156 lines
4.3 KiB
C++
156 lines
4.3 KiB
C++
/**
|
|
* PANDA 3D SOFTWARE
|
|
* Copyright (c) Carnegie Mellon University. All rights reserved.
|
|
*
|
|
* All use of this software is subject to the terms of the revised BSD
|
|
* license. You should have received a copy of this license along
|
|
* with this source code in a file named "LICENSE."
|
|
*
|
|
* @file threadSimpleImpl.h
|
|
* @author drose
|
|
* @date 2007-06-18
|
|
*/
|
|
|
|
#ifndef THREADSIMPLEIMPL_H
|
|
#define THREADSIMPLEIMPL_H
|
|
|
|
#include "pandabase.h"
|
|
#include "selectThreadImpl.h"
|
|
|
|
#ifdef THREAD_SIMPLE_IMPL
|
|
|
|
#include "pnotify.h"
|
|
#include "threadPriority.h"
|
|
#include "pvector.h"
|
|
#include "contextSwitch.h"
|
|
|
|
class Thread;
|
|
class ThreadSimpleManager;
|
|
class MutexSimpleImpl;
|
|
|
|
/**
|
|
* This is a trivial threading implementation for applications that don't
|
|
* desire full OS-managed threading. It is a user-space implementation of
|
|
* threads implemented via setjmp/longjmp, and therefore it cannot take
|
|
* advantage of multiple CPU's (the application will always run on a single
|
|
* CPU, regardless of the number of threads you spawn).
|
|
*
|
|
* However, since context switching is entirely cooperative, synchronization
|
|
* primitives like mutexes and condition variables aren't necessary, and the
|
|
* Mutex and ConditionVar classes are compiled into trivial no-op classes,
|
|
* which can reduce overhead substantially compared to a truly threaded
|
|
* application.
|
|
*
|
|
* Be sure that every thread calls Thread::consider_yield() occasionally, or
|
|
* it will starve the rest of the running threads.
|
|
*/
|
|
class EXPCL_PANDA_PIPELINE ThreadSimpleImpl {
|
|
public:
|
|
ThreadSimpleImpl(Thread *parent_obj);
|
|
~ThreadSimpleImpl();
|
|
|
|
void setup_main_thread();
|
|
bool start(ThreadPriority priority, bool joinable);
|
|
void join();
|
|
void preempt();
|
|
|
|
std::string get_unique_id() const;
|
|
|
|
static void prepare_for_exit();
|
|
|
|
INLINE static Thread *get_current_thread();
|
|
INLINE bool is_same_system_thread() const;
|
|
|
|
INLINE static void bind_thread(Thread *thread);
|
|
INLINE static bool is_threading_supported();
|
|
static bool is_true_threads();
|
|
INLINE static bool is_simple_threads();
|
|
INLINE static void sleep(double seconds);
|
|
INLINE static void yield();
|
|
INLINE static void consider_yield();
|
|
|
|
void sleep_this(double seconds);
|
|
void yield_this(bool volunteer);
|
|
INLINE void consider_yield_this();
|
|
|
|
INLINE double get_wake_time() const;
|
|
|
|
INLINE static void write_status(std::ostream &out);
|
|
|
|
private:
|
|
static void st_begin_thread(void *data);
|
|
void begin_thread();
|
|
|
|
private:
|
|
enum ThreadStatus {
|
|
TS_new,
|
|
TS_running,
|
|
TS_finished,
|
|
TS_killed,
|
|
};
|
|
|
|
static int _next_unique_id;
|
|
int _unique_id;
|
|
Thread *_parent_obj;
|
|
bool _joinable;
|
|
ThreadStatus _status;
|
|
ThreadPriority _priority;
|
|
|
|
// The relative weight of this thread, relative to other threads, in
|
|
// priority.
|
|
double _priority_weight;
|
|
|
|
// The amount of time this thread has run recently.
|
|
unsigned int _run_ticks;
|
|
|
|
// This is the time at which the currently-running thread started execution.
|
|
double _start_time;
|
|
|
|
// This is the time at which the currently-running thread should yield.
|
|
double _stop_time;
|
|
|
|
// This records the time at which a sleeping thread should wake up.
|
|
double _wake_time;
|
|
|
|
ThreadContext *_context;
|
|
unsigned char *_stack;
|
|
size_t _stack_size;
|
|
|
|
#ifdef HAVE_PYTHON
|
|
// If we might be working with Python, we have to manage the Python thread
|
|
// state as we switch contexts.
|
|
PyThreadState *_python_state;
|
|
#endif // HAVE_PYTHON
|
|
|
|
// Threads that are waiting for this thread to finish.
|
|
typedef pvector<ThreadSimpleImpl *> JoiningThreads;
|
|
JoiningThreads _joining_threads;
|
|
|
|
ThreadSimpleManager *_manager;
|
|
static ThreadSimpleImpl *volatile _st_this;
|
|
|
|
// We may not mix-and-match OS threads with Panda's SIMPLE_THREADS. If we
|
|
// ever get a Panda context switch request from a different OS thread than
|
|
// the thread we think we should be in, that's a serious error that may
|
|
// cause major consequences. For this reason, we store the OS thread's
|
|
// current thread ID here when the thread is constructed, and insist that it
|
|
// never changes during the lifetime of the thread.
|
|
#ifdef HAVE_POSIX_THREADS
|
|
pthread_t _posix_system_thread_id;
|
|
#endif
|
|
#ifdef WIN32
|
|
DWORD _win32_system_thread_id;
|
|
#endif
|
|
|
|
friend class ThreadSimpleManager;
|
|
};
|
|
|
|
// We include this down here to avoid the circularity problem.
|
|
/* okcircular */
|
|
#include "threadSimpleManager.h"
|
|
|
|
#include "threadSimpleImpl.I"
|
|
|
|
#endif // THREAD_SIMPLE_IMPL
|
|
|
|
#endif
|