Re: [Qemu-devel] [PATCH v2] qemu-thread: always keep the posix wrapper layer

[Fam Zheng <famz@redhat.com>]

On Thu, 04/12 13:34, Peter Xu wrote:
> We will conditionally have a wrapper layer depending on whether the host
> has the PTHREAD_SETNAME capability.  It complicates stuff.  Let's keep
> the wrapper there; we opt out the pthread_setname_np() call only.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> v2:
> - set thread name only conditionally [Eric]
> ---
>  util/qemu-thread-posix.c | 33 +++++++++++++--------------------
>  1 file changed, 13 insertions(+), 20 deletions(-)
> 
> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
> index b789cf32e9..a1c34ba6f2 100644
> --- a/util/qemu-thread-posix.c
> +++ b/util/qemu-thread-posix.c
> @@ -482,7 +482,6 @@ static void __attribute__((constructor)) qemu_thread_atexit_init(void)
>  }
>  
>  
> -#ifdef CONFIG_PTHREAD_SETNAME_NP
>  typedef struct {
>      void *(*start_routine)(void *);
>      void *arg;
> @@ -495,16 +494,18 @@ static void *qemu_thread_start(void *args)
>      void *(*start_routine)(void *) = qemu_thread_args->start_routine;
>      void *arg = qemu_thread_args->arg;
>  
> +#ifdef CONFIG_PTHREAD_SETNAME_NP
>      /* Attempt to set the threads name; note that this is for debug, so
>       * we're not going to fail if we can't set it.
>       */
> -    pthread_setname_np(pthread_self(), qemu_thread_args->name);
> +    if (name_threads && qemu_thread_args->name) {
> +        pthread_setname_np(pthread_self(), qemu_thread_args->name);
> +    }
> +#endif
>      g_free(qemu_thread_args->name);
>      g_free(qemu_thread_args);
>      return start_routine(arg);
>  }
> -#endif
> -
>  
>  void qemu_thread_create(QemuThread *thread, const char *name,
>                         void *(*start_routine)(void*),
> @@ -513,6 +514,7 @@ void qemu_thread_create(QemuThread *thread, const char *name,
>      sigset_t set, oldset;
>      int err;
>      pthread_attr_t attr;
> +    QemuThreadArgs *qemu_thread_args;
>  
>      err = pthread_attr_init(&attr);
>      if (err) {
> @@ -527,22 +529,13 @@ void qemu_thread_create(QemuThread *thread, const char *name,
>      sigfillset(&set);
>      pthread_sigmask(SIG_SETMASK, &set, &oldset);
>  
> -#ifdef CONFIG_PTHREAD_SETNAME_NP
> -    if (name_threads) {
> -        QemuThreadArgs *qemu_thread_args;
> -        qemu_thread_args = g_new0(QemuThreadArgs, 1);
> -        qemu_thread_args->name = g_strdup(name);
> -        qemu_thread_args->start_routine = start_routine;
> -        qemu_thread_args->arg = arg;
> -
> -        err = pthread_create(&thread->thread, &attr,
> -                             qemu_thread_start, qemu_thread_args);
> -    } else
> -#endif
> -    {
> -        err = pthread_create(&thread->thread, &attr,
> -                             start_routine, arg);
> -    }
> +    qemu_thread_args = g_new0(QemuThreadArgs, 1);
> +    qemu_thread_args->name = g_strdup(name);
> +    qemu_thread_args->start_routine = start_routine;
> +    qemu_thread_args->arg = arg;
> +
> +    err = pthread_create(&thread->thread, &attr,
> +                         qemu_thread_start, qemu_thread_args);
>  
>      if (err)
>          error_exit(err, __func__);
> -- 
> 2.14.3
> 

Reviewed-by: Fam Zheng <famz@redhat.com>