[PATCH] Cygwin: thread: Reset _my_tls.tid if it's pthread_null in init_mainthread().

[PATCH] Cygwin: thread: Reset _my_tls.tid if it's pthread_null in init_mainthread().

[Takashi Yano]

Currently, _my_tls.tid is set to pthread_null if pthread::self()
is called before pthread::init_mainthread(). As a result, pthread::
init_mainthread() does not set _my_tls.tid appropriately. Due to
this, pthread_join() fails in LDAP environment if the program is
the first program which loads cygwin1.dll.

https://cygwin.com/pipermail/cygwin/2023-June/253792.html

With this patch, _my_tls.tid is re-initialized in pthread::
init_mainthread() if it is pthread_null.

Reported-by: Mümin A. <muminaydin06@gmail.com>
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
---
 winsup/cygwin/thread.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 5c1284a93..f614e01c4 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -364,7 +364,7 @@ void
 pthread::init_mainthread ()
 {
   pthread *thread = _my_tls.tid;
-  if (!thread)
+  if (!thread || thread == pthread_null::get_null_pthread ())
     {
       thread = new pthread ();
       if (!thread)
-- 
2.39.0

Re: [PATCH] Cygwin: thread: Reset _my_tls.tid if it's pthread_null in init_mainthread().

[Corinna Vinschen]

On Jun 23 00:30, Takashi Yano wrote:
> Currently, _my_tls.tid is set to pthread_null if pthread::self()
> is called before pthread::init_mainthread(). As a result, pthread::
> init_mainthread() does not set _my_tls.tid appropriately. Due to
> this, pthread_join() fails in LDAP environment if the program is
> the first program which loads cygwin1.dll.
> 
> https://cygwin.com/pipermail/cygwin/2023-June/253792.html
> 
> With this patch, _my_tls.tid is re-initialized in pthread::
> init_mainthread() if it is pthread_null.
> 
> Reported-by: Mümin A. <muminaydin06@gmail.com>
> Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
> Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
> ---
>  winsup/cygwin/thread.cc | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
> index 5c1284a93..f614e01c4 100644
> --- a/winsup/cygwin/thread.cc
> +++ b/winsup/cygwin/thread.cc
> @@ -364,7 +364,7 @@ void
>  pthread::init_mainthread ()
>  {
>    pthread *thread = _my_tls.tid;
> -  if (!thread)
> +  if (!thread || thread == pthread_null::get_null_pthread ())
>      {
>        thread = new pthread ();
>        if (!thread)
> -- 
> 2.39.0

LGTM.


Thanks,
Corinna