google apps script lock service
// BEGIN - start lock here
var lock = LockService.getScriptLock();
try {
lock.waitLock(30000); // wait 30 seconds for others' use of the code section and lock to stop and then proceed
} catch (e) {
Logger.log('Could not obtain lock after 30 seconds.');
return HtmlService.createHtmlOutput("<b> Server Busy please try after some time <p>")
// In case this a server side code called asynchronously you return a error code and display the appropriate message on the client side
return "Error: Server busy try again later... Sorry :("
}
// note: if return is run in the catch block above the following will not run as the function will be exited
// Do lots of stuff - ie apply dynamic background colors based on previous entries colors, define the target range and set values, set data validations
lock.releaseLock();
// END - end lock here