Cooperative Multithreading

Cargo.toml

@@ -50,7 +50,10 @@ wasmtime-cranelift = { workspace = true, optional = true }
 wasmtime-environ = { workspace = true }
 wasmtime-explorer = { workspace = true, optional = true }
 wasmtime-wast = { workspace = true, optional = true }
-wasi-common = { workspace = true, default-features = true, features = ["exit", "tokio"], optional = true }
+wasi-common = { workspace = true, default-features = true, features = [
+  "exit",
+  "tokio",
+], optional = true }
 wasmtime-wasi = { workspace = true, default-features = true, optional = true }
 wasmtime-wasi-nn = { workspace = true, optional = true }
 wasmtime-wasi-config = { workspace = true, optional = true }
@@ -82,22 +85,36 @@ pulley-interpreter = { workspace = true, optional = true }
 async-trait = { workspace = true }
 bytes = { workspace = true }
 cfg-if = { workspace = true }
-tokio = { workspace = true, optional = true, features = [ "signal", "macros" ] }
+tokio = { workspace = true, optional = true, features = ["signal", "macros"] }
 hyper = { workspace = true, optional = true }
 http = { workspace = true, optional = true }
 http-body-util = { workspace = true, optional = true }
+tracing-subscriber.workspace = true
 
 [target.'cfg(unix)'.dependencies]
 rustix = { workspace = true, features = ["mm", "process"] }
 
 [dev-dependencies]
 # depend again on wasmtime to activate its default features for tests
-wasmtime = { workspace = true, features = ['default', 'winch', 'pulley', 'all-arch', 'call-hook', 'memory-protection-keys', 'component-model-async'] }
+wasmtime = { workspace = true, features = [
+  'default',
+  'winch',
+  'pulley',
+  'all-arch',
+  'call-hook',
+  'memory-protection-keys',
+  'component-model-async',
+] }
 env_logger = { workspace = true }
 log = { workspace = true }
 filecheck = { workspace = true }
 tempfile = { workspace = true }
-tokio = { workspace = true, features = ["rt", "time", "macros", "rt-multi-thread"] }
+tokio = { workspace = true, features = [
+  "rt",
+  "time",
+  "macros",
+  "rt-multi-thread",
+] }
 wast = { workspace = true }
 criterion = { workspace = true }
 num_cpus = "1.13.0"
@@ -107,7 +124,10 @@ wat = { workspace = true }
 rayon = "1.5.0"
 wasmtime-wast = { workspace = true, features = ['component-model'] }
 wasmtime-component-util = { workspace = true }
-wasmtime-test-util = { workspace = true, features = ['wasmtime-wast', 'component'] }
+wasmtime-test-util = { workspace = true, features = [
+  'wasmtime-wast',
+  'component',
+] }
 bstr = "1.6.0"
 libc = { workspace = true }
 serde = { workspace = true }
@@ -117,7 +137,11 @@ test-programs-artifacts = { workspace = true }
 bytesize = "2.0.1"
 wit-component = { workspace = true }
 cranelift-filetests = { workspace = true }
-cranelift-codegen = { workspace = true, features = ["disas", "trace-log", "timing"] }
+cranelift-codegen = { workspace = true, features = [
+  "disas",
+  "trace-log",
+  "timing",
+] }
 cranelift-reader = { workspace = true }
 toml = { workspace = true }
 similar = { workspace = true }
@@ -170,9 +194,7 @@ members = [
   "fuzz",
   "winch/codegen",
 ]
-exclude = [
-  'docs/rust_wasi_markdown_parser',
-]
+exclude = ['docs/rust_wasi_markdown_parser']
 
