diff --git a/library/std/src/sys/wasm/futex_atomics.rs b/library/std/src/sys/wasm/futex_atomics.rs new file mode 100644 index 0000000000000..3d8bf42f7255e --- /dev/null +++ b/library/std/src/sys/wasm/futex_atomics.rs @@ -0,0 +1,17 @@ +use crate::arch::wasm32; +use crate::convert::TryInto; +use crate::sync::atomic::AtomicI32; +use crate::time::Duration; + +pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option) { + let timeout = timeout.and_then(|t| t.as_nanos().try_into().ok()).unwrap_or(-1); + unsafe { + wasm32::memory_atomic_wait32(futex as *const AtomicI32 as *mut i32, expected, timeout); + } +} + +pub fn futex_wake(futex: &AtomicI32) { + unsafe { + wasm32::memory_atomic_notify(futex as *const AtomicI32 as *mut i32, 1); + } +} diff --git a/library/std/src/sys/wasm/mod.rs b/library/std/src/sys/wasm/mod.rs index 18295e1129a05..11c6896f050b2 100644 --- a/library/std/src/sys/wasm/mod.rs +++ b/library/std/src/sys/wasm/mod.rs @@ -55,6 +55,8 @@ cfg_if::cfg_if! { pub mod mutex; #[path = "rwlock_atomics.rs"] pub mod rwlock; + #[path = "futex_atomics.rs"] + pub mod futex; } else { #[path = "../unsupported/condvar.rs"] pub mod condvar; diff --git a/library/std/src/sys_common/thread_parker/mod.rs b/library/std/src/sys_common/thread_parker/mod.rs index 23c17c8e2cf26..5e75ac65de419 100644 --- a/library/std/src/sys_common/thread_parker/mod.rs +++ b/library/std/src/sys_common/thread_parker/mod.rs @@ -1,5 +1,9 @@ cfg_if::cfg_if! { - if #[cfg(any(target_os = "linux", target_os = "android"))] { + if #[cfg(any( + target_os = "linux", + target_os = "android", + all(target_arch = "wasm32", target_feature = "atomics"), + ))] { mod futex; pub use futex::Parker; } else {