The Lock and Unlock methods

The Lock and Unlock methods are used to create a global critical section when synchronization of scripts started in different streams is required. The Lock method opens a critical section and the Unlock method closes it.

Attention!

Attention! If the Lock method has been called, then the Unlock method has to be called too. Otherwise the system can freeze.

It is recommended to avoid using the Lock and Unlock methods.

Method call syntax

 function Lock()

 function Unlock()

Example. When Macro 1 starts, calculate total alarmed relays and sensors. Objects of each type are to be calculated at the same time (in an individual script). The result is to be stored to “counter” global variable.

Script 1:

 // Number of alarmed relays is calculated
var i = Number(0);
if (Event.SourceType == "MACRO" && Event.SourceId== "1" && Event.Action == "RUN")
{
var msg = CreateMsg();
msg.StringToMsg(GetObjectIds("GRELE"));
var objCount = msg.GetParam("id.count");
var k;
for(k= 0; k < objCount; k++)
if(GetObjectState("GRELE", msg.GetParam("id." + k))== "ALARM"){
        Lock();
         i = Itv_var("counter");
i++;
Itv_var("counter")=i;
Unlock();
}
}

Script 2:

 //Number of alarmed sensors is calculated
var i = Number(0);
 if (Event.SourceType == "MACRO" && Event.SourceId== "1" && Event.Action == "RUN")
{
var msg = CreateMsg();
msg.StringToMsg(GetObjectIds("GRAY"));
var objCount = msg.GetParam("id.count");
var k;
for(k = 0; k < objCount; k++)
if(GetObjectState("GRAY", msg.GetParam("id." + k))== "ALARMED"){
        Lock();
         i = Itv_var("counter");
i++;
Itv_var("counter")=i;
Unlock();
}
}

Note

If the Lock() and Unlock() methods are not used in this example, then collisions may occur and calculated value will be less than a real one

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Documentation for Axxon PSIM 1.0.0-1.0.1.