ContextApi.hpp

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/******************************************************************************/
/* REXX API support                                                           */
/*                                                                            */
/* Stub functions for all APIs accessed via the NativeFunctionContext         */
/*                                                                            */
/******************************************************************************/
 
#ifndef ContextApi_Included
#define ContextApi_Included
 
#include "RexxCore.h"
#include "RexxNativeActivation.hpp"
#include "ActivationApiContexts.hpp"
#include "RexxActivity.hpp"
 
/**
 * A stack-based API context object used for API stubs.
 */
class ApiContext
{
public:
    /**
     * Initialize an API context from a thread context.
     *
     * @param c      The source context.
     */
    inline ApiContext(RexxThreadContext *c)
    {
        // we need to cleanup on exit
        releaseLock = true;
        activity = contextToActivity(c);
        context = activity->getApiContext();
        context->enableConditionTraps();
        // go acquire the kernel lock and take care of nesting
        activity->enterCurrentThread();
        // we need to validate the thread call context to ensure this
        // is the correct thread
        activity->validateThread();
    }
 
 
    /**
     * Initialize an API context from a thread context.
     * this is a nonblocking context.  The extra argument allows
     * the overloads to work
     *
     * @param c      The source context.
     */
    inline ApiContext(RexxThreadContext *c, bool blocking)
    {
 
        // we need to cleanup on exit
        releaseLock = blocking;
        activity = contextToActivity(c);
        context = activity->getApiContext();
        context->enableConditionTraps();
    }
 
    /**
     * Initialize an API context from a call context.
     *
     * @param c      The source context.
     */
    inline ApiContext(RexxCallContext *c)
    {
        // we need to cleanup on exit
        releaseLock = true;
        activity = contextToActivity(c);
        context = contextToActivation(c);
        context->enableConditionTraps();
        // go acquire the kernel lock and take care of nesting
        activity->enterCurrentThread();
        // we need to validate the thread call context to ensure this
        // is the correct thread
        activity->validateThread();
    }
 
    /**
     * Initialize an API context from an exit context.
     *
     * @param c      The source context.
     */
    inline ApiContext(RexxExitContext *c)
    {
        // we need to cleanup on exit
        releaseLock = true;
        activity = contextToActivity(c);
        context = contextToActivation(c);
        context->enableConditionTraps();
        // go acquire the kernel lock and take care of nesting
        activity->enterCurrentThread();
        // we need to validate the thread call context to ensure this
        // is the correct thread
        activity->validateThread();
    }
 
    /**
     * Initialize an API context from a method context.
     *
     * @param c      The source context.
     */
    inline ApiContext(RexxMethodContext *c)
    {
        // we need to cleanup on exit
        releaseLock = true;
        activity = contextToActivity(c);
        context = contextToActivation(c);
        context->enableConditionTraps();
        // go acquire the kernel lock and take care of nesting
        activity->enterCurrentThread();
        // we need to validate the thread call context to ensure this
        // is the correct thread
        activity->validateThread();
    }
 
    /**
     * Destructor for an API context.  Releases the interpreter
     * access lock on exit.
     */
    inline ~ApiContext()
    {
        // we only do this sort of cleanup if we really entered on the
        // activity
        if (releaseLock)
        {
            context->disableConditionTraps();
            activity->exitCurrentThread();
        }
    }
 
    inline RexxObjectPtr ret(RexxObject *o)
    {
        context->createLocalReference(o);
        return (RexxObjectPtr)o;
    }
 
    /**
     * The activity used for the API callback.
     */
    RexxActivity *activity;
    /**
     * The top-level API context.
     */
    RexxNativeActivation *context;
 
    /**
     * Indicates whether we need to release the lock on return.
     */
    bool releaseLock;
};
 
 
/**
 * A stack-based API context object used for instance stubs.
 */
class InstanceApiContext
{
public:
    /**
     * Initialize an API context from an instance context.
     *
     * @param c      The source context.
     */
    inline InstanceApiContext(RexxInstance *c)
    {
        instance = ((InstanceContext *)c)->instance;
    }
 
    /**
     * Destructor for an API context.  Releases the interpreter
     * access lock on exit.
     */
    inline ~InstanceApiContext()
    {
    }
 
    /**
     * The top-level API context.
     */
    InterpreterInstance *instance;
};
 
#endif