From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dmta1013.nifty.com (mta-snd01003.nifty.com [106.153.227.35]) by sourceware.org (Postfix) with ESMTPS id 53CF53858D1E for ; Tue, 20 Jun 2023 12:53:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 53CF53858D1E Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=nifty.ne.jp Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=nifty.ne.jp Received: from HP-Z230 by dmta1013.nifty.com with ESMTP id <20230620125301106.LXBB.25671.HP-Z230@nifty.com> for ; Tue, 20 Jun 2023 21:53:01 +0900 Date: Tue, 20 Jun 2023 21:53:00 +0900 From: Takashi Yano To: cygwin@cygwin.com Subject: Re: Memory Barriers at pthread using CYGWIN Message-Id: <20230620215300.def2e786b8fdce10b6317381@nifty.ne.jp> In-Reply-To: <1503743851.9556.1686370084334@aps7mgn-06> References: <96718c68-af84-45a5-9332-337ec4b2f04a@email.android.com> <64831a27.170a0220.1f805.81bfSMTPIN_ADDED_BROKEN@mx.google.com> <1503743851.9556.1686370084334@aps7mgn-06> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-10.2 required=5.0 tests=BAYES_00,GIT_PATCH_0,KAM_DMARC_STATUS,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: 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