[PATCH liburing 1/1] test: add epoll test case

[Stefano Garzarella]

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
 .gitignore    |   1 +
 test/Makefile |   5 +-
 test/epoll.c  | 307 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+), 2 deletions(-)
 create mode 100644 test/epoll.c

diff --git a/.gitignore b/.gitignore
index fdb4b32..76170c9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,6 +36,7 @@
 /test/d77a67ed5f27-test
 /test/defer
 /test/eeed8b54e0df-test
+/test/epoll
 /test/fc2a85cb02ef-test
 /test/file-register
 /test/fixed-link
diff --git a/test/Makefile b/test/Makefile
index efdc3aa..773ba0e 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -19,7 +19,7 @@ all_targets += poll poll-cancel ring-leak fsync io_uring_setup io_uring_register
 		poll-many b5837bd5311d-test accept-test d77a67ed5f27-test \
 		connect 7ad0e4b2f83c-test submit-reuse fallocate open-close \
 		file-update statx accept-reuse poll-v-poll fadvise madvise \
-		short-read openat2 probe shared-wq
+		short-read openat2 probe shared-wq epoll
 
 include ../Makefile.quiet
 
@@ -45,7 +45,7 @@ test_srcs := poll.c poll-cancel.c ring-leak.c fsync.c io_uring_setup.c \
 	b5837bd5311d-test.c accept-test.c d77a67ed5f27-test.c connect.c \
 	7ad0e4b2f83c-test.c submit-reuse.c fallocate.c open-close.c \
 	file-update.c statx.c accept-reuse.c poll-v-poll.c fadvise.c \
-	madvise.c short-read.c openat2.c probe.c shared-wq.c
+	madvise.c short-read.c openat2.c probe.c shared-wq.c epoll.c
 
 test_objs := $(patsubst %.c,%.ol,$(test_srcs))
 
@@ -56,6 +56,7 @@ poll-link: XCFLAGS = -lpthread
 accept-link: XCFLAGS = -lpthread
 submit-reuse: XCFLAGS = -lpthread
 poll-v-poll: XCFLAGS = -lpthread
+epoll: XCFLAGS = -lpthread
 
