[PATCH] libstdc++: Fix return values for atomic wait on futex

[Jonathan Wakely via Gcc-patches]

This fixes a logic error in the futex-based timed wait.

Signed-off-by: Jonathan Wakely <jwak...@redhat.com>

libstdc++-v3/ChangeLog:

        * include/bits/atomic_timed_wait.h (__platform_wait_until_impl):
        Return false for ETIMEDOUT and true otherwise.

Tested x86_64-linux.

I'm not seeing any tests fail as a result of this, btu it does seem to
be incorrect. Please check my working.



commit 94dc544bbf42e95a363b916ed0d665afcfcccc88
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Tue Aug 31 10:20:41 2021

    libstdc++: Fix return values for atomic wait on futex
    
    This fixes a logic error in the futex-based timed wait.
    
    Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/atomic_timed_wait.h (__platform_wait_until_impl):
            Return false for ETIMEDOUT and true otherwise.

diff --git a/libstdc++-v3/include/bits/atomic_timed_wait.h 
b/libstdc++-v3/include/bits/atomic_timed_wait.h
index 3db08f82707..d423a7af7c3 100644
--- a/libstdc++-v3/include/bits/atomic_timed_wait.h
+++ b/libstdc++-v3/include/bits/atomic_timed_wait.h
@@ -101,12 +101,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
        if (__e)
          {
-           if ((errno != ETIMEDOUT) && (errno != EINTR)
-               && (errno != EAGAIN))
+           if (errno == ETIMEDOUT)
+             return false;
+           if (errno != EINTR && errno != EAGAIN)
              __throw_system_error(errno);
-           return true;
          }
-       return false;
+       return true;
       }
 
     // returns true if wait ended before timeout