1 files changed, 93 insertions, 0 deletions
diff --git a/library/stdarch/crates/core_arch/src/wasm32/atomic.rs b/library/stdarch/crates/core_arch/src/wasm32/atomic.rs
new file mode 100644
index 000000000..52d4bea87
--- /dev/null
+++ b/library/stdarch/crates/core_arch/src/wasm32/atomic.rs
@@ -0,0 +1,93 @@
+#[cfg(test)]
+use stdarch_test::assert_instr;
+
+extern "C" {
+    #[link_name = "llvm.wasm.memory.atomic.wait32"]
+    fn llvm_atomic_wait_i32(ptr: *mut i32, exp: i32, timeout: i64) -> i32;
+    #[link_name = "llvm.wasm.memory.atomic.wait64"]
+    fn llvm_atomic_wait_i64(ptr: *mut i64, exp: i64, timeout: i64) -> i32;
+    #[link_name = "llvm.wasm.memory.atomic.notify"]
+    fn llvm_atomic_notify(ptr: *mut i32, cnt: i32) -> i32;
+}
+
+/// Corresponding intrinsic to wasm's [`memory.atomic.wait32` instruction][instr]
+///
+/// This function, when called, will block the current thread if the memory
+/// pointed to by `ptr` is equal to `expression` (performing this action
+/// atomically).
+///
+/// The argument `timeout_ns` is a maximum number of nanoseconds the calling
+/// thread will be blocked for, if it blocks. If the timeout is negative then
+/// the calling thread will be blocked forever.
+///
+/// The calling thread can only be woken up with a call to the `wake` intrinsic
+/// once it has been blocked. Changing the memory behind `ptr` will not wake
+/// the thread once it's blocked.
+///
+/// # Return value
+///
+/// * 0 - indicates that the thread blocked and then was woken up
+/// * 1 - the loaded value from `ptr` didn't match `expression`, the thread
+///   didn't block
+/// * 2 - the thread blocked, but the timeout expired.
+///
+/// [instr]: https://webassembly.github.io/threads/core/syntax/instructions.html#syntax-instr-atomic-memory
+#[inline]
+#[cfg_attr(test, assert_instr(memory.atomic.wait32))]
+#[target_feature(enable = "atomics")]
+#[doc(alias("memory.atomic.wait32"))]
+pub unsafe fn memory_atomic_wait32(ptr: *mut i32, expression: i32, timeout_ns: i64) -> i32 {
+    llvm_atomic_wait_i32(ptr, expression, timeout_ns)
+}
+
+/// Corresponding intrinsic to wasm's [`memory.atomic.wait64` instruction][instr]
+///
+/// This function, when called, will block the current thread if the memory
+/// pointed to by `ptr` is equal to `expression` (performing this action
+/// atomically).
+///
+/// The argument `timeout_ns` is a maximum number of nanoseconds the calling
+/// thread will be blocked for, if it blocks. If the timeout is negative then
+/// the calling thread will be blocked forever.
+///
+/// The calling thread can only be woken up with a call to the `wake` intrinsic
+/// once it has been blocked. Changing the memory behind `ptr` will not wake
+/// the thread once it's blocked.
+///
+/// # Return value
+///
+/// * 0 - indicates that the thread blocked and then was woken up
+/// * 1 - the loaded value from `ptr` didn't match `expression`, the thread
+///   didn't block
+/// * 2 - the thread blocked, but the timeout expired.
+///
+/// [instr]: https://webassembly.github.io/threads/core/syntax/instructions.html#syntax-instr-atomic-memory
+#[inline]
+#[cfg_attr(test, assert_instr(memory.atomic.wait64))]
+#[target_feature(enable = "atomics")]
+#[doc(alias("memory.atomic.wait64"))]
+pub unsafe fn memory_atomic_wait64(ptr: *mut i64, expression: i64, timeout_ns: i64) -> i32 {
+    llvm_atomic_wait_i64(ptr, expression, timeout_ns)
+}
+
+/// Corresponding intrinsic to wasm's [`memory.atomic.notify` instruction][instr]
+///
+/// This function will notify a number of threads blocked on the address
+/// indicated by `ptr`. Threads previously blocked with the `i32_atomic_wait`
+/// and `i64_atomic_wait` functions above will be woken up.
+///
+/// The `waiters` argument indicates how many waiters should be woken up (a
+/// maximum). If the value is zero no waiters are woken up.
+///
+/// # Return value
+///
+/// Returns the number of waiters which were actually notified.
+///
+/// [instr]: https://webassembly.github.io/threads/core/syntax/instructions.html#syntax-instr-atomic-memory
+#[inline]
+#[cfg_attr(test, assert_instr(memory.atomic.notify))]
+#[target_feature(enable = "atomics")]
+#[doc(alias("memory.atomic.notify"))]
+pub unsafe fn memory_atomic_notify(ptr: *mut i32, waiters: u32) -> u32 {
+    llvm_atomic_notify(ptr, waiters as i32) as u32
+}