org.jikesrvm.compilers.common

Class CompiledMethods

java.lang.Object

org.jikesrvm.compilers.common.CompiledMethods

public class CompiledMethods
extends Object

Manage pool of compiled methods.

Original extracted from RVMClassLoader.

Field Summary

Fields

Modifier and Type	Field and Description
private static CompiledMethod[][]	compiledMethods Java methods that have been compiled into machine code.
private static int	currentCompiledMethodId Index of most recently allocated slot in compiledMethods[].
private static int	LOG_ROW_SIZE 2^LOG_ROW_SIZE is the number of elements per row
private static int	ROW_MASK Mask to ascertain row from id number
private static boolean	scanForObsoleteMethods Used to communicate between setCompiledMethodObsolete(org.jikesrvm.compilers.common.CompiledMethod) and snipObsoleteCompiledMethods()

Constructor Summary

Constructors

Constructor and Description
CompiledMethods()

Method Summary

Modifier and Type	Method and Description
static CompiledMethod	createCompiledMethod(RVMMethod m, int compilerType)
static CompiledMethod	createHardwareTrapCompiledMethod()
private static void	ensureCapacity(int id) Ensure space in backing array for id.
static CompiledMethod	findMethodForInstruction(Address ip) Find the method whose machine code contains the specified instruction.
static CompiledMethod	getCompiledMethod(int compiledMethodId)
static CompiledMethod	getCompiledMethodUnchecked(int cmid)
static int	numCompiledMethods()
private static void	setCompiledMethod(int cmid, CompiledMethod cm)
static void	setCompiledMethodObsolete(CompiledMethod compiledMethod)
static void	snipObsoleteCompiledMethods() Snip reference to CompiledMethod so that we can reclaim code space.
static void	spaceReport() Report on the space used by compiled code and associated mapping information

Methods inherited from class java.lang.Object

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

Field Detail

LOG_ROW_SIZE

private static final int LOG_ROW_SIZE

2^LOG_ROW_SIZE is the number of elements per row

See Also:

Constant Field Values

ROW_MASK

private static final int ROW_MASK

Mask to ascertain row from id number

See Also:

Constant Field Values

compiledMethods

private static CompiledMethod[][] compiledMethods

Java methods that have been compiled into machine code. Note that there may be more than one compiled versions of the same method (i.e. at different levels of optimization).

currentCompiledMethodId

private static int currentCompiledMethodId

Index of most recently allocated slot in compiledMethods[].

scanForObsoleteMethods

private static boolean scanForObsoleteMethods

Used to communicate between setCompiledMethodObsolete(org.jikesrvm.compilers.common.CompiledMethod) and snipObsoleteCompiledMethods()

Constructor Detail

CompiledMethods

public CompiledMethods()

Method Detail

ensureCapacity

private static void ensureCapacity(int id)

Ensure space in backing array for id.

Parameters:

id - the id we need to ensure capacity for

getCompiledMethodUnchecked

public static CompiledMethod getCompiledMethodUnchecked(int cmid)

Parameters:

cmid - id of the method

Returns:

a previously compiled method without checking

setCompiledMethod

private static void setCompiledMethod(int cmid,
                                      CompiledMethod cm)

getCompiledMethod

public static CompiledMethod getCompiledMethod(int compiledMethodId)

Parameters:

compiledMethodId - the id of the compiled method

Returns:

a previously compiled method

createCompiledMethod

public static CompiledMethod createCompiledMethod(RVMMethod m,
                                                  int compilerType)

createHardwareTrapCompiledMethod

public static CompiledMethod createHardwareTrapCompiledMethod()

Returns:

a CompiledMethod for the synthetic hardware trap frame

numCompiledMethods

public static int numCompiledMethods()

Returns:

number of methods compiled so far.

findMethodForInstruction

public static CompiledMethod findMethodForInstruction(Address ip)

Find the method whose machine code contains the specified instruction.

Assumption: caller has disabled gc (otherwise collector could move objects without fixing up the raw ip pointer)

Note: this method is highly inefficient. Normally you should use the following instead: RVMClassLoader.getCompiledMethod(Magic.getCompiledMethodID(fp))

Parameters:

ip - instruction address. Usage note: ip must point to the instruction *following* the actual instruction whose method is sought. This allows us to properly handle the case where the only address we have to work with is a return address (i.e. from a stackframe) or an exception address (i.e. from a null pointer dereference, array bounds check, or divide by zero) on a machine architecture with variable length instructions. In such situations we'd have no idea how far to back up the instruction pointer to point to the "call site" or "exception site".

Returns:

method (null --> not found)

setCompiledMethodObsolete

public static void setCompiledMethodObsolete(CompiledMethod compiledMethod)

snipObsoleteCompiledMethods

public static void snipObsoleteCompiledMethods()

Snip reference to CompiledMethod so that we can reclaim code space. If the code is currently being executed, stack scanning is responsible for marking it NOT obsolete. Keep such reference until a future GC.

NOTE: It's expected that this is processed during GC, after scanning stacks to determine which methods are currently executing.

spaceReport

public static void spaceReport()

Report on the space used by compiled code and associated mapping information