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SingularityViewer/indra/aistatemachine/aistatemachine.h
2014-08-25 18:39:46 +02:00

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/**
* @file aistatemachine.h
* @brief State machine base class
*
* Copyright (c) 2010 - 2013, Aleric Inglewood.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution.
*
* CHANGELOG
* and additional copyright holders.
*
* 01/03/2010
* Initial version, written by Aleric Inglewood @ SL
*
* 28/02/2013
* Rewritten from scratch to fully support threading.
*/
#ifndef AISTATEMACHINE_H
#define AISTATEMACHINE_H
#include "aithreadsafe.h"
#include <llpointer.h>
#include "lltimer.h"
#include <list>
#include <boost/signals2.hpp>
class AIConditionBase;
class AIStateMachine;
class AIEngine
{
private:
struct QueueElementComp;
class QueueElement {
private:
LLPointer<AIStateMachine> mStateMachine;
public:
QueueElement(AIStateMachine* statemachine) : mStateMachine(statemachine) { }
friend bool operator==(QueueElement const& e1, QueueElement const& e2) { return e1.mStateMachine == e2.mStateMachine; }
friend bool operator!=(QueueElement const& e1, QueueElement const& e2) { return e1.mStateMachine != e2.mStateMachine; }
friend struct QueueElementComp;
AIStateMachine const& statemachine(void) const { return *mStateMachine; }
AIStateMachine& statemachine(void) { return *mStateMachine; }
};
struct QueueElementComp {
inline bool operator()(QueueElement const& e1, QueueElement const& e2) const;
};
public:
typedef std::list<QueueElement> queued_type;
struct engine_state_type {
queued_type list;
bool waiting;
engine_state_type(void) : waiting(false) { }
};
private:
AIThreadSafeSimpleDC<engine_state_type, LLCondition> mEngineState;
typedef AIAccessConst<engine_state_type, LLCondition> engine_state_type_crat;
typedef AIAccess<engine_state_type, LLCondition> engine_state_type_rat;
typedef AIAccess<engine_state_type, LLCondition> engine_state_type_wat;
char const* mName;
static U64 sMaxCount;
public:
AIEngine(char const* name) : mName(name) { }
void add(AIStateMachine* state_machine);
void mainloop(void);
void threadloop(void);
void wake_up(void);
void flush(void);
char const* name(void) const { return mName; }
static void setMaxCount(F32 StateMachineMaxTime);
};
extern AIEngine gMainThreadEngine;
extern AIEngine gStateMachineThreadEngine;
#ifndef STATE_MACHINE_PROFILING
#ifndef LL_RELEASE_FOR_DOWNLOAD
#define STATE_MACHINE_PROFILING 1
#endif
#endif
class AIStateMachine : public LLThreadSafeRefCount
{
public:
typedef U32 state_type; //!< The type of run_state
// A simple timer class that will calculate time delta between ctor and GetTimerData call.
// Time data is stored as a nested TimeData object.
// If STATE_MACHINE_PROFILING is defined then a stack of all StateTimers from root is maintained for debug output.
class StateTimerBase
{
public:
class TimeData
{
friend class StateTimerBase;
public:
TimeData() : mStart(-1), mEnd(-1) {}
U64 GetDuration() { return mEnd - mStart; }
private:
U64 mStart, mEnd;
#if !STATE_MACHINE_PROFILING
TimeData(const std::string& name) : mStart(get_clock_count()), mEnd(get_clock_count()) {}
#else
TimeData(const std::string& name) : mName(name), mStart(get_clock_count()), mEnd(get_clock_count()) {}
void DumpTimer(std::ostringstream& msg, std::string prefix);
std::vector<TimeData> mChildren;
std::string mName;
static TimeData sRoot;
#endif
};
#if !STATE_MACHINE_PROFILING
StateTimerBase(const std::string& name) : mData(name) {}
~StateTimerBase() {}
protected:
TimeData mData;
// Return a copy of the underlying timer data.
