Java Code Examples for jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor#isOptimistic()

The following examples show how to use jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor#isOptimistic() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: ContinuousArrayData.java    From TencentKona-8 with GNU General Public License v2.0 6 votes vote down vote up 
/**
 * Return a fast linked array getter, or null if we have to dispatch to super class
 * @param desc     descriptor
 * @param request  link request
 * @return invocation or null if needs to be sent to slow relink
 */
@Override
public GuardedInvocation findFastGetIndexMethod(final Class<? extends ArrayData> clazz, final CallSiteDescriptor desc, final LinkRequest request) {
    final MethodType callType   = desc.getMethodType();
    final Class<?>   indexType  = callType.parameterType(1);
    final Class<?>   returnType = callType.returnType();

    if (ContinuousArrayData.class.isAssignableFrom(clazz) && indexType == int.class) {
        final Object[] args  = request.getArguments();
        final int      index = (int)args[args.length - 1];

        if (has(index)) {
            final MethodHandle getArray     = ScriptObject.GET_ARRAY.methodHandle();
            final int          programPoint = NashornCallSiteDescriptor.isOptimistic(desc) ? NashornCallSiteDescriptor.getProgramPoint(desc) : INVALID_PROGRAM_POINT;
            MethodHandle       getElement   = getElementGetter(returnType, programPoint);
            if (getElement != null) {
                getElement = MH.filterArguments(getElement, 0, MH.asType(getArray, getArray.type().changeReturnType(clazz)));
                final MethodHandle guard = MH.insertArguments(FAST_ACCESS_GUARD, 0, clazz);
                return new GuardedInvocation(getElement, guard, (SwitchPoint)null, ClassCastException.class);
            }
        }
    }

    return null;
}
Example 2
Source File: ContinuousArrayData.java    From openjdk-jdk9 with GNU General Public License v2.0 6 votes vote down vote up 
/**
 * Return a fast linked array getter, or null if we have to dispatch to super class
 * @param desc     descriptor
 * @param request  link request
 * @return invocation or null if needs to be sent to slow relink
 */
@Override
public GuardedInvocation findFastGetIndexMethod(final Class<? extends ArrayData> clazz, final CallSiteDescriptor desc, final LinkRequest request) {
    final MethodType callType   = desc.getMethodType();
    final Class<?>   indexType  = callType.parameterType(1);
    final Class<?>   returnType = callType.returnType();

    if (ContinuousArrayData.class.isAssignableFrom(clazz) && indexType == int.class) {
        final Object[] args  = request.getArguments();
        final int      index = (int)args[args.length - 1];

        if (has(index)) {
            final MethodHandle getArray     = ScriptObject.GET_ARRAY.methodHandle();
            final int          programPoint = NashornCallSiteDescriptor.isOptimistic(desc) ? NashornCallSiteDescriptor.getProgramPoint(desc) : INVALID_PROGRAM_POINT;
            MethodHandle       getElement   = getElementGetter(returnType, programPoint);
            if (getElement != null) {
                getElement = MH.filterArguments(getElement, 0, MH.asType(getArray, getArray.type().changeReturnType(clazz)));
                final MethodHandle guard = MH.insertArguments(FAST_ACCESS_GUARD, 0, clazz);
                return new GuardedInvocation(getElement, guard, (SwitchPoint)null, ClassCastException.class);
            }
        }
    }

    return null;
}
Example 3
Source File: ContinuousArrayData.java    From hottub with GNU General Public License v2.0 6 votes vote down vote up 
/**
 * Return a fast linked array getter, or null if we have to dispatch to super class
 * @param desc     descriptor
 * @param request  link request
 * @return invocation or null if needs to be sent to slow relink
 */
@Override
public GuardedInvocation findFastGetIndexMethod(final Class<? extends ArrayData> clazz, final CallSiteDescriptor desc, final LinkRequest request) {
    final MethodType callType   = desc.getMethodType();
    final Class<?>   indexType  = callType.parameterType(1);
    final Class<?>   returnType = callType.returnType();

    if (ContinuousArrayData.class.isAssignableFrom(clazz) && indexType == int.class) {
        final Object[] args  = request.getArguments();
        final int      index = (int)args[args.length - 1];

