alloc_observe.beginContext

1/// Reserves an operation identifier and establishes thread nesting without2/// publishing an event when finished. In enabled builds with an installed sink3/// and no active suppression, the context increments the active operation count4/// and links into the thread parent stack. In all other circumstances, it5/// returns an inert token with an identifier of zero. Callers must finish the6/// returned context on its originating thread, as active contexts contribute to7/// the session drain count during shutdown.8pub inline fn beginContext() Context {9    if (comptime !enabled) return .{};10    if (callback_depth != 0) return inactiveContext();11    _ = active_operations.fetchAdd(1, .acquire);12    if (active_sink.load(.acquire) == 0) {13        _ = active_operations.fetchSub(1, .release);14        return inactiveContext();15    }16    const operation_id = takeId(&next_operation_id);17    const parent_operation_id = current_operation_id;18    current_operation_id = operation_id;19    return .{20        .operation_id = operation_id,21        .parent_operation_id = parent_operation_id,22    };23}

1/// Reserves an operation identifier and establishes thread nesting without2/// publishing an event when finished. In enabled builds with an installed sink3/// and no active suppression, the context increments the active operation count4/// and links into the thread parent stack. In all other circumstances, it5/// returns an inert token with an identifier of zero. Callers must finish the6/// returned context on its originating thread, as active contexts contribute to7/// the session drain count during shutdown.8pub const beginContext = protocol.beginContext;