging a message, or writing to cerr is a cancellation point. Typically there is error/exception handling associated with an I/O operation. Ensuring the state is OK upon a cancellation is similar to preparation for a fatal I/O error that requires a return of the run method. One can use setCancelEnabled() to defer cancellation.

One can use pthread_cleanup_push and pthread_cleanup_pop to register cleanup routines that are called when a thread is cancelled if special handling is required.

Reimplemented from nidas::util::Thread.

References _sampleBufCond, nidas::util::Cond::lock(), nidas::util::Cond::signal(), and nidas::util::Cond::unlock().

Referenced by ~SampleBuffer().

bool Thread::isCancelDeferred ( ) const

inherited

Return true if the cancel type of this thread is PTHREAD_CANCEL_DEFERRED.

References nidas::util::Thread::_cancel_deferred.

bool Thread::isCancelEnabled ( ) const

inherited

Return true if the cancel state of this thread is PTHREAD_CANCEL_ENABLE.

References nidas::util::Thread::_cancel_enabled.

virtual bool nidas::util::Thread::isDetached ( ) const

inlinevirtualinherited

Is this a detached thread.

References nidas::util::Thread::_detached.

virtual bool nidas::util::Thread::isInterrupted ( ) const

inlinevirtualinherited

Return true when this thread has been interrupted.

Implements nidas::util::Runnable.

References nidas::util::Thread::_interrupted, and nidas::util::Thread::_mutex.

Referenced by nidas::core::SampleSorter::flush(), nidas::core::SampleOutputRequestThread::run(), nidas::core::StatusListener::run(), nidas::core::DerivedDataReader::run(), nidas::core::SensorOpener::run(), Sender::run(), nidas::core::DSMEngineStat::run(), nidas::core::SensorHandler::run(), nidas::core::FsMountWorkerThread::run(), ModemLineSetter::run(), ModemLineMonitor::run(), run(), nidas::core::SampleSorter::run(), ServerThread::run(), nidas::util::McSocketListener::run(), and nidas::dynld::raf::SyncServer::stop().

virtual bool nidas::util::Thread::isJoined ( ) const

inlinevirtualinherited

Has this thread been joined?

References nidas::util::Thread::getId().

Referenced by nidas::core::FsMount::cancel(), nidas::core::DerivedDataReader::deleteInstance(), nidas::core::SensorHandler::join(), nidas::dynld::isff::GOESOutput::joinThread(), nidas::util::Thread::test(), ~SampleBuffer(), nidas::core::SampleSorter::~SampleSorter(), and nidas::util::Thread::~Thread().

virtual bool nidas::util::Thread::isRunning ( ) const

inlinevirtualinherited

Is this thread running?

References nidas::util::Thread::_mutex, and nidas::util::Thread::_running.

Referenced by nidas::util::Thread::blockSignal(), nidas::core::DSMService::cancel(), nidas::core::FsMount::cancel(), nidas::dynld::isff::GOESOutput::cancelThread(), nidas::core::DSMService::checkSubThreads(), nidas::dynld::UDPSampleOutput::XMLSocketListener::checkWorkers(), nidas::dynld::UDPSampleOutput::close(), nidas::util::McSocket< SocketT >::close(), nidas::core::DerivedDataReader::deleteInstance(), nidas::core::DSMService::interrupt(), nidas::core::SamplePipeline::join(), nidas::dynld::isff::GOESOutput::joinThread(), nidas::core::DSMServerApp::killStatusThread(), nidas::dynld::isff::GOESOutput::killThread(), nidas::core::Looper::removeClient(), nidas::core::SensorHandler::run(), nidas::core::Looper::setupClientMaps(), nidas::util::Thread::test(), nidas::util::Thread::unblockSignal(), ~SampleBuffer(), nidas::core::SampleSorter::~SampleSorter(), nidas::util::Thread::~Thread(), and nidas::dynld::UDPSampleOutput::~UDPSampleOutput().

int Thread::join	(		)
throw	(	Exception
	)

virtualinherited

The calling thread joins this thread, waiting until the thread finishes, which means either that the run() method returned, the thread called pthread_exit() or the thread was cancelled.

The return value is the int return value of the run method, or PTHREAD_CANCELED (-1). If the run method threw an Exception, it will be caught and then re-thrown by join.

Reimplemented in nidas::core::SensorHandler.

