767e374dce
Since Embree v3.13.0 supports AARCH64, switch back to the official repo instead of using Embree-aarch64. `thirdparty/embree/patches/godot-changes.patch` should now contain an accurate diff of the changes done to the library.
385 lines
12 KiB
C++
385 lines
12 KiB
C++
// Copyright 2009-2021 Intel Corporation
|
|
// SPDX-License-Identifier: Apache-2.0
|
|
|
|
#pragma once
|
|
|
|
#include "../sys/platform.h"
|
|
#include "../sys/alloc.h"
|
|
#include "../sys/barrier.h"
|
|
#include "../sys/thread.h"
|
|
#include "../sys/mutex.h"
|
|
#include "../sys/condition.h"
|
|
#include "../sys/ref.h"
|
|
#include "../sys/atomic.h"
|
|
#include "../math/range.h"
|
|
#include "../../include/embree3/rtcore.h"
|
|
|
|
#include <list>
|
|
|
|
namespace embree
|
|
{
|
|
|
|
/* The tasking system exports some symbols to be used by the tutorials. Thus we
|
|
hide is also in the API namespace when requested. */
|
|
RTC_NAMESPACE_BEGIN
|
|
|
|
struct TaskScheduler : public RefCount
|
|
{
|
|
ALIGNED_STRUCT_(64);
|
|
friend class Device;
|
|
|
|
static const size_t TASK_STACK_SIZE = 4*1024; //!< task structure stack
|
|
static const size_t CLOSURE_STACK_SIZE = 512*1024; //!< stack for task closures
|
|
|
|
struct Thread;
|
|
|
|
/*! virtual interface for all tasks */
|
|
struct TaskFunction {
|
|
virtual void execute() = 0;
|
|
};
|
|
|
|
/*! builds a task interface from a closure */
|
|
template<typename Closure>
|
|
struct ClosureTaskFunction : public TaskFunction
|
|
{
|
|
Closure closure;
|
|
__forceinline ClosureTaskFunction (const Closure& closure) : closure(closure) {}
|
|
void execute() { closure(); };
|
|
};
|
|
|
|
struct __aligned(64) Task
|
|
{
|
|
/*! states a task can be in */
|
|
enum { DONE, INITIALIZED };
|
|
|
|
/*! switch from one state to another */
|
|
__forceinline void switch_state(int from, int to)
|
|
{
|
|
__memory_barrier();
|
|
MAYBE_UNUSED bool success = state.compare_exchange_strong(from,to);
|
|
assert(success);
|
|
}
|
|
|
|
/*! try to switch from one state to another */
|
|
__forceinline bool try_switch_state(int from, int to) {
|
|
__memory_barrier();
|
|
return state.compare_exchange_strong(from,to);
|
|
}
|
|
|
|
/*! increment/decrement dependency counter */
|
|
void add_dependencies(int n) {
|
|
dependencies+=n;
|
|
}
|
|
|
|
/*! initialize all tasks to DONE state by default */
|
|
__forceinline Task()
|
|
: state(DONE) {}
|
|
|
|
/*! construction of new task */
|
|
__forceinline Task (TaskFunction* closure, Task* parent, size_t stackPtr, size_t N)
|
|
: dependencies(1), stealable(true), closure(closure), parent(parent), stackPtr(stackPtr), N(N)
|
|
{
|
|
if (parent) parent->add_dependencies(+1);
|
|
switch_state(DONE,INITIALIZED);
|
|
}
|
|
|
|
/*! construction of stolen task, stealing thread will decrement initial dependency */
|
|
__forceinline Task (TaskFunction* closure, Task* parent)
|
|
: dependencies(1), stealable(false), closure(closure), parent(parent), stackPtr(-1), N(1)
|
|
{
|
|
switch_state(DONE,INITIALIZED);
|
|
}
|
|
|
|
/*! try to steal this task */
|
|
bool try_steal(Task& child)
|
|
{
|
|
if (!stealable) return false;
|
|
if (!try_switch_state(INITIALIZED,DONE)) return false;
|
|
new (&child) Task(closure, this);
|
|
return true;
|
|
}
|
|
|
|
/*! run this task */
|
|
dll_export void run(Thread& thread);
|
|
|
|
void run_internal(Thread& thread);
|
|
|
|
public:
|
|
std::atomic<int> state; //!< state this task is in
|
|
std::atomic<int> dependencies; //!< dependencies to wait for
|
|
std::atomic<bool> stealable; //!< true if task can be stolen
|
|
TaskFunction* closure; //!< the closure to execute
|
|
Task* parent; //!< parent task to signal when we are finished
|
|
size_t stackPtr; //!< stack location where closure is stored
|
|
size_t N; //!< approximative size of task
|
|
};
|
|
|
|
struct TaskQueue
|
|
{
|
|
TaskQueue ()
|
|
: left(0), right(0), stackPtr(0) {}
|
|
|
|
__forceinline void* alloc(size_t bytes, size_t align = 64)
|
|
{
|
|
size_t ofs = bytes + ((align - stackPtr) & (align-1));
|
|
if (stackPtr + ofs > CLOSURE_STACK_SIZE)
|
|
