Add some comments about timer.device.

2 files changed, 14 insertions, 3 deletions

diff --git a/amiga/libs.c b/amiga/libs.c
index c31e82ab1..cab02d265 100644
--- a/amiga/libs.c
+++ b/amiga/libs.c
@@ -105,10 +105,21 @@ bool ami_libs_open(void)
 	AMINS_LIB_OPEN("Picasso96API.library",  0, P96,         "main",        1, true)
 	AMINS_LIB_OPEN("workbench.library",    37, Workbench,   "main",        1, true)
 
+	/* NB: timer.device is opened in schedule.c (ultimately by the scheduler process).
+	 * The library base and interface are obtained there, rather than here, due to
+	 * the additional complexities of opening devices, which aren't important here
+	 * (as we only need the library interface), but are important for the scheduler
+	 * (as it also uses the device interface).  We trust that the scheduler has
+	 * initialised before any other code requires the timer's library interface
+	 * (this is ensured by waiting for the scheduler to start up) and that it is
+	 * OK to use a child process' timer interface, to avoid opening it twice.
+	 */
+
 	/* BOOPSI classes.
 	 * \todo These should be opened using OpenClass(), however as
 	 * the macros all use the deprecated _GetClass() functions,
-	 * we may as well just open them normally for now. */
+	 * we may as well just open them normally for now.
+	 */
 
 	AMINS_LIB_OPEN("classes/arexx.class",          50, ARexx,         "main", 1, true)
 	AMINS_LIB_OPEN("images/bevel.image",           50, Bevel,         "main", 1, true)
diff --git a/amiga/schedule.c b/amiga/schedule.c
index b5a115d09..cab2beecd 100755
--- a/amiga/schedule.c
+++ b/amiga/schedule.c
@@ -282,7 +282,7 @@ static void ami_scheduler_run(struct MsgPort *nsmsgport)
 static struct MsgPort *ami_schedule_open_timer(void)
 {
 	struct MsgPort *msgport = AllocSysObjectTags(ASOT_PORT,
-				ASO_NoTrack,FALSE,
+				ASO_NoTrack, FALSE,
 				TAG_DONE);
 
 	tioreq = (struct TimeRequest *)AllocSysObjectTags(ASOT_IOREQUEST,
@@ -294,7 +294,7 @@ static struct MsgPort *ami_schedule_open_timer(void)
 	OpenDevice("timer.device", UNIT_WAITUNTIL, (struct IORequest *)tioreq, 0);
 
 	TimerBase = (struct Device *)tioreq->Request.io_Device;
-	ITimer = (struct TimerIFace *)GetInterface((struct Library *)TimerBase,"main",1,NULL);
+	ITimer = (struct TimerIFace *)GetInterface((struct Library *)TimerBase, "main", 1, NULL);
 
 	return msgport;
 }