wasmer_wasix/state/handles/mod.rs
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mod global;
mod thread_local;
#[cfg(feature = "sys")]
pub(crate) use global::*;
#[cfg(feature = "js")]
pub(crate) use thread_local::*;
use wasmer::{AsStoreRef, Global, Instance, Memory, MemoryView, Module, TypedFunction};
use super::Linker;
/// Various [`TypedFunction`] and [`Global`] handles for an active WASI(X) instance.
///
/// Used to access and modify runtime state.
// TODO: make fields private
#[derive(Debug, Clone)]
pub struct WasiModuleInstanceHandles {
// TODO: the two fields below are instance specific, while all others are module specific.
// Should be split up.
/// Represents a reference to the memory
pub(crate) memory: Memory,
pub(crate) instance: wasmer::Instance,
/// Points to the current location of the memory stack pointer
pub(crate) stack_pointer: Option<Global>,
/// Points to the end of the data section
pub(crate) data_end: Option<Global>,
/// Points to the lower end of the stack
pub(crate) stack_low: Option<Global>,
/// Points to the higher end of the stack
pub(crate) stack_high: Option<Global>,
/// Points to the start of the TLS area
pub(crate) tls_base: Option<Global>,
/// Main function that will be invoked (name = "_start")
pub(crate) start: Option<TypedFunction<(), ()>>,
/// Function thats invoked to initialize the WASM module (name = "_initialize")
// TODO: review allow...
#[allow(dead_code)]
pub(crate) initialize: Option<TypedFunction<(), ()>>,
/// Represents the callback for spawning a thread (name = "wasi_thread_start")
/// (due to limitations with i64 in browsers the parameters are broken into i32 pairs)
/// [this takes a user_data field]
pub(crate) thread_spawn: Option<TypedFunction<(i32, i32), ()>>,
/// Represents the callback for signals (name = "__wasm_signal")
/// Signals are triggered asynchronously at idle times of the process
// TODO: why is this here? It can exist in WasiEnv
pub(crate) signal: Option<TypedFunction<i32, ()>>,
/// Flag that indicates if the signal callback has been set by the WASM
/// process - if it has not been set then the runtime behaves differently
/// when a CTRL-C is pressed.
pub(crate) signal_set: bool,
/// Flag that indicates if the stack capture exports are being used by
/// this WASM process which means that it will be using asyncify
pub(crate) has_stack_checkpoint: bool,
/// asyncify_start_unwind(data : i32): call this to start unwinding the
/// stack from the current location. "data" must point to a data
/// structure as described above (with fields containing valid data).
// TODO: review allow...
#[allow(dead_code)]
pub(crate) asyncify_start_unwind: Option<TypedFunction<i32, ()>>,
/// asyncify_stop_unwind(): call this to note that unwinding has
/// concluded. If no other code will run before you start to rewind,
/// this is not strictly necessary, however, if you swap between
/// coroutines, or even just want to run some normal code during a
/// "sleep", then you must call this at the proper time. Otherwise,
/// the code will think it is still unwinding when it should not be,
/// which means it will keep unwinding in a meaningless way.
// TODO: review allow...
#[allow(dead_code)]
pub(crate) asyncify_stop_unwind: Option<TypedFunction<(), ()>>,
/// asyncify_start_rewind(data : i32): call this to start rewinding the
/// stack vack up to the location stored in the provided data. This prepares
/// for the rewind; to start it, you must call the first function in the
/// call stack to be unwound.
// TODO: review allow...
#[allow(dead_code)]
pub(crate) asyncify_start_rewind: Option<TypedFunction<i32, ()>>,
/// asyncify_stop_rewind(): call this to note that rewinding has
/// concluded, and normal execution can resume.
// TODO: review allow...
#[allow(dead_code)]
pub(crate) asyncify_stop_rewind: Option<TypedFunction<(), ()>>,
/// asyncify_get_state(): call this to get the current value of the
/// internal "__asyncify_state" variable as described above.
/// It can be used to distinguish between unwinding/rewinding and normal
/// calls, so that you know when to start an asynchronous operation and
/// when to propagate results back.
