[src/trunk]: src Inform the rump kernel hypervisor of valid thread contexts so

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

details:   https://anonhg.NetBSD.org/src/rev/807643a2799d
branches:  trunk
changeset: 786584:807643a2799d
user:      pooka <pooka%NetBSD.org@localhost>
date:      Thu May 02 19:14:59 2013 +0000

description:
Inform the rump kernel hypervisor of valid thread contexts so
that the implementation can allocate and release storage for them
in an optimal fashion, if necessary.

diffstat:

 lib/librumpuser/rumpuser.3                    |   42 ++++++++-
 lib/librumpuser/rumpuser_pth.c                |  109 +++++++++++++++++++++++--
 lib/librumpuser/rumpuser_pth_dummy.c          |   17 ++-
 sys/rump/include/machine/cpu.h                |    6 +-
 sys/rump/include/rump/rumpuser.h              |    7 +-
 sys/rump/librump/rumpkern/arch/i386/rumpcpu.c |    6 +-
 sys/rump/librump/rumpkern/lwproc.c            |   14 ++-
 sys/rump/librump/rumpkern/rump.c              |   11 +-
 sys/rump/librump/rumpkern/scheduler.c         |   17 ++-
 sys/rump/librump/rumpkern/threads.c           |    6 +-
 10 files changed, 185 insertions(+), 50 deletions(-)

diffs (truncated from 534 to 300 lines):

diff -r 54ccedc28384 -r 807643a2799d lib/librumpuser/rumpuser.3
--- a/lib/librumpuser/rumpuser.3        Thu May 02 16:49:08 2013 +0000
+++ b/lib/librumpuser/rumpuser.3        Thu May 02 19:14:59 2013 +0000
@@ -1,4 +1,4 @@
-.\"     $NetBSD: rumpuser.3,v 1.5 2013/05/02 15:32:19 pooka Exp $
+.\"     $NetBSD: rumpuser.3,v 1.6 2013/05/02 19:14:59 pooka Exp $
 .\"
 .\" Copyright (c) 2013 Antti Kantee.  All rights reserved.
 .\"
@@ -450,25 +450,53 @@
 .Fn rumpuser_thread_create .
 .Pp
 .Ft void
-.Fn rumpuser_set_curlwp "struct lwp *l"
+.Fn rumpuser_curlwpop "enum rumplwpop op" "struct lwp *l"
 .Pp
+Manipulate the hypervisor's thread context database.
+The possible operations are create, destroy and set as specified by
+.Fa op :
+.Bl -tag -width "XRUMPUSER_LWP_DESTROY"
+.It Dv RUMPUSER_LWP_CREATE
+Inform the hypervisor that
+.Fa l
+is now a valid thread context which may be set.
+A currently valid value of
+.Fa l
+may not be specified.
+This operation is informational and does not mandate any action
+from the hypervisor.
+.It Dv RUMPUSER_LWP_DESTROY
+Inform the hypervisor that
+.Fa l
+is no longer a valid thread context.
+This means that it may no longer be set as the current context.
+A currently set context or an invalid one may not be destroyed.
+This operation is informational and does not mandate any action
+from the hypervisor.
+.It Dv RUMPUSER_LWP_SET
 Set
 .Fa l
-as the rump kernel thread context for the calling host thread.
+as the current host thread's rump kernel context.
 The value
 .Dv NULL
 means that an existing rump kernel context (which must exist)
 must be cleared.
+.El
 .Pp
 .Ft struct lwp *
-.Fn rumpuser_get_curlwp "void"
+.Fn rumpuser_curlwp "void"
 .Pp
-Retrieve the rump kernel thread context previously set by
-.Fn rumpuser_set_curlwp .
-This routine can be called when a context does not exist and
+Retrieve the rump kernel thread context associated with the current host
+thread, as set by
+.Fn rumpuser_curlwpop .
+This routine may be called when a context is not set and
 the routine must return
 .Dv NULL
 in that case.
+This interface is expected to be called very often.
+Any optimizations pertaining to the execution speed of this routine
+should be done in
+.Fn rumpuser_curlwpop .
 .Pp
 .Ft void
 .Fn rumpuser_seterrno "int errno"
diff -r 54ccedc28384 -r 807643a2799d lib/librumpuser/rumpuser_pth.c
--- a/lib/librumpuser/rumpuser_pth.c    Thu May 02 16:49:08 2013 +0000
+++ b/lib/librumpuser/rumpuser_pth.c    Thu May 02 19:14:59 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpuser_pth.c,v 1.22 2013/05/02 16:49:08 pooka Exp $  */
+/*     $NetBSD: rumpuser_pth.c,v 1.23 2013/05/02 19:14:59 pooka Exp $  */
 
