[src/trunk]: src/lib/librumpuser Improve reliability in cases where client di...

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

details:   https://anonhg.NetBSD.org/src/rev/db97ccb09c8f
branches:  trunk
changeset: 759050:db97ccb09c8f
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Nov 26 14:37:08 2010 +0000

description:
Improve reliability in cases where client disconnects mid-operation.

diffstat:

 lib/librumpuser/rumpuser_sp.c |  11 +++++++++--
 lib/librumpuser/sp_common.c   |  22 ++++++++++++++--------
 2 files changed, 23 insertions(+), 10 deletions(-)

diffs (114 lines):

diff -r f9201cad4846 -r db97ccb09c8f lib/librumpuser/rumpuser_sp.c
--- a/lib/librumpuser/rumpuser_sp.c     Fri Nov 26 12:04:36 2010 +0000
+++ b/lib/librumpuser/rumpuser_sp.c     Fri Nov 26 14:37:08 2010 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: rumpuser_sp.c,v 1.16 2010/11/26 10:59:14 pooka Exp $  */
+/*      $NetBSD: rumpuser_sp.c,v 1.17 2010/11/26 14:37:08 pooka Exp $  */
 
 /*
  * Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: rumpuser_sp.c,v 1.16 2010/11/26 10:59:14 pooka Exp $");
+__RCSID("$NetBSD: rumpuser_sp.c,v 1.17 2010/11/26 14:37:08 pooka Exp $");
 
 #include <sys/types.h>
 #include <sys/atomic.h>
@@ -345,6 +345,13 @@
        spc->spc_dying = 1;
        kickall(spc);
        pthread_mutex_unlock(&spc->spc_mtx);
+
+       /*
+        * Nobody's going to attempt to send/receive anymore,
+        * so reinit info relevant to that.
+        */
+       memset((char *)spc + SPC_ZEROFF, 0, sizeof(*spc) - SPC_ZEROFF);
+
        spcrelease(spc);
 }
 
diff -r f9201cad4846 -r db97ccb09c8f lib/librumpuser/sp_common.c
--- a/lib/librumpuser/sp_common.c       Fri Nov 26 12:04:36 2010 +0000
+++ b/lib/librumpuser/sp_common.c       Fri Nov 26 14:37:08 2010 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: sp_common.c,v 1.10 2010/11/25 17:59:02 pooka Exp $    */
+/*      $NetBSD: sp_common.c,v 1.11 2010/11/26 14:37:08 pooka Exp $    */
 
 /*
  * Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
@@ -47,6 +47,7 @@
 #include <poll.h>
 #include <pthread.h>
 #include <stdarg.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -123,22 +124,24 @@
        int spc_refcnt;
        int spc_dying;
 
+       pthread_mutex_t spc_mtx;
+       pthread_cond_t spc_cv;
+
        struct lwp *spc_mainlwp;
        pid_t spc_pid;
 
+       TAILQ_HEAD(, respwait) spc_respwait;
+
+       /* rest of the fields are zeroed upon disconnect */
+#define SPC_ZEROFF offsetof(struct spclient, spc_pid)
        struct pollfd *spc_pfd;
 
        struct rsp_hdr spc_hdr;
        uint8_t *spc_buf;
        size_t spc_off;
 
-       pthread_mutex_t spc_mtx;
-       pthread_cond_t spc_cv;
-
        uint64_t spc_nextreq;
        int spc_ostatus, spc_istatus;
-
-       TAILQ_HEAD(, respwait) spc_respwait;
 };
 #define SPCSTATUS_FREE 0
 #define SPCSTATUS_BUSY 1
@@ -249,7 +252,7 @@
        }
        DPRINTF(("rump_sp: client %p woke up waiter at %p\n", spc, rw));
        rw->rw_data = spc->spc_buf;
-       rw->rw_dlen = (size_t)spc->spc_off;
+       rw->rw_dlen = (size_t)(spc->spc_off - HDRSZ);
        pthread_cond_signal(&rw->rw_cv);
        pthread_mutex_unlock(&spc->spc_mtx);
 
@@ -292,7 +295,7 @@
                                case -1:
                                        rv = errno;
                                        spc->spc_dying = 1;
-                                       break;
+                                       goto cleanup;
                                default:
                                        break;
                                }
@@ -311,6 +314,7 @@
                                        break;
                                }
                        }
+ cleanup:
                        pthread_mutex_lock(&spc->spc_mtx);
                        if (spc->spc_istatus == SPCSTATUS_WANTED)
                                kickall(spc);
@@ -326,6 +330,8 @@
 
        pthread_cond_destroy(&rw->rw_cv);
 
+       if (rv == 0 && spc->spc_dying)
+               rv = ENOTCONN;
        return rv;
 }