ossimJobThreadQueue Class Reference

ossimJobThreadQueue allows one to instantiate a thread with a shared queue. More...

#include <ossimJobThreadQueue.h>

Inheritance diagram for ossimJobThreadQueue:

Public Member Functions
	ossimJobThreadQueue (std::shared_ptr< ossimJobQueue > jqueue=0)
	constructor that allows one to instantiat the thread with a shared job queue. More...
virtual	~ossimJobThreadQueue ()
	destructor. More...
void	setJobQueue (std::shared_ptr< ossimJobQueue > jqueue)
	Sets the shared queue that this thread will be pulling jobs from. More...
std::shared_ptr< ossimJobQueue >	getJobQueue ()
const std::shared_ptr< ossimJobQueue >	getJobQueue () const
std::shared_ptr< ossimJob >	currentJob ()
void	cancelCurrentJob ()
	Will cancel the current job. More...
bool	isValidQueue () const
virtual void	run ()
	This is method is overriden from the base thread class and is the main entry point of the thread. More...
void	setDone (bool done)
	Sets the done flag. More...
bool	isDone () const
virtual void	cancel ()
	Cancels the thread. More...
bool	isEmpty () const
bool	isProcessingJob () const
bool	hasJobsToProcess () const
Public Member Functions inherited from ossim::Thread
	Thread ()
	Constructor for this thread. More...
virtual	~Thread ()
	Destructor for this thread. More...
void	start ()
	Will actually start the thread and will call the. More...
bool	isRunning () const
bool	isInterruptable () const
	This is typically set if. More...
virtual void	setCancel (bool flag)
virtual void	waitForCompletion ()
	Convenience to allow one to wait for this thread to finish it's work. More...
void	pause ()
	Enables the thread to be paused. More...
void	resume ()
	This will resume a blocked thread. More...
bool	isPaused () const

Protected Member Functions
void	startThreadForQueue ()
	Internal method. More...
virtual std::shared_ptr< ossimJob >	nextJob ()
	Will return the next job on the queue. More...
Protected Member Functions inherited from ossim::Thread
virtual void	interrupt ()
	This is the interrupt interface and will cause an internal exception that is caught by. More...
virtual void	runInternal ()
	runInternal sets up internal flags such as setting m_running to true and checks to make sure it's not interrupted and will then call the More...

Protected Attributes
bool	m_doneFlag
std::mutex	m_threadMutex
std::shared_ptr< ossimJobQueue >	m_jobQueue
std::shared_ptr< ossimJob >	m_currentJob

Additional Inherited Members
Static Public Member Functions inherited from ossim::Thread
static void	sleepInSeconds (ossim_uint64 seconds)
	Utility method to allow one to sleep in seconds. More...
static void	sleepInMilliSeconds (ossim_uint64 millis)
	Utility method to allow one to sleep in milliseconds. More...
static void	sleepInMicroSeconds (ossim_uint64 micros)
	Utility method to allow one to sleep in microseconds. More...
static std::thread::id	getCurrentThreadId ()
	Utility method to get the current thread ID. More...
static ossim_uint64	getNumberOfProcessors ()
	Utility to return the number of processors (concurrent threads) More...
static void	yieldCurrentThread ()
	Will yield the current thread. More...

Detailed Description

ossimJobThreadQueue allows one to instantiate a thread with a shared queue.

the thread will block if the queue is empty and will continue to pop jobs off the queue calling the start method on the job. Once it finishes the job it is disguarded and then the next job will be popped off the queue.

