static int
tagmuxrpc(Muxrpc *r, void *tx)
{
int tag;
Mux *mux;
mux = r->mux;
/* assign the tag, add selves to response queue */
qlock(&mux->lk);
tag = gettag(mux, r);
/*print("gettag %p %d\n", r, tag); */
enqueue(mux, r);
qunlock(&mux->lk);
/* actually send the packet */
if(tag < 0 || mux->settag(mux, tx, tag) < 0 || _muxsend(mux, tx) < 0){
werrstr("settag/send tag %d: %r", tag);
fprint(2, "%r\n");
qlock(&mux->lk);
dequeue(mux, r);
puttag(mux, r);
qunlock(&mux->lk);
return -1;
}
return 0;
}
int
muxrpccanfinish(Muxrpc *r, void **vp)
{
void *p;
Mux *mux;
int ret;
mux = r->mux;
qlock(&mux->lk);
ret = 1;
if(!r->p && !mux->muxer){
mux->muxer = r;
while(!r->p){
qunlock(&mux->lk);
p = nil;
if(!_muxrecv(mux, 0, &p))
ret = 0;
if(p == nil){
qlock(&mux->lk);
break;
}
muxmsgandqlock(mux, p);
}
electmuxer(mux);
}
p = r->p;
if(p)
puttag(mux, r);
qunlock(&mux->lk);
*vp = p;
return ret;
}
void*
muxrpc(Mux *mux, void *tx)
{
int tag;
Muxrpc *r;
void *p;
if((r = allocmuxrpc(mux)) == nil)
return nil;
if((tag = tagmuxrpc(r, tx)) < 0)
return nil;
qlock(&mux->lk);
/* wait for our packet */
while(mux->muxer && mux->muxer != r && !r->p)
rsleep(&r->r);
/* if not done, there's no muxer: start muxing */
if(!r->p){
if(mux->muxer != nil && mux->muxer != r)
abort();
mux->muxer = r;
while(!r->p){
qunlock(&mux->lk);
_muxrecv(mux, 1, &p);
if(p == nil){
/* eof -- just give up and pass the buck */
qlock(&mux->lk);
dequeue(mux, r);
break;
}
muxmsgandqlock(mux, p);
}
electmuxer(mux);
}
p = r->p;
puttag(mux, r);
qunlock(&mux->lk);
if(p == nil)
werrstr("unexpected eof");
return p;
}
Packet*
_vtrpc(VtConn *z, Packet *p, VtFcall *tx)
{
int i;
uchar tag, buf[2], *top;
Rwait *r, *rr;
/* must malloc because stack could be private */
r = vtmallocz(sizeof(Rwait));
qlock(&z->lk);
r->r.l = &z->lk;
tag = gettag(z, r);
if(tx){
/* vtfcallrpc can't print packet because it doesn't have tag */
tx->tag = tag;
if(chattyventi)
fprint(2, "%s -> %F\n", argv0, tx);
}
/* slam tag into packet */
top = packetpeek(p, buf, 0, 2);
if(top == nil){
packetfree(p);
return nil;
}
if(top == buf){
werrstr("first two bytes must be in same packet fragment");
packetfree(p);
vtfree(r);
return nil;
}
top[1] = tag;
qunlock(&z->lk);
if(vtsend(z, p) < 0){
vtfree(r);
return nil;
}
qlock(&z->lk);
/* wait for the muxer to give us our packet */
r->sleeping = 1;
z->nsleep++;
while(z->muxer && !r->done)
rsleep(&r->r);
z->nsleep--;
r->sleeping = 0;
/* if not done, there's no muxer: start muxing */
if(!r->done){
if(z->muxer)
abort();
z->muxer = 1;
while(!r->done){
qunlock(&z->lk);
if((p = vtrecv(z)) == nil){
werrstr("unexpected eof on venti connection");
z->muxer = 0;
vtfree(r);
return nil;
}
qlock(&z->lk);
muxrpc(z, p);
}
z->muxer = 0;
/* if there is anyone else sleeping, wake first unfinished to mux */
if(z->nsleep)
for(i=0; i<256; i++){
rr = z->wait[i];
if(rr && rr->sleeping && !rr->done){
rwakeup(&rr->r);
break;
}
}
}
p = r->p;
puttag(z, r, tag);
vtfree(r);
qunlock(&z->lk);
return p;
}