From a034e629f7611166cae617b08b19667925fc4305 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Thu, 15 Oct 2015 13:21:30 +0200
Subject: [PATCH] lib9p: do not override Srv.end in listensrv(), simplify
 srvclose() and recounting

listensrv() used to override Srv.end() with its own handler
to free the malloc'd Srv structure and close the fd. this
makes it impossible to register your own cleanup handler.
instead, we introduce the private Srv.free() handler that
is used by listensrv to register its cleanup code. Srv.free()
is called once all the srv procs have been exited and all
requests on that srv have been responded to while Srv.end()
is called once all the procs exited the srv loop regardless
of the requests still being in flight.
---
 sys/include/9p.h       |  6 ++++--
 sys/src/lib9p/listen.c |  6 +++---
 sys/src/lib9p/srv.c    | 25 +++++++++++++++----------
 3 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/sys/include/9p.h b/sys/include/9p.h
index 27bec9b9a..d6a830a15 100644
--- a/sys/include/9p.h
+++ b/sys/include/9p.h
@@ -233,8 +233,10 @@ struct Srv {
 	char*	addr;
 
 	QLock	slock;
-	Ref	sref;
-	Ref	rref;
+	Ref	sref;	/* srvwork procs */
+	Ref	rref;	/* requests in flight */
+
+	void	(*free)(Srv*);
 };
 
 void		srv(Srv*);
diff --git a/sys/src/lib9p/listen.c b/sys/src/lib9p/listen.c
index 8ba7ecb99..afce4954a 100644
--- a/sys/src/lib9p/listen.c
+++ b/sys/src/lib9p/listen.c
@@ -7,7 +7,7 @@
 
 static void listenproc(void*);
 static void srvproc(void*);
-static void srvend(Srv *);
+static void srvfree(Srv *);
 static char *getremotesys(char*);
 
 void
@@ -58,7 +58,7 @@ listenproc(void *v)
 		s->rpool = nil;
 		s->rbuf = nil;
 		s->wbuf = nil;
-		s->end = srvend;
+		s->free = srvfree;
 		_forker(srvproc, s, 0);
 	}
 	free(os->addr);
@@ -72,7 +72,7 @@ srvproc(void *v)
 }
 
 static void
-srvend(Srv *s)
+srvfree(Srv *s)
 {
 	close(s->infd);
 	free(s->addr);
diff --git a/sys/src/lib9p/srv.c b/sys/src/lib9p/srv.c
index f2f3ee2af..ddecfa6e2 100644
--- a/sys/src/lib9p/srv.c
+++ b/sys/src/lib9p/srv.c
@@ -167,7 +167,7 @@ walkandclone(Req *r, char *(*walk1)(Fid*, char*, void*), char *(*clone)(Fid*, Fi
 static void
 sversion(Srv *srv, Req *r)
 {
-	if(srv->rref.ref != 2){
+	if(srv->rref.ref != 1){
 		respond(r, Ebotch);
 		return;
 	}
@@ -724,8 +724,6 @@ srvwork(void *v)
 	Srv *srv = v;
 	Req *r;
 
-	incref(&srv->rref);
-	incref(&srv->sref);
 	while(r = getreq(srv)){
 		incref(&srv->rref);
 		if(r->error){
@@ -753,14 +751,17 @@ srvwork(void *v)
 		}
 		qunlock(&srv->slock);
 	}
-	decref(&srv->sref);
-	srvclose(srv);
+
+	if(srv->end && srv->sref.ref == 1)
+		srv->end(srv);
+	if(decref(&srv->sref) == 0)
+		srvclose(srv);
 }
 
 static void
 srvclose(Srv *srv)
 {
-	if(decref(&srv->rref))
+	if(srv->rref.ref || srv->sref.ref)
 		return;
 
 	if(chatty9p)
@@ -776,8 +777,8 @@ srvclose(Srv *srv)
 	freereqpool(srv->rpool);
 	srv->rpool = nil;
 
-	if(srv->end)
-		srv->end(srv);
+	if(srv->free)
+		srv->free(srv);
 }
 
 void
@@ -790,8 +791,10 @@ srvacquire(Srv *srv)
 void
 srvrelease(Srv *srv)
 {
-	if(decref(&srv->sref) == 0)
+	if(decref(&srv->sref) == 0){
+		incref(&srv->sref);
 		_forker(srvwork, srv, 0);
+	}
 	qunlock(&srv->slock);
 }
 
@@ -819,6 +822,7 @@ srv(Srv *srv)
 	if(srv->start)
 		srv->start(srv);
 
+	incref(&srv->sref);
 	srvwork(srv);
 }
 
@@ -896,7 +900,8 @@ if(chatty9p)
 	else
 		free(r);
 
-	srvclose(srv);
+	if(decref(&srv->rref) == 0)
+		srvclose(srv);
 }
 
 void