https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80538
Bug ID: 80538
Summary: Probably unwanted thread yield for thread::sleep_for
with < 1s
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: zulliger at indel dot ch
Target Milestone: ---
libstdc++-v3 configured to NOT have _GLIBCXX_USE_NANOSLEEP, but to HAVE
_GLIBCXX_HAVE_SLEEP and _GLIBCXX_HAVE_USLEEP defined, causes the execution of
the following code:
::sleep(__s.count());
if (__ns.count() > 0)
{
long __us = __ns.count() / 1000;
if (__us == 0)
__us = 1;
::usleep(__us);
}
Which means that for values of __s.count() == 0, the current thread will always
"yield" (according to my understanding, sleep(0) yields), just before the
thread may actually fall asleep for some microseconds. Is this really the
desired behaviour?
Anyway, what's the desired effect of a thread::sleep_for(0.0)? should the
thread yield then? If not, then the code should look like this:
if (__s.count() > 0) ::sleep(__s.count());
if (__ns.count() > 0)
{
long __us = __ns.count() / 1000;
if (__us == 0)
__us = 1;
::usleep(__us);
}
shouldn't it?
