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Thread Class Referenceabstract

A thread; that is, a lightweight process. More...

#include "thread.h"

Inheritance diagram for Thread:
TypedReferenceCount Namable TypedObject ReferenceCount MemoryBase MemoryBase MemoryBase ExternalThread GenericThread MainThread

Classes

class  PStatsCallback
 

Public Member Functions

virtual TypeHandle force_init_type ()
 
AsyncTaskBaseget_current_task () const
 Returns the task currently executing on this thread (via the AsyncTaskManager), if any, or NULL if the thread is not currently servicing a task. More...
 
int get_pipeline_stage () const
 Returns the Pipeline stage number associated with this thread. More...
 
PStatsCallbackget_pstats_callback () const
 Returns the PStats callback associated with this thread, or NULL if no callback has yet been associated with this thread. More...
 
int get_pstats_index () const
 Returns the PStats index associated with this thread, or -1 if no index has yet been associated with this thread. More...
 
const string & get_sync_name () const
 Returns the sync name of the thread. More...
 
virtual TypeHandle get_type () const
 
string get_unique_id () const
 Returns a string that is guaranteed to be unique to this thread, across all processes on the machine, during at least the lifetime of this process. More...
 
bool is_joinable () const
 Returns the value of joinable that was passed to the start() call. More...
 
bool is_started () const
 Returns true if the thread has been started, false if it has not, or if join() has already been called. More...
 
void join ()
 Blocks the calling process until the thread terminates. More...
 
virtual void output (ostream &out) const
 
void output_blocker (ostream &out) const
 Writes a description of the mutex or condition variable that this thread is blocked on. More...
 
void preempt ()
 Indicates that this thread should run as soon as possible, preemptying any other threads that may be scheduled to run. More...
 
void set_min_pipeline_stage (int min_pipeline_stage)
 Sets this thread's pipeline stage number to at least the indicated value, unless it is already larger. More...
 
void set_pipeline_stage (int pipeline_stage)
 Specifies the Pipeline stage number associated with this thread. More...
 
void set_pstats_callback (PStatsCallback *pstats_callback)
 Stores a PStats callback to be associated with this thread. More...
 
void set_pstats_index (int pstats_index)
 Stores a PStats index to be associated with this thread. More...
 
bool start (ThreadPriority priority, bool joinable)
 Starts the thread executing. More...
 
- Public Member Functions inherited from TypedReferenceCount
 TypedReferenceCount (const TypedReferenceCount &copy)
 
void operator= (const TypedReferenceCount &copy)
 
- Public Member Functions inherited from TypedObject
 TypedObject (const TypedObject &copy)
 
TypedObjectas_typed_object ()
 Returns the object, upcast (if necessary) to a TypedObject pointer. More...
 
const TypedObjectas_typed_object () const
 Returns the object, upcast (if necessary) to a TypedObject pointer. More...
 
int get_best_parent_from_Set (const std::set< int > &) const
 
int get_type_index () const
 Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More...
 
bool is_exact_type (TypeHandle handle) const
 Returns true if the current object is the indicated type exactly. More...
 
bool is_of_type (TypeHandle handle) const
 Returns true if the current object is or derives from the indicated type. More...
 
void operator= (const TypedObject &copy)
 
- Public Member Functions inherited from ReferenceCount
int get_ref_count () const
 Returns the current reference count. More...
 
WeakReferenceListget_weak_list () const
 Returns the WeakReferenceList associated with this ReferenceCount object. More...
 
bool has_weak_list () const
 Returns true if this particular ReferenceCount object has a WeakReferenceList created, false otherwise. More...
 
void local_object ()
 This function should be called, once, immediately after creating a new instance of some ReferenceCount-derived object on the stack. More...
 
void ref () const
 Explicitly increments the reference count. More...
 
bool test_ref_count_integrity () const
 Does some easy checks to make sure that the reference count isn't completely bogus. More...
 
bool test_ref_count_nonzero () const
 Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...
 
virtual bool unref () const
 Explicitly decrements the reference count. More...
 
void weak_ref (WeakPointerToVoid *ptv)
 Adds the indicated PointerToVoid as a weak reference to this object. More...
 
void weak_unref (WeakPointerToVoid *ptv)
 Removes the indicated PointerToVoid as a weak reference to this object. More...
 
