On rtems under qemu, the frequently-interrupted nanosleep ends up
sleeping shorter than expected, by a margin of less than 0,3%.
I figured failing the library test over a system (emulator?) bug is
undesirable, so I put in some tolerance for the drift.
Regstrapped on x86_64-linux-gnu, also tested with a cross to
aarch64-rtems6. Ok to install?
PS: I see nothing wrong with the implementation of clock_nanosleep (used
by nanosleep) on rtems6 that could cause it to wake up too early. I
suspect some artifact of the emulation environment.
for libstdc++-v3/ChangeLog
* testsuite/30_threads/this_thread/60421.cc: Tolerate a
slightly early wakeup.
---
.../testsuite/30_threads/this_thread/60421.cc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
b/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
index 12dbeba1cc492..f3a5af453c4ad 100644
--- a/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
+++ b/libstdc++-v3/testsuite/30_threads/this_thread/60421.cc
@@ -51,9 +51,10 @@ test02()
std::thread t([&result, &sleeping] {
auto start = std::chrono::system_clock::now();
auto time = std::chrono::seconds(3);
+ auto tolerance = std::chrono::milliseconds(10);
sleeping = true;
std::this_thread::sleep_for(time);
- result = std::chrono::system_clock::now() >= (start + time);
+ result = std::chrono::system_clock::now() + tolerance >= (start + time);
sleeping = false;
});
while (!sleeping)
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts. Ask me about <https://stallmansupport.org>
