async: a vectored write the caller can await - #24
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The vectored write is fire-and-forget in both of its modes: the completion sends no notification and the release callback carries no status. A caller that needs the outcome therefore has to use the single-buffer write, which does not take the buffer over — so it must free it itself, and the only moment it can is when its own wait ends. Those are different moments once the waiting coroutine is cancelled: the wait is over and the write is not. ZEND_ASYNC_IO_WRITEV_AWAIT says the caller waits. Ownership stays the mode's; the completion keeps the request alive and notifies io->event with the request as the result and no exception, so a caller matching by request pointer wakes and no sibling awaiter on the same handle does. Header only: the flag word already existed, so no signature changes and the existing values keep their meaning.
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Needed by true-async/php-async and true-async/server: the HTTP/1 server frees a write buffer that libuv still points at, because the only write that reports its status is also the only one that leaves the buffer with the caller.
Both vectored modes are fire-and-forget —
io_pipe_writev_cbsends no NOTIFY and its release callback takes no status — so a caller that needs the outcome must use the single-buffer write, keep the buffer, and free it when its own wait ends. Once the waiting coroutine is cancelled that moment arrives before the write completes, and the freed bytes stay in libuv's queue.ZEND_ASYNC_IO_WRITEV_AWAITmarks a vectored write as awaited. Buffer ownership is unchanged — it stays whatever the mode says — and only the completion differs: the request stays alive andio->eventis notified with the request as the result and no exception, so a caller matching by request pointer wakes while sibling awaiters on the same handle do not.Header only. The
flagsword already existed, so nothing changes signature andZEND_ASYNC_IO_WRITEV_ZSTR/_IOVkeep their values;_MODE_MASKnames the bit they occupy. The reactor side is true-async/php-async, the consumer is true-async/server.