CIBC:Documentation:SCIRun:DevTasks:QtMigration:BoostThread

Boost Thread notes

Working from Boost 1.49.

These are notes for replacing Core/Thread with Boost threads.

AtomicCounter

In Core/Thread/AtomicCounter.h. See atomic_count.hpp.

Most important use is in Datatype as generation counter.

Mapping

• operator int() =
  • allows the atomic counter to be used in expressions like a normal integer (note that multiple calls to this function may return different values if other threads are manipulating the counter)

• operator++() =
  • 2 versions

• operator--() =
  • 2 versions

• set(int) =
  • set to new value
  • used in Module.cc to update ProgressReporter progress - we could use signals/slots to make this obsolete

Barrier

In Core/Thread/Barrier.h. See barrier.hpp.

Mapping

• wait() = boost::barrier::wait()
  • set number of threads in barrier constructor instead of arg to boost::barrier::wait()

CrowdMonitor

In Core/Thread/CrowdMonitor.h. This is a multiple reader, single writer synchronization primitive.

Boost's shared_lock looks like it could be a substitute for the multiple reader functionality, and unique_lock could be a substitute for single writer. See also http://lists.boost.org/Archives/boost/2008/01/132656.php.

Mapping

• readLock() =

• readUnlock() =

• writeLock() =

• writeUnlock() =

Guard

In Core/Thread/Guard.h. See Boost lock types. Used extensively.

Mapping

• constructors that take Mutex, RecursiveMutex, CrowdMonitor
  • Guard is mostly used with Mutex
  • CrowdMonitor is not used with Guard

RecursiveMutex

In Core/Thread/RecursiveMutex.h. See recursive_mutex.

Mapping

• lock() = boost::recursive_mutex::lock()
• tryLock() = boost::recursive_mutex::try_lock()
• unlock() = boost::recursive_mutex::unlock()

Thread

• Interruption points.

Mapping

• getThreadGroup() =
  • not used

• getRunnable() =
  • not used

• setDaemon() =
  • used in ThreadPool and main.cc for Scheduler thread, but with redesign, it is unlikely that we will need this feature

• isDaemon() =
  • not used outside of Core/Thread library

• activate() =
  • change Thread state from inactive to active
  • not supported by boost::thread class
  • used in Dataflow/Modules/Render/OpenGL.cc - not sure why it's needed there, since helper Thread is instantiated as inactive and then activated right away...call to yield() seems more important

• detach() =

• isDetached() =

• setStackSize() =

• getStackSize() =

• exitAll() =
  • used in TCLThread and NetworkEditor on exit

• exit() =

• self() =

• stop() =

• resume() =
  • not used outside of Core/Thread library

• join =

• getThreadName() =

• numProcessors() = boost::thread::hardware_concurrency()
  • used frequently

• migrate(int proc) =
  • not used outside of Core/Thread library

• parallel() = custom implementation needed
  • used frequently
  • starts up several threads that run in parallel
  • multiple overloaded versions
  • Seg3D2 has an implementation

• niceAbort() =
  • let's find a better way to fail the program gracefully (with logging too)

• couldBlock() =
  • not used outside of Core/Thread library
  • used in AtomicCounter, Barrier, CrowdMonitor default implementations
  • also used in Mailbox, SimpleReducer, FutureValue

• couldBlockDone() =
  • not used outside of Core/Thread library

• yield() = boost::thread::yield
• isInitialized() =
  • not used outside of Core/Thread library

• setDefaultAbortMode() =
  • not used

• initialize() =

ThreadGroup

In Core/Thread/ThreadGroup.h.

See the threadgroup class. I don't think thread_group supports daemon threads.

ThreadGroup is not used outside of the Core/Thread library

Mapping

• numActive() = boost::thread_group::size()
  • not used

• stop() =

• resume() =

• join() =

• detach() =

• parentGroup() =
  • not used

• gangSchedule() =
  • not used

ThreadPool

In Core/Thread/ThreadPool.h.

ThreadPool is not used outside of the Core/Thread library

Time

In Core/Thread/Time.h.

See also [[1]].

Mapping

• currentTicks() =

• currentSeconds() =

• ticksPerSecond() =

• secondsPerTick() =

• waitUntil(SysClock ticks) =
  • wait until the specified time
  • overloaded for long long (system clock ticks), double (seconds)

• waitFor(SysClock ticks) =
  • wait for the specified time
  • overloaded for long long (system clock ticks), double (seconds)

UsedWithLockingHandle

In Core/Thread/UsedWithLockingHandle.h.

Wrapper for SCIRun LockingHandle smart pointer type. If still needed, change mutex class types.