eventfd syscall wrapper and read/write wrappers

src/linux/eventfd.c

@@ -0,0 +1,7 @@
+#include <sys/eventfd.h>
+#include "syscall.h"
+
+int eventfd(unsigned int count, int flags)
+{
+	return syscall(flags ? SYS_eventfd2 : SYS_eventfd, count, flags);
+}

src/linux/eventfd_read.c

@@ -0,0 +1,7 @@
+#include <sys/eventfd.h>
+#include <unistd.h>
+
+int eventfd_read(int fd, eventfd_t *value)
+{
+	return (sizeof(*value) == read(fd, value, sizeof(*value))) ? 0 : -1;
+}

src/linux/eventfd_write.c

@@ -0,0 +1,7 @@
+#include <sys/eventfd.h>
+#include <unistd.h>
+
+int eventfd_write(int fd, eventfd_t value)
+{
+	return (sizeof(value) == write(fd, &value, sizeof(value))) ? 0 : -1;
+}