* Add `anyhow` dependency to `wasmtime-runtime`.
* Revert `get_data` back to `fn`.
* Remove `DataInitializer` and box the data in `Module` translation instead.
* Improve comments on `MemoryInitialization`.
* Remove `MemoryInitialization::OutOfBounds` in favor of proper bulk memory
semantics.
* Use segmented memory initialization except for when the uffd feature is
enabled on Linux.
* Validate modules with the allocator after translation.
* Updated various functions in the runtime to return `anyhow::Result`.
* Use a slice when copying pages instead of `ptr::copy_nonoverlapping`.
* Remove unnecessary casts in `OnDemandAllocator::deallocate`.
* Better document the `uffd` feature.
* Use WebAssembly page-sized pages in the paged initialization.
* Remove the stack pool from the uffd handler and simply protect just the guard
pages.
Last minute code clean up to fix some comments and rename `address_space_size`
to `memory_reservation_size` to better describe what the option is doing.
This was originally written to support sourcing the table and memory
definitions differently for the pooling allocator.
However, both allocators do the exact same thing, so the closure arguments are
no longer necessary.
Additionally, this cleans up the code a bit to pass in the allocation request
rather than having individual parameters.
This commit implements copying paged initialization data upon a fault of a
linear memory page.
If the initialization data is "paged", then the appropriate pages are copied
into the Wasm page (or zeroed if the page is not present in the
initialization data).
If the initialization data is not "paged", the Wasm page is zeroed so that
module instantiation can initialize the pages.
As Windows uses the native fiber implementation, the stack tests should be
ignored on Windows as the implementation intentionally errors when handing out
stacks.
This commit implements the `uffd` feature which turns on support for utilizing
the `userfaultfd` system call on Linux for the pooling instance allocator.
By handling page faults in userland, we are able to detect guard page accesses
without having to constantly change memory page protections.
This should help reduce the number of syscalls as well as kernel lock
contentions when many threads are allocating and deallocating instances.
Additionally, the user fault handler can lazy initialize linear
memories of an instance (implementation to come).
This commit implements the pooling instance allocator.
The allocation strategy can be set with `Config::with_allocation_strategy`.
The pooling strategy uses the pooling instance allocator to preallocate a
contiguous region of memory for instantiating modules that adhere to various
limits.
The intention of the pooling instance allocator is to reserve as much of the
host address space needed for instantiating modules ahead of time and to reuse
committed memory pages wherever possible.