// This allows the data live beyond the scope of the state timer.
public:
const TimeData GetTimerData()
{
mData.mEnd = get_clock_count(); //set mEnd to current time, since GetTimerData() will always be called before the dtor, obv.
return mData;
}
#else
protected:
// Ctors/dtors are hidden. Only StateTimerRoot and StateTimer are permitted to access them.
StateTimerBase() : mData(NULL) {}
~StateTimerBase()
{
// If mData is null then the timer was not registered due to being in the wrong thread or the root timer wasn't in the expected state.
if (!mData)
return;
mData->mEnd = get_clock_count();
mTimerStack.pop_back();
}
// Also hide internals from everything except StateTimerRoot and StateTimer
bool AddAsRoot(const std::string& name)
{
if (!is_main_thread())
return true; //Ignoring this timer, but pretending it was added.
if (!mTimerStack.empty())
return false;
TimeData::sRoot = TimeData(name);
mData = &TimeData::sRoot;
mData->mChildren.clear();
mTimerStack.push_back(this);
return true;
}
bool AddAsChild(const std::string& name)
{
if (!is_main_thread())
return true; //Ignoring this timer, but pretending it was added.
if (mTimerStack.empty())
return false;
mTimerStack.back()->mData->mChildren.push_back(TimeData(name));
mData = &mTimerStack.back()->mData->mChildren.back();
mTimerStack.push_back(this);
return true;
}
TimeData* mData;
static std::vector<StateTimerBase*> mTimerStack;
public:
// Debug spew
static void DumpTimers(std::ostringstream& msg)
{
TimeData::sRoot.DumpTimer(msg, "");
}
// Return a copy of the underlying timer data.
// This allows the data live beyond the scope of the state timer.
const TimeData GetTimerData() const
{
if (mData)
{
TimeData ret = *mData;
ret.mEnd = get_clock_count(); //set mEnd to current time, since GetTimerData() will always be called before the dtor, obv.
return ret;
}
return TimeData();
}
#endif
};
public:
#if !STATE_MACHINE_PROFILING
typedef StateTimerBase StateTimerRoot;
typedef StateTimerBase StateTimer;
#else
class StateTimerRoot : public StateTimerBase
{ //A StateTimerRoot can become a child if a root already exists.
public:
StateTimerRoot(const std::string& name)
{
if(!AddAsRoot(name))
AddAsChild(name);
}
};
class StateTimer : public StateTimerBase
{ //A StateTimer can never become a root
public:
StateTimer(const std::string& name)
{
AddAsChild(name);
}
};
#endif
protected:
// The type of event that causes multiplex() to be called.
enum event_type {
initial_run,
schedule_run,
normal_run,
insert_abort
};
// The type of mState
enum base_state_type {
bs_reset, // Idle state before run() is called. Reference count is zero (except for a possible external LLPointer).
bs_initialize, // State after run() and before/during initialize_impl().
bs_multiplex, // State after initialize_impl() before finish() or abort().
bs_abort,
bs_finish,
bs_callback,
bs_killed
};
public:
static state_type const max_state = bs_killed + 1;
protected:
struct multiplex_state_type {
base_state_type base_state;
AIEngine* current_engine; // Current engine.
multiplex_state_type(void) : base_state(bs_reset), current_engine(NULL) { }
};
struct sub_state_type {
state_type run_state;
state_type advance_state;
AIConditionBase* blocked;
bool reset;
bool need_run;
bool idle;
bool skip_idle;
bool aborted;
bool finished;
};
private:
// Base state.
AIThreadSafeSimpleDC<multiplex_state_type> mState;
typedef AIAccessConst<multiplex_state_type> multiplex_state_type_crat;
typedef AIAccess<multiplex_state_type> multiplex_state_type_rat;
typedef AIAccess<multiplex_state_type> multiplex_state_type_wat;
protected:
// Sub state.
AIThreadSafeSimpleDC<sub_state_type> mSubState;
typedef AIAccessConst<sub_state_type> sub_state_type_crat;
typedef AIAccess<sub_state_type> sub_state_type_rat;
typedef AIAccess<sub_state_type> sub_state_type_wat;
private:
// Mutex protecting everything below and making sure only one thread runs the state machine at a time.
LLMutex mMultiplexMutex;
// Mutex that is locked while calling *_impl() functions and the call back.