References nidas::util::Thread::_exception, nidas::util::Thread::_id, nidas::util::Thread::_mutex, nidas::util::Exception::errnoToString(), nidas::util::Thread::getId(), nidas::util::Thread::getName(), nidas::util::Thread::RUN_EXCEPTION, and nidas::util::Thread::RUN_OK.

Referenced by nidas::core::DSMService::checkSubThreads(), nidas::dynld::UDPSampleOutput::XMLSocketListener::checkWorkers(), nidas::dynld::UDPSampleOutput::close(), nidas::util::McSocketListener::close(), nidas::core::DerivedDataReader::deleteInstance(), nidas::dynld::UDPSampleOutput::XMLSocketListener::fireWorkers(), nidas::core::DSMService::join(), nidas::core::SensorHandler::join(), nidas::core::SamplePipeline::join(), nidas::core::DSMEngine::joinDataThreads(), nidas::dynld::isff::GOESOutput::joinThread(), nidas::core::DSMServerApp::killStatusThread(), nidas::core::DSMServerApp::killXmlRpcThread(), nidas::core::DSMEngine::killXmlRpcThread(), main(), nidas::core::Looper::removeClient(), nidas::util::ThreadJoiner::run(), ~SampleBuffer(), nidas::core::SampleSorter::~SampleSorter(), nidas::core::ServerSocket::~ServerSocket(), and nidas::dynld::UDPSampleOutput::~UDPSampleOutput().

void Thread::kill	(	int	sig	)
throw	(	Exception
	)

virtualinherited

Send a signal to this thread.

References nidas::util::Exception::errnoToString().

Referenced by nidas::core::FsMount::cancel(), nidas::core::XmlRpcThread::interrupt(), nidas::core::SensorOpener::interrupt(), nidas::core::DerivedDataReader::interrupt(), nidas::core::SensorHandler::interrupt(), nidas::util::McSocketListener::interrupt(), nidas::core::DSMServerApp::killStatusThread(), nidas::dynld::isff::GOESOutput::killThread(), main(), nidas::core::SensorHandler::scheduleAdd(), nidas::core::SensorHandler::scheduleClose(), nidas::core::SensorHandler::scheduleReopen(), and nidas::core::SensorHandler::sensorIsOpen().

Thread * Thread::lookupThread ( pthread_t id )

staticinherited

Referenced by nidas::util::LogContext::threadName().

SampleBuffer& nidas::core::SampleBuffer::operator= ( const SampleBuffer & )

private

No assignment.

bool SampleBuffer::receive	(	const Sample *	s	)
throw	(
	)

virtual

Insert a sample in the buffer, where it is then passed on to SampleClients.

Depending on how SampleBuffer is compiled, the buffer length may actually be 1 sample, meaning the sample is immediately passed onto the clients. In this case, this method uses a lock to force thread exclusion so that the SampleClient::receive() methods of downstream clients don't have to worry about being reentrant. If the buffer length is greater than one, then a separate thread is created which calls the SampleClient::receive() methods. Since only one thread is distributing the samples, the clients again don't have to worry about having re-entrant receive() methods.

Implements nidas::core::SampleClient.

void nidas::core::SampleBuffer::removeSampleClient	(	SampleClient *	c	)
throw	(
	)

inlinevirtual

Remove a SampleClient from this SampleSource.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::removeSampleClient().

void nidas::core::SampleBuffer::removeSampleClientForTag	(	SampleClient *	c,
		const SampleTag *
	)
throw	(
	)

inlinevirtual

Remove a SampleClient for a given SampleTag from this SampleSource.

The pointer to the SampleClient must remain valid, until after it is removed.

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::removeSampleClientForTag().

void nidas::core::SampleBuffer::removeSampleTag	(	const SampleTag *	tag	)
throw	(
	)

inlinevirtual

Implements nidas::core::SampleSource.

References _source, and nidas::core::SampleSourceSupport::removeSampleTag().

int SampleBuffer::run	(		)
throw	(	nidas::util::Exception
	)

privatevirtual

void Thread::setCancelDeferred ( bool val )

protectedinherited

Set the cancel type for this thread.

true means cancel requests are deferred until the next cancellation point. false means they occur instantly. This is protected, it should be called only from a thread's own run method. See the pthreads(7) man page for a list of the cancellation points.

Note: non-deferred canceling is difficult to get right. It has not been tested with this class, and is not recommended.

References nidas::util::Thread::_cancel_deferred.

void Thread::setCancelEnabled ( bool val )

protectedinherited

Set the cancel state for this thread - false means cancel requests are ignored.

