[{"id":3683901,"web_url":"http://patchwork.ozlabs.org/comment/3683901/","msgid":"","list_archive_url":null,"date":"2026-04-29T08:32:27","subject":"Re: [PATCH] testsuite: semaphore/try_acquire_until: reorder\n clock::now calls","submitter":{"id":48004,"url":"http://patchwork.ozlabs.org/api/people/48004/","name":"Jonathan Wakely","email":"jwakely@redhat.com"},"content":"On Wed, 29 Apr 2026 at 02:51, Alexandre Oliva wrote:\n>\n>\n> Clock calls on VxWorks are slow, so the odds that the consecutive\n> calls of *clock::now() will yield a different result are not\n> negligible. Reordering the calls avoids false positives.\n>\n> Regstrapped on x86_64-linux-gnu. Also tested on ppc-vx7r2 with gcc-15,\n> with an analogous patch for try_acquire_posix.cc. Ok to install?\n\nOK for trunk (and branches if you want, but wait until after 16.1 is released).\n\n>\n>\n> for libstdc++-v3/ChangeLog\n>\n> * testsuite/30_threads/semaphore/try_acquire_until.cc\n> (test01): Reorder calls.\n> ---\n> .../30_threads/semaphore/try_acquire_until.cc | 2 +-\n> 1 file changed, 1 insertion(+), 1 deletion(-)\n>\n> diff --git a/libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_until.cc b/libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_until.cc\n> index 44b2b90431a41..dea8c53a5a02f 100644\n> --- a/libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_until.cc\n> +++ b/libstdc++-v3/testsuite/30_threads/semaphore/try_acquire_until.cc\n> @@ -43,8 +43,8 @@ void test01()\n> }\n>\n> {\n> - auto const at = std::chrono::system_clock::now() + dur;\n> auto const t0 = std::chrono::steady_clock::now();\n> + auto const at = std::chrono::system_clock::now() + dur;\n> VERIFY( !s.try_acquire_until(at) );\n> auto const diff = std::chrono::steady_clock::now() - t0;\n> VERIFY( diff >= dur );\n>\n>\n> --\n> Alexandre Oliva, happy hacker https://blog.lx.oliva.nom.br/\n> Free Software Activist FSFLA co-founder GNU Toolchain Engineer\n> More tolerance and less prejudice are key for inclusion and diversity.\n> Excluding neuro-others for not behaving \"\"normal\"\" is *not* inclusive!\n>","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=T88yPBTc;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; 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Wed, 29 Apr 2026\n 01:32:43 -0700 (PDT)"],"MIME-Version":"1.0","References":"","In-Reply-To":"","From":"Jonathan Wakely ","Date":"Wed, 29 Apr 2026 09:32:27 +0100","X-Gm-Features":"AVHnY4IoQ3au0qDpwWEEFXsCIi-4PttCtYiKfZ0AOmsg320050KgIMXlkxipto8","Message-ID":"\n ","Subject":"Re: [PATCH] testsuite: semaphore/try_acquire_until: reorder\n clock::now calls","To":"Alexandre Oliva ","Cc":"gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"6Y9S1OrMhYXvkTKVdhtBimgDbEDQSXn0HswNoNjFIsw_1777451564","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=\"UTF-8\"","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"}}]