bool TaskScheduler::Initialize(uint fiberPoolSize, GlobalArgs *globalArgs) {
for (uint i = 0; i < fiberPoolSize; ++i) {
FiberType newFiber = FTLCreateFiber(524288, FiberStart, reinterpret_cast<fiber_arg_t>(globalArgs));
m_fiberPool.enqueue(newFiber);
}
// Create an additional thread for each logical processor
m_numThreads = FTLGetNumHardwareThreads();
m_threads = new ThreadType[m_numThreads];
m_numActiveWorkerThreads.store((uint)m_numThreads - 1);
// Create switching fibers for this thread
m_fiberSwitchingFibers[FTLGetCurrentThreadId()] = FTLCreateFiber(FTL_HELPER_FIBER_STACK_SIZE, FiberSwitchStart, reinterpret_cast<fiber_arg_t>(&globalArgs->g_taskScheduler));
m_counterWaitingFibers[FTLGetCurrentThreadId()] = FTLCreateFiber(FTL_HELPER_FIBER_STACK_SIZE, CounterWaitStart, reinterpret_cast<fiber_arg_t>(&globalArgs->g_taskScheduler));
// Set the affinity for the current thread and convert it to a fiber
FTLSetCurrentThreadAffinity(1);
m_threads[0] = FTLGetCurrentThread();
FiberType mainThreadFiber = FTLConvertThreadToFiber();
FTLSetCurrentFiber(mainThreadFiber);
// Create the remaining threads
for (uint i = 1; i < m_numThreads; ++i) {
ThreadStartArgs *threadArgs = new ThreadStartArgs();
threadArgs->globalArgs = globalArgs;
threadArgs->threadIndex = i;
ThreadType threadHandle;
if (!FTLCreateThread(&threadHandle, 524288, ThreadStart, threadArgs, i)) {
return false;
}
m_threads[i] = threadHandle;
}
return true;
}
void TaskScheduler::Run(uint fiberPoolSize, TaskFunction mainTask, void *mainTaskArg) {
// Create and populate the fiber pool
m_fiberPoolSize = fiberPoolSize;
m_fibers = new Fiber[fiberPoolSize];
m_freeFibers = new std::atomic<bool>[fiberPoolSize];
m_waitingFibers = new std::atomic<bool>[fiberPoolSize];
for (uint i = 0; i < fiberPoolSize; ++i) {
m_fibers[i] = std::move(Fiber(512000, FiberStart, reinterpret_cast<std::intptr_t>(this)));
m_freeFibers[i].store(true, std::memory_order_release);
m_waitingFibers[i].store(false, std::memory_order_release);
}
m_waitingBundles.resize(fiberPoolSize);
// 1 thread for each logical processor
m_numThreads = FTLGetNumHardwareThreads();
// Initialize all the things
m_quit.store(false, std::memory_order_release);
m_threads.resize(m_numThreads);
m_tls.resize(m_numThreads);
// Set the properties for the current thread
FTLSetCurrentThreadAffinity(1);
m_threads[0] = FTLGetCurrentThread();
// Create the remaining threads
for (uint i = 1; i < m_numThreads; ++i) {
ThreadStartArgs *threadArgs = new ThreadStartArgs();
threadArgs->taskScheduler = this;
threadArgs->threadIndex = i;
if (!FTLCreateThread(524288, ThreadStart, threadArgs, i, &m_threads[i])) {
printf("Error: Failed to create all the worker threads");
return;
}
}
// Start the main task
// Get a free fiber
std::size_t freeFiberIndex = GetNextFreeFiberIndex();
Fiber *freeFiber = &m_fibers[freeFiberIndex];
// Repurpose it as the main task fiber and switch to it
MainFiberStartArgs mainFiberArgs;
mainFiberArgs.taskScheduler = this;
mainFiberArgs.MainTask = mainTask;
mainFiberArgs.Arg = mainTaskArg;
freeFiber->Reset(MainFiberStart, reinterpret_cast<std::intptr_t>(&mainFiberArgs));
m_tls[0].CurrentFiberIndex = freeFiberIndex;
m_tls[0].ThreadFiber.SwitchToFiber(freeFiber);
// And we're back
// Wait for the worker threads to finish
for (std::size_t i = 1; i < m_numThreads; ++i) {
FTLJoinThread(m_threads[i]);
}
return;
}