 /*
  * Copyright (c) 2007-2010 Antti Kantee.  All Rights Reserved.
@@ -28,9 +28,11 @@
 #include "rumpuser_port.h"
 
 #if !defined(lint)
-__RCSID("$NetBSD: rumpuser_pth.c,v 1.22 2013/05/02 16:49:08 pooka Exp $");
+__RCSID("$NetBSD: rumpuser_pth.c,v 1.23 2013/05/02 19:14:59 pooka Exp $");
 #endif /* !lint */
 
+#include <sys/queue.h>
+
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -53,14 +55,14 @@
        int flags;
 };
 
-#define RURW_AMWRITER(rw) (rw->writer == rumpuser_get_curlwp()         \
+#define RURW_AMWRITER(rw) (rw->writer == rumpuser_curlwp()             \
                                && rw->readers == -1)
 #define RURW_HASREAD(rw)  (rw->readers > 0)
 
 #define RURW_SETWRITE(rw)                                              \
 do {                                                                   \
        assert(rw->readers == 0);                                       \
-       rw->writer = rumpuser_get_curlwp();                             \
+       rw->writer = rumpuser_curlwp();                                 \
        rw->readers = -1;                                               \
 } while (/*CONSTCOND*/0)
 #define RURW_CLRWRITE(rw)                                              \
@@ -193,7 +195,7 @@
                return;
 
        assert(mtx->owner == NULL);
-       mtx->owner = rumpuser_get_curlwp();
+       mtx->owner = rumpuser_curlwp();
 }
 
 static void
@@ -460,17 +462,106 @@
  * curlwp
  */
 
+/*
+ * the if0'd curlwp implementation is not used by this hypervisor,
+ * but serves as test code to check that the intended usage works.
+ */
+#if 0
+struct rumpuser_lwp {
+       struct lwp *l;
+       LIST_ENTRY(rumpuser_lwp) l_entries;
+};
+static LIST_HEAD(, rumpuser_lwp) lwps = LIST_HEAD_INITIALIZER(lwps);
+static pthread_mutex_t lwplock = PTHREAD_MUTEX_INITIALIZER;
+
 void
-rumpuser_set_curlwp(struct lwp *l)
+rumpuser_curlwpop(enum rumplwpop op, struct lwp *l)
 {
+       struct rumpuser_lwp *rl, *rliter;
 
-       assert(pthread_getspecific(curlwpkey) == NULL || l == NULL);
-       pthread_setspecific(curlwpkey, l);
+       switch (op) {
+       case RUMPUSER_LWP_CREATE:
+               rl = malloc(sizeof(*rl));
+               rl->l = l;
+               pthread_mutex_lock(&lwplock);
+               LIST_FOREACH(rliter, &lwps, l_entries) {
+                       if (rliter->l == l) {
+                               fprintf(stderr, "LWP_CREATE: %p exists\n", l);
+                               abort();
+                       }
+               }
+               LIST_INSERT_HEAD(&lwps, rl, l_entries);
+               pthread_mutex_unlock(&lwplock);
+               break;
+       case RUMPUSER_LWP_DESTROY:
+               pthread_mutex_lock(&lwplock);
+               LIST_FOREACH(rl, &lwps, l_entries) {
+                       if (rl->l == l)
+                               break;
+               }
+               if (!rl) {
+                       fprintf(stderr, "LWP_DESTROY: %p does not exist\n", l);
+                       abort();
+               }
+               LIST_REMOVE(rl, l_entries);
+               pthread_mutex_unlock(&lwplock);
+               free(rl);
+               break;
+       case RUMPUSER_LWP_SET:
+               assert(pthread_getspecific(curlwpkey) == NULL || l == NULL);
+
+               if (l) {
+                       pthread_mutex_lock(&lwplock);
+                       LIST_FOREACH(rl, &lwps, l_entries) {
+                               if (rl->l == l)
+                                       break;
+                       }
+                       if (!rl) {
+                               fprintf(stderr,
+                                   "LWP_SET: %p does not exist\n", l);
+                               abort();
+                       }
+                       pthread_mutex_unlock(&lwplock);
+               } else {
+                       rl = NULL;
+               }
+
+               pthread_setspecific(curlwpkey, rl);
+               break;
+       }
 }
 
