#include <sys/statvfs.h>
#endif
+#ifdef CONFIG_EVENTFD
+#include <sys/eventfd.h>
+#endif
+
#ifdef _WIN32
#include <windows.h>
#elif defined(CONFIG_BSD)
}
#ifndef _WIN32
+/*
+ * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
+ */
+int qemu_eventfd(int fds[2])
+{
+ int ret;
+
+#ifdef CONFIG_EVENTFD
+ ret = eventfd(0, 0);
+ if (ret >= 0) {
+ fds[0] = ret;
+ qemu_set_cloexec(ret);
+ if ((fds[1] = dup(ret)) == -1) {
+ close(ret);
+ return -1;
+ }
+ qemu_set_cloexec(fds[1]);
+ return 0;
+ }
+
+ if (errno != ENOSYS) {
+ return -1;
+ }
+#endif
+
+ return qemu_pipe(fds);
+}
+
/*
* Creates a pipe with FD_CLOEXEC set on both file descriptors
*/
static void qemu_event_increment(void)
{
- static const char byte = 0;
+ /* Write 8 bytes to be compatible with eventfd. */
+ static uint64_t val = 1;
ssize_t ret;
if (io_thread_fd == -1)
return;
do {
- ret = write(io_thread_fd, &byte, sizeof(byte));
+ ret = write(io_thread_fd, &val, sizeof(val));
} while (ret < 0 && errno == EINTR);
/* EAGAIN is fine, a read must be pending. */
ssize_t len;
char buffer[512];
- /* Drain the notify pipe */
+ /* Drain the notify pipe. For eventfd, only 8 bytes will be read. */
do {
len = read(fd, buffer, sizeof(buffer));
} while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
int err;
int fds[2];
- err = qemu_pipe(fds);
+ err = qemu_eventfd(fds);
if (err == -1)
return -errno;