os: wrap epoll_create

Some system C libraries do not have epoll_create1() nor EPOLL_CLOEXEC,
provide a fallback.

Add tests for the wrapper.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

src/event-loop.c

@@ -34,6 +34,7 @@
 #include <unistd.h>
 #include <assert.h>
 #include "wayland-server.h"
+#include "wayland-os.h"
 
 struct wl_event_loop {
 	int epoll_fd;
@@ -392,7 +393,7 @@ wl_event_loop_create(void)
 	if (loop == NULL)
 		return NULL;
 
-	loop->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+	loop->epoll_fd = wl_os_epoll_create_cloexec();
 	if (loop->epoll_fd < 0) {
 		free(loop);
 		return NULL;

src/wayland-os.c

@@ -25,6 +25,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <sys/epoll.h>
 
 #include "wayland-os.h"
 
@@ -124,3 +125,20 @@ wl_os_recvmsg_cloexec(int sockfd, struct msghdr *msg, int flags)
 
 	return recvmsg_cloexec_fallback(sockfd, msg, flags);
 }
+
+int
+wl_os_epoll_create_cloexec(void)
+{
+	int fd;
+
+#ifdef EPOLL_CLOEXEC
+	fd = epoll_create1(EPOLL_CLOEXEC);
+	if (fd >= 0)
+		return fd;
+	if (errno != EINVAL)
+		return -1;
+#endif
+
+	fd = epoll_create(1);
+	return set_cloexec_or_close(fd);
+}

src/wayland-os.h

@@ -32,6 +32,9 @@ wl_os_dupfd_cloexec(int fd, long minfd);
 ssize_t
 wl_os_recvmsg_cloexec(int sockfd, struct msghdr *msg, int flags);
 
+int
+wl_os_epoll_create_cloexec(void);
+
 
 /*
  * The following are for wayland-os.c and the unit tests.