 [workspace.package]
 version = "38.0.0"
@@ -253,8 +275,8 @@ wasmtime-wmemcheck = { path = "crates/wmemcheck", version = "=38.0.0", package =
 wasmtime-c-api-macros = { path = "crates/c-api-macros", version = "=38.0.0", package = 'wasmtime-internal-c-api-macros' }
 wasmtime-cache = { path = "crates/cache", version = "=38.0.0", package = 'wasmtime-internal-cache' }
 wasmtime-cranelift = { path = "crates/cranelift", version = "=38.0.0", package = 'wasmtime-internal-cranelift' }
-wasmtime-winch = { path = "crates/winch", version = "=38.0.0", package = 'wasmtime-internal-winch'  }
-wasmtime-explorer = { path = "crates/explorer", version = "=38.0.0", package = 'wasmtime-internal-explorer'  }
+wasmtime-winch = { path = "crates/winch", version = "=38.0.0", package = 'wasmtime-internal-winch' }
+wasmtime-explorer = { path = "crates/explorer", version = "=38.0.0", package = 'wasmtime-internal-explorer' }
 wasmtime-fiber = { path = "crates/fiber", version = "=38.0.0", package = 'wasmtime-internal-fiber' }
 wasmtime-jit-debug = { path = "crates/jit-debug", version = "=38.0.0", package = 'wasmtime-internal-jit-debug' }
 wasmtime-component-util = { path = "crates/component-util", version = "=38.0.0", package = 'wasmtime-internal-component-util' }
@@ -263,7 +285,7 @@ wasmtime-versioned-export-macros = { path = "crates/versioned-export-macros", ve
 wasmtime-slab = { path = "crates/slab", version = "=38.0.0", package = 'wasmtime-internal-slab' }
 wasmtime-jit-icache-coherence = { path = "crates/jit-icache-coherence", version = "=38.0.0", package = 'wasmtime-internal-jit-icache-coherence' }
 wasmtime-wit-bindgen = { path = "crates/wit-bindgen", version = "=38.0.0", package = 'wasmtime-internal-wit-bindgen' }
-wasmtime-math = { path = "crates/math", version = "=38.0.0", package = 'wasmtime-internal-math'  }
+wasmtime-math = { path = "crates/math", version = "=38.0.0", package = 'wasmtime-internal-math' }
 wasmtime-unwinder = { path = "crates/unwinder", version = "=38.0.0", package = 'wasmtime-internal-unwinder' }
 
 # Miscellaneous crates without a `wasmtime-*` prefix in their name but still
@@ -277,7 +299,10 @@ pulley-macros = { path = 'pulley/macros', version = "=38.0.0" }
 
 # Cranelift crates in this workspace
 cranelift-assembler-x64 = { path = "cranelift/assembler-x64", version = "0.125.0" }
-cranelift-codegen = { path = "cranelift/codegen", version = "0.125.0", default-features = false, features = ["std", "unwind"] }
+cranelift-codegen = { path = "cranelift/codegen", version = "0.125.0", default-features = false, features = [
+  "std",
+  "unwind",
+] }
 cranelift-frontend = { path = "cranelift/frontend", version = "0.125.0" }
 cranelift-entity = { path = "cranelift/entity", version = "0.125.0" }
 cranelift-native = { path = "cranelift/native", version = "0.125.0" }
@@ -328,7 +353,9 @@ wit-bindgen = { version = "0.46.0", default-features = false }
 wit-bindgen-rust-macro = { version = "0.46.0", default-features = false }
 
