c_AsyncFunctionWaitHandle* AsioContext::maybePopFast() {
assertx(this == AsioSession::Get()->getCurrentContext());
while (!m_fastRunnableQueue.empty()) {
auto wh = m_fastRunnableQueue.back();
m_fastRunnableQueue.pop_back();
if (wh->getState() == c_ResumableWaitHandle::STATE_READY &&
wh->isFastResumable()) {
// We only call maybePopFast() on the current context. Since `wh' was
// scheduled in this context at some point, it must still be scheduled
// here now, since the only way it could leave the context is if the
// context was destroyed. (Being scheduled here supercedes it having
// been scheduled in earlier contexts.)
assertx(wh->getContextIdx() ==
AsioSession::Get()->getCurrentContextIdx());
return wh;
} else {
// `wh' is blocked or finished in some other context.
m_fastRunnableQueue.push_back(wh);
return nullptr;
}
}
return nullptr;
}
void c_AsyncFunctionWaitHandle::onUnblocked() {
setState(STATE_READY);
if (isInContext()) {
if (isFastResumable()) {
getContext()->scheduleFast(this);
} else {
getContext()->schedule(this);
}
} else {
decRefObj(this);
}
}
void c_AsyncFunctionWaitHandle::exitContext(context_idx_t ctx_idx) {
assert(AsioSession::Get()->getContext(ctx_idx));
// stop before corrupting unioned data
if (isFinished()) {
decRefObj(this);
return;
}
// not in a context being exited
assert(getContextIdx() <= ctx_idx);
if (getContextIdx() != ctx_idx) {
decRefObj(this);
return;
}
switch (getState()) {
case STATE_BLOCKED:
// we were already ran due to duplicit scheduling; the context will be
// updated thru exitContext() call on the non-blocked wait handle we
// recursively depend on
decRefObj(this);
break;
case STATE_READY:
// Recursively move all wait handles blocked by us.
getParentChain().exitContext(ctx_idx);
// Move us to the parent context.
setContextIdx(getContextIdx() - 1);
// Reschedule if still in a context.
if (isInContext()) {
if (isFastResumable()) {
getContext()->scheduleFast(this);
} else {
getContext()->schedule(this);
}
} else {
decRefObj(this);
}
break;
default:
assert(false);
}
}
