// Only run this on the rust stack
MUST_CHECK bool rust_task::yield() {
bool killed = false;
if (disallow_yield > 0) {
call_on_c_stack(this, (void *)rust_task_yield_fail);
}
// This check is largely superfluous; it's the one after the context swap
// that really matters. This one allows us to assert a useful invariant.
// NB: This takes lifecycle_lock three times, and I believe that none of
// them are actually necessary, as per #3213. Removing the locks here may
// cause *harmless* races with a killer... but I didn't observe any
// substantial performance improvement from removing them, even with
// msgsend-ring-pipes, and also it's my last day, so I'm not about to
// remove them. -- bblum
if (must_fail_from_being_killed()) {
{
scoped_lock with(lifecycle_lock);
assert(!(state == task_state_blocked));
}
killed = true;
}
// Return to the scheduler.
ctx.next->swap(ctx);
if (must_fail_from_being_killed()) {
killed = true;
}
return killed;
}
// Only run this on the rust stack
void
rust_task::yield(bool *killed) {
if (must_fail_from_being_killed()) {
I(thread, !blocked());
*killed = true;
}
// Return to the scheduler.
ctx.next->swap(ctx);
if (must_fail_from_being_killed()) {
*killed = true;
}
}