class TestJob : public ossimJob
{
public:
   TestJob(){}
protected:
   virtual void run()
   {
      ossim::Thread::sleepInSeconds(2);
   }
};
class MyCallback : public ossimJobCallback
{
public:
   MyCallback(){}
   virtual void started(std::shared_ptr<ossimJob> job)  
   {
      std::cout << "Started job\n";
      ossimJobCallback::started(job);
   }
   virtual void finished(std::shared_ptr<ossimJob> job) 
   {
      std::cout << "Finished job\n";
      ossimJobCallback::finished(job);
   }
};
int main(int argc, char *argv[])
{
   std::shared_ptr<ossimJobQueue> jobQueue = std::make_shared<ossimJobQueue>();
   std::shared_ptr<ossimJobThreadQueue> jobThreadQueue = std::make_shared<ossimJobThreadQueue>(jobQueue);
   jobThreadQueue->start();
   std::shared_ptr<TestJob> job = std::make_shared<TestJob>();
   job->setCallback(std::make_shared<MyCallback>());
   jobQueue->add(job);
   std::cout << "Waiting 5 seconds before terminating\n";
   ossim::Thread::sleepInSeconds(5);
   jobThreadQueue->cancel();
   jobThreadQueue->waitForCompletion();

   return 0;
}

Definition at line 57 of file ossimJobThreadQueue.h.

Constructor & Destructor Documentation

ossimJobThreadQueue()

ossimJobThreadQueue::ossimJobThreadQueue

(

std::shared_ptr< ossimJobQueue >

jqueue = 0

)

constructor that allows one to instantiat the thread with a shared job queue.

Parameters

jqueue

shared job queue

Definition at line 3 of file ossimJobThreadQueue.cpp.

References setJobQueue().

:m_doneFlag(false)
{
   setJobQueue(jqueue);    
}

~ossimJobThreadQueue()

ossimJobThreadQueue::~ossimJobThreadQueue ( )

virtual

destructor.

Will terminate the thread and stop current jobs

Definition at line 183 of file ossimJobThreadQueue.cpp.

References cancel().

{
   cancel();
}

Member Function Documentation

cancel()

void ossimJobThreadQueue::cancel ( )

virtual

Cancels the thread.

Reimplemented from ossim::Thread.

Definition at line 140 of file ossimJobThreadQueue.cpp.

References ossim::Thread::isRunning(), m_currentJob, m_doneFlag, m_jobQueue, m_threadMutex, and ossim::Thread::yieldCurrentThread().

Referenced by ~ossimJobThreadQueue().

{
   
   if( isRunning() )
   {
      {
         std::lock_guard<std::mutex> lock(m_threadMutex);
         m_doneFlag = true;
         if (m_currentJob)
         {
            m_currentJob->cancel();
         }
         
         if (m_jobQueue) 
         {
            m_jobQueue->releaseBlock();
         }
      }
      
      // then wait for the the thread to stop running.
      while(isRunning())
      {
#if 1
         {
            std::lock_guard<std::mutex> lock(m_threadMutex);
            
            if (m_jobQueue) 
            {
               m_jobQueue->releaseBlock();
            }
         }
#endif
         ossim::Thread::yieldCurrentThread();
      }
   }
}

cancelCurrentJob()

void ossimJobThreadQueue::cancelCurrentJob

(

)

Will cancel the current job.

Definition at line 43 of file ossimJobThreadQueue.cpp.

References m_currentJob, and m_threadMutex.

{
   std::lock_guard<std::mutex> lock(m_threadMutex);
   if(m_currentJob)
   {
      m_currentJob->cancel();
   }
}

currentJob()

std::shared_ptr< ossimJob > ossimJobThreadQueue::currentJob

(

)

Returns

the current job that is being handled.

Definition at line 37 of file ossimJobThreadQueue.cpp.

References m_currentJob, and m_threadMutex.

{ 
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return m_currentJob; 
}

getJobQueue() [1/2]

std::shared_ptr< ossimJobQueue > ossimJobThreadQueue::getJobQueue

(

)

Returns

the current shared job queue

Definition at line 25 of file ossimJobThreadQueue.cpp.

References m_jobQueue, and m_threadMutex.

