Module brave

Package brave.internal.recorder

Class PendingSpans

java.lang.Object

java.lang.ref.ReferenceQueue<TraceContext>

brave.internal.recorder.PendingSpans

public final class PendingSpans
extends java.lang.ref.ReferenceQueue<TraceContext>

Similar to Finagle's deadline span map, except this is GC pressure as opposed to timeout driven. This means there's no bookkeeping thread required in order to flush orphaned spans. Work here is stolen from callers, though. For example, a call to Tracer.nextSpan() implicitly performs a check for orphans, invoking any handler that applies.

Spans are weakly referenced by their owning context. When the keys are collected, they are transferred to a queue, waiting to be reported. A call to modify any span will implicitly flush orphans to Zipkin. Spans in this state will have a "brave.flush" annotation added to them.

The internal implementation is derived from WeakConcurrentMap by Rafael Winterhalter. See https://github.com/raphw/weak-lock-free/blob/master/src/main/java/com/blogspot/mydailyjava/weaklockfree/WeakConcurrentMap.java

Constructor Summary

Constructors

Constructor	Description
PendingSpans(Clock clock, FinishedSpanHandler orphanedSpanHandler, java.util.concurrent.atomic.AtomicBoolean noop)

Method Summary

Modifier and Type	Method	Description
PendingSpan	getOrCreate(TraceContext context, boolean start)
boolean	remove(TraceContext context)
java.lang.String	toString()

Methods inherited from class java.lang.ref.ReferenceQueue

poll, remove, remove

Methods inherited from class java.lang.Object

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

Constructor Detail

PendingSpans

public PendingSpans(Clock clock,
                    FinishedSpanHandler orphanedSpanHandler,
                    java.util.concurrent.atomic.AtomicBoolean noop)

Method Detail

getOrCreate

public PendingSpan getOrCreate(TraceContext context,
                               boolean start)

remove

public boolean remove(TraceContext context)

See Also:

Span.abandon()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object