- Public Member Functions inherited from Namable
 Namable (const string &initial_name="")
 
 Namable (const Namable &copy)
 
void clear_name ()
 Resets the Namable's name to empty. More...
 
const string & get_name () const
 
bool has_name () const
 Returns true if the Namable has a nonempty name set, false if the name is empty. More...
 
Namableoperator= (const Namable &other)
 
void output (ostream &out) const
 Outputs the Namable. More...
 
void set_name (const string &name)
 

Static Public Member Functions

static void consider_yield ()
 Possibly suspends the current thread for the rest of the current epoch, if it has run for enough this epoch. More...
 
static void force_yield ()
 Suspends the current thread for the rest of the current epoch. More...
 
static TypeHandle get_class_type ()
 
static int get_current_pipeline_stage ()
 Returns the integer pipeline stage associated with the current thread. More...
 
static Threadget_current_thread ()
 Returns a pointer to the currently-executing Thread object. More...
 
static Threadget_external_thread ()
 Returns a pointer to the "external" Thread object–this is a special Thread object that corresponds to any thread spawned outside of Panda's threading interface. More...
 
static Threadget_main_thread ()
 Returns a pointer to the "main" Thread object–this is the Thread that started the whole process. More...
 
static void init_type ()
 
static bool is_simple_threads ()
 Returns true if Panda is currently compiled for "simple threads", which is to say, cooperative context switching only, reducing the need for quite so many critical section protections. More...
 
static bool is_threading_supported ()
 Returns true if threading support has been compiled in and enabled, or false if no threading is available (and Thread::start() will always fail). More...
 
static bool is_true_threads ()
 Returns true if a real threading library is available that supports actual OS-implemented threads, or false if the only threading we can provide is simulated user-space threading. More...
 
static void prepare_for_exit ()
 Should be called by the main thread just before exiting the program, this blocks until any remaining thread cleanup has finished. More...
 
static PT (Thread) bind_thread(const string &name
 
static void sleep (double seconds)
 Suspends the current thread for at least the indicated amount of time. More...
 
static void write_status (ostream &out)
 
- Static Public Member Functions inherited from TypedReferenceCount
static TypeHandle get_class_type ()
 
static void init_type ()
 
- Static Public Member Functions inherited from TypedObject
static TypeHandle get_class_type ()
 
static void init_type ()
 This function is declared non-inline to work around a compiler bug in g++ 2.96. More...
 
- Static Public Member Functions inherited from ReferenceCount
static TypeHandle get_class_type ()
 
static void init_type ()
 
- Static Public Member Functions inherited from Namable
static TypeHandle get_class_type ()
 
static void init_type ()
 

Public Attributes

static const string & sync_name
 

Friends

class AsyncTaskBase
 
class ConditionVarDebug
 
class ConditionVarFullDebug
 
class MainThread
 
class MutexDebug
 
class ThreadDummyImpl
 
class ThreadPosixImpl
 
class ThreadSimpleImpl
 
class ThreadWin32Impl
 

Detailed Description

A thread; that is, a lightweight process.

This is an abstract base class; to use it, you must subclass from it and redefine thread_main().

The thread itself will keep a reference count on the Thread object while it is running; when the thread returns from its root function, the Thread object will automatically be destructed if no other pointers are referencing it.

Definition at line 51 of file thread.h.

Member Function Documentation

void Thread::consider_yield ( )
inlinestatic

Possibly suspends the current thread for the rest of the current epoch, if it has run for enough this epoch.

This is especially important for the simple thread implementation, which relies on cooperative yields like this.

Definition at line 263 of file thread.I.

