mixfs: add reading (audio loopback)

diff --git a/sys/src/cmd/audio/mixfs/mixfs.c b/sys/src/cmd/audio/mixfs/mixfs.c
index 15a082e24f9b99532458388b2284f38ee24775e8..de6f4a55782671c7b1e0b0a80c12f777e131dfeb 100644 (file)
--- a/sys/src/cmd/audio/mixfs/mixfs.c
+++ b/sys/src/cmd/audio/mixfs/mixfs.c
@@ -16,6 +16,7 @@ struct Stream
 {
        int     used;
        int     run;
+       int     rd;
        ulong   wp;
        QLock;
        Rendez;
@@ -23,6 +24,7 @@ struct Stream
 
 ulong  mixrp;
 int    mixbuf[NBUF][NCHAN];
+int    lbbuf[NBUF][NCHAN];
 Lock   mixlock;
 Stream streams[16];
 
@@ -61,6 +63,7 @@ fsopen(Req *r)
                        s->used = 1;
                        qunlock(s);
 
+                       s->rd = (r->ifcall.mode&OWRITE) == 0;
                        r->fid->aux = s;
                        respond(r, nil);
                        return;
@@ -144,6 +147,7 @@ audioproc(void *)
                for(i=0; i<m; i++){
                        for(j=0; j<NCHAN; j++){
                                v = clip16(mixbuf[mixrp % NBUF][j]);
+                               lbbuf[mixrp % NBUF][j] = v;
                                mixbuf[mixrp % NBUF][j] = 0;
                                *p++ = v & 0xFF;
                                *p++ = v >> 8;
@@ -154,6 +158,56 @@ audioproc(void *)
        }
 }
 
+void
+fsread(Req *r)
+{
+       Srv *srv;
+       int i, j, n, m, v;
+       Stream *s;
+       uchar *p;
+
+       p = (uchar*)r->ofcall.data;
+       n = r->ifcall.count;
+       n &= ~(NCHAN*2 - 1);
+       r->ofcall.count = n;
+       n /= (NCHAN*2);
+
+       srv = r->srv;
+       srvrelease(srv);
+       s = r->fid->aux;
+       qlock(s);
+       while(n > 0){
+               if(s->run == 0){
+                       s->wp = mixrp;
+                       s->run = 1;
+               }
+               m = NBUF-1 - (long)(s->wp - mixrp);
+               if(m <= 0){
+                       s->run = 1;
+                       rsleep(s);
+                       continue;
+               }
+               if(m > n)
+                       m = n;
+
+               lock(&mixlock);
+               for(i=0; i<m; i++){
+                       for(j=0; j<NCHAN; j++){
+                               v = lbbuf[s->wp % NBUF][j];
+                               *p++ = v & 0xFF;
+                               *p++ = v >> 8;
+                       }
+                       s->wp++;
+               }
+               unlock(&mixlock);
+
+               n -= m;
+       }
+       qunlock(s);
+       respond(r, nil);
+       srvacquire(srv);
+}
+
 void
 fswrite(Req *r)
 {
@@ -234,7 +288,7 @@ fsstart(Srv *)
        Stream *s;
 
        for(s=streams; s < streams+nelem(streams); s++){
-               s->used = s->run = 0;
+               s->used = s->run = s->rd = 0;
                s->Rendez.l = &s->QLock;
        }
        proccreate(audioproc, nil, 16*1024);
@@ -248,6 +302,7 @@ fsend(Srv *)
 
 Srv fs = {
        .open=          fsopen,
+       .read=          fsread,
        .write=         fswrite,
        .stat=          fsstat,
        .destroyfid=    fsclunk,
@@ -286,7 +341,7 @@ threadmain(int argc, char **argv)
                usage();
 
        fs.tree = alloctree(nil, nil, DMDIR|0777, nil);
-       createfile(fs.tree->root, "audio", nil, 0222, nil);
+       createfile(fs.tree->root, "audio", nil, 0666, nil);
        threadpostmountsrv(&fs, srv, mtpt, MREPL);
 
        mtpt = smprint("%s/audio", mtpt);