Keep frame info registered until internal instance is gone (#1514)

This commit fixes an issue where the global registration of frame data
goes away once the `wasmtime::Module` has been dropped. Even after this
has been dropped, though, there may still be `wasmtime::Func` instances
which reference the original module, so it's only once the underlying
`wasmtime_runtime::Instance` has gone away that we can drop everything.

Closes #1479

crates/api/src/instance.rs

@@ -3,6 +3,7 @@ use crate::module::Module;
 use crate::runtime::{Config, Store};
 use crate::trap::Trap;
 use anyhow::{bail, Error, Result};
+use std::any::Any;
 use wasmtime_jit::{CompiledModule, Resolver};
 use wasmtime_runtime::{Export, InstanceHandle, InstantiationError, SignatureRegistry};
 
@@ -23,6 +24,7 @@ fn instantiate(
     compiled_module: &CompiledModule,
     imports: &[Extern],
     sig_registry: &SignatureRegistry,
+    host: Box<dyn Any>,
 ) -> Result<InstanceHandle, Error> {
     let mut resolver = SimpleResolver { imports };
     unsafe {
@@ -32,6 +34,7 @@ fn instantiate(
                 &mut resolver,
                 sig_registry,
                 config.memory_creator.as_ref().map(|a| a as _),
+                host,
             )
             .map_err(|e| -> Error {
                 match e {
@@ -132,13 +135,14 @@ impl Instance {
             );
         }
 
-        module.register_frame_info();
+        let info = module.register_frame_info();
         let config = store.engine().config();
         let instance_handle = instantiate(
             config,
             module.compiled_module(),
             imports,
             store.compiler().signatures(),
+            Box::new(info),
         )?;
 
         let mut exports = Vec::with_capacity(module.exports().len());

crates/api/src/module.rs

@@ -137,7 +137,7 @@ struct ModuleInner {
     imports: Box<[ImportType]>,
     exports: Box<[ExportType]>,
     compiled: CompiledModule,
-    frame_info_registration: Mutex<Option<Option<GlobalFrameInfoRegistration>>>,
+    frame_info_registration: Mutex<Option<Option<Arc<GlobalFrameInfoRegistration>>>>,
 }
 
 impl Module {
@@ -665,11 +665,13 @@ and for re-adding support for interface types you can see this issue:
     /// Register this module's stack frame information into the global scope.
     ///
     /// This is required to ensure that any traps can be properly symbolicated.
-    pub(crate) fn register_frame_info(&self) {
+    pub(crate) fn register_frame_info(&self) -> Option<Arc<GlobalFrameInfoRegistration>> {
         let mut info = self.inner.frame_info_registration.lock().unwrap();
-        if info.is_some() {
-            return;
+        if let Some(info) = &*info {
+            return info.clone();
         }
-        *info = Some(super::frame_info::register(&self.inner.compiled));
+        let ret = super::frame_info::register(&self.inner.compiled).map(Arc::new);
+        *info = Some(ret.clone());
+        return ret;
     }
 }