// -- GODOT start --
|
|
// throw std::runtime_error("closure stack overflow");
|
|
abort();
|
|
// -- GODOT end --
|
|
stackPtr += ofs;
|
|
return &stack[stackPtr-bytes];
|
|
}
|
|
|
|
template<typename Closure>
|
|
__forceinline void push_right(Thread& thread, const size_t size, const Closure& closure)
|
|
{
|
|
if (right >= TASK_STACK_SIZE)
|
|
// -- GODOT start --
|
|
// throw std::runtime_error("task stack overflow");
|
|
abort();
|
|
// -- GODOT end --
|
|
|
|
/* allocate new task on right side of stack */
|
|
size_t oldStackPtr = stackPtr;
|
|
TaskFunction* func = new (alloc(sizeof(ClosureTaskFunction<Closure>))) ClosureTaskFunction<Closure>(closure);
|
|
new (&tasks[right]) Task(func,thread.task,oldStackPtr,size);
|
|
right++;
|
|
|
|
/* also move left pointer */
|
|
if (left >= right-1) left = right-1;
|
|
}
|
|
|
|
dll_export bool execute_local(Thread& thread, Task* parent);
|
|
bool execute_local_internal(Thread& thread, Task* parent);
|
|
bool steal(Thread& thread);
|
|
size_t getTaskSizeAtLeft();
|
|
|
|
bool empty() { return right == 0; }
|
|
|
|
public:
|
|
|
|
/* task stack */
|
|
Task tasks[TASK_STACK_SIZE];
|
|
__aligned(64) std::atomic<size_t> left; //!< threads steal from left
|
|
__aligned(64) std::atomic<size_t> right; //!< new tasks are added to the right
|
|
|
|
/* closure stack */
|
|
__aligned(64) char stack[CLOSURE_STACK_SIZE];
|
|
size_t stackPtr;
|
|
};
|
|
|
|
/*! thread local structure for each thread */
|
|
struct Thread
|
|
{
|
|
ALIGNED_STRUCT_(64);
|
|
|
|
Thread (size_t threadIndex, const Ref<TaskScheduler>& scheduler)
|
|
: threadIndex(threadIndex), task(nullptr), scheduler(scheduler) {}
|
|
|
|
__forceinline size_t threadCount() {
|
|
return scheduler->threadCounter;
|
|
}
|
|
|
|
size_t threadIndex; //!< ID of this thread
|
|
TaskQueue tasks; //!< local task queue
|
|
Task* task; //!< current active task
|
|
Ref<TaskScheduler> scheduler; //!< pointer to task scheduler
|
|
};
|
|
|
|
/*! pool of worker threads */
|
|
struct ThreadPool
|
|
{
|
|
ThreadPool (bool set_affinity);
|
|
~ThreadPool ();
|
|
|
|
/*! starts the threads */
|
|
dll_export void startThreads();
|
|
|
|
/*! sets number of threads to use */
|
|
void setNumThreads(size_t numThreads, bool startThreads = false);
|
|
|
|
/*! adds a task scheduler object for scheduling */
|
|
dll_export void add(const Ref<TaskScheduler>& scheduler);
|
|
|
|
/*! remove the task scheduler object again */
|
|
dll_export void remove(const Ref<TaskScheduler>& scheduler);
|
|
|
|
/*! returns number of threads of the thread pool */
|
|
size_t size() const { return numThreads; }
|
|
|
|
/*! main loop for all threads */
|
|
void thread_loop(size_t threadIndex);
|
|
|
|
private:
|
|
std::atomic<size_t> numThreads;
|
|
std::atomic<size_t> numThreadsRunning;
|
|
bool set_affinity;
|
|
std::atomic<bool> running;
|
|
std::vector<thread_t> threads;
|
|
|
|
private:
|
|
MutexSys mutex;
|
|
ConditionSys condition;
|
|
std::list<Ref<TaskScheduler> > schedulers;
|
|
};
|
|
|
|
TaskScheduler ();
|
|
~TaskScheduler ();
|
|
|
|
/*! initializes the task scheduler */
|
|
static void create(size_t numThreads, bool set_affinity, bool start_threads);
|
|
|
|
/*! destroys the task scheduler again */
|
|
static void destroy();
|
|
|
|
/*! lets new worker threads join the tasking system */
|
|
void join();
|
|
void reset();
|
|
|
|
/*! let a worker thread allocate a thread index */
|
|
dll_export ssize_t allocThreadIndex();
|
|
|
|
/*! wait for some number of threads available (threadCount includes main thread) */
|
|
void wait_for_threads(size_t threadCount);
|
|
|
|
/*! thread loop for all worker threads */
|
|
// -- GODOT start --
|
|
// std::exception_ptr thread_loop(size_t threadIndex);
|
|
void thread_loop(size_t threadIndex);
|
|
// -- GODOT end --
|
|
|
|
/*! steals a task from a different thread */
|
|
bool steal_from_other_threads(Thread& thread);
|
|
|
|
template<typename Predicate, typename Body>
|
|
static void steal_loop(Thread& thread, const Predicate& pred, const Body& body);
|
|
|
|
/* spawn a new task at the top of the threads task stack */
