From: Takashi Yano <takashi.yano@nifty.ne.jp>
To: cygwin@cygwin.com
Subject: Re: Memory Barriers at pthread using CYGWIN
Date: Tue, 20 Jun 2023 21:53:00 +0900 [thread overview]
Message-ID: <20230620215300.def2e786b8fdce10b6317381@nifty.ne.jp> (raw)
In-Reply-To: <1503743851.9556.1686370084334@aps7mgn-06>
On Sat, 10 Jun 2023 13:08:04 +0900 (JST)
Takashi Yano wrote:
> "M?min A." wrote:
> > //windows cmd line
> > C:\cygwin64\home\maydin\test>cygcheck ./main.exe
> > C:\cygwin64\home\maydin\test\main.exe
> > C:\cygwin64\bin\cygwin1.dll
> > C:\WINDOWS\system32\KERNEL32.dll
> > C:\WINDOWS\system32\ntdll.dll
> > C:\WINDOWS\system32\KERNELBASE.dll
> >
> > C:\cygwin64\home\maydin\test>ldd ./main.exe
> > ntdll.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntdll.dll (0x7ffa92350000)
> > KERNEL32.DLL => /cygdrive/c/WINDOWS/System32/KERNEL32.DLL
> > (0x7ffa90570000)
> > KERNELBASE.dll => /cygdrive/c/WINDOWS/System32/KERNELBASE.dll
> > (0x7ffa8ffb0000)
> > cygwin1.dll => /usr/bin/cygwin1.dll (0x7ffa27960000)
>
> Looks OK.
>
> > //When cygwin terminal closed and cmd line command. Join throw fails.
> > C:\cygwin64\home\maydin\test>main.exe
> > Failed to join the thread t1.
> > Failed to join the thread t2.
> > r1 = 1, r2 = 1
> >
> > //when cygwin terminal opened. The test is passed.
> > C:\cygwin64\home\maydin\test>main.exe
> > r1 = 1, r2 = 1
> >
> >
> > I think Cygwin terminal should be always open in order to execute a file in
> > windows. Am I right ?
>
> It should not be. Weird enough.
>
> Could you please provide a strace log file such as:
> strace -o faild.log ./main.exe
> ?
I looked into this problem, and I think this is a problem regarding
_my_tls initialization order, so far. This seems to happen in LDAP
environment.
My assumption is:
If the program is the first program which load cygwin1.dll, ldap
connection seems to be made before pthread::init_mainthread().
In cyg_ldap.cc, cyg_ldap::connect(), cyg_ldap::search() or
cyg_ldap::next_page() calls cygwait() in which pthread::self()
is called.
Then, _my_tls.tid is initialized with null_pthread, therefore,
_my_tls.tid is not set in pthread::init_mainthread().
This causes pthread_join() failure at:
winsup/cygwin/thread.cc: line 2196
if (!is_good_object (&joiner))
return EINVAL;
The first idea to fix this issue is remove set_tls_self_pointer()
call from pthread::self().
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 5c1284a93..a0f2d5546 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -392,10 +392,7 @@ pthread::self ()
{
pthread *thread = _my_tls.tid;
if (!thread)
- {
- thread = pthread_null::get_null_pthread ();
- thread->set_tls_self_pointer ();
- }
+ thread = pthread_null::get_null_pthread ();
return thread;
}
The secnd approach is to re-initialize _my_tls.tid in
pthread::init_mainthread() if _my_tls.tid is null_pthread.
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)
Which is the better approach, do you think?
Or any other idea?
--
Takashi Yano <takashi.yano@nifty.ne.jp>
next prev parent reply other threads:[~2023-06-20 12:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAPxKPA6bRfF19pXrYT04TqbxettyYf=ypgfdySysqAJyB9BfxA@mail.gmail.com>
[not found] ` <CAPxKPA48sKPqwGc-jU7UQvQhsbT0N6A9LJXCAZeaa1rjeRtuNg@mail.gmail.com>
[not found] ` <96718c68-af84-45a5-9332-337ec4b2f04a@email.android.com>
2023-06-09 12:25 ` Takashi Yano
[not found] ` <64831a27.170a0220.1f805.81bfSMTPIN_ADDED_BROKEN@mx.google.com>
2023-06-10 4:08 ` Takashi Yano
2023-06-20 12:53 ` Takashi Yano [this message]
2023-06-22 10:19 ` Takashi Yano
2023-06-22 11:48 ` Corinna Vinschen
2023-06-22 23:49 ` Takashi Yano
2023-06-08 14:29 Mümin A.
2023-06-08 14:37 ` [EXTERNAL] " Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2023-06-08 22:58 ` Mümin A.
2023-06-09 0:22 ` Takashi Yano
2023-06-09 1:44 ` Duncan Roe
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