silk.platform.wasm.thread.

When to use#

NativeThread starts and joins wasm32 threads through WasmThread. Applications use silk.concurrency.thread_native.

Details#

Each thread owns a record and a 1 MiB stack from the module's heap. The host starts the thread as a new instance on the shared memory and calls the module's wasi_thread_start, which the compiler defines: it moves the shadow stack to the record's stack top, calls the entry module's thread entry, then marks the record done and wakes the joiner. The joiner releases the stack and the record only after it sees the record done, which the thread sets after its last stack use.

Public declarations: 1.

WasmThread#

pub struct WasmThread

The wasi-threads records that NativeThread starts and joins.

Implementation WasmThread#

impl WasmThread

Associated function spawn#

pub unsafe fn spawn(argument: ?*mut u8) -> Result<?[*]mut u8, i32>

Starts a thread that runs the entry module's thread entry with argument. It returns the thread's handle, or an error number when the host refuses the thread or the heap is full (12, ENOMEM).

Safety#

Join each started handle once with WasmThread.join.

Associated function argument#

pub unsafe fn argument(handle: ?[*]mut u8) -> ?*mut u8

Returns the argument the thread behind handle was started with.

Safety#

handle is a live handle from WasmThread.spawn.

Associated function done#

pub unsafe fn done(handle: ?[*]mut u8) -> *mut u32

Returns the word that wasi_thread_start sets to 1 once the thread's work is over.

Safety#

handle is a live handle from WasmThread.spawn.

Associated function join#

pub unsafe fn join(handle: ?[*]mut u8) -> ()

Waits for the thread behind handle to finish, then releases its stack and record.

Safety#

handle is a live handle from WasmThread.spawn, joined only once.

Category: Native platform.

Profiles: wasm32-unknown-unknown, wasm32-wasip1, wasm32-wasip2, wasm64-unknown-unknown.