HALCON 18.05 / HALCON Operator Reference / System / Multithreading
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create_conditionT_create_conditionCreateConditionCreateCondition (Operator)

Name

create_conditionT_create_conditionCreateConditionCreateCondition — Create a condition variable synchronization object.

Signature

create_condition( : : AttribName, AttribValue : ConditionHandle)

Herror T_create_condition(const Htuple AttribName, const Htuple AttribValue, Htuple* ConditionHandle)

void CreateCondition(const HTuple& AttribName, const HTuple& AttribValue, HTuple* ConditionHandle)

void HCondition::HCondition(const HTuple& AttribName, const HTuple& AttribValue)

void HCondition::HCondition(const HString& AttribName, const HString& AttribValue)

void HCondition::HCondition(const char* AttribName, const char* AttribValue)

void HCondition::CreateCondition(const HTuple& AttribName, const HTuple& AttribValue)

void HCondition::CreateCondition(const HString& AttribName, const HString& AttribValue)

void HCondition::CreateCondition(const char* AttribName, const char* AttribValue)

static void HOperatorSet.CreateCondition(HTuple attribName, HTuple attribValue, out HTuple conditionHandle)

public HCondition(HTuple attribName, HTuple attribValue)

public HCondition(string attribName, string attribValue)

void HCondition.CreateCondition(HTuple attribName, HTuple attribValue)

void HCondition.CreateCondition(string attribName, string attribValue)

Description

A condition variable (short: “condition”) is a synchronization device that allows threads to suspend execution and relinquish the processors until some predicate on shared data is satisfied. The basic operations on conditions are: signal the condition (when the predicate becomes true), and wait for the condition, suspending the thread execution until another thread signals the condition.

A condition variable must always be associated with a mutex, to avoid the race condition where a thread prepares to wait on a condition variable and another thread signals the condition just before the first thread actually waits on it.

create_conditioncreate_conditionCreateConditionCreateConditionCreateCondition creates and initializes the condition variable ConditionHandleConditionHandleConditionHandleConditionHandleconditionHandle, using the condition attributes specified in AttribNameAttribNameAttribNameAttribNameattribName and AttribValueAttribValueAttribValueAttribValueattribValue, or default attributes if AttribNameAttribNameAttribNameAttribNameattribName is ''"""""""". The current implementation supports no attributes for conditions, hence the AttribNameAttribNameAttribNameAttribNameattribName parameter must be set to ''"""""""".

Execution Information

Parameters

AttribNameAttribNameAttribNameAttribNameattribName (input_control)  number(-array) → HTupleHTupleHtuple (string / integer / real) (string / int / long / double) (HString / Hlong / double) (char* / Hlong / double)

Mutex attribute.

Default value: []

AttribValueAttribValueAttribValueAttribValueattribValue (input_control)  number(-array) → HTupleHTupleHtuple (string / integer / real) (string / int / long / double) (HString / Hlong / double) (char* / Hlong / double)

Mutex attribute value.

Number of elements: AttribValue == AttribName

Default value: []

ConditionHandleConditionHandleConditionHandleConditionHandleconditionHandle (output_control)  condition → HCondition, HTupleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)

Condition synchronization object.

Result

create_conditioncreate_conditionCreateConditionCreateConditionCreateCondition returns 2 (H_MSG_TRUE) if all parameters are correct. If necessary, an exception is raised.

Possible Successors

wait_conditionwait_conditionWaitConditionWaitConditionWaitCondition, timed_wait_conditiontimed_wait_conditionTimedWaitConditionTimedWaitConditionTimedWaitCondition, signal_conditionsignal_conditionSignalConditionSignalConditionSignalCondition

See also

clear_conditionclear_conditionClearConditionClearConditionClearCondition

Module

Foundation

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