DD::Image::Thread Class Reference

#include <Thread.h>

Public Types
typedef void(*	ThreadFunction) (unsigned index, unsigned nThreads, void *userData)

Static Public Member Functions
static bool	spawn (ThreadFunction, unsigned nThreads, void *userData)
static ThreadId	GetThreadId ()
static const ThreadInfo *	thisThread ()
static int	thisIndex ()
static bool	OnMainThread ()
	returns true if we're on the main-thread, false otherwise
static void	terminate_all ()
static bool	running (void *userData)
static void	wait (void *userData)
static RunningThreadsInfo	getRunningThreadsInfo ()

Static Public Attributes
static unsigned	numCPUs
	recommended count for compute-only threads
static unsigned	numThreads
	recommended count for threads that will do I/O
static unsigned	numThreadsPerReadWriteTask
	number of threads to use when multi-threading read or write ops in NukeEngine
static size_t	gMinStackSize
	the minimum stack size each pthread can have
static const size_t	kAbsoluteMinStackSize
	absolute minimum stack size permissible

Detailed Description

Namespace of functions to create and wait for parallel threads.

"Real" threads as seen by the operating system are reused. After the function passed to spawn() returns, the thread will wait until another spawn() is called and will pick up the function from that. Therefore the operating system overhead of creating and destroying threads is avoided and you can call spawn() as much as you want even with short functions.

For synchronization see the classes Lock, SignalLock, and Guard.

Member Function Documentation

spawn()

bool DD::Image::Thread::spawn ( ThreadFunction  function, unsigned  nThreads, void *  userData  )

static

Start nThreads parallel threads, all running function. The arguments to function are an index number between 0 and nThreads-1, nThreads, and the userData argument.

References gMinStackSize, DD::Image::Lock::lock(), and DD::Image::Lock::unlock().

Referenced by DD::Image::ImagePlane::fillChannelThreaded(), and DD::Image::ToBuffer::to_buffer().

GetThreadId()

ThreadId DD::Image::Thread::GetThreadId ( )

static

Returns an OS agnostic thread ID.

Referenced by thisThread().

thisThread()

const Thread::ThreadInfo * DD::Image::Thread::thisThread ( )

static

Returns a pointer to a structure containing the arguments passed to the spawn() that launched this thread, and the index number passed to the function for this thread. This pointer is good until the thread function exits.

Returns null if this thread does not appear to have been launched by spawn(), this is usually because you are in the main thread.

References GetThreadId(), DD::Image::Lock::lock(), and DD::Image::Lock::unlock().

terminate_all()

void DD::Image::Thread::terminate_all ( )

static

Destroys all the threads. This is used on program exit to because some systems (Linux?) don't seem to get rid of parallel threads on normal exit!

References DD::Image::Lock::lock(), and DD::Image::Lock::unlock().

running()

bool DD::Image::Thread::running ( void *  userData )

static

Return true if any threads launched by a call to spawn() with the given userData are still running.

References DD::Image::Lock::lock(), and DD::Image::Lock::unlock().

wait()

void DD::Image::Thread::wait ( void *  userData )

static

Wait until all threads launched by a call to spawn() with the given userData have exited.

References DD::Image::Lock::lock(), and DD::Image::Lock::unlock().

Referenced by DD::Image::ImagePlane::fillChannelThreaded(), DD::Image::ToBuffer::to_buffer(), and DD::Image::Interest::~Interest().

getRunningThreadsInfo()

Thread::RunningThreadsInfo DD::Image::Thread::getRunningThreadsInfo ( )

static

Get info on the running threads

References DD::Image::Lock::lock(), and DD::Image::Lock::unlock().