See pthread_setcancelstate. This is protected, it should be called only from a thread's own run method.

References nidas::util::Thread::_cancel_enabled.

void nidas::core::SampleBuffer::setHeapBlock ( bool val )

inlinevirtual

Parameters

val	If true, and heapSize exceeds heapMax, then wait for heapSize to be less then heapMax, which will block any SampleSources that are inserting samples into this sorter. If false, then discard any samples that are received while heapSize exceeds heapMax.

Implements nidas::core::SampleThread.

References _heapBlock.

void nidas::core::SampleBuffer::setHeapMax ( size_t val )

inlinevirtual

Set the maximum amount of heap memory to use for sorting samples.

Parameters

val	Maximum size of heap in bytes.

Implements nidas::core::SampleThread.

References _heapMax.

void nidas::core::SampleBuffer::setKeepStats ( bool val )

inlinevirtual

Implements nidas::core::SampleThread.

References _source, and nidas::core::SampleSourceSupport::setKeepStats().

void nidas::core::SampleBuffer::setLateSampleCacheSize ( unsigned int )

inlinevirtual

Implements nidas::core::SampleThread.

void nidas::core::SampleBuffer::setLengthSecs ( float )

inlinevirtual

Implements nidas::core::SampleThread.

bool Thread::setNonRealTimePriority	(		)
throw	(	Exception
	)

inherited

References nidas::util::Thread::NU_THREAD_OTHER, and nidas::util::Thread::setThreadScheduler().

void nidas::core::SampleBuffer::setRealTime ( bool val )

inlinevirtual

Is this sorter running in real-time? If so then we can screen for bad time-tags by checking against the system clock, which is trusted.

Implements nidas::core::SampleThread.

References _realTime.

bool Thread::setRealTimeFIFOPriority	(	int	val	)
throw	(	Exception
	)

inherited

Referenced by nidas::core::DSMEngine::openSensors(), nidas::core::SamplePipeline::procinit(), and nidas::core::SamplePipeline::rawinit().

bool Thread::setRealTimeRoundRobinPriority	(	int	val	)
throw	(	Exception
	)

inherited

void Thread::setThreadScheduler	(	enum SchedPolicy	policy,
		int	priority
	)
throw	(	Exception
	)

inherited

Referenced by nidas::dynld::RawSampleService::connect(), nidas::core::DSMSensor::getLooper(), and nidas::util::Thread::setNonRealTimePriority().

size_t SampleBuffer::size ( ) const

virtual

Current number of samples in the buffer.

This method does hold a lock to force exclusive access to the sample container. However, if double buffering is used, a lock is not held on the buffer of samples currently being sent on to clients. Therefore this is only an instantaneous check and should't be used by methods in this class when exclusive access is required.

Implements nidas::core::SampleThread.

References _sampleBufCond, and sizeNoLock().

size_t SampleBuffer::sizeNoLock ( ) const

private

References _consumerBuf, and _inserterBuf.

Referenced by run(), and size().

void Thread::start	(		)
throw	(	Exception
	)

virtualinherited

Start the thread running, meaning execute the run method in a separate thread.

Referenced by nidas::util::McSocketListener::accept(), nidas::dynld::RawSampleService::connect(), nidas::core::DerivedDataReader::createInstance(), nidas::util::McSocket< SocketT >::joinMulticaster(), main(), nidas::core::DSMEngine::openSensors(), nidas::core::SamplePipeline::procinit(), nidas::core::SamplePipeline::rawinit(), nidas::util::McSocket< SocketT >::request(), nidas::core::DSMServerApp::run(), nidas::core::DSMEngine::run(), PSI::run(), nidas::core::SensorHandler::run(), nidas::core::FsMountWorkerThread::run(), nidas::dynld::UDPSampleOutput::XMLSocketListener::run(), nidas::core::Socket::ConnectionThread::run(), ServerThread::run(), nidas::core::Looper::setupClientMaps(), nidas::core::DSMServerApp::startXmlRpcThread(), and nidas::core::DSMEngine::startXmlRpcThread().

int Thread::test	(	int	argc,
		char **	argv
	)

staticinherited

a test method.

References nidas::util::Runnable::amInterrupted(), nidas::util::Thread::blockSignal(), nidas::util::Thread::getFullName(), nidas::util::Thread::getName(), nidas::util::Thread::isJoined(), nidas::util::Thread::isRunning(), nidas::util::Runnable::run(), nidas::util::Thread::Thread(), and nidas::util::Exception::what().

void nidas::util::Runnable::testCancel ( ) const

inlineprotectedinherited

Check if we have been cancelled.

