Interpreter.cpp

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/*----------------------------------------------------------------------------*/
/*                                                                            */
/* Copyright (c) 1995, 2004 IBM Corporation. All rights reserved.             */
/* 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.                    */
/*                                                                           */
/*                                                                           */
/*****************************************************************************/
 
#include "Interpreter.hpp"
#include "ActivityManager.hpp"
#include "ListClass.hpp"
#include "SystemInterpreter.hpp"
#include "InterpreterInstance.hpp"
#include "DirectoryClass.hpp"
#include "ProtectedObject.hpp"
#include "RexxInternalApis.h"
#include "PackageManager.hpp"
 
 
// global resource lock
SysMutex Interpreter::resourceLock("Interpreter::resourceLock");
 
RexxList *Interpreter::interpreterInstances = OREF_NULL;
 
// the local server object
RexxObject *Interpreter::localServer = OREF_NULL;
 
// the interpreter active state flag
bool Interpreter::active = false;
// used for timeslice dispatching
bool Interpreter::timeSliceElapsed = false;
 
 
/**
 * Initialize the interpreter subsystem.
 */
void Interpreter::init()
{
    interpreterInstances = new_list();
}
 
 
void Interpreter::live(size_t liveMark)
{
    memory_mark(interpreterInstances);
    memory_mark(localServer);
    memory_mark(versionNumber);
}
 
void Interpreter::liveGeneral(int reason)
{
  if (!memoryObject.savingImage())
  {
      memory_mark_general(interpreterInstances);
      memory_mark_general(localServer);
      memory_mark_general(versionNumber);
  }
}
 
void Interpreter::processStartup()
{
    // the locks get create in order
    createLocks();
    ActivityManager::createLocks();
    RexxMemory::createLocks();
    // make sure we have a session queue created for this process
}
 
void Interpreter::processShutdown()
{
    // we destroy the locks in reverse order
    RexxMemory::closeLocks();
    ActivityManager::closeLocks();
    closeLocks();
}
 
 
/**
 * Perform interpreter startup processing.
 *
 * @param mode   The startup mode.  This indicates whether we're saving the
 *               image or in shutdown mode.
 */
void Interpreter::startInterpreter(InterpreterStartupMode mode, const char *imageTarget)
{
    ResourceSection lock("Interpreter::startInterpreter", 0);
 
    // has everything been shutdown?
    if (!isActive())
    {
        SystemInterpreter::startInterpreter();   // perform system specific initialization
        // initialize the memory manager , and restore the
        // memory image
        memoryObject.initialize(mode == RUN_MODE, imageTarget);
        RexxCreateSessionQueue();
        // create our instances list
        interpreterInstances = new_list();
        // if we have a local server created already, don't recurse.
        if (localServer == OREF_NULL)
        {
            // Get an instance.  This also gives the root activity of the instance
            // the kernel lock.
            InstanceBlock instance;
            /* get the local environment         */
            /* get the server class              */
            RexxObject *server_class = env_find(new_string("!SERVER"));
 
            // NOTE:  This is a second block so that the
            // protected object's destructor gets run before
            // the activity is removed as the current activity.
            {
                ProtectedObject result;
                /* create a new server object        */
                server_class->messageSend(OREF_NEW, OREF_NULL, 0, 0, result);
                localServer = (RexxObject *)result;
            }
        }
    }
    // we're live now
    active = true;
}
 
 
/**
 * Initialize an instance .local object.
 */
void Interpreter::initLocal()
{
    // only do this if the local server has already been created.
    if (localServer != OREF_NULL)
    {
        // this will insert the initial .local objects
        ProtectedObject result;
        localServer->messageSend(OREF_INITINSTANCE, OREF_NULL, 0, 0, result);
    }
}
 
 
/**
 * Terminate the global interpreter environment, shutting down
 * all of the interpreter instances that we can and releasing
 * the object heap memory.
 *
 * @return true if everything was shutdown, false if there are reasons
 *         why this can't be shutdown.
 */
bool Interpreter::terminateInterpreter()
{
    {
        ResourceSection lock("Interpreter::terminateInterpreter", 0);   // lock in this section
        // if never even started up, then we've got a quick return
        if (!isActive())
        {
            return true;
        }
 
