Re: [PATCH 1/1] util/oslib: Returns real thread identifier on FreeBSD and NetBSD

[David CARLIER]

>From 5f0b74a75906a9a043ce4874e7f09dedcad7e6e7 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Fri, 5 Jun 2020 17:18:25 +0100
Subject: [PATCH] util/oslib: Returns real thread identifier on FreeBSD,
 OpenBSD and NetBSD

getpid is good enough in a mono thread context,
however thr_self/getthrid/_lwp_self reflects
the real current thread identifier.

Reviewed-By: Kamil Rytarowski <kamil@netbsd.org>
Reviewed-By: Edward Tomasz Napierala <trasz@FreeBSD.org>
Signed-off-by: David Carlier <devnexen@gmail.com>
---
 util/oslib-posix.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 062236a1ab..7864a7768c 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -48,11 +48,17 @@
 #ifdef __FreeBSD__
 #include <sys/sysctl.h>
 #include <sys/user.h>
+#include <sys/thr.h>
 #include <libutil.h>
 #endif

+#ifdef __OpenBSD__
+#include <unistd.h>
+#endif
+
 #ifdef __NetBSD__
 #include <sys/sysctl.h>
+#include <lwp.h>
 #endif

 #include "qemu/mmap-alloc.h"
@@ -84,6 +90,15 @@ int qemu_get_thread_id(void)
 {
 #if defined(__linux__)
     return syscall(SYS_gettid);
+#elif defined(__FreeBSD__)
+    /* thread id is up to INT_MAX */
+    long tid;
+    thr_self(&tid);
+    return (int)tid;
+#elif defined(__OpenBSD__)
+    return getthrid();
+#elif defined(__NetBSD__)
+    return _lwp_self();
 #else
     return getpid();
 #endif
-- 
2.27.0

On Wed, 3 Jun 2020 at 16:07, Li-Wen Hsu <lwhsu@freebsd.org> wrote:
>
> Sorry that I am not familiar with this part so I asked others to help
> review (the FreeBSD related code).  It's good and please append:
>
> Reviewed-by: Edward Tomasz Napierala <trasz@FreeBSD.org>
>
> Thanks!
>
> On Wed, Jun 3, 2020 at 2:14 PM David CARLIER <devnexen@gmail.com> wrote:
> >
> > Sorry it landed in the spam.
> >
> > It does make things more accurate, thus a bit more than cosmetic, as
> > stated in the commit message, thr_self/_lwp_self represents the
> > current thread id in multi thread context.
> >
> > For OpenBSD it is syscall(SYS_getthrid) I believe
> > https://man.openbsd.org/getthrid.2
> >
> > On Wed, 3 Jun 2020 at 06:12, Philippe Mathieu-Daudé <philmd@redhat.com> 
> > wrote:
> > >
> > > ping?
> > >
> > > On 5/26/20 9:29 AM, David CARLIER wrote:
> > > > From 792fbcd9114f43bd80fd1ef5b25cd9935a536f9f Mon Sep 17 00:00:00 2001
> > > > From: David Carlier <devnexen@gmail.com>
> > > > Date: Tue, 26 May 2020 08:25:26 +0100
> > > > Subject: [PATCH] util/oslib: Returns the real thread identifier on 
> > > > FreeBSD and
> > > >  NetBSD
> > > >
> > > > getpid is good enough in a mono thread context, however
> > > >  thr_self/_lwp_self reflects the real current thread identifier
> > > >  from a given process.
> > > > ---
> > > >  util/oslib-posix.c | 9 +++++++++
> > > >  1 file changed, 9 insertions(+)
> > > >
> > > > diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> > > > index 062236a1ab..916f1be224 100644
> > > > --- a/util/oslib-posix.c
> > > > +++ b/util/oslib-posix.c
> > > > @@ -48,11 +48,13 @@
> > > >  #ifdef __FreeBSD__
> > > >  #include <sys/sysctl.h>
> > > >  #include <sys/user.h>
> > > > +#include <sys/thr.h>
> > > >  #include <libutil.h>
> > > >  #endif
> > > >
> > > >  #ifdef __NetBSD__
> > > >  #include <sys/sysctl.h>
> > > > +#include <lwp.h>
> > > >  #endif
> > > >
> > > >  #include "qemu/mmap-alloc.h"
> > > > @@ -84,6 +86,13 @@ int qemu_get_thread_id(void)
> > > >  {
> > > >  #if defined(__linux__)
> > > >      return syscall(SYS_gettid);
> > > > +#elif defined(__FreeBSD__)
> > > > +    /* thread id is up to INT_MAX */
> > > > +    long tid;
> > > > +    thr_self(&tid);
> > > > +    return (int)tid;
> > > > +#elif defined(__NetBSD__)
> > > > +    return _lwp_self();
> > > >  #else
> > > >      return getpid();
> > > >  #endif
> > > >
> > >