|
|
template<typename Closure>
|
|
void spawn_root(const Closure& closure, size_t size = 1, bool useThreadPool = true)
|
|
{
|
|
if (useThreadPool) startThreads();
|
|
|
|
size_t threadIndex = allocThreadIndex();
|
|
std::unique_ptr<Thread> mthread(new Thread(threadIndex,this)); // too large for stack allocation
|
|
Thread& thread = *mthread;
|
|
assert(threadLocal[threadIndex].load() == nullptr);
|
|
threadLocal[threadIndex] = &thread;
|
|
Thread* oldThread = swapThread(&thread);
|
|
thread.tasks.push_right(thread,size,closure);
|
|
{
|
|
Lock<MutexSys> lock(mutex);
|
|
anyTasksRunning++;
|
|
hasRootTask = true;
|
|
condition.notify_all();
|
|
}
|
|
|
|
if (useThreadPool) addScheduler(this);
|
|
|
|
while (thread.tasks.execute_local(thread,nullptr));
|
|
anyTasksRunning--;
|
|
if (useThreadPool) removeScheduler(this);
|
|
|
|
threadLocal[threadIndex] = nullptr;
|
|
swapThread(oldThread);
|
|
|
|
/* remember exception to throw */
|
|
std::exception_ptr except = nullptr;
|
|
if (cancellingException != nullptr) except = cancellingException;
|
|
|
|
/* wait for all threads to terminate */
|
|
threadCounter--;
|
|
while (threadCounter > 0) yield();
|
|
cancellingException = nullptr;
|
|
|
|
/* re-throw proper exception */
|
|
if (except != nullptr)
|
|
std::rethrow_exception(except);
|
|
}
|
|
|
|
/* spawn a new task at the top of the threads task stack */
|
|
template<typename Closure>
|
|
static __forceinline void spawn(size_t size, const Closure& closure)
|
|
{
|
|
Thread* thread = TaskScheduler::thread();
|
|
if (likely(thread != nullptr)) thread->tasks.push_right(*thread,size,closure);
|
|
else instance()->spawn_root(closure,size);
|
|
}
|
|
|
|
/* spawn a new task at the top of the threads task stack */
|
|
template<typename Closure>
|
|
static __forceinline void spawn(const Closure& closure) {
|
|
spawn(1,closure);
|
|
}
|
|
|
|
/* spawn a new task set */
|
|
template<typename Index, typename Closure>
|
|
static void spawn(const Index begin, const Index end, const Index blockSize, const Closure& closure)
|
|
{
|
|
spawn(end-begin, [=]()
|
|
{
|
|
if (end-begin <= blockSize) {
|
|
return closure(range<Index>(begin,end));
|
|
}
|
|
const Index center = (begin+end)/2;
|
|
spawn(begin,center,blockSize,closure);
|
|
spawn(center,end ,blockSize,closure);
|
|
wait();
|
|
});
|
|
}
|
|
|
|
/* work on spawned subtasks and wait until all have finished */
|
|
dll_export static bool wait();
|
|
|
|
/* returns the ID of the current thread */
|
|
dll_export static size_t threadID();
|
|
|
|
/* returns the index (0..threadCount-1) of the current thread */
|
|
dll_export static size_t threadIndex();
|
|
|
|
/* returns the total number of threads */
|
|
dll_export static size_t threadCount();
|
|
|
|
private:
|
|
|
|
/* returns the thread local task list of this worker thread */
|
|
dll_export static Thread* thread();
|
|
|
|
/* sets the thread local task list of this worker thread */
|
|
dll_export static Thread* swapThread(Thread* thread);
|
|
|
|
/*! returns the taskscheduler object to be used by the master thread */
|
|
dll_export static TaskScheduler* instance();
|
|
|
|
/*! starts the threads */
|
|
dll_export static void startThreads();
|
|
|
|
/*! adds a task scheduler object for scheduling */
|
|
dll_export static void addScheduler(const Ref<TaskScheduler>& scheduler);
|
|
|
|
/*! remove the task scheduler object again */
|
|
dll_export static void removeScheduler(const Ref<TaskScheduler>& scheduler);
|
|
|
|
private:
|
|
std::vector<atomic<Thread*>> threadLocal;
|
|
std::atomic<size_t> threadCounter;
|
|
std::atomic<size_t> anyTasksRunning;
|
|
std::atomic<bool> hasRootTask;
|
|
std::exception_ptr cancellingException;
|
|
MutexSys mutex;
|
|
ConditionSys condition;
|
|
|
|
private:
|
|
static size_t g_numThreads;
|
|
static __thread TaskScheduler* g_instance;
|
|
static __thread Thread* thread_local_thread;
|
|
static ThreadPool* threadPool;
|
|
};
|
|
|
|
RTC_NAMESPACE_END
|
|
|
|
#if defined(RTC_NAMESPACE)
|
|
using RTC_NAMESPACE::TaskScheduler;
|
|
#endif
|
|
}
|