org.objectweb.fractal.julia.asm
Class LifeCycleCodeGenerator

java.lang.Object
  org.objectweb.fractal.julia.asm.AbstractCodeGenerator
      org.objectweb.fractal.julia.asm.LifeCycleCodeGenerator

All Implemented Interfaces:

CodeGenerator, Constants

public class LifeCycleCodeGenerator

extends AbstractCodeGenerator

A CodeGenerator to generate pre and post code to enforce the component's lifecycle. More precisely the code adapters returned by the generateInterceptionCode method (see CodeGenerator) transform the original methods into methods of the following form:

 <method signature> {
   synchronized (lc) {
     if (lc.fcState != 2)
       lc.incrementFcInvocationCounter();
     else
       lc.fcInvocationCounter++;
   }
   try {
     // original method code
   } finally {
     synchronized (lc) {
       if (lc.fcState != 2)
         lc.decrementFcInvocationCounter();
       else
         lc.fcInvocationCounter--;
     }
   }
 }
 

The generateInitCode method generates code blocks of the following form:

 lc = (...)ic.getInterface("lifecycle-controller");
 

where lc is a field added to the class that is being generated (in fact, if the controller and interceptor classes are merged (see InterceptorClassGenerator), the lc field is not generated and replaced by this in the above code).

Note: as you can see the code generated by this code generator is specific to the BasicLifeCycleControllerMixin class (in fact the generated pre and post code blocks are a partially inlined version of the incrementFcInvocationCounter and decrementFcInvocationCounter methods of this class): it can not work if the lifecycle controller of the component, either merged or not with other controllers, does not include this mixin, or an equivalent (i.e. with a fcInvocationCounter field, and with the corresponding increment and decrement methods).

Field Summary

Fields inherited from interface org.objectweb.asm.Constants

AALOAD, AASTORE, ACC_ABSTRACT, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH

Fields inherited from interface org.objectweb.fractal.julia.asm.CodeGenerator

IN, IN_OUT, OUT

Constructor Summary

LifeCycleCodeGenerator()

Method Summary

void	generateCloneCode(CodeVisitor cv) Generates the cloning code for this code generator.
void	generateInitCode(CodeVisitor cv) Generates the initialization code for this code generator.
protected void	generateInterceptionCodeBlock(Method m, boolean pre, CodeVisitor cv, int formals) Generates an interception code block for the given method.
protected int	getInterceptionCodeFormals(Method m) Returns the number of local variables that are used by the generated interception code.
protected int	getInterceptionType(Method m) Returns the type of the interception code to be generated for the given method.
int	init(InterceptorClassGenerator icg) Initializes this code generator.

Methods inherited from class org.objectweb.fractal.julia.asm.AbstractCodeGenerator

close, generateInterceptionCode, intercept

Methods inherited from class java.lang.Object

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

Constructor Detail

LifeCycleCodeGenerator

public LifeCycleCodeGenerator()

Method Detail

init

public int init(InterceptorClassGenerator icg)

Description copied from interface: CodeGenerator

Initializes this code generator.

Specified by:

init in interface CodeGenerator

Overrides:

init in class AbstractCodeGenerator

generateInitCode

public void generateInitCode(CodeVisitor cv)
                      throws ClassGenerationException

Description copied from interface: CodeGenerator

Generates the initialization code for this code generator. This code is added to the initFcController method by the interceptor class generator that calls this method. By hypothesis, the stack is empty at the beginning of the generated code. Moreover, the stack must also be empty at the end of the code generated by this method.

Specified by:

generateInitCode in interface CodeGenerator

Overrides:

generateInitCode in class AbstractCodeGenerator

Throws:

ClassGenerationException

getInterceptionType

protected int getInterceptionType(Method m)

Description copied from class: AbstractCodeGenerator

Returns the type of the interception code to be generated for the given method. The default implementation of this method returns NORMAL for all methods.

Overrides:

getInterceptionType in class AbstractCodeGenerator

Parameters:

m - a method object.

Returns:

EMPTY to generate only a pre code block at the beginning of the method, NORMAL to generate both a pre code block and a post code block, or FINALLY to generate a pre code block, and a post code block inside a finally block (to be sure that the post code block will always be executed).

getInterceptionCodeFormals

protected int getInterceptionCodeFormals(Method m)

Description copied from class: AbstractCodeGenerator

Returns the number of local variables that are used by the generated interception code. The default implementation of this method returns 0 for all methods.

Overrides:

getInterceptionCodeFormals in class AbstractCodeGenerator

Parameters:

m - a method object.

Returns:

the number of local variables that are used by the generated interception code.

generateCloneCode

public void generateCloneCode(CodeVisitor cv)

Description copied from interface: CodeGenerator

Generates the cloning code for this code generator. This code is added to the clone method by the interceptor class generator that calls this method. By hypothesis, the stack is empty at the beginning of the generated code. Moreover, the stack must also be empty at the end of the code generated by this method.

Specified by:

generateCloneCode in interface CodeGenerator

Overrides:

generateCloneCode in class AbstractCodeGenerator

generateInterceptionCodeBlock

protected void generateInterceptionCodeBlock(Method m,
                                             boolean pre,
                                             CodeVisitor cv,
                                             int formals)

Description copied from class: AbstractCodeGenerator

Generates an interception code block for the given method.

Specified by:

generateInterceptionCodeBlock in class AbstractCodeGenerator

Parameters:

m - the method for which the interception code must be generated.

pre - true to generate a pre code block, or false to generate a post code block.

cv - the method visitor to be used to generate the interception code.

formals - the index of the first local variable reserved for the code block. The generated code can use the local variables between indexes formals, inclusive, and formals + getInterceptionCodeFormals(m), exclusive.