[PATCH] liburing: Add io_uring_submit_and_wait_timeout function in API

[Olivier Langlois <olivier@trillion01.com>]

before commit 0ea4ccd1c0e4 ("src/queue: don't flush SQ ring for new wait interface"),
io_uring_wait_cqes() was serving the purpose of submit sqe and wait for cqe up to a certain timeout value.

Since the commit, a new function is needed to fill this gap.

Fixes: https://github.com/axboe/liburing/issues/440
Signed-off-by: Olivier Langlois <olivier@trillion01.com>
---
 src/include/liburing.h |  5 +++++
 src/liburing.map       |  5 +++++
 src/queue.c            | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/src/include/liburing.h b/src/include/liburing.h
index 0c2c5c2..fe8bfbe 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -122,6 +122,11 @@ int io_uring_wait_cqe_timeout(struct io_uring *ring,
 			      struct __kernel_timespec *ts);
 int io_uring_submit(struct io_uring *ring);
 int io_uring_submit_and_wait(struct io_uring *ring, unsigned wait_nr);
+int io_uring_submit_and_wait_timout(struct io_uring *ring,
+				    struct io_uring_cqe **cqe_ptr,
+				    unsigned wait_nr,
+				    struct __kernel_timespec *ts,
+				    sigset_t *sigmask);
 struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);
 
 int io_uring_register_buffers(struct io_uring *ring, const struct iovec *iovecs,
diff --git a/src/liburing.map b/src/liburing.map
index 6692a3b..09f4275 100644
--- a/src/liburing.map
+++ b/src/liburing.map
@@ -44,3 +44,8 @@ LIBURING_2.1 {
 		io_uring_unregister_iowq_aff;
 		io_uring_register_iowq_max_workers;
 } LIBURING_2.0;
+
+LIBURING_2.2 {
+	global:
+		io_uring_submit_and_wait_timout;
+} LIBURING_2.1;
diff --git a/src/queue.c b/src/queue.c
index 31aa17c..9ac9fe5 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -305,6 +305,39 @@ int io_uring_wait_cqes(struct io_uring *ring, struct io_uring_cqe **cqe_ptr,
 	return __io_uring_get_cqe(ring, cqe_ptr, to_submit, wait_nr, sigmask);
 }
 
+int io_uring_submit_and_wait_timout(struct io_uring *ring,
+				    struct io_uring_cqe **cqe_ptr,
+				    unsigned wait_nr,
+				    struct __kernel_timespec *ts,
+				    sigset_t *sigmask)
+{
+	if (uring_likely(ts)) {
+		if (uring_unlikely(!(ring->features & IORING_FEAT_EXT_ARG)))
+			return io_uring_wait_cqes(ring, cqe_ptr, wait_nr,
+						  ts, sigmask);
+		else {
+			struct io_uring_getevents_arg arg = {
+				.sigmask	= (unsigned long) sigmask,
+				.sigmask_sz	= _NSIG / 8,
+				.ts		= (unsigned long) ts
+			};
+			struct get_data data = {
+				.submit		= __io_uring_flush_sq(ring),
+				.wait_nr	= wait_nr,
+				.get_flags	= IORING_ENTER_EXT_ARG,
+				.sz		= sizeof(arg),
+				.arg		= &arg
+			};
+
+			return _io_uring_get_cqe(ring, cqe_ptr, &data);
+		}
+	}
+	else
+		return __io_uring_get_cqe(ring, cqe_ptr,
+					  __io_uring_flush_sq(ring),
+					  wait_nr, sigmask);
+}
+
 /*
  * See io_uring_wait_cqes() - this function is the same, it just always uses
  * '1' as the wait_nr.
-- 
2.33.0