Referenced by PartGroup::check_hierarchy(), DatagramInputFile::get_datagram(), PNMImage::quick_filter_from(), PNMReader::read_data(), VertexDataSaveFile::read_data(), DatagramInputFile::read_header(), BamReader::read_pointer(), SceneGraphReducer::remove_unused_vertices(), GraphicsEngine::render_frame(), and PNMWriter::write_data().

void Thread::force_yield ( )
inlinestatic

Suspends the current thread for the rest of the current epoch.

Definition at line 248 of file thread.I.

Referenced by DatagramGeneratorNet::get_datagram(), VertexDataSaveFile::read_data(), GraphicsEngine::render_frame(), and ConnectionManager::wait_for_readers().

int Thread::get_current_pipeline_stage ( )
inlinestatic
AsyncTaskBase * Thread::get_current_task ( ) const
inline

Returns the task currently executing on this thread (via the AsyncTaskManager), if any, or NULL if the thread is not currently servicing a task.

Definition at line 329 of file thread.I.

Thread * Thread::get_current_thread ( )
inlinestatic

Returns a pointer to the currently-executing Thread object.

If this is called from the main thread, this will return the same value as get_main_thread().

This will always return some valid Thread pointer. It will never return NULL, even if the current thread was spawned outside of Panda's threading system, although all non-Panda threads will return the exact same Thread pointer.

Definition at line 145 of file thread.I.

References get_external_thread(), and get_main_thread().

Referenced by GeomNode::add_geom(), GeomNode::add_geoms_from(), SpeedTreeNode::add_instances(), CharacterJoint::add_local_transform(), CharacterJoint::add_net_transform(), Geom::add_primitive(), TransformBlend::add_transform(), PandaNode::adjust_draw_mask(), GeomNode::apply_attribs_to_vertices(), PartBundleNode::apply_attribs_to_vertices(), PandaNode::apply_attribs_to_vertices(), Geom::check_valid(), GeomPrimitive::check_valid(), PandaNode::clear_attrib(), PandaNode::clear_effect(), Geom::clear_primitives(), GeomVertexData::clear_rows(), GeomVertexArrayData::compare_to(), PandaNode::copy_all_properties(), PandaNode::copy_tags(), RigidBodyCombiner::cull_callback(), GeomNode::decompose(), Geom::decompose_in_place(), GeomNode::do_premunge(), MayaPview::doIt(), Geom::doubleside_in_place(), GeomNode::finalize(), PartBundle::finalize(), GraphicsEngine::flip_frame(), DriveInterface::force_dgraph(), PartBundle::force_update(), get_current_pipeline_stage(), CycleDataStageReader< CycleDataType >::get_current_thread(), CycleDataLockedStageReader< CycleDataType >::get_current_thread(), CycleDataReader< CycleDataType >::get_current_thread(), CycleDataStageWriter< CycleDataType >::get_current_thread(), CycleDataLockedReader< CycleDataType >::get_current_thread(), CycleDataWriter< CycleDataType >::get_current_thread(), GeomPrimitive::get_first_vertex(), GeomPrimitive::get_index_stride(), GeomPrimitive::get_max_vertex(), GeomPrimitive::get_min_vertex(), PandaNode::get_net_draw_control_mask(), PandaNode::get_net_draw_show_mask(), GeomVertexData::get_num_bytes(), WorkingNodePath::get_num_nodes(), GeomPrimitive::get_num_primitives(), GeomVertexData::get_num_rows(), GeomPrimitive::get_num_vertices(), PStatThread::get_thread(), GeomPrimitive::get_vertex(), RenderAttrib::init_attribs(), RenderEffects::init_states(), RenderState::init_states(), GeomPrimitive::is_indexed(), JointVertexTransform::JointVertexTransform(), PandaFramework::main_loop(), Geom::make_lines_in_place(), Geom::make_nonindexed(), GeomPrimitive::make_nonindexed(), Geom::make_patches_in_place(), Geom::make_points_in_place(), TransformBlend::normalize_weights(), Geom::offset_vertices(), GraphicsEngine::open_windows(), NodePathComponent::output(), GeomPrimitive::pack_vertices(), PandaNode::prepare_scene(), DXGraphicsStateGuardian9::prepare_vertex_buffer(), BamReader::read_cdata(), VertexDataSaveFile::read_data(), GraphicsEngine::ready_flip(), GeomTransformer::register_vertices(), GraphicsEngine::remove_all_windows(), Geom::remove_primitive(), TransformBlend::remove_transform(), GraphicsEngine::remove_window(), GraphicsEngine::render_frame(), PandaNode::replace_node(), GeomVertexData::reserve_num_rows(), SheetNode::reset_bound(), RopeNode::reset_bound(), Geom::reverse_in_place(), Geom::rotate_in_place(), GeomVertexData::set_array(), PandaNode::set_attrib(), PandaNode::set_bounds(), PandaNode::set_bounds_type(), ClockObject::set_dt(), PandaNode::set_effect(), GeomVertexData::set_format(), ClockObject::set_frame_rate(), PandaNode::set_into_collide_mask(), UserVertexTransform::set_matrix(), ClockObject::set_mode(), GeomVertexData::set_num_rows(), Geom::set_primitive(), CullTraverser::set_scene(), UserVertexSlider::set_slider(), FrameRateMeter::set_text_pattern(), GeomVertexData::set_transform_table(), Geom::set_usage_hint(), Geom::set_vertex_data(), BamCache::store(), GraphicsEngine::sync_frame(), GeomTransformer::transform_vertices(), GeomVertexData::unclean_set_format(), GeomVertexData::unclean_set_num_rows(), GeomNode::unify(), Geom::unify_in_place(), DisplayRegionCullCallbackData::upcall(), DisplayRegionDrawCallbackData::upcall(), GeomDrawCallbackData::upcall(), CallbackGraphicsWindow::RenderCallbackData::upcall(), SceneGraphAnalyzerMeter::update(), FrameRateMeter::update(), PartBundle::update(), AnimControl::wait_pending(), and BamWriter::write_cdata().

