* Makefile.in (DLL_OFILES): Add fhandler_mailslot.o.

	* devices.h (FH_KMSG): Define new device.
	* devices.in: Add "/dev/kmsg" entry.
	* devices.cc: Regenerate.
	* dtable.cc (build_fh_pc): Handle case FH_KMSG.
	* fhandler.h (class fhandler_mailslot): New class.
	(class select_stuff): Add device_specific_mailslot pointer.
	* fhandler_mailslot.cc: New file.
	* select.cc (peek_mailslot): New function.
	(verify_mailslot): Ditto.
	(struct mailslotinf): New stuct to handle select on mailslots.
	(thread_mailslot): New function.
	(start_thread_mailslot): Ditto.
	(mailslot_cleanup): Ditto.
	(fhandler_mailslot::select_read): New method.
	* syslog.cc (klog_guard): New muto.
	(dev_kmsg): Local mailslot for kernel message device.
	(vklog): New function.
	(klog): Ditto.
	* winsup.h (vklog): Declare.
	(klog): Ditto.
	* include/sys/syslog.h: Define _PATH_KLOG.

1 files changed, 32 insertions, 0 deletions

diff --git a/winsup/cygwin/syslog.cc b/winsup/cygwin/syslog.cc
index b856bb7aa..38c8ecc31 100644
--- a/winsup/cygwin/syslog.cc
+++ b/winsup/cygwin/syslog.cc
@@ -461,6 +461,38 @@ syslog (int priority, const char *message, ...)
   va_end (ap);
 }
 
+static NO_COPY muto klog_guard;
+fhandler_mailslot *dev_kmsg;
+
+extern "C" void
+vklog (int priority, const char *message, va_list ap)
+{
+  /* TODO: kernel messages are under our control entirely and they should
+     be quick.  No playing with /dev/null, but a fixed upper size for now. */
+  char buf[2060];	/* 2048 + a prority */
+  __small_sprintf (buf, "<%d>", priority);
+  __small_vsprintf (buf + strlen (buf), message, ap);
+  klog_guard.init ("klog_guard")->acquire ();
+  if (!dev_kmsg)
+    dev_kmsg = (fhandler_mailslot *) build_fh_name ("/dev/kmsg");
+  if (dev_kmsg && !dev_kmsg->get_handle ())
+    dev_kmsg->open (O_WRONLY, 0);
+  if (dev_kmsg && dev_kmsg->get_handle ())
+    dev_kmsg->write (buf, strlen (buf) + 1);
+  else
+    vsyslog (priority, message, ap);
+  klog_guard.release ();
+}
+
+extern "C" void
+klog (int priority, const char *message, ...)
+{
+  va_list ap;
+  va_start (ap, message);
+  vklog (priority, message, ap);
+  va_end (ap);
+}
+
 extern "C" void
 closelog (void)
 {