Class SafePointInstr

java.lang.Object

org.ek9lang.compiler.ir.instructions.IRInstr

org.ek9lang.compiler.ir.instructions.SafePointInstr

All Implemented Interfaces:

INode

public final class SafePointInstr
extends IRInstr

SAFE_POINT: a point where the native cycle collector may run (EK9_NATIVE_CYCLE_COLLECTOR_DESIGN.md §14). Placed only by IR_OPTIMISATION (SafePointPlacement) in an operation the runtime can never call; a garbage-collected back end emits nothing for it. No result, no debug information (it is no source line).

Three kinds. A plain SAFE_POINT collects when a collection is due (the candidate buffer has passed its threshold). SAFE_POINT after_threads follows a statement that started runtime threads and returned only once they had all stopped - an async pipeline, a server's accept or serve (§13.11, T10): there the statement's work is known to be finished on every thread, so it collects whatever is buffered. SAFE_POINT before_threads comes before a call that starts runtime threads, ahead of the evaluation of its arguments (S0b): starting a thread puts back at rest every candidate another thread may come to reach, and nothing buffers a dead island again, so it collects whatever is buffered first.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	SafePointInstr.Kind	Which safe point.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	AFTER_THREADS	The operand of a safe point that follows a statement whose runtime threads have all stopped.
static final String	BEFORE_THREADS	The operand of a safe point that comes before a call that starts runtime threads.

Constructor Summary

Constructors

Constructor	Description
SafePointInstr()
SafePointInstr(SafePointInstr.Kind kind)

Method Summary

Modifier and Type	Method	Description
SafePointInstr.Kind	getKind()
boolean	isAfterThreads()	True when this follows a statement whose runtime threads have all stopped: collect whatever is buffered.
boolean	isBeforeThreads()	True when this comes before a call that starts runtime threads: collect whatever is buffered.

Methods inherited from class IRInstr

accept, addOperand, addOperands, equals, getDebugInfo, getEscapeMetaData, getOpcode, getOperands, getResult, hasEscapeMetaData, hashCode, hasResult, isControlFlow, isLabel, isMemoryManagement, isMethodCall, setEscapeMetaData, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

AFTER_THREADS

public static final String AFTER_THREADS

The operand of a safe point that follows a statement whose runtime threads have all stopped.

See Also:

• Constant Field Values

BEFORE_THREADS

public static final String BEFORE_THREADS

The operand of a safe point that comes before a call that starts runtime threads.

See Also:

• Constant Field Values

Constructor Details

SafePointInstr

public SafePointInstr()

SafePointInstr

public SafePointInstr(SafePointInstr.Kind kind)

Method Details

getKind

public SafePointInstr.Kind getKind()

isAfterThreads

public boolean isAfterThreads()

True when this follows a statement whose runtime threads have all stopped: collect whatever is buffered.

isBeforeThreads

public boolean isBeforeThreads()

True when this comes before a call that starts runtime threads: collect whatever is buffered.