wait

Checks if ptr still contains the value expect and, if so, blocks the caller until either:

The value at ptr is no longer equal to expect.
The caller is unblocked by a matching wake().
The caller is unblocked spuriously ("at random").

The checking of ptr and expect, along with blocking the caller, is done atomically and totally ordered (sequentially consistent) with respect to other wait()/wake() calls on the same ptr.

Function parameters

Parameters

ptr:*const atomic.Value(u32)
expect:u32

Deadline is used to wait efficiently for a pointer's value to change using Futex and a fixed timeout.

Types

Deadline: Deadline is used to wait efficiently for a pointer's value to change using Futex and a fixed timeout.

Checks if `ptr` still contains the value `expect` and, if so, blocks the caller until either:

Functions

wait: Checks if `ptr` still contains the value `expect` and, if so, blocks the caller until either:
timedWait: Checks if `ptr` still contains the value `expect` and, if so, blocks the caller until either:
wake: Unblocks at most `max_waiters` callers blocked in a `wait()` call on `ptr`.

Source

Implementation

pub fn wait(ptr: *const atomic.Value(u32), expect: u32) void {
    @branchHint(.cold);

    Impl.wait(ptr, expect, null) catch |err| switch (err) {
        error.Timeout => unreachable, // null timeout meant to wait forever
    };
}