        if (has(index)) {
            final MethodHandle getArray     = ScriptObject.GET_ARRAY.methodHandle();
            final int          programPoint = NashornCallSiteDescriptor.isOptimistic(desc) ? NashornCallSiteDescriptor.getProgramPoint(desc) : INVALID_PROGRAM_POINT;
            MethodHandle       getElement   = getElementGetter(returnType, programPoint);
            if (getElement != null) {
                getElement = MH.filterArguments(getElement, 0, MH.asType(getArray, getArray.type().changeReturnType(clazz)));
                final MethodHandle guard = MH.insertArguments(FAST_ACCESS_GUARD, 0, clazz);
                return new GuardedInvocation(getElement, guard, (SwitchPoint)null, ClassCastException.class);
            }
        }
    }

    return null;
}
Example 4
Source File: ScriptObject.java    From openjdk-jdk8u with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 5
Source File: ScriptObject.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 6
Source File: OptimisticReturnFilters.java    From TencentKona-8 with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Given a guarded invocation and a callsite descriptor, perform return value filtering
 * according to the optimistic type coercion rules, using the return value from the descriptor
 * @param inv the invocation
 * @param desc the descriptor
 * @return filtered invocation
 */
public static GuardedInvocation filterOptimisticReturnValue(final GuardedInvocation inv, final CallSiteDescriptor desc) {
    if(!NashornCallSiteDescriptor.isOptimistic(desc)) {
        return inv;
    }
    return inv.replaceMethods(filterOptimisticReturnValue(inv.getInvocation(), desc.getMethodType().returnType(),
            NashornCallSiteDescriptor.getProgramPoint(desc)), inv.getGuard());
}
Example 7
Source File: OptimisticReturnFilters.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Given a guarded invocation and a callsite descriptor, perform return value filtering
 * according to the optimistic type coercion rules, using the return value from the descriptor
 * @param inv the invocation
 * @param desc the descriptor
 * @return filtered invocation
 */
public static GuardedInvocation filterOptimisticReturnValue(final GuardedInvocation inv, final CallSiteDescriptor desc) {
    if(!NashornCallSiteDescriptor.isOptimistic(desc)) {
        return inv;
    }
    return inv.replaceMethods(filterOptimisticReturnValue(inv.getInvocation(), desc.getMethodType().returnType(),
            NashornCallSiteDescriptor.getProgramPoint(desc)), inv.getGuard());
}
Example 8
Source File: ScriptObject.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 9
Source File: OptimisticReturnFilters.java    From jdk8u_nashorn with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Given a guarded invocation and a callsite descriptor, perform return value filtering
 * according to the optimistic type coercion rules, using the return value from the descriptor
 * @param inv the invocation
 * @param desc the descriptor
 * @return filtered invocation
 */
public static GuardedInvocation filterOptimisticReturnValue(final GuardedInvocation inv, final CallSiteDescriptor desc) {
    if(!NashornCallSiteDescriptor.isOptimistic(desc)) {
        return inv;
    }
    return inv.replaceMethods(filterOptimisticReturnValue(inv.getInvocation(), desc.getMethodType().returnType(),
            NashornCallSiteDescriptor.getProgramPoint(desc)), inv.getGuard());
}
Example 10
Source File: OptimisticReturnFilters.java    From openjdk-jdk8u-backup with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Given a guarded invocation and a callsite descriptor, perform return value filtering
 * according to the optimistic type coercion rules, using the return value from the descriptor
 * @param inv the invocation
 * @param desc the descriptor
 * @return filtered invocation
 */
public static GuardedInvocation filterOptimisticReturnValue(final GuardedInvocation inv, final CallSiteDescriptor desc) {
    if(!NashornCallSiteDescriptor.isOptimistic(desc)) {
        return inv;
    }
    return inv.replaceMethods(filterOptimisticReturnValue(inv.getInvocation(), desc.getMethodType().returnType(),
            NashornCallSiteDescriptor.getProgramPoint(desc)), inv.getGuard());
}
Example 11
Source File: ScriptObject.java    From TencentKona-8 with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 12
Source File: OptimisticReturnFilters.java    From openjdk-jdk8u with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Given a guarded invocation and a callsite descriptor, perform return value filtering
 * according to the optimistic type coercion rules, using the return value from the descriptor
 * @param inv the invocation
 * @param desc the descriptor
 * @return filtered invocation
 */
public static GuardedInvocation filterOptimisticReturnValue(final GuardedInvocation inv, final CallSiteDescriptor desc) {
    if(!NashornCallSiteDescriptor.isOptimistic(desc)) {
        return inv;
    }
    return inv.replaceMethods(filterOptimisticReturnValue(inv.getInvocation(), desc.getMethodType().returnType(),
            NashornCallSiteDescriptor.getProgramPoint(desc)), inv.getGuard());
}
Example 13
Source File: ScriptObject.java    From jdk8u60 with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoint(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 14
Source File: ScriptObject.java    From hottub with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 15
Source File: ScriptObject.java    From jdk8u_nashorn with GNU General Public License v2.0 5 votes vote down vote up 
private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final boolean explicitInstanceOfCheck, final String name) {
    if (NashornCallSiteDescriptor.isOptimistic(desc)) {
        throw new UnwarrantedOptimismException(UNDEFINED, NashornCallSiteDescriptor.getProgramPoint(desc), Type.OBJECT);
    }