#[allow(dead_code)]
pub(crate) asyncify_get_state: Option<TypedFunction<(), i32>>,
}
impl WasiModuleInstanceHandles {
pub fn new(memory: Memory, store: &impl AsStoreRef, instance: Instance) -> Self {
let has_stack_checkpoint = instance
.module()
.imports()
.any(|f| f.name() == "stack_checkpoint");
Self {
memory,
stack_pointer: instance.exports.get_global("__stack_pointer").cloned().ok(),
data_end: instance.exports.get_global("__data_end").cloned().ok(),
stack_low: instance.exports.get_global("__stack_low").cloned().ok(),
stack_high: instance.exports.get_global("__stack_high").cloned().ok(),
tls_base: instance.exports.get_global("__tls_base").cloned().ok(),
start: instance.exports.get_typed_function(store, "_start").ok(),
initialize: instance
.exports
.get_typed_function(store, "_initialize")
.ok(),
thread_spawn: instance
.exports
.get_typed_function(store, "wasi_thread_start")
.ok(),
signal: instance
.exports
.get_typed_function(&store, "__wasm_signal")
.ok(),
has_stack_checkpoint,
signal_set: false,
asyncify_start_unwind: instance
.exports
.get_typed_function(store, "asyncify_start_unwind")
.ok(),
asyncify_stop_unwind: instance
.exports
.get_typed_function(store, "asyncify_stop_unwind")
.ok(),
asyncify_start_rewind: instance
.exports
.get_typed_function(store, "asyncify_start_rewind")
.ok(),
asyncify_stop_rewind: instance
.exports
.get_typed_function(store, "asyncify_stop_rewind")
.ok(),
asyncify_get_state: instance
.exports
.get_typed_function(store, "asyncify_get_state")
.ok(),
instance,
}
}
pub fn module(&self) -> &Module {
self.instance.module()
}
pub fn module_clone(&self) -> Module {
self.instance.module().clone()
}
/// Providers safe access to the memory
/// (it must be initialized before it can be used)
pub fn memory_view<'a>(&'a self, store: &'a (impl AsStoreRef + ?Sized)) -> MemoryView<'a> {
self.memory.view(store)
}
/// Providers safe access to the memory
/// (it must be initialized before it can be used)
pub fn memory(&self) -> &Memory {
&self.memory
}
/// Copy the lazy reference so that when it's initialized during the
/// export phase, all the other references get a copy of it
pub fn memory_clone(&self) -> Memory {
self.memory.clone()
}
pub fn instance(&self) -> &Instance {
&self.instance
}
}
#[derive(Debug, Clone)]
pub enum WasiModuleTreeHandles {
Static(WasiModuleInstanceHandles),
Dynamic {
linker: Linker,
main_module_instance_handles: WasiModuleInstanceHandles,
},
}
impl WasiModuleTreeHandles {
/// Can be used to get the `WasiModuleInstanceHandles` of the main module.
/// If access to the side modules' instance handles is required, one must go
/// through the `Linker` to retrieve the one they need.
pub(crate) fn main_module_instance_handles(&self) -> &WasiModuleInstanceHandles {
match self {
WasiModuleTreeHandles::Static(ref handles) => handles,
WasiModuleTreeHandles::Dynamic {
ref main_module_instance_handles,
..
} => main_module_instance_handles,
}
}
/// See comments on `main_module_instance_handles`.
pub(crate) fn main_module_instance_handles_mut(&mut self) -> &mut WasiModuleInstanceHandles {
match self {
WasiModuleTreeHandles::Static(ref mut handles) => handles,
WasiModuleTreeHandles::Dynamic {
ref mut main_module_instance_handles,
..
} => main_module_instance_handles,
}
}
/// Helper function to get the instance handles of a static module, or fail otherwise.
/// See comments on ensure_static_module for more details.
pub(crate) fn static_module_instance_handles(&self) -> Option<&WasiModuleInstanceHandles> {
match self {
WasiModuleTreeHandles::Static(ref handles) => Some(handles),
WasiModuleTreeHandles::Dynamic { .. } => None,
}
}
/// See comments on `static_module_instance_handles`.
#[allow(dead_code)]
pub(crate) fn static_module_instance_handles_mut(
&mut self,
) -> Option<&mut WasiModuleInstanceHandles> {
match self {
WasiModuleTreeHandles::Static(ref mut handles) => Some(handles),
WasiModuleTreeHandles::Dynamic { .. } => None,
}
}
/// Helper function to ensure the module isn't dynamically linked, needed since
/// we only support a subset of WASIX functionality for dynamically linked modules.
/// Specifically, anything that requires asyncify is not supported right now.
pub(crate) fn ensure_static_module(&self) -> Result<(), ()> {
match self {
WasiModuleTreeHandles::Static(_) => Ok(()),
_ => Err(()),
}
}
/// Providers safe access to the memory
/// (it must be initialized before it can be used)
pub fn memory_view<'a>(&'a self, store: &'a (impl AsStoreRef + ?Sized)) -> MemoryView<'a> {
self.main_module_instance_handles().memory.view(store)
}
/// Providers safe access to the memory
/// (it must be initialized before it can be used)
pub fn memory(&self) -> &Memory {
&self.main_module_instance_handles().memory
}
/// Copy the lazy reference so that when it's initialized during the
/// export phase, all the other references get a copy of it
pub fn memory_clone(&self) -> Memory {
self.main_module_instance_handles().memory.clone()
}
pub fn linker(&self) -> Option<&Linker> {
match self {
Self::Static(_) => None,
Self::Dynamic { linker, .. } => Some(linker),
}
}
}