ossimJobMultiThreadQueue Class Reference

This allocates a thread pool used to listen on a shared job queue. More...

#include <ossimJobMultiThreadQueue.h>

Public Types
typedef std::vector< std::shared_ptr< ossimJobThreadQueue > >	ThreadQueueList

Public Member Functions
	ossimJobMultiThreadQueue (std::shared_ptr< ossimJobQueue > q=0, ossim_uint32 nThreads=0)
	allows one to create a pool of threads with a shared job queue More...
virtual	~ossimJobMultiThreadQueue ()
	Will cancel all threads and wait for completion and clear the thread queue list. More...
std::shared_ptr< ossimJobQueue >	getJobQueue ()
const std::shared_ptr< ossimJobQueue >	getJobQueue () const
void	setJobQueue (std::shared_ptr< ossimJobQueue > q)
	set the job queue to all threads More...
void	setNumberOfThreads (ossim_uint32 nThreads)
	Will set the number of threads. More...
ossim_uint32	getNumberOfThreads () const
ossim_uint32	numberOfBusyThreads () const
bool	areAllThreadsBusy () const
bool	hasJobsToProcess () const
void	cancel ()
	Allows one to cancel all threads. More...
void	waitForCompletion ()
	Allows on to wait for all thread completions. More...

Protected Attributes
std::mutex	m_mutex
std::shared_ptr< ossimJobQueue >	m_jobQueue
ThreadQueueList	m_threadQueueList

Detailed Description

This allocates a thread pool used to listen on a shared job queue.

#include <ossim/base/Thread.h>
#include <ossim/parallel/ossimJob.h>
#include <ossim/parallel/ossimJobMultiThreadQueue.h>
#include <ossim/parallel/ossimJobQueue.h>
#include <memory>
#include <iostream>

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[])
{
   int nThreads = 5;
   int nJobs = 10;
   std::shared_ptr<ossimJobQueue> jobQueue = std::make_shared<ossimJobQueue>();
   std::shared_ptr<ossimJobMultiThreadQueue> jobThreadQueue = std::make_shared<ossimJobMultiThreadQueue>(jobQueue, nThreads);
   for(int i = 0; i < nJobs; ++i)
   {
      std::shared_ptr<TestJob> job = std::make_shared<TestJob>();
      job->setCallback(std::make_shared<MyCallback>());
      jobQueue->add(job);
   }

   while(jobThreadQueue->hasJobsToProcess())
   {
      ossim::Thread::sleepInMilliSeconds(10);
   }

   std::cout << "Finished and cancelling thread queue\n";
   jobThreadQueue->cancel();
   jobThreadQueue->waitForCompletion();

   return 0;
}

Definition at line 69 of file ossimJobMultiThreadQueue.h.

Member Typedef Documentation

ThreadQueueList

typedef std::vector<std::shared_ptr<ossimJobThreadQueue> > ossimJobMultiThreadQueue::ThreadQueueList

Definition at line 72 of file ossimJobMultiThreadQueue.h.

Constructor & Destructor Documentation

ossimJobMultiThreadQueue()

ossimJobMultiThreadQueue::ossimJobMultiThreadQueue	(	std::shared_ptr< ossimJobQueue >	q = 0,
		ossim_uint32	nThreads = 0
	)

allows one to create a pool of threads with a shared job queue

Definition at line 3 of file ossimJobMultiThreadQueue.cpp.

References setNumberOfThreads().

:m_jobQueue(q?q:std::make_shared<ossimJobQueue>())
{
   setNumberOfThreads(nThreads);
}

~ossimJobMultiThreadQueue()

ossimJobMultiThreadQueue::~ossimJobMultiThreadQueue ( )

virtual

Will cancel all threads and wait for completion and clear the thread queue list.

Definition at line 10 of file ossimJobMultiThreadQueue.cpp.

References cancel(), m_threadQueueList, and waitForCompletion().

{
   cancel();
   waitForCompletion();
   m_threadQueueList.clear();
}

Member Function Documentation

areAllThreadsBusy()

bool ossimJobMultiThreadQueue::areAllThreadsBusy

(

)

const

Returns

true if all threads are busy and false otherwise

Definition at line 82 of file ossimJobMultiThreadQueue.cpp.

References m_mutex, and m_threadQueueList.

{
   std::lock_guard<std::mutex> lock(m_mutex);
   ossim_uint32 idx = 0;
   ossim_uint32 queueSize = m_threadQueueList.size();
   for(idx = 0; idx < queueSize;++idx)
   {
      if(!m_threadQueueList[idx]->isProcessingJob()) return false;
   }
   
   return true;
}

cancel()

void ossimJobMultiThreadQueue::cancel

(

)

Allows one to cancel all threads.

Definition at line 111 of file ossimJobMultiThreadQueue.cpp.

References m_threadQueueList.

Referenced by ~ossimJobMultiThreadQueue().

{
   for(auto thread:m_threadQueueList)
   {
      thread->cancel();
   }
}

getJobQueue() [1/2]

std::shared_ptr< ossimJobQueue > ossimJobMultiThreadQueue::getJobQueue

(

)

Returns

the job queue

Definition at line 17 of file ossimJobMultiThreadQueue.cpp.

References m_jobQueue, and m_mutex.

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

getJobQueue() [2/2]

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

(

)

const

Returns

the job queue

Definition at line 22 of file ossimJobMultiThreadQueue.cpp.