LLMutex mRunMutex;
S64 mSleep; //!< Non-zero while the state machine is sleeping.
// Callback facilities.
// From within an other state machine:
LLPointer<AIStateMachine> mParent; // The parent object that started this state machine, or NULL if there isn't any.
state_type mNewParentState; // The state at which the parent should continue upon a successful finish.
bool mAbortParent; // If true, abort parent on abort(). Otherwise continue as normal.
bool mOnAbortSignalParent; // If true and mAbortParent is false, change state of parent even on abort.
// From outside a state machine:
struct callback_type {
typedef boost::signals2::signal<void (bool)> signal_type;
callback_type(signal_type::slot_type const& slot) { connection = signal.connect(slot); }
~callback_type() { connection.disconnect(); }
void callback(bool success) const { signal(success); }
private:
boost::signals2::connection connection;
signal_type signal;
};
callback_type* mCallback; // Pointer to signal/connection, or NULL when not connected.
// Engine stuff.
AIEngine* mDefaultEngine; // Default engine.
AIEngine* mYieldEngine; // Requested engine.
#ifdef SHOW_ASSERT
// Debug stuff.
AIThreadID mThreadId; // The thread currently running multiplex().
base_state_type mDebugLastState; // The previous state that multiplex() had a normal run with.
bool mDebugShouldRun; // Set if we found evidence that we should indeed call multiplex_impl().
bool mDebugAborted; // True when abort() was called.
bool mDebugContPending; // True while cont() was called by not handled yet.
bool mDebugSetStatePending; // True while set_state() was called by not handled yet.
bool mDebugAdvanceStatePending; // True while advance_state() was called by not handled yet.
bool mDebugRefCalled; // True when ref() is called (or will be called within the critial area of mMultiplexMutex).
#endif
#ifdef CWDEBUG
protected:
bool mSMDebug; // Print debug output only when true.
#endif
private:
U64 mRuntime; // Total time spent running in the main thread (in clocks).
public:
AIStateMachine(CWD_ONLY(bool debug)) : mCallback(NULL), mDefaultEngine(NULL), mYieldEngine(NULL),
#ifdef SHOW_ASSERT
mThreadId(AIThreadID::none), mDebugLastState(bs_killed), mDebugShouldRun(false), mDebugAborted(false), mDebugContPending(false),
mDebugSetStatePending(false), mDebugAdvanceStatePending(false), mDebugRefCalled(false),
#endif
#ifdef CWDEBUG
mSMDebug(debug),
#endif
mRuntime(0)
{ }
protected:
// The user should call finish() (or abort(), or kill() from the call back when finish_impl() calls run()),
// not delete a class derived from AIStateMachine directly. Deleting it directly before calling run() is
// ok however.
virtual ~AIStateMachine()
{
#ifdef SHOW_ASSERT
base_state_type state = multiplex_state_type_rat(mState)->base_state;
llassert(state == bs_killed || state == bs_reset);
#endif
}
public:
// These functions may be called directly after creation, or from within finish_impl(), or from the call back function.
void run(AIStateMachine* parent, state_type new_parent_state, bool abort_parent = true, bool on_abort_signal_parent = true, AIEngine* default_engine = &gMainThreadEngine);
void run(callback_type::signal_type::slot_type const& slot, AIEngine* default_engine = &gMainThreadEngine);
void run(void) { run(NULL, 0, false, true, mDefaultEngine); }
// This function may only be called from the call back function (and cancels a call to run() from finish_impl()).
void kill(void);
protected:
// This function can be called from initialize_impl() and multiplex_impl() (both called from within multiplex()).
void set_state(state_type new_state); // Run this state the NEXT loop.