 struct lwp *
-rumpuser_get_curlwp(void)
+rumpuser_curlwp(void)
+{
+       struct rumpuser_lwp *rl;
+
+       rl = pthread_getspecific(curlwpkey);
+       return rl ? rl->l : NULL;
+}
+
+#else
+
+void
+rumpuser_curlwpop(enum rumplwpop op, struct lwp *l)
+{
+
+       switch (op) {
+       case RUMPUSER_LWP_CREATE:
+               break;
+       case RUMPUSER_LWP_DESTROY:
+               break;
+       case RUMPUSER_LWP_SET:
+               assert(pthread_getspecific(curlwpkey) == NULL || l == NULL);
+               pthread_setspecific(curlwpkey, l);
+               break;
+       }
+}
+
+struct lwp *
+rumpuser_curlwp(void)
 {
 
        return pthread_getspecific(curlwpkey);
 }
+#endif
diff -r 54ccedc28384 -r 807643a2799d lib/librumpuser/rumpuser_pth_dummy.c
--- a/lib/librumpuser/rumpuser_pth_dummy.c      Thu May 02 16:49:08 2013 +0000
+++ b/lib/librumpuser/rumpuser_pth_dummy.c      Thu May 02 19:14:59 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpuser_pth_dummy.c,v 1.12 2013/04/30 13:37:03 pooka Exp $    */
+/*     $NetBSD: rumpuser_pth_dummy.c,v 1.13 2013/05/02 19:14:59 pooka Exp $    */
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -29,7 +29,7 @@
 
 #include <sys/cdefs.h>
 #if !defined(lint)
-__RCSID("$NetBSD: rumpuser_pth_dummy.c,v 1.12 2013/04/30 13:37:03 pooka Exp $");
+__RCSID("$NetBSD: rumpuser_pth_dummy.c,v 1.13 2013/05/02 19:14:59 pooka Exp $");
 #endif /* !lint */
 
 #include <sys/time.h>
@@ -283,14 +283,21 @@
  */
 
 void
-rumpuser_set_curlwp(struct lwp *l)
+rumpuser_curlwpop(enum rumplwpop op, struct lwp *l)
 {
 
-       curlwp = l;
+       switch (op) {
+       case RUMPUSER_LWP_CREATE:
+       case RUMPUSER_LWP_DESTROY:
+               break;
+       case RUMPUSER_LWP_SET:
+               curlwp = l;
+               break;
+       }
 }
 
 struct lwp *
-rumpuser_get_curlwp(void)
+rumpuser_curlwp(void)
 {
 
        return curlwp;
diff -r 54ccedc28384 -r 807643a2799d sys/rump/include/machine/cpu.h
--- a/sys/rump/include/machine/cpu.h    Thu May 02 16:49:08 2013 +0000
+++ b/sys/rump/include/machine/cpu.h    Thu May 02 19:14:59 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.h,v 1.15 2011/03/21 16:41:08 pooka Exp $   */
+/*     $NetBSD: cpu.h,v 1.16 2013/05/02 19:15:00 pooka Exp $   */
 
 /*
  * Copyright (c) 2008-2011 Antti Kantee.  All Rights Reserved.
@@ -73,8 +73,8 @@
 void __syncicache(void *, size_t);
 #endif
 
-struct lwp *rumpuser_get_curlwp(void);
-#define curlwp rumpuser_get_curlwp()
+struct lwp *rumpuser_curlwp(void);
+#define curlwp rumpuser_curlwp()
 
 #define curcpu() (curlwp->l_cpu)
 #define cpu_number() (cpu_index(curcpu))
diff -r 54ccedc28384 -r 807643a2799d sys/rump/include/rump/rumpuser.h
--- a/sys/rump/include/rump/rumpuser.h  Thu May 02 16:49:08 2013 +0000
+++ b/sys/rump/include/rump/rumpuser.h  Thu May 02 19:14:59 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpuser.h,v 1.100 2013/04/30 16:03:44 pooka Exp $     */
+/*     $NetBSD: rumpuser.h,v 1.101 2013/05/02 19:15:01 pooka Exp $     */
 
 /*
  * Copyright (c) 2007-2013 Antti Kantee.  All Rights Reserved.