{ 
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return m_jobQueue; 
}

getJobQueue() [2/2]

const std::shared_ptr< ossimJobQueue > ossimJobThreadQueue::getJobQueue

(

)

const

Returns

the current shared job queue

Definition at line 31 of file ossimJobThreadQueue.cpp.

References m_jobQueue, and m_threadMutex.

{ 
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return m_jobQueue; 
}

hasJobsToProcess()

bool ossimJobThreadQueue::hasJobsToProcess

(

)

const

Returns

true if there are still jobs to be processed false otherwise.

Definition at line 199 of file ossimJobThreadQueue.cpp.

References m_currentJob, m_jobQueue, and m_threadMutex.

{
   bool result = false;
   {
      std::lock_guard<std::mutex> lock(m_threadMutex);
      result = (!m_jobQueue->isEmpty()||m_currentJob);
   }
   
   return result;
}

isDone()

bool ossimJobThreadQueue::isDone

(

)

const

Returns

if the done flag is set

Definition at line 128 of file ossimJobThreadQueue.cpp.

References m_doneFlag, and m_threadMutex.

{ 
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return m_doneFlag; 
}

isEmpty()

bool ossimJobThreadQueue::isEmpty

(

)

const

Returns

true if the queue is empty false otherwise.

Definition at line 177 of file ossimJobThreadQueue.cpp.

References m_jobQueue, and m_threadMutex.

{
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return m_jobQueue->isEmpty();
}

isProcessingJob()

bool ossimJobThreadQueue::isProcessingJob

(

)

const

Returns

true if a job is currently being processed false otherwise.

Definition at line 134 of file ossimJobThreadQueue.cpp.

References m_currentJob, and m_threadMutex.

{
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return (m_currentJob!=nullptr);
}

isValidQueue()

bool ossimJobThreadQueue::isValidQueue

(

)

const

Returns

is the queue valid

Definition at line 51 of file ossimJobThreadQueue.cpp.

References m_jobQueue, and m_threadMutex.

Referenced by run().

{
   std::lock_guard<std::mutex> lock(m_threadMutex);
   return (m_jobQueue!=nullptr);
}

nextJob()

std::shared_ptr< ossimJob > ossimJobThreadQueue::nextJob ( )

protectedvirtual

Will return the next job on the queue.

Definition at line 210 of file ossimJobThreadQueue.cpp.

References m_doneFlag, m_jobQueue, and m_threadMutex.

Referenced by run().

{
   std::shared_ptr<ossimJob> job;
   m_threadMutex.lock();
   std::shared_ptr<ossimJobQueue> jobQueue = m_jobQueue;
   bool checkIfValid = !m_doneFlag&&jobQueue;
   m_threadMutex.unlock();
   if(checkIfValid)
   {
      job = jobQueue->nextJob(true);
   }
   return job;
}

run()

void ossimJobThreadQueue::run ( )

virtual

This is method is overriden from the base thread class and is the main entry point of the thread.

Implements ossim::Thread.

Definition at line 57 of file ossimJobThreadQueue.cpp.

References ossim::Thread::interrupt(), isValidQueue(), m_currentJob, m_doneFlag, m_threadMutex, nextJob(), and ossim::Thread::yieldCurrentThread().

{
   bool firstTime = true;
   bool validQueue = true;
   std::shared_ptr<ossimJob> job;
   do
   {
      interrupt();
      // osg::notify(osg::NOTICE)<<"In thread loop "<<this<<std::endl;
      validQueue = isValidQueue();
      job = nextJob();
      if (job&&!m_doneFlag)
      {
         {
            std::lock_guard<std::mutex> lock(m_threadMutex);
            m_currentJob = job;
         }
         
         // if the job is ready to execute
         if(job->isReady())
         {
            job->start();
         }
         {            
            std::lock_guard<std::mutex> lock(m_threadMutex);
            m_currentJob = 0;
         }
         job.reset();
      }
      
      if (firstTime)
      {
         ossim::Thread::yieldCurrentThread();
         firstTime = false;
      }
   } while (!m_doneFlag&&validQueue);
   
   {            
      std::lock_guard<std::mutex> lock(m_threadMutex);
      m_currentJob = 0;
   }
   if(job&&m_doneFlag&&job->isReady())
   {
      job->cancel();
   }
   job = 0;
}

setDone()

void ossimJobThreadQueue::setDone

(

bool

done

)

Sets the done flag.

