Function parsing_context

src/brpc/socket.h:461–462

    void reset_parsing_context(Destroyable*);
    Destroyable* release_parsing_context();
    Destroyable* parsing_context() const
    { return _parsing_context.load(butil::memory_order_consume); }
    // Try to set _parsing_context to *ctx when _parsing_context is NULL.
    // If _parsing_context is NULL, the set is successful and true is returned.
    // Otherwise, *ctx is Destroy()-ed and replaced with the value of