Class ThreadLocalPrintStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.PrintStream

org.ek9lang.compiler.backend.jvm.ThreadLocalPrintStream

All Implemented Interfaces:

Closeable, Flushable, Appendable, AutoCloseable

public final class ThreadLocalPrintStream
extends PrintStream

A PrintStream that delegates to thread-local outputs. This enables parallel execution where each thread captures its own output without interference from other threads.

When a thread has registered an output stream (via setThreadOutput(ByteArrayOutputStream)), all writes from that thread go to its specific stream. Otherwise, writes go to the fallback stream (typically the original System.out).

This class is thread-safe. Each thread's output is completely isolated.

Used by REPL and bytecode tests to capture program output.

Field Summary

Fields inherited from class FilterOutputStream

out

Constructor Summary

Constructors

Constructor	Description
ThreadLocalPrintStream(PrintStream fallback)	Create a thread-local delegating PrintStream.

Method Summary

Modifier and Type	Method	Description
static String	clearAndGet()	Clear the thread-local output and return the captured content.
PrintStream	getFallback()	Get the fallback stream (original System.out).
static void	setThreadOutput(ByteArrayOutputStream output)	Set the output capture for the current thread.

Methods inherited from class PrintStream

append, append, append, charset, checkError, clearError, close, flush, format, format, print, print, print, print, print, print, print, print, print, printf, printf, println, println, println, println, println, println, println, println, println, println, setError, write, write, write, writeBytes

Methods inherited from class OutputStream

nullOutputStream

Methods inherited from class Object

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

Constructor Details

ThreadLocalPrintStream

public ThreadLocalPrintStream(PrintStream fallback)

Create a thread-local delegating PrintStream.

Parameters:

fallback - The stream to use when no thread-local output is registered

Method Details

setThreadOutput

public static void setThreadOutput(ByteArrayOutputStream output)

Set the output capture for the current thread. All subsequent writes from this thread will go to this stream.

Parameters:

output - The stream to capture output to

clearAndGet

public static String clearAndGet()

Clear the thread-local output and return the captured content.

Returns:

The captured output, or empty string if nothing was captured

getFallback

public PrintStream getFallback()

Get the fallback stream (original System.out).