Class DirectExecutionControl

java.lang.Object

jdk.jshell.execution.DirectExecutionControl

All Implemented Interfaces:: AutoCloseable, ExecutionControl

Direct Known Subclasses:: LocalExecutionControl, RemoteExecutionControl

public class DirectExecutionControl extends Object implements ExecutionControl

An ExecutionControl implementation that runs in the current process. May be used directly, or over a channel with Util.forwardExecutionControl(ExecutionControl, java.io.ObjectInput, java.io.ObjectOutput).

Since:: 9

Nested Class Summary

Nested classes/interfaces declared in interface ExecutionControl

ExecutionControl.ClassBytecodes, ExecutionControl.ClassInstallException, ExecutionControl.EngineTerminationException, ExecutionControl.ExecutionControlException, ExecutionControl.InternalException, ExecutionControl.NotImplementedException, ExecutionControl.ResolutionException, ExecutionControl.RunException, ExecutionControl.StoppedException, ExecutionControl.UserException

Modifier and Type	Interface	Description
`static final class`	`ExecutionControl.ClassBytecodes`	Bundles class name with class bytecodes.
`static class`	`ExecutionControl.ClassInstallException`	A class install (load or redefine) encountered a problem.
`static class`	`ExecutionControl.EngineTerminationException`	Unbidden execution engine termination has occurred.
`static class`	`ExecutionControl.ExecutionControlException`	The abstract base of all `ExecutionControl` exceptions.
`static class`	`ExecutionControl.InternalException`	An internal problem has occurred.
`static class`	`ExecutionControl.NotImplementedException`	The command is not implemented.
`static class`	`ExecutionControl.ResolutionException`	An exception indicating that a `DeclarationSnippet` with unresolved references has been encountered.
`static class`	`ExecutionControl.RunException`	The abstract base of of exceptions specific to running user code.
`static class`	`ExecutionControl.StoppedException`	An exception indicating that an `ExecutionControl.invoke(java.lang.String, java.lang.String)` (or theoretically a `ExecutionControl.varValue(java.lang.String, java.lang.String)`) has been interrupted by a `ExecutionControl.stop()`.
`static class`	`ExecutionControl.UserException`	A 'normal' user exception occurred.

Constructor Summary

Constructor	Description
`DirectExecutionControl()`	Create an instance using the default class loading.
`DirectExecutionControl(LoaderDelegate loaderDelegate)`	Creates an instance, delegating loader operations to the specified delegate.

Method Summary

Modifier and Type	Method	Description
`void`	`addToClasspath(String cp)`	Adds the path to the execution class path.
`protected void`	`classesRedefined(ExecutionControl.ClassBytecodes[] cbcs)`	Notify that classes have been redefined.
`protected void`	`clientCodeEnter()`	Marks entry into user code.
`protected void`	`clientCodeLeave()`	Marks departure from user code.
`void`	`close()`	Shuts down this execution engine.
`Object`	`extensionCommand(String command, Object arg)`	Run a non-standard command (or a standard command from a newer version).
`protected Class<?>`	`findClass(String name)`	Finds the class with the specified binary name.
`protected String`	`invoke(Method doitMethod)`	Invoke the specified "doit-method", a static method with no parameters.
`String`	`invoke(String className, String methodName)`	Invokes an executable Snippet by calling a method on the specified wrapper class.
`void`	`load(ExecutionControl.ClassBytecodes[] cbcs)`	Attempts to load new classes.
`void`	`redefine(ExecutionControl.ClassBytecodes[] cbcs)`	Attempts to redefine previously loaded classes.
`void`	`stop()`	Interrupts a running invoke.
`protected String`	`throwConvertedInvocationException(Throwable cause)`	Converts incoming exceptions in user code into instances of subtypes of `ExecutionControl.ExecutionControlException` and throws the converted exception.
`protected String`	`throwConvertedOtherException(Throwable ex)`	Converts incoming exceptions in agent code into instances of subtypes of `ExecutionControl.ExecutionControlException` and throws the converted exception.
`protected static String`	`valueString(Object value)`	Converts the `Object` value from `ExecutionControl.invoke(String, String)` or `ExecutionControl.varValue(String, String)` to `String`.
`String`	`varValue(String className, String varName)`	Returns the value of a variable.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

DirectExecutionControl

public DirectExecutionControl(LoaderDelegate loaderDelegate)

Creates an instance, delegating loader operations to the specified delegate.

Parameters:: loaderDelegate - the delegate to handle loading classes

DirectExecutionControl

public DirectExecutionControl()

Create an instance using the default class loading.

Method Details

load

public void load(ExecutionControl.ClassBytecodes[] cbcs) throws ExecutionControl.ClassInstallException, ExecutionControl.NotImplementedException, ExecutionControl.EngineTerminationException

Description copied from interface: ExecutionControl

Attempts to load new classes.

Specified by:: load in interface ExecutionControl
Parameters:: cbcs - the class name and bytecodes to load
Throws:: ExecutionControl.ClassInstallException - exception occurred loading the classes, some or all were not loaded; ExecutionControl.NotImplementedException - if not implemented; ExecutionControl.EngineTerminationException - the execution engine has terminated

redefine

public void redefine(ExecutionControl.ClassBytecodes[] cbcs) throws ExecutionControl.ClassInstallException, ExecutionControl.NotImplementedException, ExecutionControl.EngineTerminationException

Description copied from interface: ExecutionControl

Attempts to redefine previously loaded classes.