Thread * Thread::get_external_thread ( )
inlinestatic

Returns a pointer to the "external" Thread object–this is a special Thread object that corresponds to any thread spawned outside of Panda's threading interface.

Note that multiple different threads may share this same pointer.

Definition at line 124 of file thread.I.

Referenced by get_current_thread().

Thread * Thread::get_main_thread ( )
inlinestatic

Returns a pointer to the "main" Thread object–this is the Thread that started the whole process.

Definition at line 107 of file thread.I.

Referenced by get_current_thread(), RenderAttrib::init_attribs(), RenderEffects::init_states(), and RenderState::init_states().

int Thread::get_pipeline_stage ( ) const
inline
Thread::PStatsCallback * Thread::get_pstats_callback ( ) const
inline

Returns the PStats callback associated with this thread, or NULL if no callback has yet been associated with this thread.

This is used internally by the PStatClient; you should not need to call this directly.

Definition at line 379 of file thread.I.

int Thread::get_pstats_index ( ) const
inline

Returns the PStats index associated with this thread, or -1 if no index has yet been associated with this thread.

This is used internally by the PStatClient; you should not need to call this directly.

Definition at line 60 of file thread.I.

Referenced by PStatThread::PStatThread().

const string & Thread::get_sync_name ( ) const
inline

Returns the sync name of the thread.

This name collects threads into "sync groups", which are expected to run synchronously. This is mainly used for the benefit of PStats; threads with the same sync name can be ticked all at once via the thread_tick() call.

Definition at line 47 of file thread.I.

string Thread::get_unique_id ( ) const
inline

Returns a string that is guaranteed to be unique to this thread, across all processes on the machine, during at least the lifetime of this process.

Definition at line 72 of file thread.I.

Referenced by BamCache::store().

bool Thread::is_joinable ( ) const
inline

Returns the value of joinable that was passed to the start() call.

Definition at line 286 of file thread.I.

bool Thread::is_simple_threads ( )
inlinestatic

Returns true if Panda is currently compiled for "simple threads", which is to say, cooperative context switching only, reducing the need for quite so many critical section protections.

This is not necessarily the opposite of "true threads", since one possible implementation of simple threads is via true threads with mutex protection to ensure only one runs at a time.

