1 files changed, 44 insertions, 0 deletions
diff --git a/config/auto-aux/async_io.c b/config/auto-aux/async_io.c
new file mode 100644
index 000000000..2fb04a6c6
--- /dev/null
+++ b/config/auto-aux/async_io.c
@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <errno.h>
+#include "s.h"
+
+int signalled;
+
+void sigio_handler(arg)
+     int arg;
+{
+  signalled = 1;
+}
+
+int main()
+{
+#if defined(SIGIO) && defined(FASYNC) && defined(F_SETFL) && defined(F_SETOWN)
+  int p[2];
+  int ret;
+#define OUT 0
+#define IN 1
+  if (pipe(p) == -1) return 1;
+  signalled = 0;
+  signal(SIGIO, sigio_handler);
+  ret = fcntl(p[OUT], F_GETFL, 0);
+  fcntl(p[OUT], F_SETFL, ret | FASYNC);
+  fcntl(p[OUT], F_SETOWN, getpid());
+  switch(fork()) {
+  case -1:
+    return 1;
+  case 0:
+    close(p[OUT]);
+    write(p[IN], "x", 1);
+    sleep(1);
+    exit(0);
+  default:
+    close(p[IN]);
+    while(wait(NULL) == -1 && errno == EINTR) /*nothing*/;
+  }
+  if (signalled) return 0; else return 1;
+#else
+  return 1;
+#endif
+}