Calls pthread_testcancel. This is protected since it only checks the current thread - i.e. it must be called within the run method. Since it just calls pthread_testcancel, it is a cancellation point.

void Thread::unblockSignal ( int sig )

inherited

Install a signal handler and unblock the signal.

The signal handler will log a message about the receipt of the signal at severity LOG_INFO using the nidas::util::Logger. Then, if the signal handler is being invoked from a registered Thread, the virtual method signalHandler() for that Thread will be called.

The signal handler is installed with the sigaction() system call, and will be the action for the given signal in all threads, including the main() thread. If other threads do not wish to take action on a given signal, they should call blockSignal(sig). Or they can define their own signalHandler() method.

After installing the signal handler, the signal is added to those that are unblocked for the thread, or if the Thread is not yet running, the signal will be unblocked in the thread once it runs.

As with blockSignal(), this method is typically called on this Thread before it has started. If this Thread has started, then the signal will only be unblocked if the method is called from this Thread, i.e. from its own run() method.

To install a signal handler, and then block the signal so that it is held as pending until it is later unblocked, typically with pselect(), or sigwaitinfo(), do:

void Thread::run() 
{
    // get the existing signal mask
    sigset_t sigmask;
    pthread_sigmask(SIG_BLOCK,NULL,&sigmask);
    // remove SIGUSR1 from the mask passed to pselect
    sigdelset(&sigmask,SIGUSR1);
    
    for (;;) {
        pselect(nfd,&readfds,0,0,0,&sigmask);
        ...
    }
}
...
thread.unblockSignal(SIGUSR1);
thread.blockSignal(SIGUSR1);
thread.start();
...
try {
    if (thread.isRunning()) {
        thread.kill(SIGUSR1);
        thread.join()
    }
}

References nidas::util::Thread::_blockedSignals, nidas::util::Thread::_unblockedSignals, nidas::util::Thread::currentThread(), nidas::util::Thread::isRunning(), and nidas::util::Thread::thr_add_sig().

Referenced by nidas::core::DerivedDataReader::DerivedDataReader(), nidas::core::FsMountWorkerThread::FsMountWorkerThread(), nidas::core::StatusListener::StatusListener(), nidas::core::StatusThread::StatusThread(), nidas::dynld::XMLConfigService::Worker::Worker(), nidas::core::XmlRpcThread::XmlRpcThread(), and nidas::dynld::UDPSampleOutput::XMLSocketListener::XMLSocketListener().

Member Data Documentation

std::vector<const Sample*>* nidas::core::SampleBuffer::_consumerBuf

private

Referenced by emptyNoLock(), run(), SampleBuffer(), and sizeNoLock().

size_t nidas::core::SampleBuffer::_discardedSamples

private

Number of samples discarded because of _heapSize > _heapMax and heapBlock == true.

Referenced by getNumDiscardedSamples().

int nidas::core::SampleBuffer::_discardWarningCount

private

How often to log warnings about discardedSamples.

bool nidas::core::SampleBuffer::_doFlush

private

Referenced by run().

nidas::util::Cond nidas::core::SampleBuffer::_flushCond

private

Referenced by run().

bool nidas::core::SampleBuffer::_flushed

private

Referenced by run().

bool nidas::core::SampleBuffer::_heapBlock

private

_heapBlock controls what happens when the number of bytes in _samples exceeds _heapMax.

If _heapBlock is true and _heapSize exceeds _heapMax, then any threads which are calling SampleSorter::receive to insert a sample to this sorter will block on _heapCond until sample consumers have reduced _heapSize to less than _heapMax. If _heapBlock is false and _heapSize exceeds _heapMax then samples are discarded until _heapSize is less than _heapMax.

Referenced by getHeapBlock(), heapDecrement(), and setHeapBlock().

nidas::util::Cond nidas::core::SampleBuffer::_heapCond

private

Referenced by heapDecrement().

size_t nidas::core::SampleBuffer::_heapMax

private

Limit on the maximum size of memory to use while buffering samples.

Referenced by getHeapMax(), heapDecrement(), and setHeapMax().

size_t nidas::core::SampleBuffer::_heapSize

private

Current heap size, in bytes.

Referenced by getHeapSize(), and heapDecrement().