Interpreter.hpp

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/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
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/*****************************************************************************/
/* REXX Windows Support                                                      */
/*                                                                           */
/* Main interpreter control.  This is the preferred location for all         */
/* platform independent global variables.                                    */
/* The interpreter does not instantiate an instance of this                  */
/* class, so most variables and methods should be static.                    */
/*                                                                           */
/*                                                                           */
/*****************************************************************************/
 
#ifndef RexxInterpreter_Included
#define RexxInterpreter_Included
 
#include "RexxCore.h"
#include "SysSemaphore.hpp"
 
class InterpreterInstance;
class RexxList;
class RexxActivity;
 
class Interpreter
{
public:
    typedef enum
    {
        SAVE_IMAGE_MODE = 0,       // image creation
        RUN_MODE = 1               // normal run mode
    } InterpreterStartupMode;
 
    static void init();
 
    static void live(size_t);
    static void liveGeneral(int reason);
 
    static void processStartup();
    static void processShutdown();
 
    static inline void getResourceLock(const char *ds, int di) { resourceLock.request(ds, di); }
    static inline void releaseResourceLock(const char *ds, int di) { resourceLock.release(ds, di); }
    static inline void createLocks()
    {
        resourceLock.create();
    }
 
    static inline void closeLocks()
    {
        resourceLock.close();
    }
 
    static int createInstance(RexxInstance *&instance, RexxThreadContext *&threadContext, RexxOption *options);
    static bool terminateInterpreter();
    static void startInterpreter(InterpreterStartupMode mode, const char *imageTarget);
    static inline bool isTerminated() { return !active; }
    static inline bool isActive() { return active; }
    static bool lastInstance();
    static InterpreterInstance *createInterpreterInstance(RexxOption *options);
    static inline InterpreterInstance *createInterpreterInstance() { return createInterpreterInstance(NULL); }
    static bool terminateInterpreterInstance(InterpreterInstance *instance);
    static RexxString *getVersionNumber();
    static void initLocal();
    static size_t getInterpreterVersion();
    static size_t getLanguageLevel();
 
    static inline bool hasTimeSliceElapsed()
    {
        // if we've had a time slice event, flip the event flag and return true
        if (timeSliceElapsed)
        {
           timeSliceElapsed = false;
           return true;
        }
        // not time to break
        return false;
    }
 
    static inline int getWordSize()
    {
        return sizeof(void *) * 8;
    }
 
    static inline bool isBigEndian()
    {
        static  const  int mfcone=1;                 // constant 1
        static  const  char *mfctop=(char *)&mfcone; // -> top byte
        #define LITEND *mfctop             // named flag; 1=little-endian
 
        return LITEND == 0;
    }
 
 
    static void logicError (const char *desc);
    static wholenumber_t messageNumber(RexxString *);
    static inline void setTimeSliceElapsed() { timeSliceElapsed = true; }
    static inline void clearTimeSliceElapsed() { timeSliceElapsed = false; }
    static bool haltAllActivities(RexxString *);
    static void decodeConditionData(RexxDirectory *conditionObj, RexxCondition *condData);
    static RexxClass *findClass(RexxString *className);
    static RexxString *getCurrentQueue();
 
    static RexxObject *localServer;         // local environment initialization server
 
 
protected:
    static SysMutex  resourceLock;   // use to lock resources accessed outside of kernel global lock
    static int    initializations;   // indicates whether we're terminated or not
    static bool   timeSliceElapsed;  // indicates we've had a timer interrupt
    static RexxList *interpreterInstances;  // the set of interpreter instances
    static bool   active;            // indicates whether the interpreter is initialized
    static RexxString *versionNumber;  // our version number information
};
 
 
/**
 * Block control for access to the resource lock.
 */
class ResourceSection
{
public:
    inline ResourceSection(const char *ds, int di) : dbgds(ds), dbgdi(di)
    {
        Interpreter::getResourceLock(dbgds, dbgdi);
        terminated = false;
    }
 
    inline ~ResourceSection()
    {
        if (!terminated)
        {
            Interpreter::releaseResourceLock(dbgds, dbgdi);
        }
    }
 
    inline void release()
    {
        if (!terminated)
        {
            Interpreter::releaseResourceLock(dbgds, dbgdi);
            terminated = true;
        }
    }
 
 
    inline void reacquire()
    {
        if (terminated)
        {
            Interpreter::getResourceLock(dbgds, dbgdi);
            terminated = false;
        }
    }
 
private:
 
    bool terminated;       // we can release these as needed
    const char *dbgds;
    int dbgdi;
};
 
 
 
class InstanceBlock
{
public:
    InstanceBlock();
    InstanceBlock(RexxOption *options);
    InstanceBlock(PRXSYSEXIT exits, const char *env);
    ~InstanceBlock();
 
    RexxActivity         *activity;    // our current activity
    InterpreterInstance  *instance;    // potential interpreter instance
};
 
 
#endif