        // we can only shutdown interpreter instances from the
        // threads that created them.  If we have active instances,
        // this is a "no can do" situation
        if (interpreterInstances->items() != 0)
        {
            return false;
        }
 
        {
            try
            {
                // this may seem funny, but we need to create an instance
                // so shut down so that the package manager can unload
                // the libraries (it needs to pass a RexxThreadContext
                // pointer out to package unloaders, if they are defined)
                InstanceBlock instance;
                // run whatever uninits we can before we start releasing the libraries
                memoryObject.verboseMessage("Calling runUninits through lastChanceUninit from Interpreter::terminateInterpreter\n");
                memoryObject.lastChanceUninit();
 
                PackageManager::unload();
            } catch (ActivityException)
            {
                // we're shutting down, so ignore any failures while processing this
            }
        }
 
        // perform system-specific cleanup
        SystemInterpreter::terminateInterpreter();
 
        // most interpreter resources will be cleanup automatically, but
        // we need to poke the rxapi daemon and tell it to clean up our session
        // resources.
        RexxDeleteSessionQueue();
    }
    return true;
}
 
 
/**
 * Quick test if we're down to just a single interpreter instance.
 *
 * @return true if we're down to a single interpreter instance.
 */
bool Interpreter::lastInstance()
{
    return interpreterInstances->items() == 1;
}
 
 
/**
 * Create a new instance and return the instance context pointers
 * and thread context pointer for the instance.
 *
 * @param instance The returned instance pointer.
 * @param threadContext
 *                 The returned thread context pointer.
 * @param options  Options to apply to this interpreter instance.
 *
 * @return 0 if the instance was created ok.
 */
int Interpreter::createInstance(RexxInstance *&instance, RexxThreadContext *&threadContext, RexxOption *options)
{
    try
    {
        // create the instance
        InterpreterInstance *newInstance = createInterpreterInstance(options);
        instance = newInstance->getInstanceContext();
        threadContext = newInstance->getRootThreadContext();
        // we need to ensure we release the kernel lock before returning
        RexxActivity *activity = newInstance->getRootActivity();
        activity->releaseAccess();
        // the activity needs to be in a deactivated state when we return.
        activity->deactivate();
        return 0;
    } catch (ActivityException)
    {
        // not everything works until an instance is actually created, so
        // it's possible we'll see a true failure here, so give back an
        // error condition.
        return RXAPI_MEMFAIL;
    }
}
 
 
/**
 * Create a new interpreter instance.  An interpreter instance
 * is an accessible set of threads that constitutes an interpreter
 * environment for the purposes API access.
 *
 * @param exits  The set of exits to use for this invocation.
 * @param defaultEnvironment
 *               The default addressible environment.
 *
 * @return The new interpreter instance.
 */
InterpreterInstance *Interpreter::createInterpreterInstance(RexxOption *options)
{
    // We need to ensure that the interpreter is initialized before we create an
    // interpreter instance.  There are some nasty recursion problems that can result,
    // so this needs to be done carefully and the initialization needs to be protected by
    // the resource lock during the entire process.
    {
        ResourceSection lock("Interpreter::createInterpreterInstance", 0);
        // if our instances list has not been created yet, then the memory subsystem has not
        // been created yet.  Keep the lock during the entire process.
        if (interpreterInstances == OREF_NULL)
        {
            startInterpreter(RUN_MODE, NULL);
        }
    }
 
 
    // get a new root activity for this instance.  This might result in pushing a prior level down the
    // stack
    RexxActivity *rootActivity = ActivityManager::getRootActivity();
    // ok, we have an active activity here, so now we can allocate a new instance and bootstrap everything.
    InterpreterInstance *instance = new InterpreterInstance();
 
    {
        ResourceSection lock("Interpreter::createInterpreterInstance", 0);
 
        // add this to the active list
        interpreterInstances->append((RexxObject *)instance);
    }
 
    // now that this is protected from garbage collection, go and initialize everything
    instance->initialize(rootActivity, options);
    return instance;
}
 