 install: $(all_targets) runtests.sh runtests-loop.sh
 	$(INSTALL) -D -d -m 755 $(datadir)/liburing-test/
diff --git a/test/epoll.c b/test/epoll.c
new file mode 100644
index 0000000..d082f21
--- /dev/null
+++ b/test/epoll.c
@@ -0,0 +1,307 @@
+/*
+ * Description: test io_uring poll handling using a pipe
+ *
+ *              Three threads involved:
+ *              - producer: fills SQ with write requests for the pipe
+ *              - freer: consume CQ, freeing the buffers that producer allocates
+ *              - consumer: read() blocking on the pipe
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/poll.h>
+#include <sys/wait.h>
+#include <sys/epoll.h>
+
+#include "liburing.h"
+
+#define TIMEOUT 	2
+#define BUF_SIZE        16
+#define ITERATIONS      100
+
+struct thread_data {
+	struct io_uring *ring;
+	int pipe_read;
+	int pipe_write;
+	bool sqpoll;
+};
+
+static void sig_alrm(int sig)
+{
+	fprintf(stderr, "Timed out!\n");
+	exit(1);
+}
+
+static struct iovec *alloc_vec(void)
+{
+	struct iovec *vec;
+
+	vec = malloc(sizeof(struct iovec));
+	if (!vec) {
+		perror("malloc iovec");
+		exit(1);
+	}
+	vec->iov_base = malloc(BUF_SIZE);
+	if (!vec->iov_base) {
+		perror("malloc buffer");
+		exit(1);
+	}
+	vec->iov_len = BUF_SIZE;
+
+	return vec;
+}
+
+static void free_vec(struct iovec *vec) {
+	free(vec->iov_base);
+	free(vec);
+}
+
+static void *do_test_epoll_produce(void *data)
+{
+	struct thread_data *td = data;
+	struct io_uring_sqe *sqe;
+	struct epoll_event ev;
+	int fd, ret, iter = 0;
+	void *th_ret = (void *)1;
+
+	fd = epoll_create1(0);
+	if (fd < 0) {
+		perror("epoll_create");
+		return th_ret;
+	}
+
+	ev.events = EPOLLOUT;
+	ev.data.fd = td->ring->ring_fd;
+
+	if (epoll_ctl(fd, EPOLL_CTL_ADD, td->ring->ring_fd, &ev) < 0) {
+		perror("epoll_ctrl");
+		goto ret;
+	}
+
+	while (iter < ITERATIONS) {
+		bool submit = false;
+
+		ret = epoll_wait(fd, &ev, 1, -1);
+		if (ret < 0) {
+			perror("epoll_wait");
+			goto ret;
+		}
+
+		while (iter < ITERATIONS &&
+		       (sqe = io_uring_get_sqe(td->ring))) {
+			struct iovec *vec = alloc_vec();
+
+			io_uring_prep_writev(sqe, td->pipe_write, vec, 1, 0);
+
+			if (td->sqpoll)
+				sqe->flags |= IOSQE_FIXED_FILE;
+
+			io_uring_sqe_set_data(sqe, vec);
+			iter++;
+			submit = true;
+		}
+
+		if (!submit)
+			continue;
+
+		ret = io_uring_submit(td->ring);
+		if (ret <= 0) {
+			fprintf(stderr, "child: sqe submit failed - ret: %d\n",
+				ret);
+			goto ret;
+		}
+	}
+
+	printf("Successfully submitted %d requests\n", iter);
+
+	th_ret = 0;
+ret:
+	close(fd);
+	return th_ret;
+}
+
+static void *do_test_epoll_free(void *data)
+{
+	struct thread_data *td = data;
+	struct io_uring_cqe *cqe;
+	struct epoll_event ev;
+	int fd, ret, iter = 0;
+	void *th_ret = (void *)1;
+
+	fd = epoll_create1(0);
+	if (fd < 0) {
+		perror("epoll_create");
+		return th_ret;
+	}
+
+	ev.events = EPOLLIN;
+	ev.data.fd = td->ring->ring_fd;
+
+	if (epoll_ctl(fd, EPOLL_CTL_ADD, td->ring->ring_fd, &ev) < 0) {
+		perror("epoll_ctrl");
+		goto ret;
+	}
+
+	while (iter < ITERATIONS) {
+		ret = epoll_wait(fd, &ev, 1, -1);
+		if (ret < 0) {
+			perror("epoll_wait");
+			goto ret;
+		}
+
+		while (iter < ITERATIONS) {
+			struct iovec *vec;
+
+			ret = io_uring_peek_cqe(td->ring, &cqe);
+			if (ret) {
+				if (ret != -EAGAIN) {
+					goto ret;
+				}
+				break;
+			}
+
+			vec = io_uring_cqe_get_data(cqe);
+			free_vec(vec);
+			io_uring_cqe_seen(td->ring, cqe);
+			iter++;
+		}
+	}
+
+	printf("Successfully completed %d requests\n", iter);
+
+	th_ret = 0;
+ret:
+	close(fd);
+	return th_ret;
+}
+
+
+static void *do_test_epoll_consume(void *data)
+{
+	struct thread_data *td = data;
+	static uint8_t buf[BUF_SIZE];
+	int ret, iter = 0;
+	void *th_ret = (void *)1;
+
+	while(iter < ITERATIONS) {
+		errno = 0;
+		ret = read(td->pipe_read, &buf, BUF_SIZE);
+		if (ret != BUF_SIZE)
+			break;
+		iter++;
+	};
+
+	if (ret < 0) {
+		perror("read");
+		goto ret;
+	}
+
+	if (iter != ITERATIONS) {
+		fprintf(stderr, "Wrong iterations: %d [expected %d]\n",
+			iter, ITERATIONS);
+		goto ret;
+	}
+
+	printf("Successfully received %d messages\n", iter);
+
+	th_ret = 0;
+ret:
+	return th_ret;
+}
+
+static int do_test_epoll(bool sqpoll)
+{
+	int ret, pipe1[2],flags = 0;
+	struct thread_data td;
+	pthread_t threads[3];
+	struct io_uring ring;
+	void *ret_th[3];
+
+	if (pipe(pipe1) != 0) {
+		perror("pipe");
+		return 1;
+	}
+
+	td.sqpoll = sqpoll;
+	td.pipe_read = pipe1[0];
+	td.pipe_write = pipe1[1];
+
+	if (td.sqpoll)
+		flags |= IORING_SETUP_SQPOLL;
+
+	ret = io_uring_queue_init(1, &ring, flags);
+	if (ret) {
+		fprintf(stderr, "ring setup failed\n");
+		return 1;
+	}
+
+	td.ring = &ring;
+
+	if (td.sqpoll) {
+		ret = io_uring_register_files(&ring, &td.pipe_write, 1);
+		if (ret) {
+			fprintf(stderr, "file reg failed: %d\n", ret);
+			return 1;
+		}
+
+		td.pipe_write = 0;
+	}
+
+	pthread_create(&threads[0], NULL, do_test_epoll_produce, &td);
+	pthread_create(&threads[1], NULL, do_test_epoll_free, &td);
+	pthread_create(&threads[2], NULL, do_test_epoll_consume, &td);
+
+	pthread_join(threads[0], &ret_th[0]);
+	pthread_join(threads[1], &ret_th[1]);
+	pthread_join(threads[2], &ret_th[2]);
+
+	if (ret_th[0] || ret_th[1] || ret_th[2]) {
+		fprintf(stderr, "threads ended with errors\n");
+		return 1;
+	}
+
+	close(pipe1[0]);
+	close(pipe1[1]);
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct sigaction act;
+	int ret, no_sqthread = 0;
+
+	memset(&act, 0, sizeof(act));
+	act.sa_handler = sig_alrm;
+	act.sa_flags = SA_RESTART;
+	sigaction(SIGALRM, &act, NULL);
+	alarm(TIMEOUT);
+
+	if (geteuid()) {
+		no_sqthread = 1;
+	}
+
+	if (no_sqthread) {
+		printf("test_epoll_sqpoll: skipped, not root\n");
+	} else {
+		ret = do_test_epoll(true);
+		if (ret) {
+			fprintf(stderr, "test_epoll_sqpoll failed\n");
+			return ret;
+		}
+	}
+
+	ret = do_test_epoll(false);
+	if (ret) {
+		fprintf(stderr, "test_epoll failed\n");
+		return ret;
+	}
+
+	return 0;
+}
-- 
2.24.1