Parameters

done	the value to set

Definition at line 105 of file ossimJobThreadQueue.cpp.

References m_currentJob, m_doneFlag, m_jobQueue, and m_threadMutex.

{
   m_threadMutex.lock();
   if (m_doneFlag==done)
   {
      m_threadMutex.unlock();
      return;
   }
   m_doneFlag = done;
   m_threadMutex.unlock();
   if(done)
   {
      {
         std::lock_guard<std::mutex> lock(m_threadMutex);
         if (m_currentJob)
            m_currentJob->release();
      }
      
      if (m_jobQueue)
         m_jobQueue->releaseBlock();
   }
}

setJobQueue()

void ossimJobThreadQueue::setJobQueue

(

std::shared_ptr< ossimJobQueue >

jqueue

)

Sets the shared queue that this thread will be pulling jobs from.

Parameters

jqueue

the shared job queue to set

Definition at line 8 of file ossimJobThreadQueue.cpp.

References ossim::Thread::isPaused(), ossim::Thread::isRunning(), m_jobQueue, m_threadMutex, ossim::Thread::pause(), ossim::Thread::resume(), and startThreadForQueue().

Referenced by ossimJobThreadQueue().

{
   std::lock_guard<std::mutex> lock(m_threadMutex);
   
   if (m_jobQueue == jqueue) return;
   
   pause();
   while(isRunning()&&!isPaused())
   {
      m_jobQueue->releaseBlock();
   }
   m_jobQueue = jqueue;
   resume();

   if(m_jobQueue) startThreadForQueue();
}

startThreadForQueue()

void ossimJobThreadQueue::startThreadForQueue ( )

protected

Internal method.

If setJobQueue is set on this thread it will auto start this thread.

Definition at line 188 of file ossimJobThreadQueue.cpp.

References ossim::Thread::isRunning(), m_jobQueue, and ossim::Thread::start().

Referenced by setJobQueue().

{
   if(m_jobQueue)
   {
      if(!isRunning())
      {
         start();
      }
   }
}

Member Data Documentation

m_currentJob

std::shared_ptr<ossimJob> ossimJobThreadQueue::m_currentJob

protected

Definition at line 162 of file ossimJobThreadQueue.h.

Referenced by cancel(), cancelCurrentJob(), currentJob(), hasJobsToProcess(), isProcessingJob(), run(), and setDone().

m_doneFlag

bool ossimJobThreadQueue::m_doneFlag

protected

Definition at line 159 of file ossimJobThreadQueue.h.

Referenced by cancel(), isDone(), nextJob(), run(), and setDone().

m_jobQueue

std::shared_ptr<ossimJobQueue> ossimJobThreadQueue::m_jobQueue

protected

Definition at line 161 of file ossimJobThreadQueue.h.

Referenced by cancel(), getJobQueue(), hasJobsToProcess(), isEmpty(), isValidQueue(), nextJob(), setDone(), setJobQueue(), and startThreadForQueue().

m_threadMutex

std::mutex ossimJobThreadQueue::m_threadMutex

mutableprotected

Definition at line 160 of file ossimJobThreadQueue.h.

Referenced by cancel(), cancelCurrentJob(), currentJob(), getJobQueue(), hasJobsToProcess(), isDone(), isEmpty(), isProcessingJob(), isValidQueue(), nextJob(), run(), setDone(), and setJobQueue().

---

The documentation for this class was generated from the following files:

• ossimJobThreadQueue.h
• ossimJobThreadQueue.cpp