[src/trunk]: src/lib/librumpuser improve threadsafety

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/193e3aedb80b
branches:  trunk
changeset: 759014:193e3aedb80b
user:      pooka <pooka%NetBSD.org@localhost>
date:      Wed Nov 24 15:17:46 2010 +0000

description:
improve threadsafety

diffstat:

 lib/librumpuser/rumpuser_sp.c |  39 +++++++++++++++++++++++----------------
 1 files changed, 23 insertions(+), 16 deletions(-)

diffs (143 lines):

diff -r 5249a5dfe71d -r 193e3aedb80b lib/librumpuser/rumpuser_sp.c
--- a/lib/librumpuser/rumpuser_sp.c     Wed Nov 24 14:56:18 2010 +0000
+++ b/lib/librumpuser/rumpuser_sp.c     Wed Nov 24 15:17:46 2010 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: rumpuser_sp.c,v 1.11 2010/11/24 11:40:24 pooka Exp $  */
+/*      $NetBSD: rumpuser_sp.c,v 1.12 2010/11/24 15:17:46 pooka Exp $  */
 
 /*
  * Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: rumpuser_sp.c,v 1.11 2010/11/24 11:40:24 pooka Exp $");
+__RCSID("$NetBSD: rumpuser_sp.c,v 1.12 2010/11/24 15:17:46 pooka Exp $");
 
 #include <sys/types.h>
 #include <sys/atomic.h>
@@ -308,7 +308,9 @@
        if (ref > 0)
                return;
 
-       _DIAGASSERT(TAILQ_EMPTY(&spclist[i].spc_respwait));
+       DPRINTF(("spcrelease: spc %p fd %d\n", spc, spc->spc_fd));
+
+       _DIAGASSERT(TAILQ_EMPTY(spc->spc_respwait));
        _DIAGASSERT(spc->spc_buf == NULL);
 
        lwproc_switch(spc->spc_mainlwp);
@@ -317,9 +319,8 @@
 
        close(spc->spc_fd);
        spc->spc_fd = -1;
+       spc->spc_dying = 0;
 
-       spc->spc_pfd->fd = -1;
-       membar_producer();
        atomic_inc_uint(&disco);
 
 }
@@ -331,6 +332,12 @@
 
        DPRINTF(("rump_sp: disconnecting [%u]\n", idx));
 
+       pfdlist[idx].fd = -1;
+       pfdlist[idx].revents = 0;
+       pthread_mutex_lock(&spc->spc_mtx);
+       spc->spc_dying = 1;
+       kickall(spc);
+       pthread_mutex_unlock(&spc->spc_mtx);
        spcrelease(spc);
 }
 
@@ -367,7 +374,7 @@
 
        /* find empty slot the simple way */
        for (i = 0; i < MAXCLI; i++) {
-               if (pfdlist[i].fd == -1)
+               if (pfdlist[i].fd == -1 && spclist[i].spc_dying == 0)
                        break;
        }
 
@@ -427,6 +434,7 @@
        struct sysbouncearg *barg = arg;
 
        serv_handlesyscall(barg->sba_spc, &barg->sba_hdr, barg->sba_data);
+       spcrelease(barg->sba_spc);
        free(arg);
        return NULL;
 }
@@ -436,8 +444,11 @@
 {
        struct spclient *spc = arg;
        void *rdata = NULL; /* XXXuninit */
+       int rv;
 
-       copyin_req(spc, uaddr, len, &rdata);
+       rv = copyin_req(spc, uaddr, len, &rdata);
+       if (rv)
+               return EFAULT;
 
        memcpy(kaddr, rdata, len);
        free(rdata);
@@ -536,8 +547,6 @@
                pfdlist[idx].events = POLLIN;
 
                spc = &spclist[idx];
-
-               spc->spc_pfd = &pfdlist[idx];
                pthread_mutex_init(&spc->spc_mtx, NULL);
                pthread_cond_init(&spc->spc_cv, NULL);
        }
@@ -553,20 +562,20 @@
                if (disco) {
                        int discoed;
 
-                       membar_consumer();
                        discoed = atomic_swap_uint(&disco, 0);
                        while (discoed--) {
                                nfds--;
                                idx = maxidx;
-                               while (idx--) {
+                               while (idx) {
                                        if (pfdlist[idx].fd != -1) {
                                                maxidx = idx;
                                                break;
                                        }
-                                       assert(idx != 0);
+                                       idx--;
                                }
                                DPRINTF(("rump_sp: set maxidx to [%u]\n",
                                    maxidx));
+                               assert(maxidx+1 >= nfds);
                        }
                }
 
@@ -583,9 +592,7 @@
                        break;
                }
 
-               for (idx = 0; seen < rv; idx++) {
-                       assert(idx < MAXCLI);
-
+               for (idx = 0; seen < rv && idx < MAXCLI; idx++) {
                        if ((pfdlist[idx].revents & POLLIN) == 0)
                                continue;
 
@@ -594,7 +601,6 @@
                            idx, seen, rv));
                        if (idx > 0) {
                                spc = &spclist[idx];
-
                                DPRINTF(("rump_sp: mainloop read [%u]\n", idx));
                                switch (readframe(spc)) {
                                case 0:
@@ -627,6 +633,7 @@
                                        nfds++;
                                if (idx > maxidx)
                                        maxidx = idx;
+                               DPRINTF(("rump_sp: maxid now %d\n", maxidx));
                        }
                }
        }