isSharable() — netty Function Reference

Architecture documentation for the isSharable() function in ChannelHandlerAdapter.java from the netty codebase.

Function java Buffer Telemetry called by 1

Entity Profile

Buffer→ Telemetry→ isSharable() — netty Function Reference

Dependency Diagram

graph TD
  8794f3b5_081e_5ba9_b410_2d73fa5ed955["isSharable()"]
  733fd4a8_2b66_5e68_0a41_9ec76f4eeefb["ChannelHandlerAdapter"]
  8794f3b5_081e_5ba9_b410_2d73fa5ed955 -->|defined in| 733fd4a8_2b66_5e68_0a41_9ec76f4eeefb
  f27b18fb_4b39_04d7_a9c9_7cb661254c26["ensureNotSharable()"]
  f27b18fb_4b39_04d7_a9c9_7cb661254c26 -->|calls| 8794f3b5_081e_5ba9_b410_2d73fa5ed955
  style 8794f3b5_081e_5ba9_b410_2d73fa5ed955 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

transport/src/main/java/io/netty/channel/ChannelHandlerAdapter.java lines 45–62

    public boolean isSharable() {
        /**
         * Cache the result of {@link Sharable} annotation detection to workaround a condition. We use a
         * {@link ThreadLocal} and {@link WeakHashMap} to eliminate the volatile write/reads. Using different
         * {@link WeakHashMap} instances per {@link Thread} is good enough for us and the number of
         * {@link Thread}s are quite limited anyway.
         *
         * See <a href="https://github.com/netty/netty/issues/2289">#2289</a>.
         */
        Class<?> clazz = getClass();
        Map<Class<?>, Boolean> cache = InternalThreadLocalMap.get().handlerSharableCache();
        Boolean sharable = cache.get(clazz);
        if (sharable == null) {
            sharable = clazz.isAnnotationPresent(Sharable.class);
            cache.put(clazz, sharable);
        }
        return sharable;
    }