    return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
            NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
            explicitInstanceOfCheck ? null : ClassCastException.class);
}
Example 16
Source File: GlobalConstants.java    From TencentKona-8 with GNU General Public License v2.0 4 votes vote down vote up 
/**
 * Try to turn a getter into a MethodHandle.constant, if possible
 *
 * @param find      property lookup
 * @param receiver  receiver
 * @param desc      callsite descriptor
 *
 * @return resulting getter, or null if failed to create constant
 */
GuardedInvocation findGetMethod(final FindProperty find, final ScriptObject receiver, final CallSiteDescriptor desc) {
    // Only use constant getter for fast scope access, because the receiver may change between invocations
    // for slow-scope and non-scope callsites.
    // Also return null for user accessor properties as they may have side effects.
    if (invalidatedForever.get() || !NashornCallSiteDescriptor.isFastScope(desc)
            || (GLOBAL_ONLY && !find.getOwner().isGlobal())
            || find.getProperty() instanceof UserAccessorProperty) {
        return null;
    }

    final boolean  isOptimistic = NashornCallSiteDescriptor.isOptimistic(desc);
    final int      programPoint = isOptimistic ? getProgramPoint(desc) : INVALID_PROGRAM_POINT;
    final Class<?> retType      = desc.getMethodType().returnType();
    final String   name         = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    synchronized (this) {
        final Access acc = getOrCreateSwitchPoint(name);

        log.fine("Starting to look up object value " + name);
        final Object c = find.getObjectValue();

        if (log.isEnabled()) {
            log.fine("Trying to link constant GETTER " + acc + " value = " + c);
        }

        if (acc.hasBeenInvalidated() || acc.guardFailed() || invalidatedForever.get()) {
            if (log.isEnabled()) {
                log.info("*** GET: Giving up on " + quote(name) + " - retry count has exceeded " + DynamicLinker.getLinkedCallSiteLocation());
            }
            return null;
        }

        final MethodHandle cmh = constantGetter(c);

        MethodHandle mh;
        MethodHandle guard;

        if (isOptimistic) {
            if (JSType.getAccessorTypeIndex(cmh.type().returnType()) <= JSType.getAccessorTypeIndex(retType)) {
                //widen return type - this is pessimistic, so it will always work
                mh = MH.asType(cmh, cmh.type().changeReturnType(retType));
            } else {
                //immediately invalidate - we asked for a too wide constant as a narrower one
                mh = MH.dropArguments(MH.insertArguments(JSType.THROW_UNWARRANTED.methodHandle(), 0, c, programPoint), 0, Object.class);
            }
        } else {
            //pessimistic return type filter
            mh = Lookup.filterReturnType(cmh, retType);
        }

        if (find.getOwner().isGlobal()) {
            guard = null;
        } else {
            guard = MH.insertArguments(RECEIVER_GUARD, 0, acc, receiver);
        }

        if (log.isEnabled()) {
            log.info("Linked getter " + quote(name) + " as MethodHandle.constant() -> " + c + " " + acc.getSwitchPoint());
            mh = MethodHandleFactory.addDebugPrintout(log, Level.FINE, mh, "get const " + acc);
        }