// These functions can only be called from within multiplex_impl().
void idle(void); // Go idle unless cont() or advance_state() were called since the start of the current loop, or until they are called.
void wait(AIConditionBase& condition); // The same as idle(), but wake up when AICondition<T>::signal() is called.
void finish(void); // Mark that the state machine finished and schedule the call back.
void yield(void); // Yield to give CPU to other state machines, but do not go idle.
void yield(AIEngine* engine); // Yield to give CPU to other state machines, but do not go idle. Continue running from engine 'engine'.
void yield_frame(unsigned int frames); // Run from the main-thread engine after at least 'frames' frames have passed.
void yield_ms(unsigned int ms); // Run from the main-thread engine after roughly 'ms' miliseconds have passed.
bool yield_if_not(AIEngine* engine); // Do not really yield, unless the current engine is not 'engine'. Returns true if it switched engine.
public:
// This function can be called from multiplex_imp(), but also by a child state machine and
// therefore by any thread. The child state machine should use an LLPointer<AIStateMachine>
// to access this state machine.
void abort(void); // Abort the state machine (unsuccessful finish).
// These are the only three functions that can be called by any thread at any moment.
// Those threads should use an LLPointer<AIStateMachine> to access this state machine.
void cont(void); // Guarantee at least one full run of multiplex() after this function is called. Cancels the last call to idle().
void advance_state(state_type new_state); // Guarantee at least one full run of multiplex() after this function is called
// iff new_state is larger than the last state that was processed.
bool signalled(void); // Call cont() iff this state machine is still blocked after a call to wait(). Returns false if it already unblocked.
public:
// Accessors.
// Return true if the derived class is running (also when we are idle).
bool running(void) const { return multiplex_state_type_crat(mState)->base_state == bs_multiplex; }
// Return true if the derived class is running and idle.
bool waiting(void) const
{
multiplex_state_type_crat state_r(mState);
return state_r->base_state == bs_multiplex && sub_state_type_crat(mSubState)->idle;
}
// Return true if the derived class is running and idle or already being aborted.
bool waiting_or_aborting(void) const
{
multiplex_state_type_crat state_r(mState);
return state_r->base_state == bs_abort || ( state_r->base_state == bs_multiplex && sub_state_type_crat(mSubState)->idle);
}
// Return true if are added to the engine.
bool active(AIEngine const* engine) const { return multiplex_state_type_crat(mState)->current_engine == engine; }
bool aborted(void) const { return sub_state_type_crat(mSubState)->aborted; }
// Use some safebool idiom (http://www.artima.com/cppsource/safebool.html) rather than operator bool.
typedef state_type AIStateMachine::* const bool_type;
// Return true if state machine successfully finished.
operator bool_type() const
{
sub_state_type_crat sub_state_r(mSubState);
return (sub_state_r->finished && !sub_state_r->aborted) ? &AIStateMachine::mNewParentState : 0;
}
// Return stringified state, for debugging purposes.
char const* state_str(base_state_type state);
#ifdef CWDEBUG
char const* event_str(event_type event);
#endif
void add(U64 count) { mRuntime += count; }
U64 getRuntime(void) const { return mRuntime; }
// For diagnostics. Every derived class must override this.
virtual const char* getName() const = 0;
protected:
virtual void initialize_impl(void) = 0;
virtual void multiplex_impl(state_type run_state) = 0;
virtual void abort_impl(void) { }
virtual void finish_impl(void) { }
virtual char const* state_str_impl(state_type run_state) const = 0;
virtual void force_killed(void); // Called from AIEngine::flush().
private:
void reset(void); // Called from run() to (re)initialize a (re)start.
void multiplex(event_type event); // Called from AIEngine to step through the states (and from reset() to kick start the state machine).
state_type begin_loop(base_state_type base_state); // Called from multiplex() at the start of a loop.
void callback(void); // Called when the state machine finished.
bool sleep(U64 current_time) // Count frames if necessary and return true when the state machine is still sleeping.
{
if (mSleep == 0)
return false;
else if (mSleep < 0)
++mSleep;
else if ((U64)mSleep <= current_time)
mSleep = 0;
return mSleep != 0;
}
friend class AIEngine; // Calls multiplex() and force_killed().
};
bool AIEngine::QueueElementComp::operator()(QueueElement const& e1, QueueElement const& e2) const
{
return e1.mStateMachine->getRuntime() < e2.mStateMachine->getRuntime();
}
// This can be used in state_str_impl.
#define AI_CASE_RETURN(x) do { case x: return #x; } while(0)
#endif