From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 494B53857BB6; Fri, 15 Jul 2022 10:37:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 494B53857BB6 From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/63400] [C++11]precision of std::chrono::high_resolution_clock Date: Fri, 15 Jul 2022 10:37:50 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 4.9.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: minor X-Bugzilla-Who: redi at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jul 2022 10:37:50 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D63400 --- Comment #9 from Jonathan Wakely --- (In reply to frankhb1989 from comment #4) > For CLOCK_REALTIME, the Windows API GetSystemTimeAsFileTime is used. > GetSystemTimePreciseAsFileTime is an improved version which provide "the > highest possible level of precision (<1us)". Unfortunately, the latter is > only available since Windows 8/Windows 2012, which is not suited for > winpthreads for compatibility reason IMO. See this MSDN page for details: > http://msdn.microsoft.com/en-us/library/windows/desktop/hh706895(v=3Dvs.8= 5). > aspx But libstdc++ could call that directly, instead of going through the clock_gettime API.=