# Objective
- Allow rendering queue systems to use a `Res<PipelineCache>` even for queueing up new rendering pipelines. This is part of unblocking parallel execution queue systems.
## Solution
- Make `PipelineCache` internally mutable w.r.t to queueing new pipelines. Pipelines are no longer immediately updated into the cache state, but rather queued into a Vec. The Vec of pending new pipelines is then later processed at the same time we actually create the queued pipelines on the GPU device.
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## Changelog
`PipelineCache` no longer requires mutable access in order to queue render / compute pipelines.
## Migration Guide
* Most usages of `resource_mut::<PipelineCache>` and `ResMut<PipelineCache>` can be changed to `resource::<PipelineCache>` and `Res<PipelineCache>` as long as they don't use any methods requiring mutability - the only public method requiring it is `process_queue`.
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