 
/**
 * Shutdown an interpreter instance and remove it from the list
 * of accessible items.
 *
 * @param instance The instance we're shutting down.
 *
 * @return true if this instance was in a state that could be terminated.
 */
bool Interpreter::terminateInterpreterInstance(InterpreterInstance *instance)
{
    // instance has already shut itself down....we need to remove it from
    // the active list.
    ResourceSection lock("Interpreter::terminateInterpreterInstance", 0);
 
    interpreterInstances->removeItem((RexxObject *)instance);
    return true;
}
 
 
/**
 * Tell the interpreter to have all of the instances halt its activities.
 */
bool Interpreter::haltAllActivities(RexxString *name)
{
    ResourceSection lock("Interpreter::haltAllActivities", 0);
    bool result = true;
 
    for (size_t listIndex = interpreterInstances->firstIndex() ;
         listIndex != LIST_END;
         listIndex = interpreterInstances->nextIndex(listIndex) )
    {
                                         /* Get the next message object to    */
                                         /*process                            */
        InterpreterInstance *instance = (InterpreterInstance *)interpreterInstances->getValue(listIndex);
        // halt every thing
        result = result && instance->haltAllActivities(name);
    }
    return result;
}
 
 
/**
 * Manage a context where a new interpreter instance is created
 * for the purposes of acquiring an activity, and the activity
 * is released and the instance is terminated upon leaving the
 * block.
 */
InstanceBlock::InstanceBlock()
{
    // Get an instance.  This also gives the root activity of the instance
    // the kernel lock.
    instance = Interpreter::createInterpreterInstance();
    activity = instance->getRootActivity();
}
 
 
/**
 * Manage a context where a new interpreter instance is created
 * for the purposes of acquiring an activity, and the activity
 * is released and the instance is terminated upon leaving the
 * block.
 */
InstanceBlock::InstanceBlock(RexxOption *options)
{
    // Get an instance.  This also gives the root activity of the instance
    // the kernel lock.
    instance = Interpreter::createInterpreterInstance(options);
    activity = instance->getRootActivity();
}
 
 
/**
 * Manage a context where a new interpreter instance is created
 * for the purposes of acquiring an activity, and the activity
 * is released and the instance is terminated upon leaving the
 * block.
 */
InstanceBlock::InstanceBlock(PRXSYSEXIT exits, const char *env)
{
    size_t optionCount = 0;
 
    RexxOption options[3];
 
    // if we have exits specified, add this to the option set
    if (exits != NULL)
    {
        options[optionCount].optionName = REGISTERED_EXITS;
        options[optionCount].option = (void *)exits;
        optionCount++;
    }
 
    if (env != NULL)
    {
        options[optionCount].optionName = INITIAL_ADDRESS_ENVIRONMENT;
        options[optionCount].option = (CSTRING)env;
        optionCount++;
    }
 
    // set the marker for the end of the options
    options[optionCount].optionName = NULL;
 
    // Get an instance.  This also gives the root activity of the instance
    // the kernel lock.
    instance = Interpreter::createInterpreterInstance(&options[0]);
    activity = instance->getRootActivity();
}
 
 
/**
 * Release the kernal access and cleanup when the context block
 * goes out of scope.
 */
InstanceBlock::~InstanceBlock()
{
    activity->exitCurrentThread();
    // terminate the instance
    instance->terminate();
}
 
 
/**
 * Decode a condition directory into a easier to use
 * structure form for a native code user.  This breaks
 * the directory into its component pieces, including
 * converting values into primitive form using just a single
 * API call.
 *
 * @param conditionObj
 *               A directory object containing the condition information.
 * @param pRexxCondData
 *               The condition data structure that is populated with the
 *               condition information.
 */
void Interpreter::decodeConditionData(RexxDirectory *conditionObj, RexxCondition *condData)
{
    memset(condData, 0, sizeof(RexxCondition));
    condData->code = messageNumber((RexxString *)conditionObj->at(OREF_CODE));
    // just return the major part
    condData->rc = messageNumber((RexxString *)conditionObj->at(OREF_RC))/1000;
    condData->conditionName = (RexxStringObject)conditionObj->at(OREF_CONDITION);
 