Definition at line 221 of file thread.I.

bool Thread::is_started ( ) const
inline

Returns true if the thread has been started, false if it has not, or if join() has already been called.

Definition at line 275 of file thread.I.

bool Thread::is_threading_supported ( )
inlinestatic

Returns true if threading support has been compiled in and enabled, or false if no threading is available (and Thread::start() will always fail).

Definition at line 185 of file thread.I.

Referenced by ConnectionReader::ConnectionReader(), ConnectionWriter::ConnectionWriter(), AsyncTaskChain::set_num_threads(), and GraphicsEngine::set_threading_model().

bool Thread::is_true_threads ( )
inlinestatic

Returns true if a real threading library is available that supports actual OS-implemented threads, or false if the only threading we can provide is simulated user-space threading.

Definition at line 201 of file thread.I.

Referenced by GraphicsEngine::render_frame(), and NodePath::verify_complete().

void Thread::join ( )
inline

Blocks the calling process until the thread terminates.

If the thread has already terminated, this returns immediately.

Definition at line 298 of file thread.I.

void Thread::output_blocker ( ostream &  out) const

Writes a description of the mutex or condition variable that this thread is blocked on.

Writes nothing if there is no blocker, or if we are not in DEBUG_THREADS mode.

Definition at line 190 of file thread.cxx.

void Thread::preempt ( )
inline

Indicates that this thread should run as soon as possible, preemptying any other threads that may be scheduled to run.

This may not be implemented on every platform.

Definition at line 315 of file thread.I.

void Thread::prepare_for_exit ( )
inlinestatic

Should be called by the main thread just before exiting the program, this blocks until any remaining thread cleanup has finished.

Definition at line 341 of file thread.I.

Referenced by PandaFramework::close_framework(), and GraphicsEngine::remove_all_windows().

void Thread::set_min_pipeline_stage ( int  min_pipeline_stage)
inline

Sets this thread's pipeline stage number to at least the indicated value, unless it is already larger.

See set_pipeline_stage().

Definition at line 96 of file thread.I.

References set_pipeline_stage().

void Thread::set_pipeline_stage ( int  pipeline_stage)

Specifies the Pipeline stage number associated with this thread.

The default stage is 0 if no stage is specified otherwise.

This must be a value in the range [0 .. pipeline->get_num_stages() - 1]. It specifies the values that this thread observes for all pipelined data. Typically, an application thread will leave this at 0, but a render thread may set it to 1 or 2 (to operate on the previous frame's data, or the second previous frame's data).

Definition at line 158 of file thread.cxx.

Referenced by set_min_pipeline_stage().

void Thread::set_pstats_callback ( Thread::PStatsCallback pstats_callback)
inline

Stores a PStats callback to be associated with this thread.

This is used internally by the PStatClient; you should not need to call this directly.

Definition at line 365 of file thread.I.

void Thread::set_pstats_index ( int  pstats_index)
inline

Stores a PStats index to be associated with this thread.

This is used internally by the PStatClient; you should not need to call this directly.

Definition at line 353 of file thread.I.

void Thread::sleep ( double  seconds)
inlinestatic

Suspends the current thread for at least the indicated amount of time.

It might be suspended for longer.

Definition at line 236 of file thread.I.

Referenced by PStatServer::main_loop().

bool Thread::start ( ThreadPriority  priority,
bool  joinable 
)

Starts the thread executing.

It is only valid to call this once.

The thread will begin executing its thread_main() function, and will terminate when thread_main() returns.

priority is intended as a hint to the relative importance of this thread. This may be ignored by the thread implementation.

joinable should be set true if you intend to call join() to wait for the thread to terminate, or false if you don't care and you will never call join(). Note that the reference count on the Thread object is incremented while the thread itself is running, so if you just want to fire and forget a thread, you may pass joinable = false, and never store the Thread object. It will automatically destruct itself when it finishes.

The return value is true if the thread is successfully started, false otherwise.

Definition at line 242 of file thread.cxx.


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