 # wasm-tools family:
-wasmparser = { version = "0.239.0", default-features = false, features = ['simd'] }
+wasmparser = { version = "0.239.0", default-features = false, features = [
+  'simd',
+] }
 wat = "1.239.0"
 wast = "239.0.0"
 wasmprinter = "0.239.0"
@@ -346,14 +373,20 @@ json-from-wast = "0.239.0"
 arbitrary = "1.4.0"
 mutatis = "0.3.2"
 cc = "1.0"
-object = { version = "0.37.3", default-features = false, features = ['read_core', 'elf'] }
+object = { version = "0.37.3", default-features = false, features = [
+  'read_core',
+  'elf',
+] }
 gimli = { version = "0.32.0", default-features = false, features = ['read'] }
 addr2line = { version = "0.25.0", default-features = false }
 anyhow = { version = "1.0.93", default-features = false }
 windows-sys = "0.60.0"
 env_logger = "0.11.5"
 log = { version = "0.4.27", default-features = false }
-clap = { version = "4.5.17", default-features = false, features = ["std", "derive"] }
+clap = { version = "4.5.17", default-features = false, features = [
+  "std",
+  "derive",
+] }
 clap_complete = "4.4.7"
 hashbrown = { version = "0.15", default-features = false }
 capstone = "0.13.0"
@@ -382,7 +415,7 @@ tempfile = "3.21.0"
 filecheck = "0.5.0"
 libc = { version = "0.2.112", default-features = true }
 file-per-thread-logger = "0.2.0"
-tokio = { version = "1.43.0", features = [ "rt", "time" ] }
+tokio = { version = "1.43.0", features = ["rt", "time"] }
 hyper = "1.0.1"
 http = "1.0.0"
 http-body = "1.0.0"
@@ -394,10 +427,18 @@ syn = "2.0.25"
 quote = "1.0"
 proc-macro2 = "1.0"
 test-log = { version = "0.2", default-features = false, features = ["trace"] }
-tracing-subscriber = { version = "0.3.1", default-features = false, features = ['fmt', 'env-filter', 'ansi', 'tracing-log'] }
+tracing-subscriber = { version = "0.3.1", default-features = false, features = [
+  'fmt',
+  'env-filter',
+  'ansi',
+  'tracing-log',
+] }
 url = "2.3.1"
 postcard = { version = "1.0.8", default-features = false, features = ['alloc'] }
-criterion = { version = "0.6.0", default-features = false, features = ["html_reports", "rayon"] }
+criterion = { version = "0.6.0", default-features = false, features = [
+  "html_reports",
+  "rayon",
+] }
 rustc-hash = "2.0.0"
 libtest-mimic = "0.8.1"
 semver = { version = "1.0.17", default-features = false }
@@ -505,14 +546,23 @@ disable-logging = ["log/max_level_off", "tracing/max_level_off"]
 wasi-nn = ["dep:wasmtime-wasi-nn"]
 wasi-tls = ["dep:wasmtime-wasi-tls"]
 wasi-threads = ["dep:wasmtime-wasi-threads", "threads"]
-wasi-http = ["component-model", "dep:wasmtime-wasi-http", "dep:tokio", "dep:hyper", "wasmtime-wasi-http/default-send-request"]
+wasi-http = [
+  "component-model",
+  "dep:wasmtime-wasi-http",
+  "dep:tokio",
+  "dep:hyper",
+  "wasmtime-wasi-http/default-send-request",
+]
 wasi-config = ["dep:wasmtime-wasi-config"]
 wasi-keyvalue = ["dep:wasmtime-wasi-keyvalue"]
-pooling-allocator = ["wasmtime/pooling-allocator", "wasmtime-cli-flags/pooling-allocator"]
+pooling-allocator = [
+  "wasmtime/pooling-allocator",
+  "wasmtime-cli-flags/pooling-allocator",
+]
 component-model = [
   "wasmtime/component-model",
   "wasmtime-wast?/component-model",
-  "wasmtime-cli-flags/component-model"
+  "wasmtime-cli-flags/component-model",
 ]
 wat = ["dep:wat", "wasmtime/wat"]
 cache = ["dep:wasmtime-cache", "wasmtime-cli-flags/cache"]
@@ -529,7 +579,10 @@ gc = ["wasmtime-cli-flags/gc", "wasmtime/gc"]
 gc-drc = ["gc", "wasmtime/gc-drc", "wasmtime-cli-flags/gc-drc"]
 gc-null = ["gc", "wasmtime/gc-null", "wasmtime-cli-flags/gc-null"]
 pulley = ["wasmtime-cli-flags/pulley"]
-stack-switching = ["wasmtime/stack-switching", "wasmtime-cli-flags/stack-switching"]
+stack-switching = [
+  "wasmtime/stack-switching",
+  "wasmtime-cli-flags/stack-switching",
+]
 
 # CLI subcommands for the `wasmtime` executable. See `wasmtime $cmd --help`
 # for more information on each subcommand.

crates/cli-flags/src/lib.rs

@@ -381,6 +381,9 @@ wasmtime_option_group! {
         /// Component model support for async lifting/lowering: this corresponds
         /// to the 🚟 emoji in the component model specification.
         pub component_model_async_stackful: Option<bool>,
+        /// Component model support for threading: this corresponds
+        /// to the 🧵 emoji in the component model specification.
+        pub component_model_threading: Option<bool>,
         /// Component model support for `error-context`: this corresponds
         /// to the 📝 emoji in the component model specification.
         pub component_model_error_context: Option<bool>,
@@ -1052,6 +1055,7 @@ impl CommonOptions {
             ("component-model-async", component_model_async, wasm_component_model_async)
             ("component-model-async", component_model_async_builtins, wasm_component_model_async_builtins)
             ("component-model-async", component_model_async_stackful, wasm_component_model_async_stackful)
+            ("component-model-async", component_model_threading, wasm_component_model_threading)
             ("component-model", component_model_error_context, wasm_component_model_error_context)
             ("threads", threads, wasm_threads)
             ("gc", gc, wasm_gc)

