Files
ppsspp/thread/threadpool.h
T

93 lines
2.4 KiB
C++

#pragma once
#include "thread.h"
#include "base/mutex.h"
#include <functional>
#ifdef __SYMBIAN32__
#include <boost/function.hpp>
#include <boost/bind.hpp>
#include <boost/weak_ptr.hpp>
using namespace boost;
#else
#include <memory>
using namespace std;
#endif
#include <vector>
#if defined(__SYMBIAN32__) || defined(IOS) || defined(MACGNUSTD)
#ifndef __SYMBIAN32__
#include <tr1/functional>
#include <tr1/memory>
#endif
namespace std {
#ifndef __SYMBIAN32__
using tr1::bind;
using tr1::function;
using tr1::shared_ptr;
#endif
template <typename T>
inline shared_ptr<T> make_shared()
{
return shared_ptr<T>(new T());
}
template <typename T, typename Arg1>
inline shared_ptr<T> make_shared(Arg1& arg1)
{
return shared_ptr<T>(new T(arg1));
}
}
#endif
// This is the simplest possible worker implementation I can think of
// but entirely sufficient for the given purpose.
// Only handles a single item of work at a time.
class WorkerThread {
public:
WorkerThread();
~WorkerThread();
// submit a new work item
void Process(const function<void()>& work);
// wait for a submitted work item to be completed
void WaitForCompletion();
private:
std::thread *thread; // the worker thread
::condition_variable signal; // used to signal new work
::condition_variable done; // used to signal work completion
::recursive_mutex mutex, doneMutex; // associated with each respective condition variable
volatile bool active, started;
function<void()> work_; // the work to be done by this thread
void WorkFunc();
WorkerThread(const WorkerThread& other); // prevent copies
void operator =(const WorkerThread &other);
};
// A thread pool manages a set of worker threads, and allows the execution of parallel loops on them
// individual parallel loops are fully sequentialized to simplify synchronization, which should not
// be a problem as they should each use the entire system
class ThreadPool {
public:
ThreadPool(int numThreads);
// don't need a destructor, "workers" is cleared on delete,
// leading to the stopping and joining of all worker threads (RAII and all that)
void ParallelLoop(function<void(int,int)> loop, int lower, int upper);
private:
const int numThreads;
std::vector<shared_ptr<WorkerThread>> workers;
::recursive_mutex mutex; // used to sequentialize loop execution
bool workersStarted;
void StartWorkers();
ThreadPool(const ThreadPool& other); // prevent copies
void operator =(const WorkerThread &other);
};