2002-11-05 Roland McGrath <roland@frob.com>

* oskit/pc/osenv_bell.c (direct_cons_bell): Use a private timer
	instead of calling `timeout'.  If a bell is already ringing,
	turn it off for an instant before setting the new one.

1 files changed, 13 insertions, 3 deletions

diff --git a/oskit/pc/osenv_bell.c b/oskit/pc/osenv_bell.c
index 3e6b44ec..86c5b78a 100644
--- a/oskit/pc/osenv_bell.c
+++ b/oskit/pc/osenv_bell.c
@@ -6,12 +6,22 @@
 
 #include "time_out.h"
 
-
 #define BELL_FREQUENCY	750	/* Hz */
+#define	BELL_DURATION	(hz>>3)	/* 1/8th second duration */
+
+/* This is the private timer used to turn off the speaker.  */
+static timer_elt_data_t bell_timer = { fcn: (int (*)()) &pc_speaker_off };
 
 void
-direct_cons_bell(void)
+direct_cons_bell (void)
 {
+  /* Cancel the timeout for a bell we are already ringing.  */
+  if (reset_timeout (&bell_timer))
+    /* Turn the speaker off for an instant to distinguish this bell
+       from the next.  */
+    pc_speaker_off ();
+
+  /* Turn the speaker on and set the timeout to turn it off.  */
   pc_speaker_on (BELL_FREQUENCY);
-  timeout (&pc_speaker_off, 0, hz / 8);	/* 1/8th second duration */
+  set_timeout (&bell_timer, BELL_DURATION);
 }