lib9p: expose Srv.forker handler and srvforker(), threadsrvforker() and threadsrv() functions

To use srvrease()/srvaquire() we need to have a way to spawn
new processes to handle the service loop. This functionality
was provided by the internal _forker() function which was
eigther rfork or libthread based implementation depending on
if postmountsrv() or threadpostmountsrv() where called.

For servers who want to use srv() directly, _forker would not
be initialized so srvrelease() could not be used.

To untangle this, we get rid of the global _forker handler
and put the handler in the Srv structure. Which will get
initialized (when nil) to eigther srvforker() or threadsrvforker()
depending on if the thread or non-thread entry points where used.

For symmetry, we provde new threadsrv() and threadpostsrv()
functions which handle the default initialization of Srv.forker.

This also allows a user to provide his own forker function,
maybe to conserve stack space.

To avoid dead code, we put each of these function in their
own object file. Note, this also allows a user to define its
own srvforker() symbol.

1 files changed, 12 insertions, 8 deletions

diff --git a/sys/include/9p.h b/sys/include/9p.h
index 949476232..1a51ffeab 100644
--- a/sys/include/9p.h
+++ b/sys/include/9p.h
@@ -235,23 +235,29 @@ struct Srv {
 
 	int	spid;	/* pid of srv() caller */
 
+	void	(*forker)(void (*)(void*), void*, int);
 	void	(*free)(Srv*);
 };
 
+void		srvforker(void (*)(void*), void*, int);
+void		threadsrvforker(void (*)(void*), void*, int);
+
 void		srv(Srv*);
+void		postsrv(Srv*, char*);
 void		postmountsrv(Srv*, char*, char*, int);
-void		_postmountsrv(Srv*, char*, char*, int);
 void		postsharesrv(Srv*, char*, char*, char*);
-void		_postsharesrv(Srv*, char*, char*, char*);
 void		listensrv(Srv*, char*);
-void		_listensrv(Srv*, char*);
-int		chatty9p;
-void		respond(Req*, char*);
-void		responderror(Req*);
+
+void		threadsrv(Srv*);
+void		threadpostsrv(Srv*, char*);
 void		threadpostmountsrv(Srv*, char*, char*, int);
 void		threadpostsharesrv(Srv*, char*, char*, char*);
 void		threadlistensrv(Srv *s, char *addr);
 
+int		chatty9p;
+void		respond(Req*, char*);
+void		responderror(Req*);
+
 /*
  * Helper.  Assumes user is same as group.
  */
@@ -276,8 +282,6 @@ void		authwrite(Req*);
 void		authdestroy(Fid*);
 int		authattach(Req*);
 
-extern void (*_forker)(void (*)(void*), void*, int);
-
 void		srvacquire(Srv *);
 void		srvrelease(Srv *);