    RexxObject *temp = conditionObj->at(OREF_NAME_MESSAGE);
    if (temp != OREF_NULL)
    {
        condData->message = (RexxStringObject)temp;
    }
 
    temp = conditionObj->at(OREF_ERRORTEXT);
    if (temp != OREF_NULL)
    {
        condData->errortext = (RexxStringObject)temp;
    }
 
    temp = conditionObj->at(OREF_DESCRIPTION);
    if (temp != OREF_NULL)
    {
        condData->description = (RexxStringObject)temp;
    }
 
    // this could be raised by a termination exit, so there might not be
    // position information available
    temp = conditionObj->at(OREF_POSITION);
    if (temp != OREF_NULL)
    {
        condData->position = ((RexxInteger *)temp)->wholeNumber();
    }
    else
    {
        condData->position = 0;
    }
 
    temp = conditionObj->at(OREF_PROGRAM);
    if (temp != OREF_NULL)
    {
        condData->program = (RexxStringObject)temp;
    }
 
    temp = conditionObj->at(OREF_ADDITIONAL);
    if (temp != OREF_NULL)
    {
        condData->additional = (RexxArrayObject)temp;
    }
}
 
 
/**
 * Default class resolution processing done without benefit of
 * a program context.
 *
 * @param className The class name.
 *
 * @return A resolved class object (if any).
 */
RexxClass *Interpreter::findClass(RexxString *className)
{
    RexxString *internalName = className->upper();   /* upper case it                     */
    ProtectedObject p(internalName);
    /* send message to .local            */
    RexxClass *classObject = (RexxClass *)(ActivityManager::getLocalEnvironment(internalName));
    if (classObject != OREF_NULL)
    {
        return classObject;
    }
 
    /* last chance, try the environment  */
    return(RexxClass *)(TheEnvironment->at(internalName));
}
 
 
/**
 * Return the current queue name.
 *
 * @return The name of the current queue.
 */
RexxString *Interpreter::getCurrentQueue()
{
    RexxObject *queue = ActivityManager::getLocalEnvironment(OREF_REXXQUEUE);
 
    if (queue == OREF_NULL)              /* no queue?                         */
    {
        return OREF_SESSION;             // the session queue is the default
    }
    // get the current name from the queue object.
    return(RexxString *)queue->sendMessage(OREF_GET);
}
 
 
void Interpreter::logicError (const char *desc)
/******************************************************************************/
/* Function:  Raise a fatal logic error                                       */
/******************************************************************************/
{
    printf("Logic error: %s\n",desc);
    exit(RC_LOGIC_ERROR);
}
 
wholenumber_t Interpreter::messageNumber(
    RexxString *errorcode)             /* REXX error code as string         */
/******************************************************************************/
/* Function:  Parse out the error code string into the messagecode valuey     */
/******************************************************************************/
{
    const char *decimalPoint;            /* location of decimalPoint in errorcode*/
    wholenumber_t  primary = 0;          /* Primary part of error code, major */
    wholenumber_t  secondary = 0;        /* Secondary protion (minor code)    */
    sizeB_t  count;
 
    /* make sure we get errorcode as str */
    errorcode = (RexxString *)errorcode->stringValue();
    /* scan to decimal Point or end of   */
    /* error code.                       */
    for (decimalPoint = errorcode->getStringData(), count = 0; *decimalPoint && *decimalPoint != '.'; decimalPoint++, count++);
 
    // must be a whole number in the correct range
    if (!new_string(errorcode->getStringData(), count)->numberValue(primary) || primary < 1 || primary >= 100)
    {
        /* Nope raise an error.              */
        reportException(Error_Expression_result_raise);
 
    }
    // now shift over the decimal position.
    primary *= 1000;
 
 
    if (*decimalPoint)
    {                 /* Was there a decimal point specified?*/
                      /* is the subcode invalid or too big?*/
        if (!new_string(decimalPoint + 1, (errorcode->getBLength() - count -1))->numberValue(secondary) || secondary < 0  || secondary >= 1000)
        {
            /* Yes, raise an error.              */
            reportException(Error_Expression_result_raise);
        }
    }
    return primary + secondary;          /* add two portions together, return */
}