CODEWITHSUNDEEP
omnet++inet
Vlad Royik
Vlad Royik

Reputation: 3

How to declare a set of parameters in omnetpp.ini

I have hosts of two types: wirelessHostA[0..N], wirelessHostB[0..N]. I want to declare each of hosts wirelessHostA[0..N] to send messages to respective wirelessHostB[0..N]. Example: A[0] sends to B[0], A[10] sends to B[10]. Expression-wise I have got something like this:

*.wirelessHostA[0..${N}].app[ * ].destAddresses = "wirelessHostB[0..${N}]"

although this one is not correct. I am a bit unsure about how to declare a variable that can be iterated during a run and not a value per run.

Upvotes: 0

Views: 1824

Answers (1)

Rudi
Rudi

Reputation: 6681

You should not see the lines in the INI file as assignments where you can create procedural constructs like loops etc. Instead think about them as pattern matching rules. When a module needs a parameter, it scans the INI file from start, line by line and tries to match the first part (i.e. the part before =) to the current module path. If it matches, it assigns the second part to the parameter. If not, in continues with the next line in the INI file.

So first, write a pattern rule, then a value that can be evaluated in that context. When you specify the value, you may refer to other parameters (that are available in the module's context) or you may refer to other extra contextual information, such as the matching submodule's index (if it is part of a vector). There are other functions to access the index of parent of etc.

In this case, we have a submodule vector of hosts where each one contains a submodule vector of apps. The index operator would return the index of the current context module (which is the position in the app vector), but we need actually the index of the parent of the app vector (which is the host vector). There is a NED function for this too, called parentIndex(). So the solution would look like this:

*.wirelessHostA[*].app[*].destAddresses = "wirelessHostB[" + string(parentIndex()) + "]"

See https://doc.omnetpp.org/omnetpp/manual/#sec:ned-functions:category-ned for more info.

Upvotes: 2

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