# Avoiding race conditions on flow start
**URL:** https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421
**Category:** General
**Created:** [29 February 2020 19:07 UTC](https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421 "2020-02-29T19:07:09Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@techraf](https://discourse.nodered.org/u/techraf)
#### Post date: [29 February 2020 19:07 UTC](https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421/1 "2020-02-29T19:07:10Z")
Let's consider I have two generic processes being triggered on flow start and I want to withhold message(s) from one of them (`Process 2`) until some condition calculated by the other (`Process 1`) is met, and then pass all messages intact and with no delay.
I could withhold a message with either `delay`, `trigger`, or `join` node, but then I would need to do it for every message, not only the initial one.
With `delay` I thought of modifying the delay through `msg.delay` but I would need to add it to all messages except for the first one, and I end up with a requirement to move the logic ahead.
With `trigger` and `join` I could merge two messages (either with `msg.reset` or `msg.complete`), but then it would be required for each and every message.
* * *
Another idea: use context to store a Boolean value to distinguish between the first and subsequent messages - but then on flow restart, I would need to manually clear the context and thus have a third contender in the initial race.
I could add another Boolean to mark "context cleared", but this gets ugly.
Similarly, I tried adding a `trust_level` to `Process 1` and `Process 2` messages and use a simple condition in `function`, but then I need to use context and have the same problem with clearing.
* * *
Whatever I think of, gets patchy and ugly, and I am stuck in some dead-end street with ideas.
Isn't there a clean way to achieve the above?
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### Author:  [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)
#### Post date: [29 February 2020 20:08 UTC](https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421/2 "2020-02-29T20:08:44Z")
Could you make use of `node-red-contrib-queue-gate` in the 'Process 1' flow.
Set the 'default state' as closed, then open the gate via the condition from 'Process 2'?
'Process 1's messages would be queued, and then released.
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### Author:  [@techraf](https://discourse.nodered.org/u/techraf)
#### Post date: [29 February 2020 21:16 UTC](https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421/3 "2020-02-29T21:16:33Z")
A real gem. 🥳 Exactly what I was looking for!
Thank you
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [14 March 2020 21:16 UTC](https://discourse.nodered.org/t/avoiding-race-conditions-on-flow-start/22421/4 "2020-03-14T21:16:34Z")
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