Ticket #11688: 0001-thread-try_join_until-Avoid-busy-wait-if-system-cloc.patch

File 0001-thread-try_join_until-Avoid-busy-wait-if-system-cloc.patch, 1.6 KB (added by Mike Crowe <mac@…>, 7 years ago)

Patch to fix problem.

  • include/boost/thread/detail/thread.hpp 

    From 5b9d96912ddd9bfd05ea03994ae733a031cdcfcb Mon Sep 17 00:00:00 2001
From: Mike Crowe <mac@mcrowe.com>
Date: Mon, 22 Jun 2015 12:01:22 +0100
Subject: [PATCH] thread::try_join_until: Avoid busy wait if system clock
 changes

If system clock changes by an amount larger than the outstanding duration
according to the supplied clock then the code loops around again but
continues to pass a time point based on the original value of the system
clock to the system_clock variant of try_join.

If we're going to recalculate the outstanding duration in the loop then it
is necessary to get the current time according to the system clock to use
with this duration.

Signed-off-by: Mike Crowe <mac@mcrowe.com>
---
 include/boost/thread/detail/thread.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/boost/thread/detail/thread.hpp b/include/boost/thread/detail/thread.hpp
index b80eacf..727282b 100644
    a b namespace boost  
    485485        bool try_join_until(const chrono::time_point<Clock, Duration>& t)
    486486        {
    487487          using namespace chrono;
    488           system_clock::time_point     s_now = system_clock::now();
    489488          bool joined= false;
    490489          do {
     490            system_clock::time_point   s_now = system_clock::now();
    491491            typename Clock::duration   d = ceil<nanoseconds>(t-Clock::now());
    492492            if (d <= Clock::duration::zero()) return false; // in case the Clock::time_point t is already reached
    493493            joined = try_join_until(s_now + d);