fill /acme

1 files changed, 32 insertions, 0 deletions

diff --git a/acme/bin/source/acd/outline b/acme/bin/source/acd/outline
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+acd is composed of four procs
+
+wineventproc (win.c:/^wineventproc)
+	reads acme window events, sends them along w->cevent.
+
+cdstatusproc (mmc.c:/^cdstatusproc)
+	reads cd status once per second, sending
+		status updates to d->cstatus.
+	detects disk changes, sends new tocs to d->ctocdisp.
+
+cddbproc (cddb.c:/^cddbproc)
+	reads tocs from d->cdbreq, if it finds
+		translations in the cddb, sends new tocs to d->cdbreply.
+
+eventwatcher (main.c:/^eventwatcher)
+	the main event loop.
+		reads status from d->cstatus.
+		reads events from w->cevent.
+		reads new tocs to display from d->ctocdisp.
+		sends new tocs to translate to d->cdbreq.
+		reads new translated tocs from d->cdbreply.
+
+an interesting bug in the original design:
+	both cdstatusproc and the eventwatcher proc
+	issue scsi commands.  (the eventwatcher responds to
+	things such as Play, Stop, etc., as well as advancing the track.)
+
+	the sd(3) driver did not expect overlapped commands,
+	and crashed.
+
+	this has been fixed by making the scsi(2) commands threadsafe,
+	and making the sd(3) driver more robust.