1 files changed, 52 insertions, 0 deletions
diff --git a/meta-rtmod1/model_answer/files/rt-sysfs-poll.c b/meta-rtmod1/model_answer/files/rt-sysfs-poll.c
new file mode 100644
index 0000000000..8d0a5314e9
--- /dev/null
+++ b/meta-rtmod1/model_answer/files/rt-sysfs-poll.c
@@ -0,0 +1,52 @@
+/*   Copyright (C) 2021 by Linaro */
+/*   Permission to use, copy, modify, and/or distribute this software for any */
+/*   purpose with or without fee is hereby granted. */
+/*   THE SOFTWARE IS PROVIDED AS IS AND THE AUTHOR DISCLAIMS ALL WARRANTIES */
+/*   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF */
+/*   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR */
+/*   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES */
+/*   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN */
+/*   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF */
+/*   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h> 
+#include <sys/stat.h> 
+#include <poll.h>
+
+#define TEST_SYSFS_NOTIFY	"/sys/demo-poll/notify"
+
+int main(void)
+{
+	int notify_fd, rv, cnt;
+	char attr_data[100];
+	struct pollfd ufds;
+
+	if ((notify_fd = open(TEST_SYSFS_NOTIFY, O_RDWR)) < 0) {
+		printf("Unable to open %s", TEST_SYSFS_NOTIFY);
+		exit(1);
+	}
+
+	cnt = read(notify_fd, attr_data, 100);
+	lseek(notify_fd, 0, SEEK_SET);
+	ufds.fd = notify_fd;
+	ufds.events = POLLPRI | POLLERR;
+	ufds.revents = 0;
+
+	if ((rv = poll(&ufds, 1, 100000)) < 0) {
+		perror("poll error");
+	} else if (rv == 0) {
+		printf("Timeout occurred!\n");
+	} else if (ufds.revents & (POLLPRI | POLLERR)) {
+		cnt = read(notify_fd, attr_data, 100);
+		printf("sysfs_notify() triggered, revents: %08X,"
+		       " attribute data[%d] %s", ufds.revents, cnt, attr_data);
+	}
+
+	close(notify_fd);
+}