gistfile1.js

var http = require('http');
var exec = require("child_process").exec;


http.createServer(function (request, response) {
    console.log('Response being generated..');
    response.writeHead(200, {'Content-Type': 'text/plain'});
    call_execs(response);
}).listen(8000);

function call_execs(response) {
    // Two var's to store output in.
    var output_a;
    var output_b;
    
    console.log('Calling blocking code..');
    // Call our blocking code
    exec("ls /home",
        { timeout: 10000, maxBuffer: 20000*1024 },
        function (error, stdout, stderr) {
            output_a = stdout;
            exec_complete();
    });
    exec("find /home",
        { timeout: 10000, maxBuffer: 20000*1024 },
        function (error, stdout, stderr) {
            output_b = stdout;
            exec_complete();
    });
    
    function exec_complete() {
        console.log('Exec complete!');
        // Check to see if both execs were written to.
        if (output_a !== undefined && output_b !== undefined) {
            console.log('Both execs complete!');
            response.end('Output A: '+ output_a +'\n\n\nOutput B: '+ output_b);
        }
    }
}

just a sketch of how i'd approach the problem:

function call_execs(response) {
    // Two var's to store output in.
    var output = {}
      , check_done = []
      , store = function(into) {
        check_done.push(into)
        return function(error, stdout, stderr) {
          // remove the check
          check_done.splice(check_done.indexOf(into), 1)
          output[into] = stdout
          if(check_done.length === 0) {
            exec_complete()
          }
        }
      }
      , config = {timeout:10000, maxBuffer:20000*1024}

    console.log('Calling blocking code..');
    // Call our blocking code
    exec("ls /home", config, store('a'))
    exec("find /home", config, store('b'))

    function exec_complete() {
      console.log('All execs complete!');
      response.end('Output A: '+ output.a +'\n\n\nOutput B: '+ output.b);
    }
}