Commit Detail
Commit 7b3f3ae
Dedicated memory snapshots This adds dedicated memory snapshots. It's pretty finicky how you load shared libraries in a memory snapshot since their metadata needs to be allocated in the same location whether starting from scratch or from the snapshot. The simplest way to deal with it is to preload the libraries in a given order before the runtime starts. This approach leaves us without a good way of figuring out which ones are needed so we take a naive approach and preload all of them. We then parse the user code into abstract syntax trees and look for import nodes. We try to import all of these and catch and throw away if it fails. Then we record which dynamic libraries have been dlopened and where the handles are located. We put the handle data together with the heap snapshot. This required pretty major surgery since some information about the packages is needed much earlier than it was previously available. Some steps like updating paths are not possible to do on the not-yet-initialized runtime and have to be separated.