        return new GuardedInvocation(mh, guard, acc.getSwitchPoint(), null);
    }
}
Example 17
Source File: GlobalConstants.java    From hottub with GNU General Public License v2.0 4 votes vote down vote up 
/**
 * Try to turn a getter into a MethodHandle.constant, if possible
 *
 * @param find      property lookup
 * @param receiver  receiver
 * @param desc      callsite descriptor
 *
 * @return resulting getter, or null if failed to create constant
 */
GuardedInvocation findGetMethod(final FindProperty find, final ScriptObject receiver, final CallSiteDescriptor desc) {
    // Only use constant getter for fast scope access, because the receiver may change between invocations
    // for slow-scope and non-scope callsites.
    // Also return null for user accessor properties as they may have side effects.
    if (invalidatedForever.get() || !NashornCallSiteDescriptor.isFastScope(desc)
            || (GLOBAL_ONLY && !find.getOwner().isGlobal())
            || find.getProperty() instanceof UserAccessorProperty) {
        return null;
    }

    final boolean  isOptimistic = NashornCallSiteDescriptor.isOptimistic(desc);
    final int      programPoint = isOptimistic ? getProgramPoint(desc) : INVALID_PROGRAM_POINT;
    final Class<?> retType      = desc.getMethodType().returnType();
    final String   name         = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    synchronized (this) {
        final Access acc = getOrCreateSwitchPoint(name);

        log.fine("Starting to look up object value " + name);
        final Object c = find.getObjectValue();

        if (log.isEnabled()) {
            log.fine("Trying to link constant GETTER " + acc + " value = " + c);
        }

        if (acc.hasBeenInvalidated() || acc.guardFailed() || invalidatedForever.get()) {
            if (log.isEnabled()) {
                log.info("*** GET: Giving up on " + quote(name) + " - retry count has exceeded " + DynamicLinker.getLinkedCallSiteLocation());
            }
            return null;
        }

        final MethodHandle cmh = constantGetter(c);

        MethodHandle mh;
        MethodHandle guard;

        if (isOptimistic) {
            if (JSType.getAccessorTypeIndex(cmh.type().returnType()) <= JSType.getAccessorTypeIndex(retType)) {
                //widen return type - this is pessimistic, so it will always work
                mh = MH.asType(cmh, cmh.type().changeReturnType(retType));
            } else {
                //immediately invalidate - we asked for a too wide constant as a narrower one
                mh = MH.dropArguments(MH.insertArguments(JSType.THROW_UNWARRANTED.methodHandle(), 0, c, programPoint), 0, Object.class);
            }
        } else {
            //pessimistic return type filter
            mh = Lookup.filterReturnType(cmh, retType);
        }

        if (find.getOwner().isGlobal()) {
            guard = null;
        } else {
            guard = MH.insertArguments(RECEIVER_GUARD, 0, acc, receiver);
        }

        if (log.isEnabled()) {
            log.info("Linked getter " + quote(name) + " as MethodHandle.constant() -> " + c + " " + acc.getSwitchPoint());
            mh = MethodHandleFactory.addDebugPrintout(log, Level.FINE, mh, "get const " + acc);
        }

        return new GuardedInvocation(mh, guard, acc.getSwitchPoint(), null);
    }
}
Example 18
Source File: GlobalConstants.java    From jdk8u_nashorn with GNU General Public License v2.0 4 votes vote down vote up 
/**
 * Try to turn a getter into a MethodHandle.constant, if possible
 *
 * @param find      property lookup
 * @param receiver  receiver
 * @param desc      callsite descriptor
 *
 * @return resulting getter, or null if failed to create constant
 */
GuardedInvocation findGetMethod(final FindProperty find, final ScriptObject receiver, final CallSiteDescriptor desc) {
    // Only use constant getter for fast scope access, because the receiver may change between invocations
    // for slow-scope and non-scope callsites.
    // Also return null for user accessor properties as they may have side effects.
    if (invalidatedForever.get() || !NashornCallSiteDescriptor.isFastScope(desc)
            || (GLOBAL_ONLY && !find.getOwner().isGlobal())
            || find.getProperty() instanceof UserAccessorProperty) {
        return null;
    }

