ObjectEvent

The Event module provides an event object for collaborative shared data operations. It allows synchronized operations between multiple fibers (coroutines) to achieve cooperative multitasking. The event object has three methods: wait, pulse and clear. The wait method will block the current fiber until the event is triggered, the pulse method will wake up all fibers waiting for the event, and the clear method will reset the event flag to false. by usingcoroutine.EventModule, developers can control the execution sequence and data sharing between fibers to implement complex business logic.

For example, suppose we need to share data between two fibers, but the order of their execution is uncertain. You can control the execution order of fibers through an event object to ensure that one fiber is triggered before the other is executed. Fiber events.

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const coroutine = require('coroutine');

var evt = new coroutine.Event();

coroutine.start(function() {
    console.log('[1] wait for event');
    evt.wait();
    console.log('[1] receive event');
});

coroutine.start(function() {
    loop: for (var i = 0; i < 10; i++) {
        console.log('[2] do some work');
        if (i === 5) {
            evt.pulse();
        }
        coroutine.sleep(1000);
    }
});

In the above example, we created an event object evt, used the wait method in fiber 1 to wait for the event to be triggered, and used the pulse method to trigger the event in fiber 2. When i equals 5, fiber 2 triggers the event. , Fiber 1 is awakened through event listening and continues execution. In this process, no locks or other synchronization tools are used between the two fibers, but they ensure data synchronization at the fiber level.

inheritance relationship

Constructor

Event

event object constructor

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new Event(Boolean value = false);

Call parameters:

• value: Boolean, specifies whether to wait, wait when true, default is false

member function

isSet

Determine whether the event object is true

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Boolean Event.isSet();

Return results:

• Boolean, if the event is true, return true

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set

Activate the event (change the event status to true) and call pulse()

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Event.set();

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pulse

Activate all fibers waiting for this event

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Event.pulse();

---

clear

Reset event (change event status to false)

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Event.clear();

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wait

wait for an event

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Event.wait();

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acquire

Get ownership of the lock

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Boolean Event.acquire(Boolean blocking = true);

Call parameters:

• blocking: Boolean, specifies whether to wait, wait when true, default is true

Return results:

• Boolean, returns whether the lock was successfully acquired, true indicates successful acquisition.

The acquire method is used to obtain ownership of the lock. When the lock is in the acquireable state, this method returns true immediately.

When the lock cannot be acquired and blocking is true, the current fiber goes to sleep. When other fibers release the lock, this method returns true.

When the lock cannot be acquired and blocking is false, the method returns false.

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release

Release ownership of the lock

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Event.release();

This method will release ownership of the lock or throw an error if the current fiber does not own the lock.

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count

Query the current number of waiting tasks

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Integer Event.count();

Return results:

• Integer, returns the number of tasks

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toString

Returns the string representation of the object. Generally, "[Native Object]" is returned. The object can be re-implemented according to its own characteristics.

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String Event.toString();

Return results:

• String, returns the string representation of the object

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toJSON

Returns a JSON format representation of the object, generally returning a collection of readable properties defined by the object.

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Value Event.toJSON(String key = "");

Call parameters:

• key: String, not used

Return results:

• Value, returns a value containing JSON serializable