tbb::interface6::task_scheduler_observer Class Reference

#include <task_scheduler_observer.h>

Inheritance diagram for tbb::interface6::task_scheduler_observer:

Collaboration diagram for tbb::interface6::task_scheduler_observer:

Public Member Functions
	task_scheduler_observer (bool local=false)
	Construct local or global observer in inactive state (observation disabled). More...
	task_scheduler_observer (task_arena &a)
	Construct local observer for a given arena in inactive state (observation disabled). More...
virtual	~task_scheduler_observer ()
void	observe (bool state=true)
	Enable or disable observation. More...
Public Member Functions inherited from tbb::internal::task_scheduler_observer_v3
void __TBB_EXPORTED_METHOD	observe (bool state=true)
	Enable or disable observation. More...
bool	is_observing () const
	Returns true if observation is enabled, false otherwise. More...
	task_scheduler_observer_v3 ()
	Construct observer with observation disabled. More...
virtual void	on_scheduler_entry (bool)
	Entry notification. More...
virtual void	on_scheduler_exit (bool)
	Exit notification. More...
virtual	~task_scheduler_observer_v3 ()
	Destructor automatically switches observation off if it is enabled. More...

Private Types
enum	{ global_tag = 0, implicit_tag = 1 }

Private Attributes
intptr_t	my_context_tag
	contains task_arena pointer or tag indicating local or global semantics of the observer More...

Static Private Attributes
static const intptr_t	v6_trait = (intptr_t)((~(uintptr_t)0 >> 1) + 1)

Friends
class	internal::task_scheduler_observer_v3
class	internal::observer_proxy
class	internal::observer_list

Detailed Description

Definition at line 92 of file task_scheduler_observer.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
global_tag
implicit_tag

Definition at line 104 of file task_scheduler_observer.h.

{ global_tag = 0, implicit_tag = 1 };

Constructor & Destructor Documentation

task_scheduler_observer() [1/2]

tbb::interface6::task_scheduler_observer::task_scheduler_observer ( bool  local = false )

inlineexplicit

Construct local or global observer in inactive state (observation disabled).

For a local observer entry/exit notifications are invoked whenever a worker thread joins/leaves the arena of the observer's owner thread. If a thread is already in the arena when the observer is activated, the entry notification is called before it executes the first stolen task. TODO: Obsolete. Global observer semantics is obsolete as it violates master thread isolation guarantees and is not composable. Thus the current default behavior of the constructor is obsolete too and will be changed in one of the future versions of the library.

Definition at line 117 of file task_scheduler_observer.h.

                                                           {
#if  __TBB_ARENA_OBSERVER
        my_context_tag = local? implicit_tag : global_tag;
#else
        __TBB_ASSERT_EX( !local, NULL );
        my_context_tag = global_tag;
#endif
    }

References __TBB_ASSERT_EX, global_tag, implicit_tag, and my_context_tag.

task_scheduler_observer() [2/2]

tbb::interface6::task_scheduler_observer::task_scheduler_observer ( task_arena &  a )

inlineexplicit

Construct local observer for a given arena in inactive state (observation disabled).

entry/exit notifications are invoked whenever a thread joins/leaves arena. If a thread is already in the arena when the observer is activated, the entry notification is called before it executes the first stolen task.

Definition at line 131 of file task_scheduler_observer.h.

                                                      {
        my_context_tag = (intptr_t)&a;
    }

References my_context_tag.

~task_scheduler_observer()

virtual tbb::interface6::task_scheduler_observer::~task_scheduler_observer ( )

inlinevirtual

Destructor protects instance of the observer from concurrent notification. It is recommended to disable observation before destructor of a derived class starts, otherwise it can lead to concurrent notification callback on partly destroyed object

Definition at line 139 of file task_scheduler_observer.h.

{ if(my_proxy) observe(false); }

References tbb::internal::task_scheduler_observer_v3::my_proxy, and observe().

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Member Function Documentation

observe()

void tbb::interface6::task_scheduler_observer::observe ( bool  state = true )

inline

Enable or disable observation.

Warning: concurrent invocations of this method are not safe. Repeated calls with the same state are no-ops.

Definition at line 144 of file task_scheduler_observer.h.

                                    {
        if( state && !my_proxy ) {
            __TBB_ASSERT( !my_busy_count, "Inconsistent state of task_scheduler_observer instance");
            my_busy_count.store<relaxed>(v6_trait);
        }
        internal::task_scheduler_observer_v3::observe(state);
    }

References __TBB_ASSERT, tbb::internal::task_scheduler_observer_v3::my_busy_count, tbb::internal::task_scheduler_observer_v3::my_proxy, tbb::internal::task_scheduler_observer_v3::observe(), tbb::relaxed, and v6_trait.

Referenced by ~task_scheduler_observer().

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Friends And Related Function Documentation

internal::observer_list

friend class internal::observer_list

friend

Definition at line 95 of file task_scheduler_observer.h.

internal::observer_proxy

friend class internal::observer_proxy

friend

Definition at line 94 of file task_scheduler_observer.h.

internal::task_scheduler_observer_v3

friend class internal::task_scheduler_observer_v3

friend

Definition at line 93 of file task_scheduler_observer.h.

Member Data Documentation

my_context_tag

intptr_t tbb::interface6::task_scheduler_observer::my_context_tag

private

contains task_arena pointer or tag indicating local or global semantics of the observer

Definition at line 103 of file task_scheduler_observer.h.

Referenced by task_scheduler_observer().

v6_trait

const intptr_t tbb::interface6::task_scheduler_observer::v6_trait = (intptr_t)((~(uintptr_t)0 >> 1) + 1)

staticprivate

Negative numbers with the largest absolute value to minimize probability of coincidence in case of a bug in busy count usage.

Definition at line 100 of file task_scheduler_observer.h.

Referenced by observe().

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

• task_scheduler_observer.h