Handle partial nanosleeps in this_thread::sleep_for

Signals may result in nanosleep returning with only some of the
requested sleeping performed.

Utilize nanosleep's "time-remaining" out parameter to continue sleeping
when this occurs.

llvm-svn: 210210

1 files changed, 3 insertions, 1 deletions

diff --git a/libcxx/src/thread.cpp b/libcxx/src/thread.cpp
index bd2b7c39238..e6f57c46a7d 100644
--- a/libcxx/src/thread.cpp
+++ b/libcxx/src/thread.cpp
@@ -121,7 +121,9 @@ sleep_for(const chrono::nanoseconds& ns)
             ts.tv_sec = ts_sec_max;
             ts.tv_nsec = giga::num - 1;
         }
-        nanosleep(&ts, 0);
+
+        while (nanosleep(&ts, &ts) == -1 && errno == EINTR)
+            ;
     }
 }