Changes in perfmap.rs

bedbcd85 - Make profiling more amenable to other in-process engines (#11865)

Wed, 15 Oct 2025 21:56:16 +0000

Make profiling more amenable to other in-process engines (#11865)Both the perfmap and jitdump protocols for profiling JITs require thatthere's a single file with metadata per-process. This has theunfortunate side effect of if there are multiple engines in the sameprocess there's no real way for them to coordinate when writing outrecords to this file. In an attempt to at least try to synchronize thiscommit updates these two implementations to issue a single `write`syscall with the full contents of the record to a file opened in`O_APPEND` mode.If all the stars align and a partial write doesn't happen then thatmeans we're doing our best effort to cooperate with other engines in thesame process. If a partial write happens the decision in this PR is togo ahead and retry the rest of the write (using the `write_all` helper).This is a tradeoff where it makes the single-engine use case more robust(partial writes are handled correctly) but the multi-engine use casewill produce corrupt files. It doesn't feel like a great tradeoff to saythat profiling can't be done in Wasmtime when a partial write wouldhappen for this niche use case of multiple engines, hence the directionof this tradeoff.Closes #11862 List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs

b5e31a5c - Refactor internal profiling APIs to be safer (#8914)

Mon, 08 Jul 2024 18:53:16 +0000

Refactor internal profiling APIs to be safer (#8914)Pass around `&[u8]` instead of `*const u8` and `usize` to avoid the needfor raw unsafe abstractions.Closes #8905 List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs

1512a954 - Add `anyhow` stuff to our internal `wasmtime` crate prelude (#8804)

Fri, 14 Jun 2024 15:24:12 +0000

Add `anyhow` stuff to our internal `wasmtime` crate prelude (#8804)* Add `anyhow` stuff to our internal `wasmtime` crate preludeWe use it basically everywhere and it is annoying to have to import.I also did an audit of existing `use` statements and removed the now-redundantones and replaced one-off imports with usage of the prelude, so that the preludeis available by default in more places.* Fix `cargo doc` List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs

0e9121da - Fix some typos (#8641)

Thu, 16 May 2024 23:21:22 +0000

Fix some typos (#8641)* occurred* winch typos* tests typos* cli typos* fuzz typos* examples typos* docs typos* crates/wasmtime typos* crates/environ typos* crates/cranelift typos* crates/test-programs typos* crates/c-api typos* crates/cache typos* crates other typos* cranelift/codegen/src/isa typos* cranelift/codegen/src other typos* cranelift/codegen other typos* cranelift other typos* ci js typo* .github workflows typo* RELEASES typo* Fix clang-format documentation line---------Co-authored-by: Andrew Brown List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs

81a89169 - Add support for `#![no_std]` to the `wasmtime` crate (#8533)

Sat, 04 May 2024 22:02:26 +0000

Add support for `#![no_std]` to the `wasmtime` crate (#8533)* Always fall back to custom platform for WasmtimeThis commit updates Wasmtime's platform support to no longer require anopt-in `RUSTFLAGS` `--cfg` flag to be specified. With `no_std` becomingofficially supported this should provide a better onboarding experiencewhere the fallback custom platform is used. This will cause linkererrors if the symbols aren't implemented and searching/googling shouldlead back to our docs/repo (eventually, hopefully).* Change Wasmtime's TLS state to a single pointerThis commit updates the management of TLS to rely on just a singlepointer rather than a pair of a pointer and a `bool`. Additionallymanagement of the TLS state is pushed into platform-specific modules toenable different means of managing it, namely the "custom" platform nowhas a C function required to implement TLS state for Wasmtime.* Delay conversion to `Instant` in atomic intrinsicsThe `Duration` type is available in `no_std` but the `Instant` type isnot. The intention is to only support the `threads` proposal if `std` isactive but to assist with this split push the `Duration` further intoWasmtime to avoid using a type that can't be mentioned in `no_std`.* Gate more parts of Wasmtime on the `profiling` featureMove `serde_json` to an optional dependency and gate the guest profilerentirely on the `profiling` feature.* Refactor conversion to `anyhow::Error` in `wasmtime-environ`Have a dedicated trait for consuming `self` in addition to a`Result`-friendly trait.* Gate `gimli` in Wasmtime on `addr2line`Cut down the dependency list if `addr2line` isn't enabled since thenthe dependency is not used. While here additionally lift the versionrequirement for `addr2line` up to the workspace level.* Update `bindgen!` to have `no_std`-compatible outputPull most types from Wasmtime's `__internal` module as the source oftruth.* Use an `Option` for `gc_store` instead of `OnceCell`No need for synchronization here when mutability is already available inthe necessary contexts.* Enable embedder-defined host feature detection* Add `#![no_std]` support to the `wasmtime` crateThis commit enables compiling the `runtime`, `gc`, and `component-model`features of the `wasmtime` crate on targets that do not have `std`. Thistags the crate as `#![no_std]` and then updates everything internally toimport from `core` or `alloc` and adapt for the various idioms. Thisended up requiring some relatively extensive changes, but nothing tootoo bad in the grand scheme of things.* Require `std` for the perfmap profiling agentprtest:full* Fix build on wasm* Fix windows build* Remove unused import* Fix Windows/Unix build without `std` feature* Fix some doc links* Remove unused import* Fix build of wasi-common in isolation* Fix no_std build on macos* Re-fix build* Fix standalone build of wasmtime-cli-flags* Resolve a merge conflict* Review comments* Remove unused import List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs

2fcf41f0 - Remove `wasmtime-jit` (#7769)

Tue, 16 Jan 2024 17:49:50 +0000

Remove `wasmtime-jit` (#7769)* Move `jit` crate to `environ`Move the platform agnostic parts of the crate `wasmtime-jit` to`wasmtime-environ`. This is the first part of the refactoring discussedhere: https://github.com/bytecodealliance/wasmtime/issues/7652 and afollow up will move the remaining parts of `wasmtime-jit` so that thecrate can be deleted.* Move `jit` crate to `wasmtime`Move the remaining parts of `wasmtime-jit` to the `wasmtime` crate andremove `wasmtime-jit`. This is part of the refactoring discussed inhttps://github.com/bytecodealliance/wasmtime/issues/7652.* undo toml formatting* Trigger pipeline: prtest:full* Remove `jit` directory* move `ProfilingAgent` out of `profiling` feature* add links to ELF_NAME_DATA List of files: /wasmtime-44.0.1/crates/wasmtime/src/profiling_agent/perfmap.rs