    final boolean  isOptimistic = NashornCallSiteDescriptor.isOptimistic(desc);
    final int      programPoint = isOptimistic ? getProgramPoint(desc) : INVALID_PROGRAM_POINT;
    final Class<?> retType      = desc.getMethodType().returnType();
    final String   name         = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    synchronized (this) {
        final Access acc = getOrCreateSwitchPoint(name);

        log.fine("Starting to look up object value " + name);
        final Object c = find.getObjectValue();

        if (log.isEnabled()) {
            log.fine("Trying to link constant GETTER " + acc + " value = " + c);
        }

        if (acc.hasBeenInvalidated() || acc.guardFailed() || invalidatedForever.get()) {
            if (log.isEnabled()) {
                log.info("*** GET: Giving up on " + quote(name) + " - retry count has exceeded " + DynamicLinker.getLinkedCallSiteLocation());
            }
            return null;
        }

        final MethodHandle cmh = constantGetter(c);

        MethodHandle mh;
        MethodHandle guard;

        if (isOptimistic) {
            if (JSType.getAccessorTypeIndex(cmh.type().returnType()) <= JSType.getAccessorTypeIndex(retType)) {
                //widen return type - this is pessimistic, so it will always work
                mh = MH.asType(cmh, cmh.type().changeReturnType(retType));
            } else {
                //immediately invalidate - we asked for a too wide constant as a narrower one
                mh = MH.dropArguments(MH.insertArguments(JSType.THROW_UNWARRANTED.methodHandle(), 0, c, programPoint), 0, Object.class);
            }
        } else {
            //pessimistic return type filter
            mh = Lookup.filterReturnType(cmh, retType);
        }

        if (find.getOwner().isGlobal()) {
            guard = null;
        } else {
            guard = MH.insertArguments(RECEIVER_GUARD, 0, acc, receiver);
        }

        if (log.isEnabled()) {
            log.info("Linked getter " + quote(name) + " as MethodHandle.constant() -> " + c + " " + acc.getSwitchPoint());
            mh = MethodHandleFactory.addDebugPrintout(log, Level.FINE, mh, "get const " + acc);
        }

        return new GuardedInvocation(mh, guard, acc.getSwitchPoint(), null);
    }
}
Example 19
Source File: GlobalConstants.java    From jdk8u60 with GNU General Public License v2.0 4 votes vote down vote up 
/**
 * Try to turn a getter into a MethodHandle.constant, if possible
 *
 * @param find      property lookup
 * @param receiver  receiver
 * @param desc      callsite descriptor
 *
 * @return resulting getter, or null if failed to create constant
 */
GuardedInvocation findGetMethod(final FindProperty find, final ScriptObject receiver, final CallSiteDescriptor desc) {
    // Only use constant getter for fast scope access, because the receiver may change between invocations
    // for slow-scope and non-scope callsites.
    // Also return null for user accessor properties as they may have side effects.
    if (invalidatedForever.get() || !NashornCallSiteDescriptor.isFastScope(desc)
            || (GLOBAL_ONLY && !find.getOwner().isGlobal())
            || find.getProperty() instanceof UserAccessorProperty) {
        return null;
    }

    final boolean  isOptimistic = NashornCallSiteDescriptor.isOptimistic(desc);
    final int      programPoint = isOptimistic ? getProgramPoint(desc) : INVALID_PROGRAM_POINT;
    final Class<?> retType      = desc.getMethodType().returnType();
    final String   name         = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

    synchronized (this) {
        final Access acc = getOrCreateSwitchPoint(name);

        log.fine("Starting to look up object value " + name);
        final Object c = find.getObjectValue();

        if (log.isEnabled()) {
            log.fine("Trying to link constant GETTER " + acc + " value = " + c);
        }

        if (acc.hasBeenInvalidated() || acc.guardFailed() || invalidatedForever.get()) {
            if (log.isEnabled()) {
                log.info("*** GET: Giving up on " + quote(name) + " - retry count has exceeded " + DynamicLinker.getLinkedCallSiteLocation());
            }
            return null;
        }

        final MethodHandle cmh = constantGetter(c);

