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Control group

New to the concept? See Tools — Mailbox first.

wakeUpAll

pub fn wakeUpAll(self: *Mbox) error{Closed}!void
  • Wakes every receiver currently blocked in receive() — no item is sent, nothing is queued.
  • Blocked receivers return error.Wakeup.
  • Future receivers (those that call receive() after wakeUpAll() returns) are not affected.
  • Distinct from close(): the mailbox is not torn down, and the effect does not persist for receivers that start later.

close

pub fn close(self: *Mbox) polynode.ItemList
  • Can be called more than once.
  • Returns remaining handles as list (empty list on second call).
  • Collects all handles still in the queue.
  • Wakes up any receivers waiting on the mailbox.

The caller holds every item in that list. Release them — free them, or
put them back into a pool. The mailbox does not know which, and never did.

Run the release unconditionally:

var rem: polynode.ItemList = mbx.close();
// release every item in `rem`

close can be called more than once and returns an empty list after the
first, so an empty list costs nothing. No call site has to work out whether
the mailbox was empty first.

Never write _ = mbx.close(). It drops items the mailbox gave back, and
the items it drops keep their list links — send asserts an unlinked item,
so they cannot be sent again.

destroy

pub fn destroy(mbx: *Mbox, alloc: std.mem.Allocator) void
  • Frees the mailbox.
  • Must be closed first.
  • Calling destroy on an open mailbox is a programming error (panic).

is_it_you

pub fn is_it_you(tag: *const anyopaque) bool
  • Returns true if tag identifies a *Mbox.