Add io_uring_sq_space_left()

io_uring_sq_space_left(), returns the amount of space left in the submission queue.

test/sq-space_left.c tests io_uring_sq_space_left

Signed-off-by: James Rouzier <rouzier@gmail.com>

3 files changed, 61 insertions, 2 deletions

diff --git a/src/include/liburing.h b/src/include/liburing.h
index 7c6731f..1cae1cd 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -241,6 +241,11 @@ static inline void io_uring_prep_timeout(struct io_uring_sqe *sqe,
 	io_uring_prep_rw(IORING_OP_TIMEOUT, sqe, 0, ts, 1, count);
 }
 
+static inline unsigned io_uring_sq_space_left(struct io_uring *ring)
+{
+	return *ring->sq.kring_entries - (ring->sq.sqe_tail - ring->sq.sqe_head);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/test/Makefile b/test/Makefile
index 8bd96c1..a5898a2 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -4,7 +4,8 @@ override CFLAGS += -Wall -D_GNU_SOURCE -L../src/ -I../src/include/
 all_targets += poll poll-cancel ring-leak fsync io_uring_setup io_uring_register \
 	       io_uring_enter nop sq-full cq-full 35fa71a030ca-test \
 		917257daa0fe-test b19062a56726-test eeed8b54e0df-test link \
-		send_recvmsg a4c0b3decb33-test 500f9fbadef8-test timeout
+		send_recvmsg a4c0b3decb33-test 500f9fbadef8-test timeout \
+		sq-space_left
 
 all: $(all_targets)
 
@@ -12,7 +13,7 @@ test_srcs := poll.c poll-cancel.c ring-leak.c fsync.c io_uring_setup.c \
 	io_uring_register.c io_uring_enter.c nop.c sq-full.c cq-full.c \
 	35fa71a030ca-test.c 917257daa0fe-test.c b19062a56726-test.c \
 	eeed8b54e0df-test.c link.c send_recvmsg.c a4c0b3decb33-test.c \
-	500f9fbadef8-test.c timeout.c
+	500f9fbadef8-test.c timeout.c sq-space_left.c
 
 test_objs := $(patsubst %.c,%.ol,$(test_srcs))
 
@@ -34,6 +35,8 @@ nop: nop.c
 	$(CC) $(CFLAGS) -o $@ nop.c -luring
 sq-full: sq-full.c
 	$(CC) $(CFLAGS) -o $@ sq-full.c -luring
+sq-space_left: sq-space_left.c
+	$(CC) $(CFLAGS) -o $@ sq-space_left.c -luring
 cq-full: cq-full.c
 	$(CC) $(CFLAGS) -o $@ cq-full.c -luring
 35fa71a030ca-test: 35fa71a030ca-test.c
diff --git a/test/sq-space_left.c b/test/sq-space_left.c
new file mode 100644
index 0000000..71fc871
--- /dev/null
+++ b/test/sq-space_left.c
@@ -0,0 +1,51 @@
+/*
+ * Description: test SQ queue space left
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include "liburing.h"
+
+int main(int argc, char *argv[])
+{
+	struct io_uring_sqe *sqe;
+	struct io_uring ring;
+	int ret, i = 0, s;
+
+	ret = io_uring_queue_init(8, &ring, 0);
+	if (ret) {
+		printf("ring setup failed\n");
+		return 1;
+
+	}
+
+	if ((s = io_uring_sq_space_left(&ring)) != 8) {
+		printf("Got %d SQEs left, expected %d\n", s, 8);
+		goto err;
+	}
+
+	i = 0;
+	while ((sqe = io_uring_get_sqe(&ring)) != NULL) {
+		i++;
+		if ((s = io_uring_sq_space_left(&ring)) != 8 - i) {
+			printf("Got %d SQEs left, expected %d\n", s, 8 - i);
+			goto err;
+		}
+	}
+
+	if (i != 8) {
+		printf("Got %d SQEs, expected %d\n", i, 8);
+		goto err;
+	}
+
+	io_uring_queue_exit(&ring);
+	return 0;
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}