        MethodHandle mh;
        MethodHandle guard;

        if (isOptimistic) {
            if (JSType.getAccessorTypeIndex(cmh.type().returnType()) <= JSType.getAccessorTypeIndex(retType)) {
                //widen return type - this is pessimistic, so it will always work
                mh = MH.asType(cmh, cmh.type().changeReturnType(retType));
            } else {
                //immediately invalidate - we asked for a too wide constant as a narrower one
                mh = MH.dropArguments(MH.insertArguments(JSType.THROW_UNWARRANTED.methodHandle(), 0, c, programPoint), 0, Object.class);
            }
        } else {
            //pessimistic return type filter
            mh = Lookup.filterReturnType(cmh, retType);
        }

        if (find.getOwner().isGlobal()) {
            guard = null;
        } else {
            guard = MH.insertArguments(RECEIVER_GUARD, 0, acc, receiver);
        }

        if (log.isEnabled()) {
            log.info("Linked getter " + quote(name) + " as MethodHandle.constant() -> " + c + " " + acc.getSwitchPoint());
            mh = MethodHandleFactory.addDebugPrintout(log, Level.FINE, mh, "get const " + acc);
        }

        return new GuardedInvocation(mh, guard, acc.getSwitchPoint(), null);
    }
}
Example 20
Source File: GlobalConstants.java    From openjdk-jdk9 with GNU General Public License v2.0 4 votes vote down vote up 
/**
 * Try to turn a getter into a MethodHandle.constant, if possible
 *
 * @param find      property lookup
 * @param receiver  receiver
 * @param desc      callsite descriptor
 *
 * @return resulting getter, or null if failed to create constant
 */
GuardedInvocation findGetMethod(final FindProperty find, final ScriptObject receiver, final CallSiteDescriptor desc) {
    // Only use constant getter for fast scope access, because the receiver may change between invocations
    // for slow-scope and non-scope callsites.
    // Also return null for user accessor properties as they may have side effects.
    if (invalidatedForever.get() || !NashornCallSiteDescriptor.isFastScope(desc)
            || (GLOBAL_ONLY && !find.getOwner().isGlobal())
            || find.getProperty() instanceof UserAccessorProperty) {
        return null;
    }

    final boolean  isOptimistic = NashornCallSiteDescriptor.isOptimistic(desc);
    final int      programPoint = isOptimistic ? getProgramPoint(desc) : INVALID_PROGRAM_POINT;
    final Class<?> retType      = desc.getMethodType().returnType();
    final String   name         = NashornCallSiteDescriptor.getOperand(desc);

    synchronized (this) {
        final Access acc = getOrCreateSwitchPoint(name);

        log.fine("Starting to look up object value " + name);
        final Object c = find.getObjectValue();

        if (log.isEnabled()) {
            log.fine("Trying to link constant GETTER " + acc + " value = " + c);
        }

        if (acc.hasBeenInvalidated() || acc.guardFailed() || invalidatedForever.get()) {
            if (log.isEnabled()) {
                log.info("*** GET: Giving up on " + quote(name) + " - retry count has exceeded " + DynamicLinker.getLinkedCallSiteLocation());
            }
            return null;
        }

        final MethodHandle cmh = constantGetter(c);

        MethodHandle mh;
        MethodHandle guard;

        if (isOptimistic) {
            if (JSType.getAccessorTypeIndex(cmh.type().returnType()) <= JSType.getAccessorTypeIndex(retType)) {
                //widen return type - this is pessimistic, so it will always work
                mh = MH.asType(cmh, cmh.type().changeReturnType(retType));
            } else {
                //immediately invalidate - we asked for a too wide constant as a narrower one
                mh = MH.dropArguments(MH.insertArguments(JSType.THROW_UNWARRANTED.methodHandle(), 0, c, programPoint), 0, Object.class);
            }
        } else {
            //pessimistic return type filter
            mh = Lookup.filterReturnType(cmh, retType);
        }

        if (find.getOwner().isGlobal()) {
            guard = null;
        } else {
            guard = MH.insertArguments(RECEIVER_GUARD, 0, acc, receiver);
        }

        if (log.isEnabled()) {
            log.info("Linked getter " + quote(name) + " as MethodHandle.constant() -> " + c + " " + acc.getSwitchPoint());
            mh = MethodHandleFactory.addDebugPrintout(log, Level.FINE, mh, "get const " + acc);
        }

        return new GuardedInvocation(mh, guard, acc.getSwitchPoint(), null);
    }
}