T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Remove the jit_function_registry global state (#915)

Browse Source 
* Remove the `jit_function_registry` global state

This commit removes on the final pieces of global state in wasmtime
today, the `jit_function_registry` module. The purpose of this module is
to help translate a native backtrace with native program counters into a
wasm backtrace with module names, function names, and wasm module
indices. To that end this module retained a global map of function
ranges to this metadata information for each compiled function.

It turns out that we already had a `NAMES` global in the `wasmtime`
crate for symbolicating backtrace addresses, so this commit moves that
global into its own file and restructures the internals to account for
program counter ranges as well. The general set of changes here are:

* Remove `jit_function_registry`
* Remove `NAMES`
* Create a new `frame_info` module which has a singleton global
  registering compiled module's frame information.
* Update traps to use the `frame_info` module to symbolicate pcs,
  directly extracting a `FrameInfo` from the module.
* Register and unregister information on a module level instead of on a
  per-function level (at least in terms of locking granluarity).

This commit leaves the new `FRAME_INFO` global variable as the only
remaining "critical" global variable in `wasmtime`, which only exists
due to the API of `Trap` where it doesn't take in any extra context when
capturing a stack trace through which we could hang off frame
information. I'm thinking though that this is ok, and we can always
tweak the API of `Trap` in the future if necessary if we truly need to
accomodate this.

* Remove a lazy_static dep

* Add some comments and restructure
This commit is contained in:
Alex Crichton
2020-02-07 07:33:21 -06:00
committed by GitHub
parent a6adf52429
commit f5b505de04
16 changed files with 239 additions and 244 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
crates/jit/src/compiler.rs
View File

@@ -21,8 +21,7 @@ use wasmtime_environ::{
Traps, Tunables, VMOffsets,
};
use wasmtime_runtime::{
jit_function_registry, InstantiationError, SignatureRegistry, TrapRegistration, TrapRegistry,
VMFunctionBody,
InstantiationError, SignatureRegistry, TrapRegistration, TrapRegistry, VMFunctionBody,
};
/// Select which kind of compilation to use.
@@ -51,7 +50,6 @@ pub struct Compiler {
isa: Box<dyn TargetIsa>,
code_memory: CodeMemory,
jit_function_ranges: Vec<(usize, usize)>,
trap_registry: TrapRegistry,
trampoline_park: HashMap<*const VMFunctionBody, *const VMFunctionBody>,
signatures: SignatureRegistry,
@@ -72,7 +70,6 @@ impl Compiler {
Self {
isa,
code_memory: CodeMemory::new(),
jit_function_ranges: Vec::new(),
trampoline_park: HashMap::new(),
signatures: SignatureRegistry::new(),
fn_builder_ctx: FunctionBuilderContext::new(),
@@ -83,14 +80,6 @@ impl Compiler {
}
}
impl Drop for Compiler {
fn drop(&mut self) {
for (start, end) in self.jit_function_ranges.iter() {
jit_function_registry::unregister(*start, *end);
}
}
}
impl Compiler {
/// Return the target's frontend configuration settings.
pub fn frontend_config(&self) -> TargetFrontendConfig {
@@ -157,19 +146,6 @@ impl Compiler {
let trap_registration = register_traps(&allocated_functions, &traps, &self.trap_registry);
for (i, allocated) in allocated_functions.iter() {
let ptr = (*allocated) as *const VMFunctionBody;
let body_len = compilation.get(i).body.len();
self.jit_function_ranges
.push((ptr as usize, ptr as usize + body_len));
let func_index = module.func_index(i);
let tag = jit_function_registry::JITFunctionTag {
module_id: module.id,
func_index,
};
jit_function_registry::register(ptr as usize, ptr as usize + body_len, tag);
}
// Translate debug info (DWARF) only if at least one function is present.
let dbg = if debug_data.is_some() && !allocated_functions.is_empty() {
let target_config = self.isa.frontend_config();