AutomaticEvent (Variable type)

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Declaration
Using the AutomaticEvent variables

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AutomaticEvent (Variable type)

In french: SignalAutomatique

The AutomaticEvent type is used to manage an automatic event. An automatic event is used to simplify the synchronization between several threads.

After its opening, an "Automatic" event is automatically closed as soon as a single thread is unlocked.

Note: It is preferable to use a variable of type SignalAutomatique or ManualEvent to create a signal, rather than naming it using a character string.. Indeed, using a variable allows you to:

manage the variable scope,
avoid having 2 events with the same name in 2 different threads.

Example

// THREAD PRINCIPAL
//------------------
// Définition du signal
s is AutomaticEvent
// Lancement du thread
ThreadExecute("Thread", threadNormal, ProcThread, s)

// Code en parallèle du thread
...
// On attend le signal déclenché par le thread
EventWait(s)

// THREAD SECONDAIRE
// ----------------------
PROCEDURE ProcThread(s)

// Code dans le thread
...
// Déblocage du thread principal
EventOpen(s)

Declaration

Declaring an automatic event (simple syntax) Hide the details

MyVariable is AutomaticEvent

In this case, the automatic event is closed when it is created.

Declaring an automatic event (advanced syntax) Hide the details

MyVariable is AutomaticEvent(<Initial state>)

<Initial state>: Integer constant

Initial status of the event:
eventOpen The event is open when it is created.
eventClose The event is closed when it is created.

Remarks

Using the AutomaticEvent variables

The AutomaticEvent variables can be used to synchronize threads in functions:

standard syntax:


EventClose	Closes a synchronization event between several threads.
EventOpen	Opens a synchronization event between several threads.
EventWait	Locks the current thread while waiting for the specified event to be opened.

prefix syntax:


<AutomaticEvent variable>.Close	Closes a synchronization event between several threads.
<AutomaticEvent variable>.Open	Opens a synchronization event between several threads.
<AutomaticEvent variable>.Wait	Locks the current thread while waiting for the specified event to be opened.

When EventOpen (or <AutomaticEvent variable>.Open) is called:

if there is at least one pending thread, a single thread is freed.
if there is no pending thread, the event remains open until a thread calls EventWait (or <AutomaticEvent variable>.Wait).