References m_jobQueue, and m_mutex.

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

getNumberOfThreads()

ossim_uint32 ossimJobMultiThreadQueue::getNumberOfThreads

(

)

const

Returns

the number of threads

Definition at line 63 of file ossimJobMultiThreadQueue.cpp.

References m_mutex, and m_threadQueueList.

{
   std::lock_guard<std::mutex> lock(m_mutex);
   return static_cast<ossim_uint32>( m_threadQueueList.size() );
}

hasJobsToProcess()

bool ossimJobMultiThreadQueue::hasJobsToProcess

(

)

const

Returns

true if it has jobs that it's processing

Definition at line 95 of file ossimJobMultiThreadQueue.cpp.

References m_mutex, and m_threadQueueList.

{
   bool result = false;
   {
      std::lock_guard<std::mutex> lock(m_mutex);
      ossim_uint32 queueSize = m_threadQueueList.size();
      ossim_uint32 idx = 0;
      for(idx = 0; ((idx<queueSize)&&!result);++idx)
      {
         result = m_threadQueueList[idx]->hasJobsToProcess();
      }
   }
   
   return result;
}

numberOfBusyThreads()

ossim_uint32 ossimJobMultiThreadQueue::numberOfBusyThreads

(

)

const

Returns

the number of threads that are busy

Definition at line 69 of file ossimJobMultiThreadQueue.cpp.

References m_mutex, and m_threadQueueList.

{
   ossim_uint32 result = 0;
   std::lock_guard<std::mutex> lock(m_mutex);
   ossim_uint32 idx = 0;
   ossim_uint32 queueSize = m_threadQueueList.size();
   for(idx = 0; idx < queueSize;++idx)
   {
      if(m_threadQueueList[idx]->isProcessingJob()) ++result;
   }
   return result;
}

setJobQueue()

void ossimJobMultiThreadQueue::setJobQueue

(

std::shared_ptr< ossimJobQueue >

q

)

set the job queue to all threads

Parameters

q	the job queue to set

Definition at line 27 of file ossimJobMultiThreadQueue.cpp.

References m_jobQueue, m_mutex, and m_threadQueueList.

{
   std::lock_guard<std::mutex> lock(m_mutex);
   ossim_uint32 idx = 0;
   m_jobQueue = q;
   for(idx = 0; idx < m_threadQueueList.size(); ++idx)
   {
      m_threadQueueList[idx]->setJobQueue(m_jobQueue);
   }
}

setNumberOfThreads()

void ossimJobMultiThreadQueue::setNumberOfThreads

(

ossim_uint32

nThreads

)

Will set the number of threads.

Definition at line 37 of file ossimJobMultiThreadQueue.cpp.

References m_jobQueue, m_mutex, and m_threadQueueList.

Referenced by ossimJobMultiThreadQueue().

{
   std::lock_guard<std::mutex> lock(m_mutex);
   ossim_uint32 idx = 0;
   ossim_uint32 queueSize = m_threadQueueList.size();
   
   if(nThreads > queueSize)
   {
      for(idx = queueSize; idx < nThreads;++idx)
      {
         std::shared_ptr<ossimJobThreadQueue> threadQueue = std::make_shared<ossimJobThreadQueue>();
         threadQueue->setJobQueue(m_jobQueue);
         m_threadQueueList.push_back(threadQueue);
      }
   }
   else if(nThreads < queueSize)
   {
      ThreadQueueList::iterator iter = m_threadQueueList.begin()+nThreads;
      while(iter != m_threadQueueList.end())
      {
         (*iter)->cancel();
         iter = m_threadQueueList.erase(iter);
      }
   }
}

waitForCompletion()

void ossimJobMultiThreadQueue::waitForCompletion

(

)

Allows on to wait for all thread completions.

Usually called after

See also

cancel

Definition at line 119 of file ossimJobMultiThreadQueue.cpp.

References m_threadQueueList.

Referenced by ~ossimJobMultiThreadQueue().

{
   for(auto thread:m_threadQueueList)
   {
      thread->waitForCompletion();
   }
}

Member Data Documentation

m_jobQueue

std::shared_ptr<ossimJobQueue> ossimJobMultiThreadQueue::m_jobQueue

protected

Definition at line 140 of file ossimJobMultiThreadQueue.h.

Referenced by getJobQueue(), setJobQueue(), and setNumberOfThreads().

m_mutex

std::mutex ossimJobMultiThreadQueue::m_mutex

mutableprotected

Definition at line 139 of file ossimJobMultiThreadQueue.h.

Referenced by areAllThreadsBusy(), getJobQueue(), getNumberOfThreads(), hasJobsToProcess(), numberOfBusyThreads(), setJobQueue(), and setNumberOfThreads().

m_threadQueueList

ThreadQueueList ossimJobMultiThreadQueue::m_threadQueueList

protected

Definition at line 141 of file ossimJobMultiThreadQueue.h.

Referenced by areAllThreadsBusy(), cancel(), getNumberOfThreads(), hasJobsToProcess(), numberOfBusyThreads(), setJobQueue(), setNumberOfThreads(), waitForCompletion(), and ~ossimJobMultiThreadQueue().

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

• ossimJobMultiThreadQueue.h
• ossimJobMultiThreadQueue.cpp