How to create multiple instances from a template map in groovy - variables

Question

For an internal status logging in my jenkins pipeline I have created a "template map which I want do use in multiple stages which are running independently in parallel
def status= [
a : '',
b: [
b1: '',
b2: '',
b3: ''
],
c: [
c1: '',
c2 : ''
]
]
this status template I want to pass to multiple parallel running functions/executors. Inside the parallel branches I want to modify the status independently. See the following minimal example
def status= [
a : '',
b: [
b1: '',
b2: '',
b3: ''
],
c: [
c1: '',
c2 : ''
]
]
def label1 = "windows"
def label2 = ''
parallel firstBranch: {
run_node(label1, status)
}, secondBranch: {
run_node(label2, status)
},
failFast: true|false
def run_node (label, status){
node(label) {
status.b.b1 = env.NODE_NAME +"_"+ env.EXECUTOR_NUMBER
sleep(1)
echo "env.NODE_NAME_env.EXECUTOR_NUMBER: ${status.b.b1}"
// expected: env.NODE_NAME_env.EXECUTOR_NUMBER
this.a_function(status)
echo "env.NODE_NAME_env.EXECUTOR_NUMBER: ${status.b.b1}"
// expected(still): env.NODE_NAME_env.EXECUTOR_NUMBER (off current node)
// is: env.NODE_NAME_env.EXECUTOR_NUMBERmore Info AND probably from the wrong node
}
}
def a_function(status){
status.b.b1 += "more Info"
echo "env.NODE_NAME_env.EXECUTOR_NUMBERmore Info: ${status.b.b1}"
// expected: env.NODE_NAME_env.EXECUTOR_NUMBERmore Info
sleep(0.5)
echo "env.NODE_NAME_env.EXECUTOR_NUMBERmore Info: ${status.b.b1}"
// expected: env.NODE_NAME_env.EXECUTOR_NUMBERmore Info
}
Which results in
[firstBranch] env.NODE_NAME_env.EXECUTOR_NUMBER:
LR-Z4933-39110bdb_0
[firstBranch] env.NODE_NAME_env.EXECUTOR_NUMBERmore Info:
LR-Z4933-39110bdb_0more Info
[firstBranch] env.NODE_NAME_env.EXECUTOR_NUMBER>more Info:
LR-Z4933-39110bdb_0more Info
[firstBranch] env.NODE_NAME_env.EXECUTOR_NUMBER:
LR-Z4933-39110bdb_0more Info
[secondBranch] env.NODE_NAME_env.EXECUTOR_NUMBER:
LR-Z4933-39110bdb_0more Info
[secondBranch] env.NODE_NAME_env.EXECUTOR_NUMBERmore Info:
LR-Z4933-39110bdb_0more Infomore Info
[secondBranch] env.NODE_NAME_env.EXECUTOR_NUMBERmore Info:
LR-Z4933-39110bdb_0more Infomore Info
[secondBranch] env.NODE_NAME_env.EXECUTOR_NUMBER:
LR-Z4933-39110bdb_0more Infomore Info
Note that in the status in the first branch is overwritten by the second branch and the other way around.
How to realize independent status variables when passing thm as a parameter to functions

Answer 1

You could define the template map. When you need multiple instances of the same which you may want to modify differently per instance by using cloned template map.
Here is short code snippet to show the example.
def template = [a: '', b: '']
def instancea = template.clone()
def instanceb = template.clone()
def instancec = template.clone()
instancea.a = 'testa'
instanceb.a = 'testb'
instancec.a = 'testc'
println instancea
println instanceb
println instancec
Of course, you can include bigger map, the above is only for demonstration.

Answer 2

You are passing status by reference to the function. But even if you do a status.clone(), I suspect this isn't a deep copy of status. status.b probably still points to the same reference. You need to make a deep copy of status and send that deep copy to the function.
I'm not sure a deep copy of a framework map is the right way to do this. You could just send an empty map [:] and let the called functions add the pieces to the map that they need. If you really need to pre-define the content of the map, then I think you should add a class and create new objects from that class.