examples

commit e745bc260c0b094e692e4dc198797e87fa9d33f6
parent b7acadc829f6d835137fd72de76689db9c9a91e7
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Mon,  6 Feb 2023 21:57:57 +0000

eventfd: Add eventfd example - A better version of the pipe trick.

Diffstat:
M
.gitignore
 | 
1
+
A
src/eventfd.c
 | 
33
+++++++++++++++++++++++++++++++++

2 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -22,6 +22,7 @@
 /elastic-tabstops
 /enviro
 /epoll
+/eventfd
 /flat-set
 /gl-asteroids
 /glob
diff --git a/src/eventfd.c b/src/eventfd.c
@@ -0,0 +1,33 @@
+#include <errno.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/eventfd.h>
+#include <unistd.h>
+
+void check_err(char const* msg)
+{
+	if (errno)
+		err(EXIT_FAILURE, "%s", msg);
+}
+
+int main()
+{
+	int fd = eventfd(0, 0);
+	check_err("eventfd");
+
+	if (!fork())
+	{
+		sleep(1);
+		eventfd_write(fd, 1);
+		check_err("eventfd_write");
+
+		exit(0);
+	}
+
+	eventfd_t out;
+	eventfd_read(fd, &out);
+	check_err("eventfd_read");
+
+	printf("%lu\n", out);
+}