panda3d/panda/src/event/asyncTaskManager.h
2007-06-29 21:44:55 +00:00

135 lines
3.9 KiB
C++

// Filename: asyncTaskManager.h
// Created by: drose (23Aug06)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license. You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////
#ifndef ASYNCTASKMANAGER_H
#define ASYNCTASKMANAGER_H
#include "pandabase.h"
#include "asyncTask.h"
#include "typedReferenceCount.h"
#include "thread.h"
#include "pmutex.h"
#include "conditionVarFull.h"
#include "pvector.h"
#include "pdeque.h"
#include "pStatCollector.h"
////////////////////////////////////////////////////////////////////
// Class : AsyncTaskManager
// Description : A class to manage a loose queue of isolated tasks,
// which can be performed by a background thread (in
// particular, for instance, loading a model file).
//
// The AsyncTaskManager will spawn a specified number of
// threads (possibly 0) to serve the tasks. If there
// are no threads, you must call poll() from time to
// time to serve the tasks in the main thread.
//
// Each task, once added to the FIFO queue, will
// eventually be executed by one of the threads; if the
// task then indicates it has more work to do, it will
// be replaced at the end of the queue to go around
// again.
////////////////////////////////////////////////////////////////////
class EXPCL_PANDA AsyncTaskManager : public TypedReferenceCount, public Namable {
PUBLISHED:
AsyncTaskManager(const string &name, int num_threads);
virtual ~AsyncTaskManager();
INLINE int get_num_threads() const;
BLOCKING void stop_threads();
void start_threads();
INLINE bool is_started() const;
void add(AsyncTask *task);
bool add_and_do(AsyncTask *task);
bool remove(AsyncTask *task);
bool has_task(AsyncTask *task) const;
INLINE int get_num_tasks() const;
void poll();
virtual void output(ostream &out) const;
virtual void write(ostream &out, int indent_level = 0) const;
protected:
class AsyncTaskManagerThread;
int find_task(AsyncTask *task) const;
void service_one_task(AsyncTaskManagerThread *thread);
void task_done(AsyncTask *task);
void do_start_threads();
protected:
class AsyncTaskManagerThread : public Thread {
public:
AsyncTaskManagerThread(AsyncTaskManager *manager);
virtual void thread_main();
AsyncTaskManager *_manager;
AsyncTask *_servicing;
};
typedef pvector< PT(AsyncTaskManagerThread) > Threads;
typedef pdeque< PT(AsyncTask) > Tasks;
int _num_threads;
Mutex _lock; // Protects all the following members.
ConditionVarFull _cvar; // singaled when _active or _state changes, or a task finishes.
enum State {
S_initial, // no threads yet
S_started, // threads have been started
S_shutdown // waiting for thread shutdown
};
Threads _threads;
Tasks _active;
int _num_tasks;
State _state;
static PStatCollector _task_pcollector;
static PStatCollector _wait_pcollector;
public:
static TypeHandle get_class_type() {
return _type_handle;
}
static void init_type() {
TypedReferenceCount::init_type();
register_type(_type_handle, "AsyncTaskManager",
TypedReferenceCount::get_class_type());
}
virtual TypeHandle get_type() const {
return get_class_type();
}
virtual TypeHandle force_init_type() {init_type(); return get_class_type();}
private:
static TypeHandle _type_handle;
friend class AsyncTaskManagerThread;
};
#include "asyncTaskManager.I"
#endif