Package party.iroiro.luajava.luaj

Class LuaJ

java.lang.Object

party.iroiro.luajava.AbstractLua

party.iroiro.luajava.luaj.LuaJ

All Implemented Interfaces:

AutoCloseable, Lua, LuaThread

public class LuaJ
extends AbstractLua

A thin wrapper around LuaJ to provide Lua C API-like API.

Please note that LuaJ bindings are limited in its capabilities. Other bindings provided by LuaJava utilizes JNI functions to provide functionalities like calling default methods in interfaces. However, LuaJ uses no JNI, and thus won't be able to do things beyond the Java reflection API.

Nested Class Summary

Nested classes/interfaces inherited from interface party.iroiro.luajava.Lua

Lua.Conversion, Lua.LuaType

Field Summary

Fields inherited from class party.iroiro.luajava.AbstractLua

C, id, instances, L, loader, mainThread, recordedReferences, recyclableReferences, requireFunction, subThreads

Fields inherited from interface party.iroiro.luajava.Lua

GLOBAL_THROWABLE

Constructor Summary

Constructors

Constructor	Description
LuaJ()
LuaJ(long L, int id, AbstractLua mainThread)

Method Summary

Modifier and Type	Method	Description
LuaException.LuaError	convertError(int code)	Converts a native error code to a LuaError enum value.
Lua.LuaType	convertType(int code)	Converts a native type code to a LuaType enum value.
protected AbstractLua	newThread(long L, int id, AbstractLua mainThread)	Creates a new sub-thread attached to this main thread.
protected boolean	shouldSynchronize()	A method specifically for working around deadlocks caused by LuaJ.

Methods inherited from class party.iroiro.luajava.AbstractLua

addSubThread, checkError, checkStack, close, concat, createProxy, createTable, dump, equal, error, error, eval, from, from, from, from, from, fromNull, gc, get, get, getField, getGlobal, getId, getJavaError, getLuaNatives, getMainState, getMetaField, getMetatable, getPointer, getRegisteredMetatable, getTable, getTop, insert, invokeSpecial, isBoolean, isClosed, isFunction, isInteger, isJavaObject, isNil, isNone, isNoneOrNil, isNumber, isString, isTable, isThread, isUserdata, lessThan, load, load, loadExternal, newRegisteredMetatable, newTable, newThread, next, openLibraries, openLibrary, pCall, pop, push, push, push, push, push, push, push, push, push, push, push, pushArray, pushJavaArray, pushJavaClass, pushJavaObject, pushJavaObjectOrArray, pushNil, pushThread, pushValue, rawEqual, rawGet, rawGetI, rawLength, rawSet, rawSetI, ref, ref, refGet, register, remove, replace, require, resume, run, run, set, setExternalLoader, setField, setGlobal, setMetatable, setTable, setTop, status, toAbsoluteIndex, toBoolean, toBuffer, toDirectBuffer, toInteger, toJavaObject, toList, toMap, toNumber, toObject, toObject, toString, type, unref, unRef, xMove, yield

Methods inherited from class java.lang.Object

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

Constructor Details

LuaJ

public LuaJ(long L,
 int id,
 AbstractLua mainThread)

LuaJ

public LuaJ()

Method Details

newThread

protected AbstractLua newThread(long L,
 int id,
 AbstractLua mainThread)

Description copied from class: AbstractLua

Creates a new sub-thread attached to this main thread.

Specified by:

newThread in class AbstractLua

Parameters:

L - the pointer to the new Lua state

id - the unique identifier for the new state

mainThread - the main thread this state belongs to

Returns:

the new sub-thread

convertError

public LuaException.LuaError convertError(int code)

Description copied from class: AbstractLua

Converts a native error code to a LuaError enum value.

Specified by:

convertError in class AbstractLua

Parameters:

code - the native error code

Returns:

the corresponding LuaError value

convertType

public Lua.LuaType convertType(int code)

Description copied from class: AbstractLua

Converts a native type code to a LuaType enum value.

Specified by:

convertType in class AbstractLua

Parameters:

code - the native type code

Returns:

the corresponding LuaType value

shouldSynchronize

protected boolean shouldSynchronize()

Description copied from class: AbstractLua

A method specifically for working around deadlocks caused by LuaJ.

In LuaJ bindings, without this work-around, deadlocks can happen when:

 1. (Thread#A) The user synchronizes on mainThread as is required by LuaJava when used
    in multi-threaded environment.
 2. (Thread#A) The user calls AbstractLua.run(String) for example, to run a Lua snippet.
 3. The snippet creates a coroutine, mandating LuaJ to create a Java thread (#B).
 4. Inside the coroutine (i.e., the Java thread#B), the code calls a Lua proxy object.
 5. (Thread#B) LuaProxy.invoke(Object, Method, Object[]) tries to synchronizes
    on mainThread.
 6. Since thread#A is already inside a synchronization block, the two threads deadlocks.
 

This work-around asks LuaProxy.invoke(Object, Method, Object[]) to avoid synchronization when it detects that it is called from a coroutine thread created by LuaJ.

Overrides:

shouldSynchronize in class AbstractLua

Returns:

false only when invoke within a coroutine thread created by LuaJ