u64 RuntimeQueue::Queue(
ThreadId const& targetThread, RuntimeTask&& task, rqe& ec)
{
if(!VerifyTask(task, ec))
return 0;
if(task.flags & RuntimeTask::Periodic)
{
task.time = RuntimeTask::clock::now() + task.interval;
}
if(!context->globalMod.try_lock())
{
ec = RQE::ShuttingDown;
return 0;
}
auto thread_id = targetThread.hash();
auto q_it = context->queues.find(thread_id);
if(q_it == context->queues.end())
{
context->globalMod.unlock();
ec = RQE::InvalidQueue;
return 0;
} else
{
context->globalMod.unlock();
return Queue(&q_it->second, std::move(task), ec);
}
}
bool RuntimeQueue::Block(const ThreadId& targetThread, u64 taskId, rqe& ec)
{
if(context->shutdownFlag.load())
{
ec = RQE::ShuttingDown;
return false;
}
DProfContext __(RQ_API "Blocking task");
auto thread_id = targetThread.hash();
RuntimeQueue* pQueue = nullptr;
{
Lock _(context->globalMod);
auto q_it = context->queues.find(thread_id);
if(q_it == context->queues.end())
{
ec = RQE::InvalidQueue;
return false;
}
pQueue = &(*q_it).second;
}
auto& queue = *pQueue;
RuntimeTask const* task = nullptr;
szptr idx = 0;
if(!(task = GetTask(queue.mTasks, taskId, ec, &idx)))
{
ec = RQE::InvalidTaskId;
return false;
}
{
/* We do this check in case we are executing in the queue */
/* Otherwise we deadlock */
RecLock ___(queue.mTasksLock);
if(!queue.mTasks[idx].alive)
{
ec = RQE::TaskAlreadyBlocked;
return false;
}
auto currentBase = RuntimeTask::clock::now();
auto previousNextTime = queue.timeTillNext(currentBase);
queue.mTasks[idx].alive = false;
NotifyThread(context, thread_id, previousNextTime, currentBase);
}
return true;
}
bool RuntimeQueue::CancelTask(const ThreadId& targetThread, u64 taskId, rqe& ec)
{
if(context->shutdownFlag.load())
{
ec = RQE::ShuttingDown;
return false;
}
auto thread_id = targetThread.hash();
RuntimeQueue* pQueue = nullptr;
{
Lock _(context->globalMod);
auto q_it = context->queues.find(thread_id);
if(q_it == context->queues.end())
{
ec = RQE::InvalidQueue;
return false;
}
pQueue = &(*q_it).second;
}
auto& queue = *pQueue;
{
RecLock _(queue.mTasksLock);
RuntimeTask const* task = nullptr;
szptr idx = 0;
if(!(task = GetTask(queue.mTasks, taskId, ec, &idx)))
{
ec = RQE::InvalidTaskId;
return false;
}
queue.mTasks[idx].alive = false;
queue.mTasks[idx].to_dispose = true;
auto currentBase = RuntimeTask::clock::now();
auto previousNextTime = queue.timeTillNext(currentBase);
NotifyThread(context, thread_id, previousNextTime, currentBase);
}
return true;
}
void RuntimeQueue::AwaitTask(const ThreadId& targetThread, u64 taskId, rqe& ec)
{
if(taskId == 0)
return;
if(context->shutdownFlag.load())
{
ec = RQE::ShuttingDown;
return;
}
if(ThreadId().hash() == targetThread.hash())
{
ec = RQE::SameThread;
return;
}
RuntimeQueue const* queueRef = nullptr;
{
Lock _(context->globalMod);
auto queue = context->queues.find(targetThread.hash());
/* If thread has no queue, return */
if(queue == context->queues.end())
{
ec = RQE::InvalidQueue;
return;
}
queueRef = &queue->second;
}
RuntimeTask const* task = nullptr;
szptr idx = 0;
if(!(task = GetTask(queueRef->mTasks, taskId, ec, &idx)))
{
ec = RQE::InvalidTaskId;
return;
}
/* We cannot reliably await periodic tasks */
if(task->flags & RuntimeTask::Periodic)
{
ec = RQE::IncompatibleTaskAwait;
return;
}
/* Do not await a past event */
if(!(task->flags & RuntimeTask::Immediate) &&
RuntimeTask::clock::now() > task->time)
{
ec = RQE::ExpiredTaskDeadline;
return;
}
DProfContext _(RQ_API "Awaiting task...");
CurrentThread::sleep_until(task->time);
{
DProfContext _(RQ_API "Busy-waiting task");
/* I know this is bad, but we must await the task */
while(queueRef->mTasks[idx].alive)
CurrentThread::yield();
}
}