pub fn cancel(batch: *Batch, io: Io) void703
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725 pub fn cancel(batch: *Batch, io: Io) void {
{ // abort pending submissions
var tail_index = batch.unused.tail;
defer batch.unused.tail = tail_index;
var index = batch.submitted.head;
errdefer batch.submissions.head = index;
while (index != .none) {
const next_index = batch.storage[index.toIndex()].submission.node.next;
switch (tail_index) {
.none => batch.unused.head = index,
else => batch.storage[tail_index.toIndex()].unused.next = index,
}
batch.storage[index.toIndex()] = .{ .unused = .{ .prev = tail_index, .next = .none } };
tail_index = index;
index = next_index;
}
batch.submitted = .{ .head = .none, .tail = .none };
}
io.vtable.batchCancel(io.userdata, batch);
assert(batch.submitted.head == .none and batch.submitted.tail == .none);
assert(batch.pending.head == .none and batch.pending.tail == .none);
assert(batch.userdata == null); // that was the last chance to deallocate resources
}
Requests all pending operations to be interrupted, then waits for all pending operations to complete. After this returns, the
Batchis in a well-defined state, ready to be iterated withnext. Successfully canceled operations will be absent from the iteration. Some operations may have successfully completed regardless of the cancel request and will appear in the iteration.