How to check return status of parallel branches in jenkins pipeline

I am running a Jenkins job on multiple slaves. Following is the code structure:

def branches = [:]
def allNodes = Jenkins.getInstance().getNodes()
for (int i =0; i < allNodes.size(); i++) {
branches[allNodes[i].name.toString()] = {
    node(allNodes[i].name.toString()) { 
    .
    .
    stuff
    }
}
parallel branches

Now, I want to get the status of the job parts running on nodes so that in case some job part fails on some node I can mark that node as offline. Is there any way to do this?

I tried storing the slave job part status in a file and stashing it on node and then unstashing it back on master. It works but I am looking for a cleaner way. Following is the current approach i am using:

def branches = [:]
def allNodes = Jenkins.getInstance().getNodes()
for (int i =0; i < allNodes.size(); i++) {
String nodeName = allNodes[i].name.toString()
branches[nodeName] = {
    node(nodeName) { 
    .
    .
    String outputFile = nodeName + "-output"
    writeFile file: outputFile, text: result.toString()
    stash includes: "*output", name: outputFile
    }
}
parallel branches

for (int i = 0; i < allNodes.size(); i++) 
{
    String filename = allNodes[i].name.toString() + "-output"
    unstash filename
    def value = readFile filename

    // Mark node offline based on the variable value
}

StackExchange DevOps Q#2711, answer score: 4