Function core::arch::wasm::memory_atomic_wait64
source · pub unsafe fn memory_atomic_wait64(
ptr: *mut i64,
expression: i64,
timeout_ns: i64
) -> i32
🔬This is a nightly-only experimental API. (
stdsimd
#48556)Available on
target_family="wasm"
and target feature atomics
only.Expand description
Corresponding intrinsic to wasm’s memory.atomic.wait64
instruction
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 matchexpression
, the thread didn’t block - 2 - the thread blocked, but the timeout expired.