Specified by:: redefine in interface ExecutionControl
Parameters:: cbcs - the class name and bytecodes to redefine
Throws:: ExecutionControl.ClassInstallException - exception occurred redefining the classes, some or all were not redefined; ExecutionControl.NotImplementedException - if not implemented; ExecutionControl.EngineTerminationException - the execution engine has terminated

classesRedefined

protected void classesRedefined(ExecutionControl.ClassBytecodes[] cbcs) throws ExecutionControl.NotImplementedException, ExecutionControl.EngineTerminationException

Notify that classes have been redefined.

Parameters:: cbcs - the class name and bytecodes to redefine
Throws:: ExecutionControl.NotImplementedException - if not implemented; ExecutionControl.EngineTerminationException - the execution engine has terminated

invoke

public String invoke(String className, String methodName) throws ExecutionControl.RunException, ExecutionControl.InternalException, ExecutionControl.EngineTerminationException

Description copied from interface: ExecutionControl

Invokes an executable Snippet by calling a method on the specified wrapper class. The method must have no arguments and return String.

Specified by:: invoke in interface ExecutionControl
Parameters:: className - the class whose method should be invoked; methodName - the name of method to invoke
Returns:: the result of the execution or null if no result
Throws:: ExecutionControl.UserException - the invoke raised a user exception; ExecutionControl.ResolutionException - the invoke attempted to directly or indirectly invoke an unresolved snippet; ExecutionControl.StoppedException - if the invoke() was canceled by ExecutionControl.stop(); ExecutionControl.InternalException - an internal problem occurred; ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.RunException

varValue

public String varValue(String className, String varName) throws ExecutionControl.RunException, ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Description copied from interface: ExecutionControl

Returns the value of a variable.

Specified by:: varValue in interface ExecutionControl
Parameters:: className - the name of the wrapper class of the variable; varName - the name of the variable
Returns:: the value of the variable
Throws:: ExecutionControl.UserException - formatting the value raised a user exception; ExecutionControl.ResolutionException - formatting the value attempted to directly or indirectly invoke an unresolved snippet; ExecutionControl.StoppedException - if the formatting the value was canceled by ExecutionControl.stop(); ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.InternalException - an internal problem occurred; ExecutionControl.RunException

addToClasspath

public void addToClasspath(String cp) throws ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Description copied from interface: ExecutionControl

Adds the path to the execution class path.

Specified by:: addToClasspath in interface ExecutionControl
Parameters:: cp - the path to add
Throws:: ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.InternalException - an internal problem occurred

stop

public void stop() throws ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Interrupts a running invoke.

Not supported.

Specified by:: stop in interface ExecutionControl
Throws:: ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.InternalException - an internal problem occurred

extensionCommand

public Object extensionCommand(String command, Object arg) throws ExecutionControl.RunException, ExecutionControl.EngineTerminationException, ExecutionControl.InternalException

Description copied from interface: ExecutionControl

Run a non-standard command (or a standard command from a newer version).

Specified by:: extensionCommand in interface ExecutionControl
Parameters:: command - the non-standard command; arg - the commands argument
Returns:: the commands return value
Throws:: ExecutionControl.UserException - the command raised a user exception; ExecutionControl.ResolutionException - the command attempted to directly or indirectly invoke an unresolved snippet; ExecutionControl.StoppedException - if the command was canceled by ExecutionControl.stop(); ExecutionControl.EngineTerminationException - the execution engine has terminated; ExecutionControl.NotImplementedException - if not implemented; ExecutionControl.InternalException - an internal problem occurred; ExecutionControl.RunException

close

public void close()

Description copied from interface: ExecutionControl

Shuts down this execution engine. Implementation should free all resources held by this execution engine.

No calls to methods on this interface should be made after close.

Specified by:: close in interface AutoCloseable
Specified by:: close in interface ExecutionControl

findClass

protected Class<?> findClass(String name) throws ClassNotFoundException

Finds the class with the specified binary name.

Parameters:: name - the binary name of the class
Returns:: the Class Object
Throws:: ClassNotFoundException - if the class could not be found

invoke

protected String invoke(Method doitMethod) throws Exception

Invoke the specified "doit-method", a static method with no parameters. The invoke(java.lang.String, java.lang.String) in this class will call this to invoke.

Parameters:: doitMethod - the Method to invoke
Returns:: the value or null
Throws:: Exception - any exceptions thrown by Method.invoke(Object, Object...) or any ExecutionControl.ExecutionControlException to pass-through.

valueString

protected static String valueString(Object value)

Converts the Object value from ExecutionControl.invoke(String, String) or ExecutionControl.varValue(String, String) to String.

Parameters:: value - the value to convert
Returns:: the String representation

throwConvertedInvocationException

protected String throwConvertedInvocationException(Throwable cause) throws ExecutionControl.RunException, ExecutionControl.InternalException

Converts incoming exceptions in user code into instances of subtypes of ExecutionControl.ExecutionControlException and throws the converted exception.

Parameters:: cause - the exception to convert
Returns:: never returns as it always throws
Throws:: ExecutionControl.RunException - for normal exception occurrences; ExecutionControl.InternalException - for internal problems

throwConvertedOtherException

protected String throwConvertedOtherException(Throwable ex) throws ExecutionControl.RunException, ExecutionControl.InternalException

Converts incoming exceptions in agent code into instances of subtypes of ExecutionControl.ExecutionControlException and throws the converted exception.

Parameters:: ex - the exception to convert
Returns:: never returns as it always throws
Throws:: ExecutionControl.RunException - for normal exception occurrences; ExecutionControl.InternalException - for internal problems

clientCodeEnter

protected void clientCodeEnter() throws ExecutionControl.InternalException

Marks entry into user code.

Throws:: ExecutionControl.InternalException - in unexpected failure cases

clientCodeLeave

protected void clientCodeLeave() throws ExecutionControl.InternalException

Marks departure from user code.

Throws:: ExecutionControl.InternalException - in unexpected failure cases

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