crates/cranelift/src/compiler/component.rs

@@ -789,6 +789,92 @@ impl<'a> TrampolineCompiler<'a> {
                     },
                 );
             }
+            Trampoline::ThreadIndex => {
+                self.translate_libcall(
+                    host::thread_index,
+                    TrapSentinel::NegativeOne,
+                    WasmArgs::InRegisters,
+                    |_, _| {},
+                );
+            }
+            Trampoline::ThreadNewIndirect {
+                instance,
+                start_func_table_idx,
+                start_func_ty_idx,
+            } => {
+                self.translate_libcall(
+                    host::thread_new_indirect,
+                    TrapSentinel::NegativeOne,
+                    WasmArgs::InRegisters,
+                    |me, params| {
+                        params.push(me.index_value(*instance));
+                        params.push(me.index_value(*start_func_table_idx));
+                        params.push(me.index_value(*start_func_ty_idx));
+                    },
+                );
+            }
+            Trampoline::ThreadSwitchTo {
+                instance,
+                cancellable,
+            } => {
+                self.translate_libcall(
+                    host::thread_switch_to,
+                    TrapSentinel::NegativeOne,
+                    WasmArgs::InRegisters,
+                    |me, params| {
+                        params.push(me.index_value(*instance));
+                        params.push(
+                            me.builder
+                                .ins()
+                                .iconst(ir::types::I8, i64::from(*cancellable)),
+                        );
+                    },
+                );
+            }
+            Trampoline::ThreadSuspend {
+                instance,
+                cancellable,
+            } => {
+                self.translate_libcall(
+                    host::thread_suspend,
+                    TrapSentinel::NegativeOne,
+                    WasmArgs::InRegisters,
+                    |me, params| {
+                        params.push(me.index_value(*instance));
+                        params.push(
+                            me.builder
+                                .ins()
+                                .iconst(ir::types::I8, i64::from(*cancellable)),
+                        );
+                    },
+                );
+            }
+            Trampoline::ThreadResumeLater => {
+                self.translate_libcall(
+                    host::thread_resume_later,
+                    TrapSentinel::Falsy,
+                    WasmArgs::InRegisters,
+                    |_, _| {},
+                );
+            }
+            Trampoline::ThreadYieldTo {
+                instance,
+                cancellable,
+            } => {
+                self.translate_libcall(
+                    host::thread_yield_to,
+                    TrapSentinel::NegativeOne,
+                    WasmArgs::InRegisters,
+                    |me, params| {
+                        params.push(me.index_value(*instance));
+                        params.push(
+                            me.builder
+                                .ins()
+                                .iconst(ir::types::I8, i64::from(*cancellable)),
+                        );
+                    },
+                );
+            }
         }
     }
 

crates/environ/src/component.rs

@@ -187,6 +187,18 @@ macro_rules! foreach_builtin_component_function {
             context_get(vmctx: vmctx, caller_instance: u32, slot: u32) -> u64;
             #[cfg(feature = "component-model-async")]
             context_set(vmctx: vmctx, caller_instance: u32, slot: u32, val: u32) -> bool;
+            #[cfg(feature = "component-model-async")]
+            thread_index(vmctx: vmctx) -> u64;
+            #[cfg(feature = "component-model-async")]
+            thread_new_indirect(vmctx: vmctx, caller_instance: u32, func_ty_id: u32, func_table_idx: u32, func_idx: u32, context: u32) -> u64;
+            #[cfg(feature = "component-model-async")]
+            thread_switch_to(vmctx: vmctx, caller_instance: u32, cancellable: u8, thread_idx: u32) -> u32;
+            #[cfg(feature = "component-model-async")]
+            thread_suspend(vmctx: vmctx, caller_instance: u32, cancellable: u8) -> u32;
+            #[cfg(feature = "component-model-async")]
+            thread_resume_later(vmctx: vmctx, thread_idx: u32) -> bool;
+            #[cfg(feature = "component-model-async")]
+            thread_yield_to(vmctx: vmctx, caller_instance: u32, cancellable: u8, thread_idx: u32) -> u32;
 
             trap(vmctx: vmctx, code: u8) -> bool;